openssl: remove conn->data use

We still make the trace callback function get the connectdata struct
passed to it, since the callback is anchored on the connection.

Repeatedly updating the callback pointer to set 'data' with
SSL_CTX_set_msg_callback_arg() doesn't seem to work, probably because
there might already be messages in the queue with the old pointer.

This code therefore makes sure to set the "logger" handle before using
OpenSSL calls so that the right easy handle gets used for tracing.

Closes #6522

1 files changed, 21 insertions, 13 deletions

diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index ed374dc32..54487e46d 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -234,6 +234,8 @@
 #endif
 
 struct ssl_backend_data {
+  struct Curl_easy *logger; /* transfer handle to pass trace logs to, only
+                               using sockindex 0 */
   /* these ones requires specific SSL-types */
   SSL_CTX* ctx;
   SSL*     handle;
@@ -1356,10 +1358,16 @@ static struct curl_slist *ossl_engines_list(struct Curl_easy *data)
   return list;
 }
 
-static void ossl_closeone(struct ssl_connect_data *connssl)
+#define set_logger(conn, data)                  \
+  conn->ssl[0].backend->logger = data
+
+static void ossl_closeone(struct Curl_easy *data,
+                          struct connectdata *conn,
+                          struct ssl_connect_data *connssl)
 {
   struct ssl_backend_data *backend = connssl->backend;
   if(backend->handle) {
+    set_logger(conn, data);
     (void)SSL_shutdown(backend->handle);
     SSL_set_connect_state(backend->handle);
 
@@ -1378,10 +1386,9 @@ static void ossl_closeone(struct ssl_connect_data *connssl)
 static void ossl_close(struct Curl_easy *data, struct connectdata *conn,
                        int sockindex)
 {
-  (void) data;
-  ossl_closeone(&conn->ssl[sockindex]);
+  ossl_closeone(data, conn, &conn->ssl[sockindex]);
 #ifndef CURL_DISABLE_PROXY
-  ossl_closeone(&conn->proxy_ssl[sockindex]);
+  ossl_closeone(data, conn, &conn->proxy_ssl[sockindex]);
 #endif
 }
 
@@ -2055,25 +2062,24 @@ static const char *tls_rt_type(int type)
   }
 }
 
-
 /*
  * Our callback from the SSL/TLS layers.
  */
-static void ssl_tls_trace(int direction, int ssl_ver, int content_type,
-                          const void *buf, size_t len, SSL *ssl,
-                          void *userp)
+static void ossl_trace(int direction, int ssl_ver, int content_type,
+                       const void *buf, size_t len, SSL *ssl,
+                       void *userp)
 {
-  struct Curl_easy *data;
   char unknown[32];
   const char *verstr = NULL;
   struct connectdata *conn = userp;
+  struct ssl_connect_data *connssl = &conn->ssl[0];
+  struct ssl_backend_data *backend = connssl->backend;
+  struct Curl_easy *data = backend->logger;
 
-  if(!conn || !conn->data || !conn->data->set.fdebug ||
+  if(!conn || !data || !data->set.fdebug ||
      (direction != 0 && direction != 1))
     return;
 
-  data = conn->data;
-
   switch(ssl_ver) {
 #ifdef SSL2_VERSION /* removed in recent versions */
   case SSL2_VERSION:
@@ -2609,7 +2615,7 @@ static CURLcode ossl_connect_step1(struct Curl_easy *data,
 #ifdef SSL_CTRL_SET_MSG_CALLBACK
   if(data->set.fdebug && data->set.verbose) {
     /* the SSL trace callback is only used for verbose logging */
-    SSL_CTX_set_msg_callback(backend->ctx, ssl_tls_trace);
+    SSL_CTX_set_msg_callback(backend->ctx, ossl_trace);
     SSL_CTX_set_msg_callback_arg(backend->ctx, conn);
   }
 #endif
@@ -4176,6 +4182,7 @@ static ssize_t ossl_send(struct Curl_easy *data,
   ERR_clear_error();
 
   memlen = (len > (size_t)INT_MAX) ? INT_MAX : (int)len;
+  set_logger(conn, data);
   rc = SSL_write(backend->handle, mem, memlen);
 
   if(rc <= 0) {
@@ -4254,6 +4261,7 @@ static ssize_t ossl_recv(struct Curl_easy *data,   /* transfer */
   ERR_clear_error();
 
   buffsize = (buffersize > (size_t)INT_MAX) ? INT_MAX : (int)buffersize;
+  set_logger(conn, data);
   nread = (ssize_t)SSL_read(backend->handle, buf, buffsize);
   if(nread <= 0) {
     /* failed SSL_read */