r11521: Add in client support for checking supportedSASLmechanisms, and then

determining a mechanism to use.

Currently it doesn't to fallbacks like SPNEGO does, but this could be
added (to GENSEC, not to here).

This also adds a new function to GENSEC, which returns a list of SASL
names in our preference order (currently determined by the build
system of all things...).

Also make the similar function used for OIDs in SPNEGO do the same.

This is all a very long-winded way of moving from a hard-coded NTLM to
GSS-SPNEGO in our SASL client...

Andrew Bartlett
(This used to be commit 130eb9bb9a37957614c87e0e6846a812abb51e00)

1 files changed, 55 insertions, 2 deletions

diff --git a/source4/libcli/ldap/ldap_bind.c b/source4/libcli/ldap/ldap_bind.c
index c08ffabc22..81e0c8b4e6 100644
--- a/source4/libcli/ldap/ldap_bind.c
+++ b/source4/libcli/ldap/ldap_bind.c
@@ -145,6 +145,18 @@ NTSTATUS ldap_bind_sasl(struct ldap_connection *conn, struct cli_credentials *cr
 	DATA_BLOB input = data_blob(NULL, 0);
 	DATA_BLOB output = data_blob(NULL, 0);
 
+	struct ldap_message **sasl_mechs_msgs;
+	struct ldap_SearchResEntry *search;
+	int count, i;
+
+	const char **sasl_names;
+	const struct gensec_security_ops **mechs;
+	
+	static const char *supported_sasl_mech_attrs[] = {
+		"supportedSASLMechanisms", 
+		NULL 
+	};
+
 	status = gensec_client_start(conn, &conn->gensec, NULL);
 	if (!NT_STATUS_IS_OK(status)) {
 		DEBUG(0, ("Failed to start GENSEC engine (%s)\n", nt_errstr(status)));
@@ -174,16 +186,57 @@ NTSTATUS ldap_bind_sasl(struct ldap_connection *conn, struct cli_credentials *cr
 		goto failed;
 	}
 
-	status = gensec_start_mech_by_sasl_name(conn->gensec, "NTLM");
+	status = ildap_search(conn, "", LDAP_SEARCH_SCOPE_BASE, "", supported_sasl_mech_attrs, 
+			      False, &sasl_mechs_msgs);
 	if (!NT_STATUS_IS_OK(status)) {
-		DEBUG(1, ("Failed to set GENSEC client SPNEGO mechanism: %s\n",
+		DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: %s\n", 
 			  nt_errstr(status)));
 		goto failed;
 	}
+	
+	count = ildap_count_entries(conn, sasl_mechs_msgs);
+	if (count != 1) {
+		DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: wrong number of replies: %d\n",
+			  count));
+		goto failed;
+	}
 
 	tmp_ctx = talloc_new(conn);
 	if (tmp_ctx == NULL) goto failed;
 
+	search = &sasl_mechs_msgs[0]->r.SearchResultEntry;
+	if (search->num_attributes != 1) {
+		DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: wrong number of attributes: %d\n",
+			  search->num_attributes));
+		goto failed;
+	}
+
+	sasl_names = talloc_array(tmp_ctx, const char *, search->attributes[0].num_values + 1);
+	if (!sasl_names) {
+		DEBUG(1, ("talloc_arry(char *, %d) failed\n",
+			  count));
+		goto failed;
+	}
+		
+	for (i=0; i<search->attributes[0].num_values; i++) {
+		sasl_names[i] = (const char *)search->attributes[0].values[i].data;
+	}
+	sasl_names[i] = NULL;
+	
+	mechs = gensec_security_by_sasl(tmp_ctx, sasl_names);
+	if (!mechs || !mechs[0]) {
+		DEBUG(1, ("None of the %d proposed SASL mechs were acceptable\n",
+			  count));
+		goto failed;
+	}
+
+	status = gensec_start_mech_by_ops(conn->gensec, mechs[0]);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("Failed to set GENSEC client mechanism: %s/%s %s\n",
+			  mechs[0]->name, mechs[0]->sasl_name, nt_errstr(status)));
+		goto failed;
+	}
+
 	while (1) {
 		NTSTATUS gensec_status;
 		struct ldap_message *response;