# HG changeset patch
# User Rob Mueller <robm@fastmail.fm>
# Date 1628841467 14400
# Node ID 13d0c1d26d47c203b1874ca1ffdb7a9ba7fd2d77
# Parent  419c066cb7103165fe008339d210037f68a72d4f
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
--- 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_ma
     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_ma
 
 #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_ma
 
     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_ma
         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);