sasl: Implement SASL authorisation identity via CURLOPT_SASL_AUTHZID

Added the ability for the calling program to specify the authorisation
identity (authzid), the identity to act as, in addition to the
authentication identity (authcid) and password when using SASL PLAIN
authentication.

Fixed #3653
Closes #3790

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/url.c b/lib/url.c
index 16d910b71..5b4b00eac 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -713,6 +713,7 @@ static void conn_free(struct connectdata *conn)
   Curl_safefree(conn->user);
   Curl_safefree(conn->passwd);
   Curl_safefree(conn->oauth_bearer);
+  Curl_safefree(conn->sasl_authzid);
   Curl_safefree(conn->options);
   Curl_safefree(conn->http_proxy.user);
   Curl_safefree(conn->socks_proxy.user);
@@ -3461,6 +3462,14 @@ static CURLcode create_conn(struct Curl_easy *data,
     }
   }
 
+  if(data->set.str[STRING_SASL_AUTHZID]) {
+    conn->sasl_authzid = strdup(data->set.str[STRING_SASL_AUTHZID]);
+    if(!conn->sasl_authzid) {
+      result = CURLE_OUT_OF_MEMORY;
+      goto out;
+    }
+  }
+
 #ifdef USE_UNIX_SOCKETS
   if(data->set.str[STRING_UNIX_SOCKET_PATH]) {
     conn->unix_domain_socket = strdup(data->set.str[STRING_UNIX_SOCKET_PATH]);