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Web Security Overview
Supported and well configured
HTTPS

Web sites need to use encryption to help their visitors know they're in the right place, as well as provide confidentiality and content integrity. Sites that don't support HTTPS may expose sensitive data and have their pages modified and subverted.

For all sites VERY IMPORTANT medium EFFORT
Supported and well configured
HTTPS Redirection

To deploy HTTPS properly, web sites must redirect all unsafe (plaintext) traffic to the encrypted variant. This approach ensures that no sensitive data is exposed and that further security technologies can be activated.

For all sites VERY IMPORTANT low EFFORT
Supported and well configured
HTTP Strict Transport Security

HTTP Strict Transport Security (HSTS) is an HTTPS extension that instructs browsers to remember sites that use encryption and enforce strict security requirements. Without HSTS, active network attacks are easy to carry out.

For important sites VERY IMPORTANT medium EFFORT
Supported and well configured
HSTS Preloaded

HSTS Preloading is informing browsers in advance about a site's use of HSTS, which means that strict security can be enforced even on the first visit. This approach provides best HTTPS security available today.

For important sites VERY IMPORTANT medium EFFORT
Supported and well configured
Content Security Policy

Content Security Policy (CSP) is an additional security layer that enables web sites to control browser behavior, creating a safety net that can counter attacks such as cross-site scripting.

For important sites IMPORTANT high EFFORT
Email Security Overview
Supported and well configured
STARTTLS

All hosts that receive email need encryption to ensure confidentiality of email messages. Email servers thus need to support STARTTLS, as well as provide decent TLS configuration and correct certificates.

For all sites VERY IMPORTANT low EFFORT
Supported and well configured
SPF

Sender Policy Framework (SPF) enables organizations to designate servers that are allowed to send email messages on their behalf. With SPF in place, spam is easier to identify.

For important sites IMPORTANT low EFFORT
Supported and well configured
DMARC

Domain-based Message Authentication, Reporting, and Conformance (DMARC) is a mechanism that allows organizations to specify how unauthenticated email (identified using SPF and DKIM) should be handled.

For important sites IMPORTANT low EFFORT

DNS Zone

The global DNS infrastructure is organized as a series of hierarchical DNS zones. The root zone hosts a number of global and country TLDs, which in turn host further zones that are delegated to their customers. Each organization that controls a zone can delegate parts of its namespace to other zones. In this test we perform detailed inspection of a DNS zone, but only if the host being tested matches the zone.

Test passed
Everything seems to be well configured. Well done.

Nameserver Names

Nameservers can be referred to by name and by address. In this section we show the names, which can appear in the NS records, the referrals from the parent zone, and the SOA record. In some situations, servers from the parent zone respond authoritatively, in which case we will include them in the list as well.

Nameserver Operational IPv4 IPv6 Sources
heidi.ns.cloudflare.com. PRIMARY
108.162.194.236
162.159.38.236
172.64.34.236
2606:4700:50::a29f:26ec
2803:f800:50::6ca2:c2ec
2a06:98c1:50::ac40:22ec
The server is online. Name resolves to an IPv4 address. Name resolves to an IPv6 address. NS REFERRAL SOA
yevgen.ns.cloudflare.com.
108.162.195.223
162.159.44.223
172.64.35.223
2606:4700:58::a29f:2cdf
2803:f800:50::6ca2:c3df
2a06:98c1:50::ac40:23df
The server is online. Name resolves to an IPv4 address. Name resolves to an IPv6 address. NS REFERRAL

Nameserver Addresses

This section shows the configuration of all discovered nameservers by their IP address. To find all applicable nameservers, we inspect the parent zone nameservers for names and glue and then the tested zone nameservers for NS records. We then resolve all discovered names to IP addresses. Finally, we test each address individually.

Nameserver Operational Authoritative Recursive UDP TCP Sources Payload Size
108.162.194.236 PRIMARY
heidi.ns.cloudflare.com.
PTR: heidi.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232
108.162.195.223
yevgen.ns.cloudflare.com.
PTR: yevgen.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232
162.159.38.236 PRIMARY
heidi.ns.cloudflare.com.
PTR: heidi.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232
162.159.44.223
yevgen.ns.cloudflare.com.
PTR: yevgen.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232
172.64.34.236 PRIMARY
heidi.ns.cloudflare.com.
PTR: heidi.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232
172.64.35.223
yevgen.ns.cloudflare.com.
PTR: yevgen.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232
2606:4700:50::a29f:26ec PRIMARY
heidi.ns.cloudflare.com.
PTR: heidi.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232
2606:4700:58::a29f:2cdf
yevgen.ns.cloudflare.com.
PTR: yevgen.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232
2803:f800:50::6ca2:c2ec PRIMARY
heidi.ns.cloudflare.com.
PTR: heidi.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232
2803:f800:50::6ca2:c3df
yevgen.ns.cloudflare.com.
PTR: yevgen.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232
2a06:98c1:50::ac40:22ec PRIMARY
heidi.ns.cloudflare.com.
PTR: heidi.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232
2a06:98c1:50::ac40:23df
yevgen.ns.cloudflare.com.
PTR: yevgen.ns.cloudflare.com.
The server appears to be online. Nameserver provides authoritative responses Nameserver doesn't provide recursive service Nameserver responds to UDP queries Nameserver responds to TCP queries NAME, GLUE 1232

Start of Authority (SOA) Record

Start of Authority (SOA) records contain administrative information pertaining to one DNS zone, especially the configuration that's used for zone transfers between the primary nameserver and the secondaries. Only one SOA record should exist, with all nameservers providing the same information.

The domain name of the primary nameserver for the zone. Also known as MNAME.Primary nameserver heidi.ns.cloudflare.com.
Email address of the persons responsible for this zone. Also known as RNAME.Admin email dns.cloudflare.com.
Zone serial or version number.Serial number -1953868290
The length of time secondary nameservers should wait before querying the primary for changes.Refresh interval 10,000 seconds (about 2 hours 46 minutes)
The length of time secondary nameservers should wait before querying an unresponsive primary again.Retry interval 2,400 seconds (about 40 minutes)
The length of time after which secondary nameservers should stop responding to queries for a zone, assuming no updates were obtained from the primary.Expire interval 604,800 seconds (about 7 days)
TTL for purposes of negative response caching. Negative cache TTL 1,800 seconds (about 30 minutes)
Time To Live (TTL) indicates for how long a record remains valid. SOA record TTL 1,800 seconds (about 30 minutes)

Analysis

Good
No problems detected with the zone configuration
Excellent. This DNS zone is in a good working order. No problems detected.

Backing DNS Queries

Below are all DNS queries we submitted during the zone inspection.

ID Server Transport Question Name Type Status

DNS Records

Correctly functioning name servers are necessary to hold and distribute information that's necessary for your domain name to operate correctly. Examples include converting names to IP addresses, determining where email should go, and so on. More recently, the DNS is being used to communicate email and other security policies.

Test passed
Everything seems to be well configured. Well done.

DNS Records

These are the results of individual DNS queries against your nameserver for common resource record types.

Name TTL Type Data
skiff.com.     300 A 172.66.41.24            
skiff.com.     300 A 172.66.42.232            
www.skiff.com.     300 A 172.66.42.232            
www.skiff.com.     300 A 172.66.41.24            
skiff.com.     300 AAAA 2606:4700:3108:0:0:0:ac42:2918            
skiff.com.     300 AAAA 2606:4700:3108:0:0:0:ac42:2ae8            
www.skiff.com.     300 AAAA 2606:4700:3108:0:0:0:ac42:2ae8            
www.skiff.com.     300 AAAA 2606:4700:3108:0:0:0:ac42:2918            
skiff.com.     300 CAA 0 issue "letsencrypt.org"            
skiff.com.     300 CAA 0 iodef "mailto:security@skiff.org"            
skiff.com.     300 CAA 0 issue "amazon.com"            
skiff.com.     3600 DNSKEY 257 3 13 mdsswUyr3DPW132mOi8V9xESWE8jTo0dxCjjnopKl+GqJxpVXckHAeF+KkxLbxILfDLUT0rAK9iUzy1L53eKGQ==            
skiff.com.     3600 DNSKEY 256 3 13 oJMRESz5E4gYzS/q6XDrvU1qMPYIjCWzJaOau8XNEZeqCYKD5ar0IRd8KqXXFJkqmVfRvMGPmM1x8fGAa2XhSA==            
skiff.com.     300 MX 1 inbound-smtp.skiff.com.            
skiff.com.     86400 NS heidi.ns.cloudflare.com.            
skiff.com.     86400 NS yevgen.ns.cloudflare.com.            
skiff.com.     1800 SOA heidi.ns.cloudflare.com. dns.cloudflare.com. 2341099006 10000 2400 604800 1800            
skiff.com.     60 TXT "v=spf1 ip4:34.223.139.255 ip4:52.33.229.188 ip4:52.27.131.180 ip4:44.233.0.116 ip4:35.82.207.188 ip4:35.166.143.94 ip4:204.122.17.4/30 -all"            
skiff.com.     60 TXT "<03.15.2023>"            
skiff.com.     60 TXT "IR-a9c30691a111329d3b4a129ef44357e0ce6cfeffad73d9fcb68fd7ea6265a363"            
skiff.com.     60 TXT "MS=ms46306238"            
skiff.com.     60 TXT "MS=ms76043800"            
skiff.com.     60 TXT "MS=ms81723164"            
skiff.com.     60 TXT "ca3-dbb30cfd8fa64b0daec218ba57140e5b"            
skiff.com.     60 TXT "google-site-verification=4STeRgj8YkMzj__BsCqeIy08lfo83rGyzYwpcxREW3s"            
skiff.com.     60 TXT "google-site-verification=BKa9NWFnlHAivSYuEKaIzWni7qjFiVlBNHWqOHN-UxQ"            
skiff.com.     60 TXT "google-site-verification=CL9hOZcRvcPB3MbzIXK0lM5inm88rQzeKIwAj5u673g"            
skiff.com.     60 TXT "google-site-verification=cFZeODTSuzK_Uf5hsbkK-4Lf6yowQILKcBgM-sePmRY"            
_dmarc.skiff.com.     300 TXT "v=DMARC1;p=reject;pct=100;adkim=s;aspf=r;rua=mailto:rua-com@skiff.org,mailto:re+b36bf17d2996@inbound.dmarcdigests.com;ruf=mailto:ruf-com@skiff.org;fo=1;"            
_mta-sts.skiff.com.     300 TXT "v=STSv1; id=202305220217"            
_smtp._tls.skiff.com.     300 TXT "v=TLSRPTv1; rua=https://tlsrpt.skiff.com"            

Backing DNS Queries

Below are all DNS queries we submitted while inspecting the resource records.

ID Server Question Name Type Status

DNSSEC

DNSSEC is an extension of the DNS protocol that provides cryptographic assurance of the authenticity and integrity of responses; it's intended as a defense against network attackers who are able to manipulate DNS to redirect their victims to servers of their choice. DNSSEC is controversial, with the industry split largely between those who think it's essential and those who believe that it's problematic and unnecessary.

Test passed
Everything seems to be well configured. Well done.

Analysis

Good
DNSSEC is well configured
Good. This domain name has well-configured DNSSEC.

Useful DNSSEC Tools

Certification Authority Authorization

CAA (RFC 8659) is a new standard that allows domain name owners to restrict which CAs are allowed to issue certificates for their domains. This can help to reduce the chance of misissuance, either accidentally or maliciously. In September 2017, CAA became mandatory for CAs to implement.

Test passed
Everything seems to be well configured. Well done.

CAA Policy Information

The DNS hostname where this policy is located.Policy host skiff.com
The issue property tag is used to request that certificate
issuers perform CAA issue restriction processing for the domain
and to grant authorization to specific certificate issuers.
issue
letsencrypt.org  flags: 0
The iodef property specifies a means of reporting certificate
issue requests or cases of certificate issue for the corresponding
domain that violate the security policy of the issuer or the domain
name holder.
iodef
mailto:security@skiff.org  flags: 0
The issue property tag is used to request that certificate
issuers perform CAA issue restriction processing for the domain
and to grant authorization to specific certificate issuers.
issue
amazon.com  flags: 0

Analysis

Good
CAA policy found
Good. This domain name uses CAA to restrict which CAs are allowed to issue certificates for it.
Good
Policy uses reporting
Great. This policy uses reporting, which means that your contact information is available should someone need to contact you about a CAA violation. Do note that you're not guaranteed to be notified, given that CAs generally don't support notifications yet.

Email (SMTP)

An internet hostname can be served by zero or more mail servers, as specified by MX (mail exchange) DNS resource records. Each server can further resolve to multiple IP addresses, for example to handle IPv4 and IPv6 clients. Thus, in practice, hosts that wish to receive email reliably are supported by many endpoint.

Test passed
Everything seems to be well configured. Well done.
Server Preference Operational STARTTLS TLS PKI DNSSEC DANE
inbound-smtp.skiff.com
54.70.29.253
PTR: inbound-smtp.skiff.com
1
220 inbound-smtp.skiff.com ESMTP Skiff SMTP
EHLO outbound.hardenize.com
250-inbound-smtp.skiff.com Hello outbound.hardenize.com [172.99.67.55]Skiff SMTP
250-PIPELINING
250-8BITMIME
250-SMTPUTF8
250-SIZE 0
250 STARTTLS
QUIT
221 inbound-smtp.skiff.com closing connection
Supports STARTTLS.
inbound-smtp.skiff.com
52.27.246.88
PTR: inbound-smtp.skiff.com
1
220 inbound-smtp.skiff.com ESMTP Skiff SMTP
EHLO outbound.hardenize.com
250-inbound-smtp.skiff.com Hello outbound.hardenize.com [172.99.67.55]Skiff SMTP
250-PIPELINING
250-8BITMIME
250-SMTPUTF8
250-SIZE 0
250 STARTTLS
QUIT
221 inbound-smtp.skiff.com closing connection
Supports STARTTLS.
inbound-smtp.skiff.com
52.88.57.209
PTR: inbound-smtp.skiff.com
1
220 inbound-smtp.skiff.com ESMTP Skiff SMTP
EHLO outbound.hardenize.com
250-inbound-smtp.skiff.com Hello outbound.hardenize.com [172.99.67.55]Skiff SMTP
250-PIPELINING
250-8BITMIME
250-SMTPUTF8
250-SIZE 0
250 STARTTLS
QUIT
221 inbound-smtp.skiff.com closing connection
Supports STARTTLS.

Analysis

Good
Email servers match MTA-STS policy
Good. This host supports MTA-STS, which means that it restricts which MX servers can be used and how they are configured. We've verified that all MX servers listed here match the policy.

Email TLS (SMTP)

Transport Layer Security (TLS) is the most widely used encryption protocol on the Internet. In combination with valid certificates, servers can establish trusted communication channels even with users who have never visited them before. Network attackers can't uncover what is being communicated, even when they can see all the traffic.

Test passed
Everything seems to be well configured. Well done.

TLS Configuration: inbound-smtp.skiff.com (54.70.29.253)

Encryption protocol version determines what features are
available for negotiation between client and server.
Supported protocols
TLS v1.3
TLS v1.2
Servers should always enforce their own cipher
suite preference, as that is the only approach
that guarantees that the best possible suite is
selected.
Server suite preference
Shows cipher suite configuration for this protocol version.TLS v1.3
Server preference
Suite: TLS_AES_256_GCM_SHA384
Suite ID: 0x1302
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_CHACHA20_POLY1305_SHA256
Suite ID: 0x1303
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_AES_128_GCM_SHA256
Suite ID: 0x1301
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference
Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc030
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc028
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc027
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca8
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_ARIA_256_GCM_SHA384
Suite ID: 0xc061
Cipher name: ARIA
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_ARIA_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_ARIA_128_GCM_SHA256
Suite ID: 0xc060
Cipher name: ARIA
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_ARIA_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc014
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc013
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0x9f
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA384
TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xccaa
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CCM_8
Suite ID: 0xc0a3
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_256_CCM_8
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CCM
Suite ID: 0xc09f
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_256_CCM
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_ARIA_256_GCM_SHA384
Suite ID: 0xc053
Cipher name: ARIA
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA384
TLS_DHE_RSA_WITH_ARIA_256_GCM_SHA384
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0x9e
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CCM_8
Suite ID: 0xc0a2
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_CCM_8
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CCM
Suite ID: 0xc09e
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_CCM
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_ARIA_128_GCM_SHA256
Suite ID: 0xc052
Cipher name: ARIA
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_ARIA_128_GCM_SHA256
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
Suite ID: 0x6b
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0x67
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0x39
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA
TLS_DHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0x33
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA
TLS_DHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (DHE 2048 bits)

Analysis

Good
TLS 1.2 supported
Good. This server supports TLS 1.2, which can provide strong security when configured correctly. This version of the TLS protocol is necessary to provide good security with a wide range of clients that don't yet support TLS 1.3.
Good
Server enforces cipher suite preferences
Excellent. This server enforces server cipher suite preference, which means that it is able to select the best suite from the options submitted by clients. Combined with a well designed list of supported cipher suites, this settings enables negotiation of best security.
Good
Strong key exchange detected
Excellent. All cipher suites on this server rely on strong key exchange. The sweet spot is 2048 bits for DHE and 256 bits for ECDHE. Putting ECDHE suites first guarantees best security and best performance.
Good
Server prefers forward secrecy and authenticated encryption suites
Excellent. Not only does this server enforce its server preference, but it also has at the top of the list suites that support both forward secrecy and authenticated encryption. This is the best TLS 1.2 can offer.
Notice
Relaxed TLS assessment criteria applied to SMTP on port 25
We apply relaxed assessment criteria when evaluating TLS configuration of SMTP servers on port 25. This is because most delivery agents fall back to delivering via plaintext on failure to negotiate encryption. Some configuration elements that can be abused to attack other ports and protocols (e.g., SSLv2 and export cipher suites) are penalized in the same way as for other protocols. We will review this policy in the future.
Good
DHE server parameter not reused
This server does not reuse the private value used for the Diffie-Hellman key exchange.

TLS Configuration: inbound-smtp.skiff.com (52.27.246.88)

Encryption protocol version determines what features are
available for negotiation between client and server.
Supported protocols
TLS v1.3
TLS v1.2
Servers should always enforce their own cipher
suite preference, as that is the only approach
that guarantees that the best possible suite is
selected.
Server suite preference
Shows cipher suite configuration for this protocol version.TLS v1.3
Server preference
Suite: TLS_AES_256_GCM_SHA384
Suite ID: 0x1302
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_CHACHA20_POLY1305_SHA256
Suite ID: 0x1303
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_AES_128_GCM_SHA256
Suite ID: 0x1301
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference
Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc030
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc028
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc027
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca8
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_ARIA_256_GCM_SHA384
Suite ID: 0xc061
Cipher name: ARIA
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_ARIA_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_ARIA_128_GCM_SHA256
Suite ID: 0xc060
Cipher name: ARIA
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_ARIA_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc014
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc013
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0x9f
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA384
TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xccaa
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CCM_8
Suite ID: 0xc0a3
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_256_CCM_8
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CCM
Suite ID: 0xc09f
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_256_CCM
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_ARIA_256_GCM_SHA384
Suite ID: 0xc053
Cipher name: ARIA
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA384
TLS_DHE_RSA_WITH_ARIA_256_GCM_SHA384
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0x9e
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CCM_8
Suite ID: 0xc0a2
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_CCM_8
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CCM
Suite ID: 0xc09e
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_CCM
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_ARIA_128_GCM_SHA256
Suite ID: 0xc052
Cipher name: ARIA
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_ARIA_128_GCM_SHA256
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
Suite ID: 0x6b
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0x67
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0x39
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA
TLS_DHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0x33
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA
TLS_DHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (DHE 2048 bits)

Analysis

Good
TLS 1.2 supported
Good. This server supports TLS 1.2, which can provide strong security when configured correctly. This version of the TLS protocol is necessary to provide good security with a wide range of clients that don't yet support TLS 1.3.
Good
Server enforces cipher suite preferences
Excellent. This server enforces server cipher suite preference, which means that it is able to select the best suite from the options submitted by clients. Combined with a well designed list of supported cipher suites, this settings enables negotiation of best security.
Good
Strong key exchange detected
Excellent. All cipher suites on this server rely on strong key exchange. The sweet spot is 2048 bits for DHE and 256 bits for ECDHE. Putting ECDHE suites first guarantees best security and best performance.
Good
Server prefers forward secrecy and authenticated encryption suites
Excellent. Not only does this server enforce its server preference, but it also has at the top of the list suites that support both forward secrecy and authenticated encryption. This is the best TLS 1.2 can offer.
Notice
Relaxed TLS assessment criteria applied to SMTP on port 25
We apply relaxed assessment criteria when evaluating TLS configuration of SMTP servers on port 25. This is because most delivery agents fall back to delivering via plaintext on failure to negotiate encryption. Some configuration elements that can be abused to attack other ports and protocols (e.g., SSLv2 and export cipher suites) are penalized in the same way as for other protocols. We will review this policy in the future.
Good
DHE server parameter not reused
This server does not reuse the private value used for the Diffie-Hellman key exchange.

TLS Configuration: inbound-smtp.skiff.com (52.88.57.209)

Encryption protocol version determines what features are
available for negotiation between client and server.
Supported protocols
TLS v1.3
TLS v1.2
Servers should always enforce their own cipher
suite preference, as that is the only approach
that guarantees that the best possible suite is
selected.
Server suite preference
Shows cipher suite configuration for this protocol version.TLS v1.3
Server preference
Suite: TLS_AES_256_GCM_SHA384
Suite ID: 0x1302
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_CHACHA20_POLY1305_SHA256
Suite ID: 0x1303
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_AES_128_GCM_SHA256
Suite ID: 0x1301
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference
Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc030
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc028
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc027
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca8
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_ARIA_256_GCM_SHA384
Suite ID: 0xc061
Cipher name: ARIA
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_ARIA_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_ARIA_128_GCM_SHA256
Suite ID: 0xc060
Cipher name: ARIA
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_ARIA_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc014
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc013
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0x9f
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA384
TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xccaa
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CCM_8
Suite ID: 0xc0a3
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_256_CCM_8
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CCM
Suite ID: 0xc09f
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_256_CCM
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_ARIA_256_GCM_SHA384
Suite ID: 0xc053
Cipher name: ARIA
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA384
TLS_DHE_RSA_WITH_ARIA_256_GCM_SHA384
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0x9e
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CCM_8
Suite ID: 0xc0a2
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_CCM_8
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CCM
Suite ID: 0xc09e
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_CCM
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_ARIA_128_GCM_SHA256
Suite ID: 0xc052
Cipher name: ARIA
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_ARIA_128_GCM_SHA256
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
Suite ID: 0x6b
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0x67
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA256
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0x39
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA
TLS_DHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (DHE 2048 bits)
Suite: TLS_DHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0x33
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: DHE_RSA
Key exchange strength: 2048 bits
Forward secrecy: Yes
PRF: SHA
TLS_DHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (DHE 2048 bits)

Analysis

Good
TLS 1.2 supported
Good. This server supports TLS 1.2, which can provide strong security when configured correctly. This version of the TLS protocol is necessary to provide good security with a wide range of clients that don't yet support TLS 1.3.
Good
Server enforces cipher suite preferences
Excellent. This server enforces server cipher suite preference, which means that it is able to select the best suite from the options submitted by clients. Combined with a well designed list of supported cipher suites, this settings enables negotiation of best security.
Good
Strong key exchange detected
Excellent. All cipher suites on this server rely on strong key exchange. The sweet spot is 2048 bits for DHE and 256 bits for ECDHE. Putting ECDHE suites first guarantees best security and best performance.
Good
Server prefers forward secrecy and authenticated encryption suites
Excellent. Not only does this server enforce its server preference, but it also has at the top of the list suites that support both forward secrecy and authenticated encryption. This is the best TLS 1.2 can offer.
Notice
Relaxed TLS assessment criteria applied to SMTP on port 25
We apply relaxed assessment criteria when evaluating TLS configuration of SMTP servers on port 25. This is because most delivery agents fall back to delivering via plaintext on failure to negotiate encryption. Some configuration elements that can be abused to attack other ports and protocols (e.g., SSLv2 and export cipher suites) are penalized in the same way as for other protocols. We will review this policy in the future.
Good
DHE server parameter not reused
This server does not reuse the private value used for the Diffie-Hellman key exchange.

Email Certificates (SMTP)

A certificate is a digital document that contains a public key, some information about the entity associated with it, and a digital signature from the certificate issuer. It’s a mechanism that enables us to exchange, store, and use public keys. Being able to reliably verify the identity of a remote server is crucial in order to achieve secure encrypted communication.

Test passed
Everything seems to be well configured. Well done.

Certificate #1

Leaf certificate inbound-smtp.skiff.com
Issuer: Sectigo
Not Before: 23 Nov 2023 00:00:00 UTC
Not After: 22 Nov 2024 23:59:59 UTC (expires in 6 months 9 days)
Key: RSA 2048 bits
Signature: SHA384withRSA
 View details

Analysis

Good
Strong private key
Good. The private key associated with this certificate is secure.
Good
Strong signature algorithm
Good. This certificate uses a strong signature algorithm.
Good
Certificate matches hostname
Good. The provided certificate matches the expected hostnames.
Good
Certificate dates match
Good. The certificate is valid for use at this point of time.
Good
Certificate has not been revoked
Good. This certificate has not been revoked.
Good
Certificate satisfies Apple's CT compliance requirements
Good. This certificate satisfies Apple's CT requirements at present.

Certificate Chain

Leaf certificate
inbound-smtp.skiff.com | c573669
Not After: 22 Nov 2024 23:59:59 UTC (expires in 6 months 9 days)
Authentication: RSA 2048 bits (SHA384withRSA)
 View details
Intermediate certificate
ZeroSSL RSA Domain Secure Site CA | 21acc1d
Not After: 29 Jan 2030 23:59:59 UTC (expires in 5 years 8 months)
Authentication: RSA 4096 bits (SHA384withRSA)
 View details
Root certificate
USERTrust RSA Certification Authority | e793c9b
Not After: 18 Jan 2038 23:59:59 UTC (expires in 13 years 8 months)
Authentication: RSA 4096 bits (SHA384withRSA)
 View details

Analysis

Good
Certificate chain is correct
Good. This chain contains all the right certificates and in the right order.

Email DANE (SMTP)

DNS-based Authentication of Named Entities (DANE) is a bridge between DNSSEC and TLS. In one possible scenario, DANE can be used for public key pinning, building on an existing publicly-trusted certificate. In another approach, it can be used to completely bypass the CA ecosystem and establish trust using DNSSEC alone.

Test passed
Everything seems to be well configured. Well done.

DANE: inbound-smtp.skiff.com (54.70.29.253)

Specifies which certificate in the chain
is being pinned and how validation should
be performed.
Certificate Usage
Domain-issued certificate / DANE-EE (3) Creates a leaf pin for a certificate that must be
present in the certificate chain. PKIX validation is
not performed and the pinned certificate is assumed
to be trusted.
Determines if the association is made with
a certificate or with a public key (via
its SPKI structure).
Selector
Certificate (0)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data c57366938c6dd77ee09f87cd34036dae6d55b76be2b3c30c661ce2039a18debd

Leaf certificate: RSA 2048 bits
Subject: CN=inbound-smtp.skiff.com
Issuer: CN=ZeroSSL RSA Domain Secure Site CA, O=ZeroSSL, C=AT
inbound-smtp.skiff.com (RSA 2048 bits)

Analysis

Good
Valid DANE configuration
Excellent. Your DANE configuration matches the certificate chain(s) provided by the service. Your TLS configuration enjoys the additional benefit of DANE validation.

DANE: inbound-smtp.skiff.com (52.27.246.88)

Specifies which certificate in the chain
is being pinned and how validation should
be performed.
Certificate Usage
Domain-issued certificate / DANE-EE (3) Creates a leaf pin for a certificate that must be
present in the certificate chain. PKIX validation is
not performed and the pinned certificate is assumed
to be trusted.
Determines if the association is made with
a certificate or with a public key (via
its SPKI structure).
Selector
Certificate (0)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data c57366938c6dd77ee09f87cd34036dae6d55b76be2b3c30c661ce2039a18debd

Leaf certificate: RSA 2048 bits
Subject: CN=inbound-smtp.skiff.com
Issuer: CN=ZeroSSL RSA Domain Secure Site CA, O=ZeroSSL, C=AT
inbound-smtp.skiff.com (RSA 2048 bits)

Analysis

Good
Valid DANE configuration
Excellent. Your DANE configuration matches the certificate chain(s) provided by the service. Your TLS configuration enjoys the additional benefit of DANE validation.

DANE: inbound-smtp.skiff.com (52.88.57.209)

Specifies which certificate in the chain
is being pinned and how validation should
be performed.
Certificate Usage
Domain-issued certificate / DANE-EE (3) Creates a leaf pin for a certificate that must be
present in the certificate chain. PKIX validation is
not performed and the pinned certificate is assumed
to be trusted.
Determines if the association is made with
a certificate or with a public key (via
its SPKI structure).
Selector
Certificate (0)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data c57366938c6dd77ee09f87cd34036dae6d55b76be2b3c30c661ce2039a18debd

Leaf certificate: RSA 2048 bits
Subject: CN=inbound-smtp.skiff.com
Issuer: CN=ZeroSSL RSA Domain Secure Site CA, O=ZeroSSL, C=AT
inbound-smtp.skiff.com (RSA 2048 bits)

Analysis

Good
Valid DANE configuration
Excellent. Your DANE configuration matches the certificate chain(s) provided by the service. Your TLS configuration enjoys the additional benefit of DANE validation.

SPF

Sender Policy Framework (SPF) is a protocol that allows domain name owners to control which internet hosts are allowed to send email on their behalf. This simple mechanism can be used to reduce the effect of email spoofing and cut down on spam.

Test passed
Everything seems to be well configured. Well done.

SPF Policy Information Main policy

Host where this policy is located.Location skiff.com
SPF version used by this policy.v spf1
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network.
ip4
34.223.139.255
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network.
ip4
52.33.229.188
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network.
ip4
52.27.131.180
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network.
ip4
44.233.0.116
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network.
ip4
35.82.207.188
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network.
ip4
35.166.143.94
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network.
ip4
204.122.17.4/30
This policy element always matches. It's normally used
at the end of a policy to specify the handling of hosts
that don't match earlier mechanisms.
-all

Analysis

Info
SPF policy found

Policy text: v=spf1 ip4:34.223.139.255 ip4:52.33.229.188 ip4:52.27.131.180 ip4:44.233.0.116 ip4:35.82.207.188 ip4:35.166.143.94 ip4:204.122.17.4/30 -all

Location: skiff.com

Good
SPF policy is valid
Good. Your SPF policy is syntactically valid.
Good
Policy uses default fail
Excellent. This policy fails hosts that are not allowed to send email for this domain name.
Good
Policy DNS lookups under limit
Good. Your policy stays under the limit of up to 10 DNS queries. The SPF specification Section 4.6.4. requires implementations to limit the total number of DNS queries. Policies that exceed the limit should not be used and may not work in practice.

Lookups: 0

DMARC

Domain-based Message Authentication, Reporting, and Conformance (DMARC) is a scalable mechanism by which a mail-originating organization can express domain-level policies and preferences for message validation, disposition, and reporting, that a mail-receiving organization can use to improve mail handling.

Test passed
Everything seems to be well configured. Well done.

DMARC Policy Information

The location from which we obtained this policy.Policy location _dmarc.skiff.com
DMARC version used by this policy.v DMARC1
Indicates the policy to be enacted by the receiver at
the request of the domain owner. Possible values are:
none, quarantine, and reject.
p
reject
Percentage of messages from mail stream to
which the DMARC policy is to be applied.
pct
100
Indicates whether strict or relaxed DKIM
alignment mode is required.
adkim
s
Indicates whether strict or relaxed SPF
alignment mode is required.
aspf
r
Addresses to which aggregate feedback is to be sent.rua mailto:rua-com@skiff.org,mailto:re+b36bf17d2996@inbound.dmarcdigests.com
Addresses to which message-specific failure
information is to be reported.
ruf
mailto:ruf-com@skiff.org
Configures failure reporting.fo 1

Analysis

Info
DMARC policy found

Policy: v=DMARC1;p=reject;pct=100;adkim=s;aspf=r;rua=mailto:rua-com@skiff.org,mailto:re+b36bf17d2996@inbound.dmarcdigests.com;ruf=mailto:ruf-com@skiff.org;fo=1;

Host: _dmarc.skiff.com

Good
Valid external destination

Permission record location: skiff.com._report._dmarc.skiff.org

External destination: mailto:rua-com@skiff.org

Permission record contents: v=DMARC1

Good
Valid external destination

Permission record location: skiff.com._report._dmarc.inbound.dmarcdigests.com

External destination: mailto:re+b36bf17d2996@inbound.dmarcdigests.com

Permission record contents: v=DMARC1;

Good
Policy is valid
Good. You have a valid DMARC policy.

MTA Strict Transport Security

SMTP Mail Transfer Agent Strict Transport Security (MTA-STS) is a mechanism enabling mail service providers to declare their ability to receive Transport Layer Security (TLS) secure SMTP connections, and to specify whether sending SMTP servers should refuse to deliver to MX hosts that do not offer TLS with a trusted server certificate.

Test passed
Everything seems to be well configured. Well done.

MTA-STS Policy Indicator

Location from which we retrieved the policy indicator.Location _mta-sts.skiff.com
MTA-STS standard version used by this policy indicator.Version STSv1
Unique policy identifier, whose value must change
every time the underlying policy changes.
ID
202305220217

Analysis

Good
MTA-STS policy indicator valid
Good. Your MTA-STS policy indicator is valid.

MTA-STS Policy

The URL from which the policy was obtained.Location https://mta-sts.skiff.com/.well-known/mta-sts.txt
Policy standard version.version STSv1
Policy duration, which specifies how long the sending
MTAs should remember and enforce the server policy for.
max‑age
86,400 seconds (about 1 day)
Policy mode, which can be one of 'none', 'testing' and
'enforcing'. Guess which is best! :)
mode
enforce
One 'mx' directive specifies one email server
pattern that's allowed for this host.
mx
inbound-smtp.skiff.com

Analysis

Good
MTA-STS policy is valid
Good. Your MTA-STS policy is valid.
Good
Policy host certificate is valid
Good. Your MTA-STS policy is delivered via a web server that has a valid publicly trusted certificate. This is a necessary condition for the policy to be recognized.
Notice
Policy HTTPS response information

Status code: 200

Length: 75 bytes

Content-Type: text/plain;charset=UTF-8

Certificate: mta-sts.skiff.com

Leaf certificate skiff.com
Issuer: Let's Encrypt
Not Before: 25 Mar 2024 14:38:49 UTC
Not After: 23 Jun 2024 14:38:48 UTC (expires in 1 month 9 days)
Key: EC 256 bits
Signature: SHA384withECDSA
 View details

Analysis

Good
Strong private key
Good. The private key associated with this certificate is secure.
Good
Strong signature algorithm
Good. This certificate uses a strong signature algorithm.
Good
Certificate matches hostname
Good. The provided certificate matches the expected hostnames.
Good
Certificate dates match
Good. The certificate is valid for use at this point of time.
Good
Certificate has not been revoked
Good. This certificate has not been revoked.
Good
Certificate satisfies Apple's CT compliance requirements
Good. This certificate satisfies Apple's CT requirements at present.

Certificate Chain

Leaf certificate
skiff.com | 4149ece
Not After: 23 Jun 2024 14:38:48 UTC (expires in 1 month 9 days)
Authentication: EC 256 bits (SHA384withECDSA)
 View details
Intermediate certificate
E1 | 46494e3
Not After: 15 Sep 2025 16:00:00 UTC (expires in 1 year 4 months)
Authentication: EC 384 bits (SHA384withECDSA)
 View details
Intermediate certificate
ISRG Root X2 | 8b05b68
Not After: 15 Sep 2025 16:00:00 UTC (expires in 1 year 4 months)
Authentication: EC 384 bits (SHA256withRSA)
 View details
Intermediate certificate
ISRG Root X1 | 6d99fb2
Not After: 30 Sep 2024 18:14:03 UTC (expires in 4 months 17 days)
Authentication: RSA 4096 bits (SHA256withRSA)
 View details
Root certificate
DST Root CA X3 | 0687260
Not After: 30 Sep 2021 14:01:15 UTC (expired 2 years 7 months ago)
Authentication: RSA 2048 bits (SHA1withRSA)
 View details

Analysis

Good
Certificate chain is correct
Good. This chain contains all the right certificates and in the right order.

SMTP TLS Reporting

SMTP TLS Reporting (RFC 8460), or TLS-RPT for short, describes a reporting mechanism and format by which systems sending email can share statistics and specific information about potential failures with recipient domains. Recipient domains can then use this information to both detect potential attacks and diagnose unintentional misconfigurations. TLS-RPT can be used with DANE or MTA-STS.

Test passed
Everything seems to be well configured. Well done.

TLS-RPT Policy

Location from which we retrieved the policy indicator.Location _smtp._tls.skiff.com
TLS-RPT standard version used by this policy indicator.Version TLSRPTv1
Reporting endpoints specified in the policy.Reporting Endpoints https://tlsrpt.skiff.com

Analysis

Good
SMTP TLS-RPT policy valid
Good. Your TLS-RPT policy is valid. SMTP TLS Reporting is a young standard that is not yet widely supported, but support is probably going to increase over time.

HTTP (80)

To observe your HTTP implementation, we submit a request to the homepage of your site on port 80, follow all redirections (even when they take us to other domain names), and record the returned HTTP headers.

Test passed
Everything seems to be well configured. Well done.

URL: http://skiff.com/

1
http://skiff.com/
HTTP/1.1 301 Moved Permanently
2
https://skiff.com/
HTTP/1.1 200 OK

Analysis

Good
HTTP redirects to HTTPS
Good. This plaintext HTTP server redirects to HTTPS.

URL: http://www.skiff.com/

1
http://www.skiff.com/
HTTP/1.1 301 Moved Permanently
2
https://skiff.com/
HTTP/1.1 200 OK

Analysis

Good
HTTP redirects to HTTPS
Good. This plaintext HTTP server redirects to HTTPS.

HTTP (443)

To observe your HTTPS implementation, we submit a request to the homepage of your site on port 443, follow all redirections (even when they take us to other domain names), and record the returned HTTP headers. We use the most recent set of headers returned from the tested hostname for further tests such as HSTS and HPKP.

Test passed
Everything seems to be well configured. Well done.

URL: https://skiff.com/

1
https://skiff.com/
HTTP/1.1 200 OK

URL: https://www.skiff.com/

1
https://www.skiff.com/
HTTP/1.1 301 Moved Permanently
2
https://skiff.com/
HTTP/1.1 200 OK

WWW TLS

Transport Layer Security (TLS) is the most widely used encryption protocol on the Internet. In combination with valid certificates, servers can establish trusted communication channels even with users who have never visited them before. Network attackers can't uncover what is being communicated, even when they can see all the traffic.

Test passed
Everything seems to be well configured. Well done.

TLS Configuration: skiff.com (2606:4700:3108:0:0:0:ac42:2ae8)

Encryption protocol version determines what features are
available for negotiation between client and server.
Supported protocols
TLS v1.3
TLS v1.2
Servers should always enforce their own cipher
suite preference, as that is the only approach
that guarantees that the best possible suite is
selected.
Server suite preference
Shows cipher suite configuration for this protocol version.TLS v1.3
Server preference
Suite: TLS_CHACHA20_POLY1305_SHA256
Suite ID: 0x1303
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_AES_128_GCM_SHA256
Suite ID: 0x1301
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_AES_256_GCM_SHA384
Suite ID: 0x1302
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference
Suite: AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc14
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca9
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02b
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc009
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc02c
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc00a
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc023
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc024
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc13
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca8
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc013
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0x9c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_GCM_SHA256
 128 bits
Suite: TLS_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0x2f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_128_CBC_SHA
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc030
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc014
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0x9d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA384
TLS_RSA_WITH_AES_256_GCM_SHA384
 256 bits
Suite: TLS_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0x35
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_256_CBC_SHA
 256 bits
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc027
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0x3c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_CBC_SHA256
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc028
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_CBC_SHA256
Suite ID: 0x3d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
 256 bits

Analysis

Good
TLS 1.3 supported
Excellent. This server supports TLS 1.3, which is the latest revision of the TLS protocol and a significant improvement over earlier versions. Developed over a period of several years and extensively analyzed prior to the release, TLS 1.3 removed insecure features, and improved both security and performance.
Good
TLS 1.2 supported
Good. This server supports TLS 1.2, which can provide strong security when configured correctly. This version of the TLS protocol is necessary to provide good security with a wide range of clients that don't yet support TLS 1.3.
Good
Deprecated protocols not supported
Excellent. This server doesn't support any of the deprecated protocol (TLS 1.1 and earlier).
Good
Strong key exchange detected
Excellent. All cipher suites on this server rely on strong key exchange. The sweet spot is 2048 bits for DHE and 256 bits for ECDHE. Putting ECDHE suites first guarantees best security and best performance.
Good
Server prefers forward secrecy and authenticated encryption suites
Excellent. Not only does this server enforce its server preference, but it also has at the top of the list suites that support both forward secrecy and authenticated encryption. This is the best TLS 1.2 can offer.
Good
Server enforces cipher suite preferences
Excellent. This server enforces server cipher suite preference, which means that it is able to select the best suite from the options submitted by clients. Combined with a well designed list of supported cipher suites, this settings enables negotiation of best security.
Good
All TLS connections with this server satisfy Apple's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Good
All TLS connections with this server satisfy Chrome's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Notice
DHE suites not supported
This server doesn't support the Diffie-Hellman (DH) key exchange.

TLS Configuration: skiff.com (2606:4700:3108:0:0:0:ac42:2918)

Encryption protocol version determines what features are
available for negotiation between client and server.
Supported protocols
TLS v1.3
TLS v1.2
Servers should always enforce their own cipher
suite preference, as that is the only approach
that guarantees that the best possible suite is
selected.
Server suite preference
Shows cipher suite configuration for this protocol version.TLS v1.3
Server preference
Suite: TLS_CHACHA20_POLY1305_SHA256
Suite ID: 0x1303
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_AES_128_GCM_SHA256
Suite ID: 0x1301
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_AES_256_GCM_SHA384
Suite ID: 0x1302
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference
Suite: AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc14
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca9
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02b
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc009
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc02c
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc00a
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc023
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc024
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc13
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca8
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc013
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0x9c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_GCM_SHA256
 128 bits
Suite: TLS_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0x2f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_128_CBC_SHA
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc030
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc014
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0x9d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA384
TLS_RSA_WITH_AES_256_GCM_SHA384
 256 bits
Suite: TLS_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0x35
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_256_CBC_SHA
 256 bits
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc027
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0x3c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_CBC_SHA256
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc028
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_CBC_SHA256
Suite ID: 0x3d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
 256 bits

Analysis

Good
TLS 1.3 supported
Excellent. This server supports TLS 1.3, which is the latest revision of the TLS protocol and a significant improvement over earlier versions. Developed over a period of several years and extensively analyzed prior to the release, TLS 1.3 removed insecure features, and improved both security and performance.
Good
TLS 1.2 supported
Good. This server supports TLS 1.2, which can provide strong security when configured correctly. This version of the TLS protocol is necessary to provide good security with a wide range of clients that don't yet support TLS 1.3.
Good
Deprecated protocols not supported
Excellent. This server doesn't support any of the deprecated protocol (TLS 1.1 and earlier).
Good
Strong key exchange detected
Excellent. All cipher suites on this server rely on strong key exchange. The sweet spot is 2048 bits for DHE and 256 bits for ECDHE. Putting ECDHE suites first guarantees best security and best performance.
Good
Server prefers forward secrecy and authenticated encryption suites
Excellent. Not only does this server enforce its server preference, but it also has at the top of the list suites that support both forward secrecy and authenticated encryption. This is the best TLS 1.2 can offer.
Good
Server enforces cipher suite preferences
Excellent. This server enforces server cipher suite preference, which means that it is able to select the best suite from the options submitted by clients. Combined with a well designed list of supported cipher suites, this settings enables negotiation of best security.
Good
All TLS connections with this server satisfy Apple's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Good
All TLS connections with this server satisfy Chrome's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Notice
DHE suites not supported
This server doesn't support the Diffie-Hellman (DH) key exchange.

TLS Configuration: www.skiff.com (172.66.41.24)

Encryption protocol version determines what features are
available for negotiation between client and server.
Supported protocols
TLS v1.3
TLS v1.2
Servers should always enforce their own cipher
suite preference, as that is the only approach
that guarantees that the best possible suite is
selected.
Server suite preference
Shows cipher suite configuration for this protocol version.TLS v1.3
Server preference
Suite: TLS_CHACHA20_POLY1305_SHA256
Suite ID: 0x1303
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_AES_128_GCM_SHA256
Suite ID: 0x1301
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_AES_256_GCM_SHA384
Suite ID: 0x1302
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference
Suite: AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc14
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca9
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02b
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc009
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc02c
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc00a
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc023
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc024
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc13
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca8
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc013
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0x9c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_GCM_SHA256
 128 bits
Suite: TLS_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0x2f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_128_CBC_SHA
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc030
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc014
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0x9d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA384
TLS_RSA_WITH_AES_256_GCM_SHA384
 256 bits
Suite: TLS_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0x35
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_256_CBC_SHA
 256 bits
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc027
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0x3c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_CBC_SHA256
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc028
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_CBC_SHA256
Suite ID: 0x3d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
 256 bits

Analysis

Good
TLS 1.3 supported
Excellent. This server supports TLS 1.3, which is the latest revision of the TLS protocol and a significant improvement over earlier versions. Developed over a period of several years and extensively analyzed prior to the release, TLS 1.3 removed insecure features, and improved both security and performance.
Good
TLS 1.2 supported
Good. This server supports TLS 1.2, which can provide strong security when configured correctly. This version of the TLS protocol is necessary to provide good security with a wide range of clients that don't yet support TLS 1.3.
Good
Deprecated protocols not supported
Excellent. This server doesn't support any of the deprecated protocol (TLS 1.1 and earlier).
Good
Strong key exchange detected
Excellent. All cipher suites on this server rely on strong key exchange. The sweet spot is 2048 bits for DHE and 256 bits for ECDHE. Putting ECDHE suites first guarantees best security and best performance.
Good
Server prefers forward secrecy and authenticated encryption suites
Excellent. Not only does this server enforce its server preference, but it also has at the top of the list suites that support both forward secrecy and authenticated encryption. This is the best TLS 1.2 can offer.
Good
Server enforces cipher suite preferences
Excellent. This server enforces server cipher suite preference, which means that it is able to select the best suite from the options submitted by clients. Combined with a well designed list of supported cipher suites, this settings enables negotiation of best security.
Good
All TLS connections with this server satisfy Apple's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Good
All TLS connections with this server satisfy Chrome's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Notice
DHE suites not supported
This server doesn't support the Diffie-Hellman (DH) key exchange.

TLS Configuration: www.skiff.com (2606:4700:3108:0:0:0:ac42:2ae8)

Encryption protocol version determines what features are
available for negotiation between client and server.
Supported protocols
TLS v1.3
TLS v1.2
Servers should always enforce their own cipher
suite preference, as that is the only approach
that guarantees that the best possible suite is
selected.
Server suite preference
Shows cipher suite configuration for this protocol version.TLS v1.3
Server preference
Suite: TLS_CHACHA20_POLY1305_SHA256
Suite ID: 0x1303
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_AES_128_GCM_SHA256
Suite ID: 0x1301
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_AES_256_GCM_SHA384
Suite ID: 0x1302
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference
Suite: AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc14
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca9
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02b
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc009
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc02c
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc00a
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc023
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc024
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc13
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca8
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc013
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0x9c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_GCM_SHA256
 128 bits
Suite: TLS_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0x2f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_128_CBC_SHA
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc030
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc014
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0x9d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA384
TLS_RSA_WITH_AES_256_GCM_SHA384
 256 bits
Suite: TLS_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0x35
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_256_CBC_SHA
 256 bits
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc027
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0x3c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_CBC_SHA256
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc028
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_CBC_SHA256
Suite ID: 0x3d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
 256 bits

Analysis

Good
TLS 1.3 supported
Excellent. This server supports TLS 1.3, which is the latest revision of the TLS protocol and a significant improvement over earlier versions. Developed over a period of several years and extensively analyzed prior to the release, TLS 1.3 removed insecure features, and improved both security and performance.
Good
TLS 1.2 supported
Good. This server supports TLS 1.2, which can provide strong security when configured correctly. This version of the TLS protocol is necessary to provide good security with a wide range of clients that don't yet support TLS 1.3.
Good
Deprecated protocols not supported
Excellent. This server doesn't support any of the deprecated protocol (TLS 1.1 and earlier).
Good
Strong key exchange detected
Excellent. All cipher suites on this server rely on strong key exchange. The sweet spot is 2048 bits for DHE and 256 bits for ECDHE. Putting ECDHE suites first guarantees best security and best performance.
Good
Server prefers forward secrecy and authenticated encryption suites
Excellent. Not only does this server enforce its server preference, but it also has at the top of the list suites that support both forward secrecy and authenticated encryption. This is the best TLS 1.2 can offer.
Good
Server enforces cipher suite preferences
Excellent. This server enforces server cipher suite preference, which means that it is able to select the best suite from the options submitted by clients. Combined with a well designed list of supported cipher suites, this settings enables negotiation of best security.
Good
All TLS connections with this server satisfy Apple's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Good
All TLS connections with this server satisfy Chrome's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Notice
DHE suites not supported
This server doesn't support the Diffie-Hellman (DH) key exchange.

TLS Configuration: www.skiff.com (2606:4700:3108:0:0:0:ac42:2918)

Encryption protocol version determines what features are
available for negotiation between client and server.
Supported protocols
TLS v1.3
TLS v1.2
Servers should always enforce their own cipher
suite preference, as that is the only approach
that guarantees that the best possible suite is
selected.
Server suite preference
Shows cipher suite configuration for this protocol version.TLS v1.3
Server preference
Suite: TLS_CHACHA20_POLY1305_SHA256
Suite ID: 0x1303
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_AES_128_GCM_SHA256
Suite ID: 0x1301
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_AES_256_GCM_SHA384
Suite ID: 0x1302
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference
Suite: AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc14
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca9
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02b
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc009
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc02c
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc00a
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc023
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc024
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc13
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca8
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc013
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0x9c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_GCM_SHA256
 128 bits
Suite: TLS_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0x2f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_128_CBC_SHA
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc030
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc014
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0x9d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA384
TLS_RSA_WITH_AES_256_GCM_SHA384
 256 bits
Suite: TLS_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0x35
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_256_CBC_SHA
 256 bits
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc027
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0x3c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_CBC_SHA256
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc028
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_CBC_SHA256
Suite ID: 0x3d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
 256 bits

Analysis

Good
TLS 1.3 supported
Excellent. This server supports TLS 1.3, which is the latest revision of the TLS protocol and a significant improvement over earlier versions. Developed over a period of several years and extensively analyzed prior to the release, TLS 1.3 removed insecure features, and improved both security and performance.
Good
TLS 1.2 supported
Good. This server supports TLS 1.2, which can provide strong security when configured correctly. This version of the TLS protocol is necessary to provide good security with a wide range of clients that don't yet support TLS 1.3.
Good
Deprecated protocols not supported
Excellent. This server doesn't support any of the deprecated protocol (TLS 1.1 and earlier).
Good
Strong key exchange detected
Excellent. All cipher suites on this server rely on strong key exchange. The sweet spot is 2048 bits for DHE and 256 bits for ECDHE. Putting ECDHE suites first guarantees best security and best performance.
Good
Server prefers forward secrecy and authenticated encryption suites
Excellent. Not only does this server enforce its server preference, but it also has at the top of the list suites that support both forward secrecy and authenticated encryption. This is the best TLS 1.2 can offer.
Good
Server enforces cipher suite preferences
Excellent. This server enforces server cipher suite preference, which means that it is able to select the best suite from the options submitted by clients. Combined with a well designed list of supported cipher suites, this settings enables negotiation of best security.
Good
All TLS connections with this server satisfy Apple's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Good
All TLS connections with this server satisfy Chrome's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Notice
DHE suites not supported
This server doesn't support the Diffie-Hellman (DH) key exchange.

TLS Configuration: www.skiff.com (172.66.42.232)

Encryption protocol version determines what features are
available for negotiation between client and server.
Supported protocols
TLS v1.3
TLS v1.2
Servers should always enforce their own cipher
suite preference, as that is the only approach
that guarantees that the best possible suite is
selected.
Server suite preference
Shows cipher suite configuration for this protocol version.TLS v1.3
Server preference
Suite: TLS_CHACHA20_POLY1305_SHA256
Suite ID: 0x1303
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_AES_128_GCM_SHA256
Suite ID: 0x1301
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_AES_256_GCM_SHA384
Suite ID: 0x1302
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference
Suite: AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc14
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca9
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02b
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc009
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc02c
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc00a
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc023
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc024
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc13
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca8
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc013
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0x9c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_GCM_SHA256
 128 bits
Suite: TLS_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0x2f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_128_CBC_SHA
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc030
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc014
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0x9d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA384
TLS_RSA_WITH_AES_256_GCM_SHA384
 256 bits
Suite: TLS_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0x35
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_256_CBC_SHA
 256 bits
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc027
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0x3c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_CBC_SHA256
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc028
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_CBC_SHA256
Suite ID: 0x3d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
 256 bits

Analysis

Good
TLS 1.3 supported
Excellent. This server supports TLS 1.3, which is the latest revision of the TLS protocol and a significant improvement over earlier versions. Developed over a period of several years and extensively analyzed prior to the release, TLS 1.3 removed insecure features, and improved both security and performance.
Good
TLS 1.2 supported
Good. This server supports TLS 1.2, which can provide strong security when configured correctly. This version of the TLS protocol is necessary to provide good security with a wide range of clients that don't yet support TLS 1.3.
Good
Deprecated protocols not supported
Excellent. This server doesn't support any of the deprecated protocol (TLS 1.1 and earlier).
Good
Strong key exchange detected
Excellent. All cipher suites on this server rely on strong key exchange. The sweet spot is 2048 bits for DHE and 256 bits for ECDHE. Putting ECDHE suites first guarantees best security and best performance.
Good
Server prefers forward secrecy and authenticated encryption suites
Excellent. Not only does this server enforce its server preference, but it also has at the top of the list suites that support both forward secrecy and authenticated encryption. This is the best TLS 1.2 can offer.
Good
Server enforces cipher suite preferences
Excellent. This server enforces server cipher suite preference, which means that it is able to select the best suite from the options submitted by clients. Combined with a well designed list of supported cipher suites, this settings enables negotiation of best security.
Good
All TLS connections with this server satisfy Apple's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Good
All TLS connections with this server satisfy Chrome's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Notice
DHE suites not supported
This server doesn't support the Diffie-Hellman (DH) key exchange.

TLS Configuration: skiff.com (172.66.41.24)

Encryption protocol version determines what features are
available for negotiation between client and server.
Supported protocols
TLS v1.3
TLS v1.2
Servers should always enforce their own cipher
suite preference, as that is the only approach
that guarantees that the best possible suite is
selected.
Server suite preference
Shows cipher suite configuration for this protocol version.TLS v1.3
Server preference
Suite: TLS_CHACHA20_POLY1305_SHA256
Suite ID: 0x1303
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_AES_128_GCM_SHA256
Suite ID: 0x1301
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_AES_256_GCM_SHA384
Suite ID: 0x1302
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference
Suite: AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc14
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca9
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02b
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc009
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc02c
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc00a
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc023
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc024
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc13
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca8
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc013
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0x9c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_GCM_SHA256
 128 bits
Suite: TLS_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0x2f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_128_CBC_SHA
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc030
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc014
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0x9d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA384
TLS_RSA_WITH_AES_256_GCM_SHA384
 256 bits
Suite: TLS_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0x35
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_256_CBC_SHA
 256 bits
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc027
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0x3c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_CBC_SHA256
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc028
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_CBC_SHA256
Suite ID: 0x3d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
 256 bits

Analysis

Good
TLS 1.3 supported
Excellent. This server supports TLS 1.3, which is the latest revision of the TLS protocol and a significant improvement over earlier versions. Developed over a period of several years and extensively analyzed prior to the release, TLS 1.3 removed insecure features, and improved both security and performance.
Good
TLS 1.2 supported
Good. This server supports TLS 1.2, which can provide strong security when configured correctly. This version of the TLS protocol is necessary to provide good security with a wide range of clients that don't yet support TLS 1.3.
Good
Deprecated protocols not supported
Excellent. This server doesn't support any of the deprecated protocol (TLS 1.1 and earlier).
Good
Strong key exchange detected
Excellent. All cipher suites on this server rely on strong key exchange. The sweet spot is 2048 bits for DHE and 256 bits for ECDHE. Putting ECDHE suites first guarantees best security and best performance.
Good
Server prefers forward secrecy and authenticated encryption suites
Excellent. Not only does this server enforce its server preference, but it also has at the top of the list suites that support both forward secrecy and authenticated encryption. This is the best TLS 1.2 can offer.
Good
Server enforces cipher suite preferences
Excellent. This server enforces server cipher suite preference, which means that it is able to select the best suite from the options submitted by clients. Combined with a well designed list of supported cipher suites, this settings enables negotiation of best security.
Good
All TLS connections with this server satisfy Apple's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Good
All TLS connections with this server satisfy Chrome's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Notice
DHE suites not supported
This server doesn't support the Diffie-Hellman (DH) key exchange.

TLS Configuration: skiff.com (172.66.42.232)

Encryption protocol version determines what features are
available for negotiation between client and server.
Supported protocols
TLS v1.3
TLS v1.2
Servers should always enforce their own cipher
suite preference, as that is the only approach
that guarantees that the best possible suite is
selected.
Server suite preference
Shows cipher suite configuration for this protocol version.TLS v1.3
Server preference
Suite: TLS_CHACHA20_POLY1305_SHA256
Suite ID: 0x1303
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_AES_128_GCM_SHA256
Suite ID: 0x1301
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_AES_256_GCM_SHA384
Suite ID: 0x1302
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ecdh_x25519
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference
Suite: AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc14
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca9
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02b
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc009
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc02c
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc00a
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc023
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc024
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_ECDSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcc13
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
AGL_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
Suite ID: 0xcca8
Cipher name: CHACHA20
Cipher strength: 256 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0xc02f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0xc013
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_GCM_SHA256
Suite ID: 0x9c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_GCM_SHA256
 128 bits
Suite: TLS_RSA_WITH_AES_128_CBC_SHA
Suite ID: 0x2f
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_128_CBC_SHA
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0xc030
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0xc014
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_GCM_SHA384
Suite ID: 0x9d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: AEAD
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA384
TLS_RSA_WITH_AES_256_GCM_SHA384
 256 bits
Suite: TLS_RSA_WITH_AES_256_CBC_SHA
Suite ID: 0x35
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA
TLS_RSA_WITH_AES_256_CBC_SHA
 256 bits
Suite: TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0xc027
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
 128 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_128_CBC_SHA256
Suite ID: 0x3c
Cipher name: AES
Cipher strength: 128 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_128_CBC_SHA256
 128 bits
Suite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Suite ID: 0xc028
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: ECDHE_RSA
Key exchange strength: EC ecdh_x25519 (256 bits)
Forward secrecy: Yes
PRF: SHA384
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
 256 bits (ECDHE 256 bits)
Suite: TLS_RSA_WITH_AES_256_CBC_SHA256
Suite ID: 0x3d
Cipher name: AES
Cipher strength: 256 bits
Cipher block size: 128 bits
Cipher mode: CBC
Key exchange: RSA
Key exchange strength: 2048 bits
Forward secrecy: No (WEAK)
PRF: SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
 256 bits

Analysis

Good
TLS 1.3 supported
Excellent. This server supports TLS 1.3, which is the latest revision of the TLS protocol and a significant improvement over earlier versions. Developed over a period of several years and extensively analyzed prior to the release, TLS 1.3 removed insecure features, and improved both security and performance.
Good
TLS 1.2 supported
Good. This server supports TLS 1.2, which can provide strong security when configured correctly. This version of the TLS protocol is necessary to provide good security with a wide range of clients that don't yet support TLS 1.3.
Good
Deprecated protocols not supported
Excellent. This server doesn't support any of the deprecated protocol (TLS 1.1 and earlier).
Good
Strong key exchange detected
Excellent. All cipher suites on this server rely on strong key exchange. The sweet spot is 2048 bits for DHE and 256 bits for ECDHE. Putting ECDHE suites first guarantees best security and best performance.
Good
Server prefers forward secrecy and authenticated encryption suites
Excellent. Not only does this server enforce its server preference, but it also has at the top of the list suites that support both forward secrecy and authenticated encryption. This is the best TLS 1.2 can offer.
Good
Server enforces cipher suite preferences
Excellent. This server enforces server cipher suite preference, which means that it is able to select the best suite from the options submitted by clients. Combined with a well designed list of supported cipher suites, this settings enables negotiation of best security.
Good
All TLS connections with this server satisfy Apple's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Good
All TLS connections with this server satisfy Chrome's CT requirements
All TLS connections established with this server satisfy Chrome's CT requirements, using certificate, TLS extension, or OCSP response as SCT transport method.

SCT transports: CERT

Notice
DHE suites not supported
This server doesn't support the Diffie-Hellman (DH) key exchange.

WWW Certificates

A certificate is a digital document that contains a public key, some information about the entity associated with it, and a digital signature from the certificate issuer. It’s a mechanism that enables us to exchange, store, and use public keys. Being able to reliably verify the identity of a remote server is crucial in order to achieve secure encrypted communication.

Test passed
Everything seems to be well configured. Well done.

Certificate: www.skiff.com

Leaf certificate skiff.com
Issuer: Let's Encrypt
Not Before: 25 Mar 2024 14:38:40 UTC
Not After: 23 Jun 2024 14:38:39 UTC (expires in 1 month 9 days)
Key: RSA 2048 bits
Signature: SHA256withRSA
 View details

Analysis

Good
Strong private key
Good. The private key associated with this certificate is secure.
Good
Strong signature algorithm
Good. This certificate uses a strong signature algorithm.
Good
Certificate matches hostname
Good. The provided certificate matches the expected hostnames.
Good
Certificate dates match
Good. The certificate is valid for use at this point of time.
Good
Certificate has not been revoked
Good. This certificate has not been revoked.
Good
Certificate satisfies Apple's CT compliance requirements
Good. This certificate satisfies Apple's CT requirements at present.

Certificate Trust

Determining whether a certificate is considered valid is a complicated process that depends on the exact configuration of the validating party. For trust to be established, the certificate must form a chain that ends with a trusted root. In this section we evaluate the server's certificate against major root stores.

Platform Trusted
Apple
Google AOSP
Microsoft
Mozilla

Certificate Chain

For a server certificate to be valid, it must be presented as part of a complete and valid certificate chain. The last certificate in the chain should be the root and is usually not included in the configuration.

Leaf certificate
skiff.com | 1515b55
Not After: 23 Jun 2024 14:38:39 UTC (expires in 1 month 9 days)
Authentication: RSA 2048 bits (SHA256withRSA)
 View details
Intermediate certificate
R3 | 67add11
Not After: 15 Sep 2025 16:00:00 UTC (expires in 1 year 4 months)
Authentication: RSA 2048 bits (SHA256withRSA)
 View details
Intermediate certificate
ISRG Root X1 | 6d99fb2
Not After: 30 Sep 2024 18:14:03 UTC (expires in 4 months 17 days)
Authentication: RSA 4096 bits (SHA256withRSA)
 View details
Root certificate
DST Root CA X3 | 0687260
Not After: 30 Sep 2021 14:01:15 UTC (expired 2 years 7 months ago)
Authentication: RSA 2048 bits (SHA1withRSA)
 View details

Analysis

Good
Certificate chain is correct
Good. This chain contains all the right certificates and in the right order.

Certificate: skiff.com

Leaf certificate skiff.com
Issuer: Let's Encrypt
Not Before: 25 Mar 2024 14:38:40 UTC
Not After: 23 Jun 2024 14:38:39 UTC (expires in 1 month 9 days)
Key: RSA 2048 bits
Signature: SHA256withRSA
 View details

Analysis

Good
Strong private key
Good. The private key associated with this certificate is secure.
Good
Strong signature algorithm
Good. This certificate uses a strong signature algorithm.
Good
Certificate matches hostname
Good. The provided certificate matches the expected hostnames.
Good
Certificate dates match
Good. The certificate is valid for use at this point of time.
Good
Certificate has not been revoked
Good. This certificate has not been revoked.
Good
Certificate satisfies Apple's CT compliance requirements
Good. This certificate satisfies Apple's CT requirements at present.

Certificate Trust

Determining whether a certificate is considered valid is a complicated process that depends on the exact configuration of the validating party. For trust to be established, the certificate must form a chain that ends with a trusted root. In this section we evaluate the server's certificate against major root stores.

Platform Trusted
Apple
Google AOSP
Microsoft
Mozilla

Certificate Chain

For a server certificate to be valid, it must be presented as part of a complete and valid certificate chain. The last certificate in the chain should be the root and is usually not included in the configuration.

Leaf certificate
skiff.com | 1515b55
Not After: 23 Jun 2024 14:38:39 UTC (expires in 1 month 9 days)
Authentication: RSA 2048 bits (SHA256withRSA)
 View details
Intermediate certificate
R3 | 67add11
Not After: 15 Sep 2025 16:00:00 UTC (expires in 1 year 4 months)
Authentication: RSA 2048 bits (SHA256withRSA)
 View details
Intermediate certificate
ISRG Root X1 | 6d99fb2
Not After: 30 Sep 2024 18:14:03 UTC (expires in 4 months 17 days)
Authentication: RSA 4096 bits (SHA256withRSA)
 View details
Root certificate
DST Root CA X3 | 0687260
Not After: 30 Sep 2021 14:01:15 UTC (expired 2 years 7 months ago)
Authentication: RSA 2048 bits (SHA1withRSA)
 View details