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Public Report | protonmail.com

TEST ANOTHER

protonmail.com

15 Apr 2024 07:32 UTC

Domain Name System

DNS Zonegood
DNS Recordsgood
DNSSECgood
CAAgood

Email

Mail serversgood
TLSgood
Certificatesgood
MTA-STSgood
TLS-RPTgood
DANEgood
SPFgood
DMARCgood

WWW

HTTP (80)good
HTTPS (443)good
TLSgood
Certificatesgood
Cookiesgood
Mixed Contentgood
Strict Transport Securitygood
Content Security Policyneutral
Subresource Integritygood
Frame Optionsgood
XSS Protectiongood
Content Type Optionsgood
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
Not supported
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
ns1.protonmail.com. PRIMARY
185.70.42.150 		The server is online. Name resolves to an IPv4 address. Name doesn't resolve to an IPv6 address. REFERRAL NS SOA
ns2.protonmail.com.
176.119.200.150 		The server is online. Name resolves to an IPv4 address. Name doesn't resolve to an IPv6 address. REFERRAL NS
ns3.protonmail.com.
205.132.47.1 		The server is online. Name resolves to an IPv4 address. Name doesn't resolve to an IPv6 address. REFERRAL NS

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
176.119.200.150
ns2.protonmail.com.
PTR: 176-119-200-150.protonmail.ch. 		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
185.70.42.150 PRIMARY
ns1.protonmail.com.
PTR: 185-70-42-150.protonmail.ch. 		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
205.132.47.1
ns3.protonmail.com.
PTR: ns3.protonmail.ch. 		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 ns1.protonmail.com.
Email address of the persons responsible for this zone. Also known as RNAME.Admin email support.protonmail.ch.
Zone serial or version number.Serial number -1983665407
The length of time secondary nameservers should wait before querying the primary for changes.Refresh interval 1,200 seconds (about 20 minutes)
The length of time secondary nameservers should wait before querying an unresponsive primary again.Retry interval 144 seconds (about 2 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 1,814,400 seconds (about 21 days)
TTL for purposes of negative response caching. Negative cache TTL 7,200 seconds (about 2 hours)
Time To Live (TTL) indicates for how long a record remains valid. SOA record TTL 1,200 seconds (about 20 minutes)

Analysis

Powerup!
Nameserver A and AAAA records should have matching reverse records
According to RFC 1912, nameserver's PTR records must match their A and AAAA records to ensure maximum interoperability.
Powerup!
Improve IPv6 support
The Internet is in a slow transition to supporting IPv6 widely. Although at this time it is expected that most recursive DNS servers will use IPv4, adding support for IPv6 will enable transition to networks that use IPv6 exclusively.
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
protonmail.com.     1200 A 185.70.42.12            
www.protonmail.com.     1200 A 185.70.42.31            
protonmail.com.     1200 CAA 0 issue "digicert.com"            
protonmail.com.     1200 CAA 0 iodef "mailto:security@protonmail.com"            
protonmail.com.     1200 CAA 0 issue "sectigo.com"            
protonmail.com.     1200 CAA 0 issue "letsencrypt.org"            
protonmail.com.     1200 DNSKEY 257 3 13 VRvrqp0hFPeZdrFLfO9f/rtqZg/mlxCAgqkIeeGkTuAmCRLciJv995/2aU1cvGDuKEMVuH23v8OdgqkqqtLIYA==            
protonmail.com.     1200 DNSKEY 256 3 13 a99hiIsSCxd/tXoMy1N5A0bqStx2ULvlBQ8KNOiBITu7cMsjjaMOKz7+Ww3dKvc7U/HepwLRAml9AOTueCa1mA==            
protonmail.com.     1200 MX 5 mail.protonmail.ch.            
protonmail.com.     1200 MX 10 mailsec.protonmail.ch.            
protonmail.com.     1194 NS ns3.protonmail.com.            
protonmail.com.     1194 NS ns2.protonmail.com.            
protonmail.com.     1194 NS ns1.protonmail.com.            
protonmail.com.     1200 SOA ns1.protonmail.com. support.protonmail.ch. 2311301889 1200 144 1814400 7200            
protonmail.com.     1200 TXT "google-site-verification=aq9zJnp3H3bNE0Y4D4rH5I5Dhj8VMaLYx0uQ7Rozfgg"            
protonmail.com.     1200 TXT "brave-ledger-verification=66a7f27fb99949cc0c564ab98efcc58ea1bac3e97eb557c782ab2d44b49aefd7"            
protonmail.com.     1200 TXT "ahrefs-site-verification_4bdac6bbaa81e0d591d7c0f3ef238905c0521b69bf3d74e64d3775bcb2743afd"            
protonmail.com.     1200 TXT "yandex-verification: 6059b187e78de544"            
protonmail.com.     1200 TXT "google-site-verification=RVUCKIFDkg-Spau8kEohQRsgyHEBUQcVehZqF6PAQcQ"            
protonmail.com.     1200 TXT "v=spf1 include:_spf.protonmail.ch ~all"            
protonmail.com.     1200 TXT "mailru-verification: 14505c6eb222c847"            
protonmail.com.     1200 TXT "google-site-verification=uXVNQLivTppnZssXHtMY7QVn70Mpd0x2U8pKj324Krk"            
_dmarc.protonmail.com.     1200 TXT "v=DMARC1; p=quarantine; fo=1; aspf=s; adkim=s;"            
_mta-sts.protonmail.com.     1200 CNAME _mta-sts.protonmail.ch.            
_mta-sts.protonmail.ch.     1200 TXT "v=STSv1; id=190906205100Z;"            
_smtp._tls.protonmail.com.     1200 CNAME _smtp._tls.protonmail.ch.            
_smtp._tls.protonmail.ch.     1200 TXT "v=TLSRPTv1; rua=https://reports.proton.me/reports/smtptls"            

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 protonmail.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 		sectigo.com  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 		letsencrypt.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 		digicert.com  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@protonmail.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.
Some TLS and PKI information shown may have been retrieved from cache. The notes provide more information.
Server Preference Operational STARTTLS TLS PKI DNSSEC DANE
mail.protonmail.ch
176.119.200.128
PTR: mail.protonmail.ch		 5 
220 mailin030.protonmail.ch ESMTP Postfix

EHLO outbound.hardenize.com
250-mailin030.protonmail.ch
250-PIPELINING
250-SIZE 36480000
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 CHUNKING

STARTTLS
220 2.0.0 Ready to start TLS
Supports STARTTLS.
mail.protonmail.ch
185.70.42.128
PTR: mail.protonmail.ch		 5 
220 mailin036.protonmail.ch ESMTP Postfix

EHLO outbound.hardenize.com
250-mailin036.protonmail.ch
250-PIPELINING
250-SIZE 36480000
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 CHUNKING

STARTTLS
220 2.0.0 Ready to start TLS
Supports STARTTLS.
mail.protonmail.ch
185.205.70.128
PTR: mail.protonmail.ch		 5 
220 mailin049.protonmail.ch ESMTP Postfix

EHLO outbound.hardenize.com
250-mailin049.protonmail.ch
250-PIPELINING
250-SIZE 36480000
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 CHUNKING

STARTTLS
220 2.0.0 Ready to start TLS
Supports STARTTLS.
mailsec.protonmail.ch
185.70.42.129
PTR: mailsec.protonmail.ch		 10 
220 mailin027.protonmail.ch ESMTP Postfix

EHLO outbound.hardenize.com
250-mailin027.protonmail.ch
250-PIPELINING
250-SIZE 36480000
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 CHUNKING

STARTTLS
220 2.0.0 Ready to start TLS
Supports STARTTLS.
mailsec.protonmail.ch
176.119.200.129
PTR: mailsec.protonmail.ch		 10 
220 mailin004.protonmail.ch ESMTP Postfix

EHLO outbound.hardenize.com
250-mailin004.protonmail.ch
250-PIPELINING
250-SIZE 36480000
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 CHUNKING

STARTTLS
220 2.0.0 Ready to start TLS
Supports STARTTLS.
mailsec.protonmail.ch
185.205.70.129
PTR: mailsec.protonmail.ch		 10 
220 mailin028.protonmail.ch ESMTP Postfix

EHLO outbound.hardenize.com
250-mailin028.protonmail.ch
250-PIPELINING
250-SIZE 36480000
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 CHUNKING

STARTTLS
220 2.0.0 Ready to start TLS
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.
Notice
Some SMTP server assessments have been retrieved from cache
Some SMTP server assessment results have been retrieved from our cache. Because many hosts point to the same SMTP servers, we use a short-term cache to avoid testing the same SMTP servers over and over again.

Latest cache timestamp: 12 Apr 2024 01:59 UTC

Earliest cache timestamp: 12 Apr 2024 01:59 UTC

Notice
Some SMTP server assessments contain partial information
Comprehensive TLS assessments require many connections, which is exactly what many SMTP servers don't like. We implement a two-tier assessment approach. To give you some results as fast as possible, we perform shallow assessments that use only one connection per SMTP server. We then have a background process that performs complete assessments slowly, trying to accommodate each server individually. The results presented here contain partial information. If you come back later we may be able to provide complete assessment resuls.

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.
Some TLS and PKI information shown may have been retrieved from cache. The notes provide more information.

TLS Configuration: mail.protonmail.ch (176.119.200.128) Cached

Encryption protocol version determines what features are
available for negotiation between client and server.Supported protocols 		TLS v1.2
Shows cipher suite configuration for this protocol version.TLS v1.2 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)
These results have been retrieved from
our cache. This row indicates when was
that the original test ran.Retrieved from cache 		12 Apr 2024 01:59 UTC

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
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.
Notice
Partial results shown
SMTP assessments usually take a long time. To get you some results faster, we initially perform shallow checks. If you come back later we may be able to show you complete results.
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.

TLS Configuration: mail.protonmail.ch (185.70.42.128) Cached

Encryption protocol version determines what features are
available for negotiation between client and server.Supported protocols 		TLS v1.2
Shows cipher suite configuration for this protocol version.TLS v1.2 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)
These results have been retrieved from
our cache. This row indicates when was
that the original test ran.Retrieved from cache 		12 Apr 2024 01:59 UTC

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
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.
Notice
Partial results shown
SMTP assessments usually take a long time. To get you some results faster, we initially perform shallow checks. If you come back later we may be able to show you complete results.
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.

TLS Configuration: mail.protonmail.ch (185.205.70.128) Cached

Encryption protocol version determines what features are
available for negotiation between client and server.Supported protocols 		TLS v1.2
Shows cipher suite configuration for this protocol version.TLS v1.2 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)
These results have been retrieved from
our cache. This row indicates when was
that the original test ran.Retrieved from cache 		12 Apr 2024 01:59 UTC

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
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.
Notice
Partial results shown
SMTP assessments usually take a long time. To get you some results faster, we initially perform shallow checks. If you come back later we may be able to show you complete results.
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.

TLS Configuration: mailsec.protonmail.ch (185.70.42.129) Cached

Encryption protocol version determines what features are
available for negotiation between client and server.Supported protocols 		TLS v1.2
Shows cipher suite configuration for this protocol version.TLS v1.2 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)
These results have been retrieved from
our cache. This row indicates when was
that the original test ran.Retrieved from cache 		12 Apr 2024 01:59 UTC

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
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.
Notice
Partial results shown
SMTP assessments usually take a long time. To get you some results faster, we initially perform shallow checks. If you come back later we may be able to show you complete results.
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.

TLS Configuration: mailsec.protonmail.ch (176.119.200.129) Cached

Encryption protocol version determines what features are
available for negotiation between client and server.Supported protocols 		TLS v1.2
Shows cipher suite configuration for this protocol version.TLS v1.2 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)
These results have been retrieved from
our cache. This row indicates when was
that the original test ran.Retrieved from cache 		12 Apr 2024 01:59 UTC

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
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.
Notice
Partial results shown
SMTP assessments usually take a long time. To get you some results faster, we initially perform shallow checks. If you come back later we may be able to show you complete results.
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.

TLS Configuration: mailsec.protonmail.ch (185.205.70.129) Cached

Encryption protocol version determines what features are
available for negotiation between client and server.Supported protocols 		TLS v1.2
Shows cipher suite configuration for this protocol version.TLS v1.2 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)
These results have been retrieved from
our cache. This row indicates when was
that the original test ran.Retrieved from cache 		12 Apr 2024 01:59 UTC

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
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.
Notice
Partial results shown
SMTP assessments usually take a long time. To get you some results faster, we initially perform shallow checks. If you come back later we may be able to show you complete results.
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.

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.
Some TLS and PKI information shown may have been retrieved from cache. The notes provide more information.

Certificate #1  Cached

Leaf certificate protonmail.com
Issuer: Let's Encrypt
Not Before: 27 Mar 2024 13:20:09 UTC
Not After: 25 Jun 2024 13:20:08 UTC (expires in 2 months 10 days)
Key: RSA 4096 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 Chain

Leaf certificate
protonmail.com | ab2218c
Not After: 25 Jun 2024 13:20:08 UTC (expires in 2 months 10 days)
Authentication: RSA 4096 bits (SHA256withRSA)
 View details
Intermediate certificate
R3 | 67add11
Not After: 15 Sep 2025 16:00:00 UTC (expires in 1 year 5 months)
Authentication: RSA 2048 bits (SHA256withRSA)
 View details
Root certificate
ISRG Root X1 | 96bcec0
Not After: 04 Jun 2035 11:04:38 UTC (expires in 11 years 1 month)
Authentication: RSA 4096 bits (SHA256withRSA)
 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.
Some TLS and PKI information shown may have been retrieved from cache. The notes provide more information.

DANE: mail.protonmail.ch (176.119.200.128)

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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 6111a5698d23c89e09c36ff833c1487edc1b0c841f87c49dae8f7a09e11e979e
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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 76bb66711da416433ca890a5b2e5a0533c6006478f7d10a4469a947acc8399e1

Leaf certificate: RSA 4096 bits
Subject: CN=protonmail.com
Issuer: CN=R3, O=Let's Encrypt, C=US protonmail.com (RSA 4096 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: mail.protonmail.ch (185.70.42.128)

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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 6111a5698d23c89e09c36ff833c1487edc1b0c841f87c49dae8f7a09e11e979e
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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 76bb66711da416433ca890a5b2e5a0533c6006478f7d10a4469a947acc8399e1

Leaf certificate: RSA 4096 bits
Subject: CN=protonmail.com
Issuer: CN=R3, O=Let's Encrypt, C=US protonmail.com (RSA 4096 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: mail.protonmail.ch (185.205.70.128)

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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 6111a5698d23c89e09c36ff833c1487edc1b0c841f87c49dae8f7a09e11e979e
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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 76bb66711da416433ca890a5b2e5a0533c6006478f7d10a4469a947acc8399e1

Leaf certificate: RSA 4096 bits
Subject: CN=protonmail.com
Issuer: CN=R3, O=Let's Encrypt, C=US protonmail.com (RSA 4096 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: mailsec.protonmail.ch (185.70.42.129)

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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 76bb66711da416433ca890a5b2e5a0533c6006478f7d10a4469a947acc8399e1

Leaf certificate: RSA 4096 bits
Subject: CN=protonmail.com
Issuer: CN=R3, O=Let's Encrypt, C=US protonmail.com (RSA 4096 bits)

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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 6111a5698d23c89e09c36ff833c1487edc1b0c841f87c49dae8f7a09e11e979e

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: mailsec.protonmail.ch (176.119.200.129)

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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 76bb66711da416433ca890a5b2e5a0533c6006478f7d10a4469a947acc8399e1

Leaf certificate: RSA 4096 bits
Subject: CN=protonmail.com
Issuer: CN=R3, O=Let's Encrypt, C=US protonmail.com (RSA 4096 bits)

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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 6111a5698d23c89e09c36ff833c1487edc1b0c841f87c49dae8f7a09e11e979e

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: mailsec.protonmail.ch (185.205.70.129)

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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 76bb66711da416433ca890a5b2e5a0533c6006478f7d10a4469a947acc8399e1

Leaf certificate: RSA 4096 bits
Subject: CN=protonmail.com
Issuer: CN=R3, O=Let's Encrypt, C=US protonmail.com (RSA 4096 bits)

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 		SPKI structure (1)
Determines how matching is done; directly or via a hash. Matching Type SHA2-256 (1)
Contains the data necessary to perform the matching. Data 6111a5698d23c89e09c36ff833c1487edc1b0c841f87c49dae8f7a09e11e979e

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 protonmail.com
SPF version used by this policy.v spf1
Evaluates SPF policy specified in another DNS location. This
directive is typically used to allow hosts controlled by
another organization. include 		_spf.protonmail.ch
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 include:_spf.protonmail.ch ~all

Location: protonmail.com

Good
SPF policy is valid
Good. Your SPF policy is syntactically valid.
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: 2

SPF Policy Information Included policy

Host where this policy is located.Location _spf.protonmail.ch
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 		185.70.40.0/24
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network. ip4 		185.70.41.0/24
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network. ip4 		185.70.43.0/24
Evaluates SPF policy specified in another DNS location. This
directive is typically used to allow hosts controlled by
another organization. include 		_spf2.protonmail.ch
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

SPF Policy Information Included policy

Host where this policy is located.Location _spf2.protonmail.ch
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 		51.89.119.103
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network. ip4 		91.134.188.129
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network. ip4 		51.77.79.158
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network. ip4 		54.38.221.122
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network. ip4 		188.165.51.139
This mechanism tests whether the IP address being
tested is contained within a given IPv4 network. ip4 		54.36.149.183
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

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.protonmail.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 		quarantine
Configures failure reporting.fo 1
Indicates whether strict or relaxed SPF
alignment mode is required.aspf 		s
Indicates whether strict or relaxed DKIM
alignment mode is required.adkim 		s

Analysis

Info
DMARC policy found

Policy: v=DMARC1; p=quarantine; fo=1; aspf=s; adkim=s;

Host: _dmarc.protonmail.com

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.protonmail.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 		190906205100Z

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.protonmail.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 		604,800 seconds (about 7 days)
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 		mail.protonmail.ch
One 'mx' directive specifies one email server
pattern that's allowed for this host.mx 		mailsec.protonmail.ch

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: 93 bytes

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

Certificate: mta-sts.protonmail.com

Leaf certificate protonmail.com
Issuer: Let's Encrypt
Not Before: 27 Mar 2024 13:20:09 UTC
Not After: 25 Jun 2024 13:20:08 UTC (expires in 2 months 10 days)
Key: RSA 4096 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 Chain

Leaf certificate
protonmail.com | ab2218c   HPKP-RO-PIN
Not After: 25 Jun 2024 13:20:08 UTC (expires in 2 months 10 days)
Authentication: RSA 4096 bits (SHA256withRSA)
 View details
Intermediate certificate
R3 | 67add11
Not After: 15 Sep 2025 16:00:00 UTC (expires in 1 year 5 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 5 months 15 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 6 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.protonmail.com
TLS-RPT standard version used by this policy indicator.Version TLSRPTv1
Reporting endpoints specified in the policy.Reporting Endpoints https://reports.proton.me/reports/smtptls

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://protonmail.com/

1
http://protonmail.com/
HTTP/1.1 301 Moved Permanently
2
https://protonmail.com/
HTTP/1.1 301 Moved Permanently
3
https://proton.me/mail
HTTP/1.1 200 OK

Analysis

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

URL: http://www.protonmail.com/

1
http://www.protonmail.com/
HTTP/1.1 301 Moved Permanently
2
https://protonmail.com
HTTP/1.1 301 Moved Permanently
3
https://proton.me/mail
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://protonmail.com/

1
https://protonmail.com/
HTTP/1.1 301 Moved Permanently
2
https://proton.me/mail
HTTP/1.1 200 OK

URL: https://www.protonmail.com/

1
https://www.protonmail.com/
HTTP/1.1 301 Moved Permanently
2
https://proton.me
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: protonmail.com (185.70.42.12)

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_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_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_128_CCM_SHA256
Suite ID: 0x1304
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_CCM_SHA256  128 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference 		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_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_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_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)

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
Only strong suites supported
Excellent. This server supports only strong cipher suites, which use strong authenticated encryption and provide forward secrecy.
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

Good
DHE server parameter not reused
This server does not reuse the private value used for the Diffie-Hellman key exchange.

TLS Configuration: www.protonmail.com (185.70.42.31)

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_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_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_128_CCM_SHA256
Suite ID: 0x1304
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_CCM_SHA256  128 bits (ECDHE 256 bits)
Shows cipher suite configuration for this protocol version.TLS v1.2
Server preference 		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_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_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_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)

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
Only strong suites supported
Excellent. This server supports only strong cipher suites, which use strong authenticated encryption and provide forward secrecy.
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

Good
DHE server parameter not reused
This server does not reuse the private value used for the Diffie-Hellman 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.protonmail.com

Leaf certificate protonmail.com
Issuer: Let's Encrypt
Not Before: 27 Mar 2024 13:20:09 UTC
Not After: 25 Jun 2024 13:20:08 UTC (expires in 2 months 10 days)
Key: RSA 4096 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
protonmail.com | ab2218c   HPKP-RO-PIN
Not After: 25 Jun 2024 13:20:08 UTC (expires in 2 months 10 days)
Authentication: RSA 4096 bits (SHA256withRSA)
 View details
Intermediate certificate
R3 | 67add11
Not After: 15 Sep 2025 16:00:00 UTC (expires in 1 year 5 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 5 months 15 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 6 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: protonmail.com

Leaf certificate protonmail.com
Issuer: Let's Encrypt
Not Before: 27 Mar 2024 13:11:48 UTC
Not After: 25 Jun 2024 13:11:47 UTC (expires in 2 months 10 days)
Key: RSA 4096 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
protonmail.com | 123da7d   HPKP-RO-PIN
Not After: 25 Jun 2024 13:11:47 UTC (expires in 2 months 10 days)
Authentication: RSA 4096 bits (SHA256withRSA)
 View details
Intermediate certificate
R3 | 67add11
Not After: 15 Sep 2025 16:00:00 UTC (expires in 1 year 5 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 5 months 15 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 6 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.

DANE (443)

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.

Feature not applicable, not implemented, or disabled
Your server doesn't support this feature.

Cookies

Cookies are small chunks of text that are sent between your browser and a website. They are often essential to the operation of the site and sometimes contain sensitive information. Session cookies sent from secure sites must be explicitly marked as secure to prevent being obtained by active network attackers.

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

Mixed Content

On virtually all web sites, HTML markup, images, style sheets, JavaScript, and other page resources arrive not only over multiple connections but possibly from multiple servers and sites spread across the entire Internet. For a page to be properly encrypted, it’s necessary that all the content is retrieved over HTTPS. In practice, that’s very often not the case, leading to mixed content security problems.

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

Embedded Resources

In this section we look at the security of all embedded resources. Mixed active content occurs when there are unprotected scripts or styles embedded in a page. This is typically not allowed by modern browsers. Mixed passive content (images, videos and such) are typically allowed, but shouldn't be present.

0 script(s)
  0 out of 0 are secure
0 CSS file(s)
  0 out of 0 are secure
0 media file(s)
  0 out of 0 are secure

Outbound Links

Ideally, an encrypted page should only have links that lead to other encrypted pages. If plaintext links are used, passive network attackers can see where people go after they visit your web site. It's also possible that some sensitive information is leaked in the Referer header.

0 link(s)
  0 out of 0 are encrypted

HTTP Strict Transport Security

HTTP Strict Transport Security (HSTS) vastly improves security of the network encryption layer. With HSTS enabled, browsers no longer allow clicking through certificate warnings errors, which are typically trivial to exploit. Additionally, they will no longer submit insecure (plaintext) requests to the site in question, even if asked.

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

HSTS Policy  Main host

URL from which this policy was obtained.Location https://www.protonmail.com/
Specifies policy duration. Once activated, HSTS stays in force
until this time lapses. Browsers update policy cache duration
every time they receive a new HSTS header from a site.max‑age 		31,536,000 seconds (about 1 year)
When present, this directive forces HSTS activation
on allsubdomains. For best security, HSTS should be
deployed on the bare domain name (e.g., example.com)
and all its subdomains.includeSubDomains
Presence of this directive indicates that a web site wishes to
permanently use HSTS and that its policy information should be
preloaded (embedded in browsers).preload

Analysis

Good
Policy is valid
OK. Your HSTS policy uses correct syntax.
Good
Long policy age
Your HSTS policy has a long max-age value, which offers better protection.
Good
Policy covers subdomains
When subdomains are included, network attackers are unable to manufacture arbitrary subdomains to manipulate cookies and trick users.
Good
Redirection from HTTP to HTTPS is to a parent host that activates HSTS
For simplicity, it's best when there is a redirection on port 80 that sends clients to the same host on port 443. In that case, you know that HSTS will always be activated on the host. There isn't a same-host redirection in this instance, but the redirection is to a parent that activates HSTS via the includeSubDomains directive. That's all right.

Starting point: http://www.protonmail.com

Current redirection: https://protonmail.com

Good
Policy preloaded
Excellent. This host is covered by a preloaded HSTS policy.

Preloaded host: protonmail.com; includeSubDomains=true

HSTS Policy  Apex host

URL from which this policy was obtained.Location https://protonmail.com/
Specifies policy duration. Once activated, HSTS stays in force
until this time lapses. Browsers update policy cache duration
every time they receive a new HSTS header from a site.max‑age 		31,536,000 seconds (about 1 year)
When present, this directive forces HSTS activation
on allsubdomains. For best security, HSTS should be
deployed on the bare domain name (e.g., example.com)
and all its subdomains.includeSubDomains
Presence of this directive indicates that a web site wishes to
permanently use HSTS and that its policy information should be
preloaded (embedded in browsers).preload

Analysis

Good
Policy is valid
OK. Your HSTS policy uses correct syntax.
Good
Long policy age
Your HSTS policy has a long max-age value, which offers better protection.
Good
Policy covers subdomains
When subdomains are included, network attackers are unable to manufacture arbitrary subdomains to manipulate cookies and trick users.
Good
Preload intent declared
Good. With the preload directive set, browsers have a green light to embed the HSTS policy.
Good
Redirection from HTTP to HTTPS to the same host
Good. The redirection from HTTP to HTTPS is to the same host. This approach ensures that HSTS is activated on the hostname when it's accessed via plaintext.
Good
Policy preloaded
Excellent. This host is covered by a preloaded HSTS policy.

Preloaded host: protonmail.com; includeSubDomains=true

HTTP Public Key Pinning

HTTP Public Key Pinning (HPKP) enables site operators to restrict which certificates are considered valid for their domain names. With a valid HPKP configuration, sites can defeat man in the middle (MITM) attacks using fraudulent or misissued certificates. HPKP is an advanced feature, suitable for use by only high-profile web sites.

Feature not applicable, not implemented, or disabled
Your server doesn't support this feature.

HPKP Policy (Reporting Only)

This directive signals to the user agent that
the pinning policy applies to the current host
as well as all its subdomains.includeSubDomains
Contains the URI to which user agents
should report pinning policy violations.report-uri 		https://reports.proton.me/reports/tls
Specifies a cryptographic identity that should
be bound to the given web host. The binding is
done via the hash of the desired public key. pin-sha256 		8joiNBdqaYiQpKskgtkJsqRxF7zN0C0aqfi8DacknnI=
Specifies a cryptographic identity that should
be bound to the given web host. The binding is
done via the hash of the desired public key. pin-sha256 		drtmcR2kFkM8qJClsuWgUzxgBkePfRCkRpqUesyDmeE=

Leaf certificate: RSA 4096 bits
Subject: CN=protonmail.com
Issuer: CN=R3, O=Let's Encrypt, C=US protonmail.com (RSA 4096 bits)

Analysis

Powerup!
Subdomains not covered by policy
Pinning policies that don't cover subdomains are potentially vulnerable to active network attacks involving cookies. Because the cookie specification is lax, it's possible that active network attackers abuse and even "create" subdomains to use for attack.

Analysis

Info
Report-only policy discovered

Header: public-key-pins-report-only

Value: pin-sha256="8joiNBdqaYiQpKskgtkJsqRxF7zN0C0aqfi8DacknnI="; pin-sha256="drtmcR2kFkM8qJClsuWgUzxgBkePfRCkRpqUesyDmeE="; report-uri="https://reports.proton.me/reports/tls"

Good
Report-only policy is valid
Good. Your policy uses the correct syntax.

Content Security Policy

Content Security Policy (CSP) is a security mechanism that allows web sites control how browsers process their pages. In essence, sites can restrict what types of resources are loaded and from where. CSP policies can be used to defend against cross-site scripting, prevent mixed content issues, as well as report violations for investigation.

Feature not applicable, not implemented, or disabled
Your server doesn't support this feature.

Subresource Integrity

Subresource Integrity (SRI) is a new standard that enables browsers to verify the integrity of embedded page resources (e.g., scripts and stylesheets) when they are loaded from third-party web sites. With SRI deployed, remote resources can be used safely, without fear of them being modified by malicious parties.

Test passed
Everything seems to be well configured. Well done.
No external scripts
  SRI not needed
No external stylesheets
  SRI not needed

Analysis

Good
No remote resources
The homepage of this site doesn't contain any remote resources so SRI is not needed.

Expect CT

Expect-CT is a deprecated response HTTP header designed to enable web sites to monitor problems related to their Certificate Transparency (CT) compliance. Should any CT issues arise, browsers that supported this header will submit reports to the specified reporting endpoint. Chrome was the browser that introduced support for this response header, but later deprecated it and removed it in version 107.

Feature not applicable, not implemented, or disabled
Your server doesn't support this feature.

Analysis

Powerup!
Deploy Expect-CT to enable reporting
An Expect-CT policy enables web sites to monitor for any problems related to their Expect-CT compliance, detecting potentially serious issues quickly. When issues arise, compliant browsers will submit reports to the specified reporting endpoints. Before CT became required for all public certificates the Expect-CT was also used to require CT, but that use case no longer applies.

Frame Options

The X-Frame-Options header controls page framing, which occurs when a page is incorporated into some other page, possibly on a different site. If framing is allowed, attackers can employ clever tricks to make victims perform arbitrary actions on your site; they do this by showing their web site while forwarding the victim's clicks to yours.

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

Analysis

Info
Header information

Name: x-frame-options

Value: deny

Good
Framing blocked
Good. Your site doesn't allow page framing from any other page.

XSS Protection

Some browsers ship with so-called XSS Auditors, built-in defenses against XSS. Although these defenses work against simple reflective XSS attacks, they can be abused by skillful attackers to add weaknesses to otherwise secure web sites. These dangers are present in both filtering and blocking modes. At this time, the Safari browser ships with its XSS defenses enabled by default. For this reason, the best approach is to explicitly disable this functionality.

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

Analysis

Info
Header information

Name: x-xss-protection

Value: 0

Good
Browser XSS protection disabled
Great. XSS protection is explicitly disabled, making this web site safe even with browsers that have this functionality enabled by default.

Content Type Options

Some browsers use a technique called content sniffing to override response MIME types provided by HTTP servers and interpret responses as something else (usually HTML). This behavior, which could potentially lead to security issues, should be disabled by attaching an X-Content-Type-Options header to all responses.

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

Analysis

Info
Header information

Name: x-content-type-options

Value: nosniff

Good
Valid configuration
Good. Your configuration is valid. This means that browsers won't try to guess file MIME type on this web site.
Close Details