fix several major flaws, to make it work

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@356 dc483132-0cff-0310-8789-dd5450dbe970

diff --git a/src/lib/kdb/decrypt_key.c b/src/lib/kdb/decrypt_key.c
index 50b96315368269aa3db23810b94b1f36190ee0a2..80f10c99faeb072969738273a13fc155b7a7bc34 100644 (file)
--- a/src/lib/kdb/decrypt_key.c
+++ b/src/lib/kdb/decrypt_key.c
@@ -36,34 +36,40 @@ krb5_keyblock *out;
 {
     krb5_error_code retval;
 
-    *out = *in;
-    out->length = krb5_encrypt_size(in->length, eblock->crypto_entry);
+    /* the encrypted version is stored as the unencrypted key length
+       (in host byte order), followed by the encrypted key.
+     */
+    out->keytype = in->keytype;
+    out->length = krb5_encrypt_size(in->length-sizeof(in->length),
+                                   eblock->crypto_entry);
     out->contents = (krb5_octet *)malloc(out->length);
     if (!out->contents) {
        out->contents = 0;
        out->length = 0;
        return ENOMEM;
     }
+    /* copy out the real length count */
+    bcopy((char *)in->contents, (char *)&out->length,
+         sizeof(out->length));
+
+    /* remember the contents of the encrypted version has a sizeof(in->length)
+       integer length of the real embedded key, followed by the
+       encrypted key, so the offset here is needed */
     if (retval = (*eblock->crypto_entry->
-                 decrypt_func)((krb5_pointer) in->contents,
+                 decrypt_func)((krb5_pointer) (((char *) in->contents) +
+                                               sizeof(in->length)),
                                (krb5_pointer) out->contents,
-                               in->length, eblock)) {
+                               in->length-sizeof(in->length), eblock)) {
        free((char *)out->contents);
        out->contents = 0;
        out->length = 0;
        return retval;
     }
-    out->length -= sizeof(out->length);
     if (out->length < 0) {
        free((char *)out->contents);
        out->contents = 0;
        out->length = 0;
        return KRB5_KDB_INVALIDKEYSIZE;
     }
-    /* shift key down to beginning of contents, and ignore extra wasted
-       space */
-    bcopy((char *)out->contents,
-         ((char *) out->contents ) + sizeof(out->length),
-         out->length);
     return retval;
 }