upstream: Treat all PEM_read_bio_PrivateKey() errors when a passphrase

is specified as "incorrect passphrase" instead of trying to choose between
that and "invalid format".

libcrypto can return ASN1 parsing errors rather than the expected
decrypt error in certain infrequent cases when trying to decrypt/parse
PEM private keys when supplied with an invalid passphrase.

Report and repro recipe from Thomas Deutschmann in bz#2901

ok markus@

OpenBSD-Commit-ID: b1d4cd92395f9743f81c0d23aab2524109580870

diff --git a/sshkey.c b/sshkey.c
index 63c01ea67ce133d99462528919dfa5bb8247f797..e1e882b72617bc8b26335880c0fb7c5f64ebac66 100644 (file)
--- a/sshkey.c
+++ b/sshkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshkey.c,v 1.70 2018/09/14 04:17:44 djm Exp $ */
+/* $OpenBSD: sshkey.c,v 1.71 2018/10/09 05:42:23 djm Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Alexander von Gernler.  All rights reserved.
@@ -3936,7 +3936,16 @@ sshkey_parse_private_pem_fileblob(struct sshbuf *blob, int type,
        clear_libcrypto_errors();
        if ((pk = PEM_read_bio_PrivateKey(bio, NULL, NULL,
            (char *)passphrase)) == NULL) {
-               r = convert_libcrypto_error();
+              /*
+               * libcrypto may return various ASN.1 errors when attempting
+               * to parse a key with an incorrect passphrase.
+               * Treat all format errors as "incorrect passphrase" if a
+               * passphrase was supplied.
+               */
+               if (passphrase != NULL && *passphrase != '\0')
+                       r = SSH_ERR_KEY_WRONG_PASSPHRASE;
+               else
+                       r = convert_libcrypto_error();
                goto out;
        }
        if (EVP_PKEY_base_id(pk) == EVP_PKEY_RSA &&