Had an issue where we had a client that couldn’t access a particular site, in this case we wanted to determine what encryption ciphers a particular website was offering on its HTTPS server, SSLScan which is a Linux tool available on Ubuntu and other distributions can help, for example:<\/p>\n\n\n\n
$ sslscan www.domain.com\nVersion: 2.0.7\nOpenSSL 3.0.2 15 Mar 2022\n\nConnected to 124.43.16.202\n\nTesting SSL server www.domain.com on port 443 using SNI name www.domain.com\n\n SSL\/TLS Protocols:\nSSLv2 disabled\nSSLv3 disabled\nTLSv1.0 disabled\nTLSv1.1 disabled\nTLSv1.2 enabled\nTLSv1.3 enabled\n\n TLS Fallback SCSV:\nServer supports TLS Fallback SCSV\n\n TLS renegotiation:\nSession renegotiation not supported\n\n TLS Compression:\nOpenSSL version does not support compression\nRebuild with zlib1g-dev package for zlib support\n\n Heartbleed:\nTLSv1.3 not vulnerable to heartbleed\nTLSv1.2 not vulnerable to heartbleed\n\n Supported Server Cipher(s):\nPreferred TLSv1.3 256 bits TLS_AES_256_GCM_SHA384 Curve 25519 DHE 253\nAccepted TLSv1.3 256 bits TLS_CHACHA20_POLY1305_SHA256 Curve 25519 DHE 253\nAccepted TLSv1.3 128 bits TLS_AES_128_GCM_SHA256 Curve 25519 DHE 253\nPreferred TLSv1.2 256 bits ECDHE-RSA-AES256-GCM-SHA384 Curve 25519 DHE 253\nAccepted TLSv1.2 256 bits ECDHE-RSA-CHACHA20-POLY1305 Curve 25519 DHE 253\nAccepted TLSv1.2 256 bits ECDHE-ARIA256-GCM-SHA384 Curve 25519 DHE 253\nAccepted TLSv1.2 128 bits ECDHE-RSA-AES128-GCM-SHA256 Curve 25519 DHE 253\nAccepted TLSv1.2 128 bits ECDHE-ARIA128-GCM-SHA256 Curve 25519 DHE 253\nAccepted TLSv1.2 256 bits ECDHE-RSA-AES256-SHA384 Curve 25519 DHE 253\nAccepted TLSv1.2 256 bits ECDHE-RSA-CAMELLIA256-SHA384 Curve 25519 DHE 253\nAccepted TLSv1.2 128 bits ECDHE-RSA-AES128-SHA256 Curve 25519 DHE 253\nAccepted TLSv1.2 128 bits ECDHE-RSA-CAMELLIA128-SHA256 Curve 25519 DHE 253\nAccepted TLSv1.2 256 bits ECDHE-RSA-AES256-SHA Curve 25519 DHE 253\nAccepted TLSv1.2 128 bits ECDHE-RSA-AES128-SHA Curve 25519 DHE 253\nAccepted TLSv1.2 256 bits AES256-GCM-SHA384\nAccepted TLSv1.2 256 bits AES256-CCM8\nAccepted TLSv1.2 256 bits AES256-CCM\nAccepted TLSv1.2 256 bits ARIA256-GCM-SHA384\nAccepted TLSv1.2 128 bits AES128-GCM-SHA256\nAccepted TLSv1.2 128 bits AES128-CCM8\nAccepted TLSv1.2 128 bits AES128-CCM\nAccepted TLSv1.2 128 bits ARIA128-GCM-SHA256\nAccepted TLSv1.2 256 bits AES256-SHA256\nAccepted TLSv1.2 256 bits CAMELLIA256-SHA256\nAccepted TLSv1.2 128 bits AES128-SHA256\nAccepted TLSv1.2 128 bits CAMELLIA128-SHA256\nAccepted TLSv1.2 256 bits AES256-SHA\nAccepted TLSv1.2 256 bits CAMELLIA256-SHA\nAccepted TLSv1.2 128 bits AES128-SHA\nAccepted TLSv1.2 128 bits CAMELLIA128-SHA\n\n Server Key Exchange Group(s):\nTLSv1.3 128 bits secp256r1 (NIST P-256)\nTLSv1.3 192 bits secp384r1 (NIST P-384)\nTLSv1.3 260 bits secp521r1 (NIST P-521)\nTLSv1.3 128 bits x25519\nTLSv1.3 224 bits x448\nTLSv1.3 112 bits ffdhe2048\nTLSv1.3 128 bits ffdhe3072\nTLSv1.3 150 bits ffdhe4096\nTLSv1.3 175 bits ffdhe6144\nTLSv1.3 192 bits ffdhe8192\nTLSv1.2 128 bits secp256r1 (NIST P-256)\nTLSv1.2 192 bits secp384r1 (NIST P-384)\nTLSv1.2 260 bits secp521r1 (NIST P-521)\nTLSv1.2 128 bits x25519\nTLSv1.2 224 bits x448\n\n SSL Certificate:\nSignature Algorithm: sha256WithRSAEncryption\nRSA Key Strength: 2048\n\nSubject: www.domain.com\nAltnames: DNS:www2.domain.com,\nIssuer: Some Certificate Authority\n\nNot valid before: Mar 19 16:51:10 2024 GMT\nNot valid after: Apr 18 16:51:10 2025 GMT<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"Had an issue where we had a client that couldn’t access a particular site, in this case we wanted to determine what encryption ciphers a particular website was offering on its HTTPS server, SSLScan which is a Linux tool available on Ubuntu and other distributions can help, for example:<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20,22],"tags":[],"class_list":["post-4215","post","type-post","status-publish","format-standard","hentry","category-random","category-security"],"_links":{"self":[{"href":"https:\/\/geekmungus.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/4215","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/geekmungus.co.uk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/geekmungus.co.uk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/geekmungus.co.uk\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/geekmungus.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4215"}],"version-history":[{"count":1,"href":"https:\/\/geekmungus.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/4215\/revisions"}],"predecessor-version":[{"id":4216,"href":"https:\/\/geekmungus.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/4215\/revisions\/4216"}],"wp:attachment":[{"href":"https:\/\/geekmungus.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4215"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/geekmungus.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4215"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/geekmungus.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4215"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}