Fix bug 6157

This patch picks the alphabetically smallest one of the multi-value attribute
"uid". This fixes a regression against 3.0 and also becomes deterministic.

3 files changed, 60 insertions, 1 deletions

diff --git a/source3/include/smbldap.h b/source3/include/smbldap.h
index 353e01aba6..3ac770a548 100644
--- a/source3/include/smbldap.h
+++ b/source3/include/smbldap.h
@@ -211,6 +211,9 @@ const char** get_userattr_list( TALLOC_CTX *mem_ctx, int schema_ver );
 char * smbldap_talloc_single_attribute(LDAP *ldap_struct, LDAPMessage *entry,
 				       const char *attribute,
 				       TALLOC_CTX *mem_ctx);
+char * smbldap_talloc_smallest_attribute(LDAP *ldap_struct, LDAPMessage *entry,
+					 const char *attribute,
+					 TALLOC_CTX *mem_ctx);
 void talloc_autofree_ldapmsg(TALLOC_CTX *mem_ctx, LDAPMessage *result);
 void talloc_autofree_ldapmod(TALLOC_CTX *mem_ctx, LDAPMod **mod);
 char *smbldap_talloc_dn(TALLOC_CTX *mem_ctx, LDAP *ld,
diff --git a/source3/lib/smbldap.c b/source3/lib/smbldap.c
index 63629265f1..4360d3ab57 100644
--- a/source3/lib/smbldap.c
+++ b/source3/lib/smbldap.c
@@ -333,6 +333,62 @@ ATTRIB_MAP_ENTRY sidmap_attr_list[] = {
 	return result;
 }
 
+ char * smbldap_talloc_smallest_attribute(LDAP *ldap_struct, LDAPMessage *entry,
+					  const char *attribute,
+					  TALLOC_CTX *mem_ctx)
+{
+	char **values;
+	char *result;
+	size_t converted_size;
+	int i, num_values;
+
+	if (attribute == NULL) {
+		return NULL;
+	}
+
+	values = ldap_get_values(ldap_struct, entry, attribute);
+
+	if (values == NULL) {
+		DEBUG(10, ("attribute %s does not exist\n", attribute));
+		return NULL;
+	}
+
+	if (!pull_utf8_talloc(mem_ctx, &result, values[0], &converted_size)) {
+		DEBUG(10, ("pull_utf8_talloc failed\n"));
+		ldap_value_free(values);
+		return NULL;
+	}
+
+	num_values = ldap_count_values(values);
+
+	for (i=1; i<num_values; i++) {
+		char *tmp;
+
+		if (!pull_utf8_talloc(mem_ctx, &tmp, values[i],
+				      &converted_size)) {
+			DEBUG(10, ("pull_utf8_talloc failed\n"));
+			TALLOC_FREE(result);
+			ldap_value_free(values);
+			return NULL;
+		}
+
+		if (StrCaseCmp(tmp, result) < 0) {
+			TALLOC_FREE(result);
+			result = tmp;
+		} else {
+			TALLOC_FREE(tmp);
+		}
+	}
+
+	ldap_value_free(values);
+
+#ifdef DEBUG_PASSWORDS
+	DEBUG (100, ("smbldap_get_single_attribute: [%s] = [%s]\n",
+		     attribute, result));
+#endif
+	return result;
+}
+
  static int ldapmsg_destructor(LDAPMessage **result) {
 	ldap_msgfree(*result);
 	return 0;
diff --git a/source3/passdb/pdb_ldap.c b/source3/passdb/pdb_ldap.c
index 2d3b91f184..a8fdbdae33 100644
--- a/source3/passdb/pdb_ldap.c
+++ b/source3/passdb/pdb_ldap.c
@@ -560,7 +560,7 @@ static bool init_sam_from_ldap(struct ldapsam_privates *ldap_state,
 		goto fn_exit;
 	}
 
-	if (!(username = smbldap_talloc_single_attribute(priv2ld(ldap_state),
+	if (!(username = smbldap_talloc_smallest_attribute(priv2ld(ldap_state),
 					entry,
 					"uid",
 					ctx))) {