Restore interoperability with 1.6 addprinc -randkey

The arcfour string-to-key operation in krb5 1.7 (or later) disagrees
with the dummy password used by the addprinc -randkey operation in
krb5 1.6's kadmin client, because it's not valid UTF-8.  Recognize the
1.6 dummy password and use a random password instead.

ticket: 6626
tags: pullup
target_version: 1.8

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@23610 dc483132-0cff-0310-8789-dd5450dbe970

1 files changed, 28 insertions, 0 deletions

diff --git a/src/lib/kadm5/srv/svr_principal.c b/src/lib/kadm5/srv/svr_principal.c
index a58c798..2f2faaa 100644
--- a/src/lib/kadm5/srv/svr_principal.c
+++ b/src/lib/kadm5/srv/svr_principal.c
@@ -186,6 +186,32 @@ static void cleanup_key_data(context, count, data)
     krb5_db_free(context, data);
 }
 
+/*
+ * Set *passptr to NULL if the request looks like the first part of a krb5 1.6
+ * addprinc -randkey operation.  The krb5 1.6 dummy password for these requests
+ * was invalid UTF-8, which runs afoul of the arcfour string-to-key.
+ */
+static void
+check_1_6_dummy(kadm5_principal_ent_t entry, long mask,
+                int n_ks_tuple, krb5_key_salt_tuple *ks_tuple, char **passptr)
+{
+    int i;
+    char *password = *passptr;
+
+    /* Old-style randkey operations disallowed tickets to start. */
+    if (!(mask & KADM5_ATTRIBUTES) ||
+        !(entry->attributes & KRB5_KDB_DISALLOW_ALL_TIX))
+        return;
+
+    /* The 1.6 dummy password was the octets 1..255. */
+    for (i = 0; (unsigned char) password[i] == i + 1; i++);
+    if (password[i] != '\0' || i != 255)
+        return;
+
+    /* This will make the caller use a random password instead. */
+    *passptr = NULL;
+}
+
 kadm5_ret_t
 kadm5_create_principal(void *server_handle,
                        kadm5_principal_ent_t entry, long mask,
@@ -215,6 +241,8 @@ kadm5_create_principal_3(void *server_handle,
 
     krb5_clear_error_message(handle->context);
 
+    check_1_6_dummy(entry, mask, n_ks_tuple, ks_tuple, &password);
+
     /*
      * Argument sanity checking, and opening up the DB
      */