feature: ngx_http_lua_ffi_ssl_set_ciphers().#2513
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Lua API + docs + tests: openresty/lua-resty-core#535 |
Sets the connection's TLS <= 1.2 cipher list and/or TLS 1.3 ciphersuites from ssl_client_hello_by_lua*, e.g. keyed on the client hello server name. Both strings are validated on a scratch SSL_CTX before being applied to the connection, because a failed SSL_set_cipher_list() still installs the parsed list on the connection (emptying the TLS <= 1.2 list on unknown tokens) and leaves the thread error queue dirty, which makes SSL_do_handshake() report failure after the callback returns. The guarantee: if ngx_http_lua_ffi_ssl_set_ciphers returns NGX_ERROR for an invalid ciphers and/or ciphersuites string, the connection's SSL object is left exactly as it was -- cipher list, ciphersuites, and thread error queue all untouched -- so the handshake proceeds with whatever the connection already had, which is the default list inherited from the vhost's SSL_CTX (ssl_ciphers/ssl_conf_command). A partially invalid string is not an error: OpenSSL's parsers drop unknown tokens and succeed if any token matches, so the surviving subset is applied with no fallback to the default list. See openssl/openssl#7759 for the check-after- install behaviour of SSL_set_cipher_list() and https://docs.openssl.org/3.0/man3/SSL_get_error/ for the empty-queue requirement.
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Adds
ngx_http_lua_ffi_ssl_set_ciphers()to set the connection's TLS <= 1.2 cipher list and/or TLS 1.3 ciphersuites fromssl_client_hello_by_lua*, e.g. keyed on the client hello server name. Complementsngx_http_lua_ffi_ssl_set_protocols().Both strings are validated on a scratch
SSL_CTXbefore being applied to the connection, because a failedSSL_set_cipher_list()still installs the parsed list on the connection (emptying the TLS <= 1.2 list on unknown tokens, see the check-after-install discussion in openssl/openssl#7759) and leaves the thread error queue dirty, which makesSSL_do_handshake()report failure after the callback returns (SSL_get_error() requires an empty queue).The guarantee: if
ngx_http_lua_ffi_ssl_set_ciphersreturnsNGX_ERRORfor an invalid ciphers and/or ciphersuites string, the connection's SSL object is left exactly as it was -- cipher list, ciphersuites, and thread error queue all untouched -- so the handshake proceeds with whatever the connection already had, which is the default list inherited from the server'sSSL_CTX(ssl_ciphers/ssl_conf_command).A partially invalid string is not an error: OpenSSL's parsers drop unknown tokens and succeed if any token matches, so the surviving subset is applied with no fallback to the default list. The
NGX_ERRORpath only covers strings OpenSSL rejects outright.Lua API + docs + tests: companion PR openresty/lua-resty-core (link in first comment).