crypto: switch to newer gnutls API for distinguished name

The new API automatically allocates the right amount of memory
to hold the distinguished name, avoiding the need to loop and
realloc.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

diff --git a/crypto/tlssession.c b/crypto/tlssession.c
index 8c0bf457ad7d1ed6eda0bceb70d3d208f6ec51f5..92fe4f038098039df17009f06c8a70ee652d7ff7 100644 (file)
--- a/crypto/tlssession.c
+++ b/crypto/tlssession.c
@@ -409,20 +409,14 @@ qcrypto_tls_session_check_certificate(QCryptoTLSSession *session,
         }
 
         if (i == 0) {
-            size_t dnameSize = 1024;
-            session->peername = g_malloc(dnameSize);
-        requery:
-            ret = gnutls_x509_crt_get_dn(cert, session->peername, &dnameSize);
+            gnutls_datum_t dname = {};
+            ret = gnutls_x509_crt_get_dn2(cert, &dname);
             if (ret < 0) {
-                if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER) {
-                    session->peername = g_realloc(session->peername,
-                                                  dnameSize);
-                    goto requery;
-                }
                 error_setg(errp, "Cannot get client distinguished name: %s",
                            gnutls_strerror(ret));
                 goto error;
             }
+            session->peername = (char *)g_steal_pointer(&dname.data);
             if (session->authzid) {
                 bool allow;