Mail: Auth-SSL-Protocol and Auth-SSL-Cipher headers (ticket #2134).

This adds new Auth-SSL-Protocol and Auth-SSL-Cipher headers to
the mail proxy auth protocol when SSL is enabled.

This can be useful for detecting users using older clients that
negotiate old ciphers when you want to upgrade to newer
TLS versions of remove suppport for old and insecure ciphers.
You can use your auth backend to notify these users before the
upgrade that they either need to upgrade their client software
or contact your support team to work out an upgrade path.

diff --git a/src/mail/ngx_mail_auth_http_module.c b/src/mail/ngx_mail_auth_http_module.c
index 2a198f4942811aa99764f2a840358cc7c9676fde..27f64b92e0d95a89db9c707c76900b949b4ba1f4 100644 (file)
--- a/src/mail/ngx_mail_auth_http_module.c
+++ b/src/mail/ngx_mail_auth_http_module.c
@@ -1137,8 +1137,8 @@ ngx_mail_auth_http_create_request(ngx_mail_session_t *s, ngx_pool_t *pool,
     ngx_str_t                  login, passwd;
     ngx_connection_t          *c;
 #if (NGX_MAIL_SSL)
-    ngx_str_t                  verify, subject, issuer, serial, fingerprint,
-                               raw_cert, cert;
+    ngx_str_t                  protocol, cipher, verify, subject, issuer,
+                               serial, fingerprint, raw_cert, cert;
     ngx_mail_ssl_conf_t       *sslcf;
 #endif
     ngx_mail_core_srv_conf_t  *cscf;
@@ -1155,6 +1155,25 @@ ngx_mail_auth_http_create_request(ngx_mail_session_t *s, ngx_pool_t *pool,
 
 #if (NGX_MAIL_SSL)
 
+    if (c->ssl) {
+
+        if (ngx_ssl_get_protocol(c, pool, &protocol) != NGX_OK) {
+            return NULL;
+        }
+
+        protocol.len = ngx_strlen(protocol.data);
+
+        if (ngx_ssl_get_cipher_name(c, pool, &cipher) != NGX_OK) {
+            return NULL;
+        }
+
+        cipher.len = ngx_strlen(cipher.data);
+
+    } else {
+        ngx_str_null(&protocol);
+        ngx_str_null(&cipher);
+    }
+
     sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
 
     if (c->ssl && sslcf->verify) {
@@ -1252,6 +1271,10 @@ ngx_mail_auth_http_create_request(ngx_mail_session_t *s, ngx_pool_t *pool,
 
     if (c->ssl) {
         len += sizeof("Auth-SSL: on" CRLF) - 1
+               + sizeof("Auth-SSL-Protocol: ") - 1 + protocol.len
+                     + sizeof(CRLF) - 1
+               + sizeof("Auth-SSL-Cipher: ") - 1 + cipher.len
+                     + sizeof(CRLF) - 1
                + sizeof("Auth-SSL-Verify: ") - 1 + verify.len
                      + sizeof(CRLF) - 1
                + sizeof("Auth-SSL-Subject: ") - 1 + subject.len
@@ -1373,6 +1396,20 @@ ngx_mail_auth_http_create_request(ngx_mail_session_t *s, ngx_pool_t *pool,
         b->last = ngx_cpymem(b->last, "Auth-SSL: on" CRLF,
                              sizeof("Auth-SSL: on" CRLF) - 1);
 
+        if (protocol.len) {
+            b->last = ngx_cpymem(b->last, "Auth-SSL-Protocol: ",
+                                 sizeof("Auth-SSL-Protocol: ") - 1);
+            b->last = ngx_copy(b->last, protocol.data, protocol.len);
+            *b->last++ = CR; *b->last++ = LF;
+        }
+
+        if (cipher.len) {
+            b->last = ngx_cpymem(b->last, "Auth-SSL-Cipher: ",
+                                 sizeof("Auth-SSL-Cipher: ") - 1);
+            b->last = ngx_copy(b->last, cipher.data, cipher.len);
+            *b->last++ = CR; *b->last++ = LF;
+        }
+
         if (verify.len) {
             b->last = ngx_cpymem(b->last, "Auth-SSL-Verify: ",
                                  sizeof("Auth-SSL-Verify: ") - 1);