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

libraries with handling blank passwords.

diff --git a/source/libads/kerberos.c b/source/libads/kerberos.c
index 194a71275eaa80ddef002469d82f52c8aa52efbb..85518a6769802252d03e31e7b9c397bf2437681f 100644 (file)
--- a/source/libads/kerberos.c
+++ b/source/libads/kerberos.c
@@ -24,6 +24,28 @@
 
 #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;