DocFraggle
I tried this: https://docs.mailcow.email/manual-guides/u_e-reeanble-weak-protocols/ but wasn’t enough.
I’m not happy to soften to every client in the world, but I could do if it is possible for just some ip…
With TLS 1.0 and 1.1 re-enabled MailCow accept this:
465/tcp open smtps
| ssl-enum-ciphers:
| TLSv1.0:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| compressors:
| NULL
| cipher preference: server
| TLSv1.1:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| compressors:
| NULL
| cipher preference: server
| TLSv1.2:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CCM (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_ARIA_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_CAMELLIA_256_CBC_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CCM (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_ARIA_128_GCM_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_CAMELLIA_128_CBC_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| compressors:
| NULL
| cipher preference: server
| TLSv1.3:
| ciphers:
| TLS_AKE_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_AKE_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
| TLS_AKE_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
| cipher preference: server
|_ least strength: A
On the other hand, GMail accept this:
465/tcp open smtps
| ssl-enum-ciphers:
| TLSv1.0:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
| compressors:
| NULL
| cipher preference: server
| warnings:
| 64-bit block cipher 3DES vulnerable to SWEET32 attack
| TLSv1.1:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
| compressors:
| NULL
| cipher preference: server
| warnings:
| 64-bit block cipher 3DES vulnerable to SWEET32 attack
| TLSv1.2:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
| TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
| TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 2048) - A
| TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 2048) - A
| compressors:
| NULL
| cipher preference: client
| warnings:
| 64-bit block cipher 3DES vulnerable to SWEET32 attack
| TLSv1.3:
| ciphers:
| TLS_AKE_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
| TLS_AKE_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_AKE_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
| cipher preference: client
|_ least strength: C
With TLS 1.0 and 1.1 re-enabled MailCow accept this:
465/tcp open smtps
| ssl-enum-ciphers:
| TLSv1.0:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| compressors:
| NULL
| cipher preference: server
| TLSv1.1:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| compressors:
| NULL
| cipher preference: server
| TLSv1.2:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CCM (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_ARIA_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_CAMELLIA_256_CBC_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CCM (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_ARIA_128_GCM_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_CAMELLIA_128_CBC_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| compressors:
| NULL
| cipher preference: server
| TLSv1.3:
| ciphers:
| TLS_AKE_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_AKE_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
| TLS_AKE_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
| cipher preference: server
|_ least strength: A
On the other hand, GMail accept this:
465/tcp open smtps
| ssl-enum-ciphers:
| TLSv1.0:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
| compressors:
| NULL
| cipher preference: server
| warnings:
| 64-bit block cipher 3DES vulnerable to SWEET32 attack
| TLSv1.1:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
| compressors:
| NULL
| cipher preference: server
| warnings:
| 64-bit block cipher 3DES vulnerable to SWEET32 attack
| TLSv1.2:
| ciphers:
| TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
| TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
| TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 2048) - A
| TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
| TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 2048) - A
| compressors:
| NULL
| cipher preference: client
| warnings:
| 64-bit block cipher 3DES vulnerable to SWEET32 attack
| TLSv1.3:
| ciphers:
| TLS_AKE_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
| TLS_AKE_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
| TLS_AKE_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
| cipher preference: client
|_ least strength: C