Recommended configurations
Mozilla maintains three recommended configurations for servers using TLS. Pick the correct configuration depending on your audience:
- Modern: Modern clients that support TLS 1.3, with no need for
backwards compatibility - Intermediate: Recommended configuration for a general-purpose server
- Old: Services accessed by very old clients or libraries, such as
Internet Explorer 8 (Windows XP), Java 6, or OpenSSL 0.9.8
| Configuration | Firefox | Android | Chrome | Edge | Internet Explorer | Java | OpenSSL | Opera | Safari |
|---|---|---|---|---|---|---|---|---|---|
| Modern | 63 | 10.0 | 70 | 75 | -- | 11 | 1.1.1 | 57 | 12.1 |
| Intermediate | 27 | 4.4.2 | 31 | 12 | 11 (Win7) | 8u31 | 1.0.1 | 20 | 9 |
| Old | 1 | 2.3 | 1 | 12 | 8 (WinXP) | 6 | 0.9.8 | 5 | 1 |
The ordering of cipher suites in the Intermediate and Old configurations is very important, as it determines the priority with which algorithms are selected.
OpenSSL will ignore cipher suites it doesn't understand, so always use the full set of cipher suites below, in their recommended order. The use of the Old configuration with modern versions of OpenSSL may require custom builds with support for deprecated ciphers.
Modern compatibility
For services with clients that support TLS 1.3 and don't need backward compatibility, the Modern configuration provides an extremely high level of security.
- Cipher suites (TLS 1.3): TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256
- Cipher suites (TLS 1.2): (none)
- Protocols: TLS 1.3
- Certificate type: ECDSA (P-256)
- TLS curves: X25519, prime256v1, secp384r1
- HSTS: max-age=63072000 (two years)
- Maximum certificate lifespan: 90 days
- Cipher preference: client chooses
0x13,0x01 - TLS_AES_128_GCM_SHA256 TLSv1.3 Kx=any Au=any Enc=AESGCM(128) Mac=AEAD 0x13,0x02 - TLS_AES_256_GCM_SHA384 TLSv1.3 Kx=any Au=any Enc=AESGCM(256) Mac=AEAD 0x13,0x03 - TLS_CHACHA20_POLY1305_SHA256 TLSv1.3 Kx=any Au=any Enc=CHACHA20/POLY1305(256) Mac=AEAD
- Rationale:
- All cipher suites are forward secret and authenticated
- The cipher suites are all strong and so we allow the client to choose, as they will know best if they have support for hardware-accelerated AES
- We recommend ECDSA certificates using P-256, as P-384 provides negligable improvements to security and Ed25519 is not yet widely supported
Intermediate compatibility (recommended)
For services that don't need compatibility with legacy clients, such as Windows XP or old versions of OpenSSL. This is the recommended configuration for the vast majority of services, as it is highly secure and compatible with nearly every client released in the last five (or more) years.
- Cipher suites (TLS 1.3): TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256
- Cipher suites (TLS 1.2): ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384
- Protocols: TLS 1.2, TLS 1.3
- TLS curves: X25519, prime256v1, secp384r1
- Certificate type: ECDSA (P-256) (recommended), or RSA (2048 bits)
- DH parameter size: 2048 (ffdhe2048, RFC 7919)
- HSTS: max-age=63072000 (two years)
- Maximum certificate lifespan: 90 days (recommended) to 2 years
- Cipher preference: client chooses
0x13,0x01 - TLS_AES_128_GCM_SHA256 TLSv1.3 Kx=any Au=any Enc=AESGCM(128) Mac=AEAD 0x13,0x02 - TLS_AES_256_GCM_SHA384 TLSv1.3 Kx=any Au=any Enc=AESGCM(256) Mac=AEAD 0x13,0x03 - TLS_CHACHA20_POLY1305_SHA256 TLSv1.3 Kx=any Au=any Enc=CHACHA20/POLY1305(256) Mac=AEAD 0xC0,0x2B - ECDHE-ECDSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(128) Mac=AEAD 0xC0,0x2F - ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(128) Mac=AEAD 0xC0,0x2C - ECDHE-ECDSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(256) Mac=AEAD 0xC0,0x30 - ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(256) Mac=AEAD 0xCC,0xA9 - ECDHE-ECDSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH Au=ECDSA Enc=CHACHA20/POLY1305(256) Mac=AEAD 0xCC,0xA8 - ECDHE-RSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH Au=RSA Enc=CHACHA20/POLY1305(256) Mac=AEAD 0x00,0x9E - DHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(128) Mac=AEAD 0x00,0x9F - DHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(256) Mac=AEAD
- Rationale:
- All cipher suites are forward secret and authenticated
- TLS 1.2 is the minimum supported protocol, as recommended by RFC 7525, PCI DSS, and others
- ECDSA certificates are recommended over RSA certificates, as they allow the use of ECDHE with Windows 7 clients using Internet Explorer 11
- The cipher suites are all strong and so we allow the client to choose, as they will know best if they have support for hardware-accelerated AES
- Windows XP (including all embedded versions) are no longer supported by Microsoft, eliminating the need for many older protocols and ciphers
- While the goal is to support a broad range of clients, we reasonably disable a number of ciphers that have little support (such as ARIA, Camellia, 3DES, and SEED)
- 90 days is the recommended maximum certificate lifespan, to encourage certificate issuance automation
Old backward compatibility
This configuration is compatible with a number of very old clients, and should be used only as a last resort.
- Cipher suites (TLS 1.3): TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256
- Cipher suites (TLS 1.0 - 1.2): ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA
- Protocols: TLS 1.0, TLS 1.1, TLS 1.2, TLS 1.3
- TLS curves: X25519, prime256v1, secp384r1
- Certificate type: RSA (2048-bits)
- Certificate curve: None
- DH parameter size: 1024 (generated with openssl dhparam 1024)
- HSTS: max-age=63072000 (two years)
- Maximum certificate lifespan: 90 days (recommended) to 2 years
- Cipher preference: server chooses
0x13,0x01 - TLS_AES_128_GCM_SHA256 TLSv1.3 Kx=any Au=any Enc=AESGCM(128) Mac=AEAD 0x13,0x02 - TLS_AES_256_GCM_SHA384 TLSv1.3 Kx=any Au=any Enc=AESGCM(256) Mac=AEAD 0x13,0x03 - TLS_CHACHA20_POLY1305_SHA256 TLSv1.3 Kx=any Au=any Enc=CHACHA20/POLY1305(256) Mac=AEAD 0xC0,0x2B - ECDHE-ECDSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(128) Mac=AEAD 0xC0,0x2F - ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(128) Mac=AEAD 0xC0,0x2C - ECDHE-ECDSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(256) Mac=AEAD 0xC0,0x30 - ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(256) Mac=AEAD 0xCC,0xA9 - ECDHE-ECDSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH Au=ECDSA Enc=CHACHA20/POLY1305(256) Mac=AEAD 0xCC,0xA8 - ECDHE-RSA-CHACHA20-POLY1305 TLSv1.2 Kx=ECDH Au=RSA Enc=CHACHA20/POLY1305(256) Mac=AEAD 0x00,0x9E - DHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(128) Mac=AEAD 0x00,0x9F - DHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(256) Mac=AEAD 0xCC,0xAA - DHE-RSA-CHACHA20-POLY1305 TLSv1.2 Kx=DH Au=RSA Enc=CHACHA20/POLY1305(256) Mac=AEAD 0xC0,0x23 - ECDHE-ECDSA-AES128-SHA256 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AES(128) Mac=SHA256 0xC0,0x27 - ECDHE-RSA-AES128-SHA256 TLSv1.2 Kx=ECDH Au=RSA Enc=AES(128) Mac=SHA256 0xC0,0x09 - ECDHE-ECDSA-AES128-SHA TLSv1 Kx=ECDH Au=ECDSA Enc=AES(128) Mac=SHA1 0xC0,0x13 - ECDHE-RSA-AES128-SHA TLSv1 Kx=ECDH Au=RSA Enc=AES(128) Mac=SHA1 0xC0,0x24 - ECDHE-ECDSA-AES256-SHA384 TLSv1.2 Kx=ECDH Au=ECDSA Enc=AES(256) Mac=SHA384 0xC0,0x28 - ECDHE-RSA-AES256-SHA384 TLSv1.2 Kx=ECDH Au=RSA Enc=AES(256) Mac=SHA384 0xC0,0x0A - ECDHE-ECDSA-AES256-SHA TLSv1 Kx=ECDH Au=ECDSA Enc=AES(256) Mac=SHA1 0xC0,0x14 - ECDHE-RSA-AES256-SHA TLSv1 Kx=ECDH Au=RSA Enc=AES(256) Mac=SHA1 0x00,0x67 - DHE-RSA-AES128-SHA256 TLSv1.2 Kx=DH Au=RSA Enc=AES(128) Mac=SHA256 0x00,0x6B - DHE-RSA-AES256-SHA256 TLSv1.2 Kx=DH Au=RSA Enc=AES(256) Mac=SHA256 0x00,0x9C - AES128-GCM-SHA256 TLSv1.2 Kx=RSA Au=RSA Enc=AESGCM(128) Mac=AEAD 0x00,0x9D - AES256-GCM-SHA384 TLSv1.2 Kx=RSA Au=RSA Enc=AESGCM(256) Mac=AEAD 0x00,0x3C - AES128-SHA256 TLSv1.2 Kx=RSA Au=RSA Enc=AES(128) Mac=SHA256 0x00,0x3D - AES256-SHA256 TLSv1.2 Kx=RSA Au=RSA Enc=AES(256) Mac=SHA256 0x00,0x2F - AES128-SHA SSLv3 Kx=RSA Au=RSA Enc=AES(128) Mac=SHA1 0x00,0x35 - AES256-SHA SSLv3 Kx=RSA Au=RSA Enc=AES(256) Mac=SHA1 0x00,0x0A - DES-CBC3-SHA SSLv3 Kx=RSA Au=RSA Enc=3DES(168) Mac=SHA1
- Rationale:
- Take a hard look at your infrastructure needs before using this configuration; it is intended for special use cases only
- If possible, use this configuration only for endpoints that require it, segregating it from other traffic
- SSLv3 has been disabled entirely, ending support for older Windows XP SP2 clients. Users requiring support for Windows XP SP2 may use previous versions of this configuration, with the caveat that SSLv3 is no longer safe to use
- This configuration requires custom builds to work with modern versions of OpenSSL, using enable-ssl3, enable-ssl3-method, enable-deprecated, and enable-weak-ssl-ciphers
- Most ciphers that are not clearly broken and dangerous to use are supported