krb5_gssapi: Only process challenge when present

This wouldn't cause a problem because of the way the function is called,
but prior to this change, we were processing the challenge message when
the credentials were NULL rather than when the challenge message was
populated.

This also brings this part of the Kerberos 5 code in line with the
Negotiate code.

diff --git a/lib/vauth/krb5_gssapi.c b/lib/vauth/krb5_gssapi.c
index 888a279c62335911fb9976fe48b6e952682eadb2..0e0db5bc4ab7b4831773f9e4734478f00f04d0e7 100644 (file)
--- a/lib/vauth/krb5_gssapi.c
+++ b/lib/vauth/krb5_gssapi.c
@@ -113,9 +113,9 @@ CURLcode Curl_auth_create_gssapi_user_message(struct SessionHandle *data,
     free(spn);
   }
 
-  if(krb5->context != GSS_C_NO_CONTEXT) {
+  if(chlg64 && strlen(chlg64)) {
     /* Decode the base-64 encoded challenge message */
-    if(strlen(chlg64) && *chlg64 != '=') {
+    if(*chlg64 != '=') {
       result = Curl_base64_decode(chlg64, &chlg, &chlglen);
       if(result)
         return result;