by using a prompter function we can avoid the bug in the MIT kerberos

libraries with handling blank passwords.
(This used to be commit 59d755ffb57c322a104ff8f52819956cafff1bac)

1 files changed, 25 insertions, 7 deletions

diff --git a/source3/libads/kerberos.c b/source3/libads/kerberos.c
index 194a71275e..85518a6769 100644
--- a/source3/libads/kerberos.c
+++ b/source3/libads/kerberos.c
@@ -25,6 +25,28 @@
 #ifdef HAVE_KRB5
 
 /*
+  we use a prompter to avoid a crash bug in the kerberos libs when 
+  dealing with empty passwords
+  this prompter is just a string copy ...
+*/
+static krb5_error_code 
+kerb_prompter(krb5_context ctx, void *data,
+	       const char *name,
+	       const char *banner,
+	       int num_prompts,
+	       krb5_prompt prompts[])
+{
+	if (num_prompts == 0) return 0;
+
+	memset(prompts[0].reply->data, 0, prompts[0].reply->length);
+	if (prompts[0].reply->length > 0) {
+		strncpy(prompts[0].reply->data, data, prompts[0].reply->length-1);
+		prompts[0].reply->length = strlen(prompts[0].reply->data);
+	}
+	return 0;
+}
+
+/*
   simulate a kinit, putting the tgt in the default cache location
   remus@snapserver.com
 */
@@ -36,11 +58,6 @@ int kerberos_kinit_password(const char *principal, const char *password)
 	krb5_principal me;
 	krb5_creds my_creds;
 
-	if (! *password) {
-		/* kerberos dies on an empty password! */
-		return KRB5_PARSE_MALFORMED;
-	}
-
 	if ((code = krb5_init_context(&ctx)))
 		return code;
 	
@@ -54,8 +71,9 @@ int kerberos_kinit_password(const char *principal, const char *password)
 		return code;
 	}
 	
-	if ((code = krb5_get_init_creds_password(ctx, &my_creds, me, (char*)password, NULL, 
-						NULL, 0, NULL, NULL))) {
+	if ((code = krb5_get_init_creds_password(ctx, &my_creds, me, NULL, 
+						 kerb_prompter, 
+						 password, 0, NULL, NULL))) {
 		krb5_free_principal(ctx, me);
 		krb5_free_context(ctx);		
 		return code;