commit bd636f40911094a39c2920bf87d2ec340533c152
author djm@openbsd.org <djm@openbsd.org> Sun May 07 23:15:59 2017 +0000
committer Damien Miller <djm@mindrot.org> Mon May 08 09:21:22 2017 +1000
tree 53c4c9655827d6433a26a510f46081dfc4b72b6d
parent 70c1218fc45757a030285051eb4d209403f54785

upstream commit

Refuse RSA keys <1024 bits in length. Improve reporting
for keys that do not meet this requirement. ok markus@

Upstream-ID: b385e2a7b13b1484792ee681daaf79e1e203df6c

ssh-rsa.c

diff --git a/ssh-rsa.c b/ssh-rsa.c
index cde05df..e8acc01 100644
--- a/ssh-rsa.c
+++ b/ssh-rsa.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-rsa.c,v 1.60 2016/09/12 23:39:34 djm Exp $ */
+/* $OpenBSD: ssh-rsa.c,v 1.61 2017/05/07 23:15:59 djm Exp $ */
 /*
  * Copyright (c) 2000, 2003 Markus Friedl <markus@openbsd.org>
  *
@@ -99,9 +99,10 @@
 	else
 		hash_alg = rsa_hash_alg_from_ident(alg_ident);
 	if (key == NULL || key->rsa == NULL || hash_alg == -1 ||
-	    sshkey_type_plain(key->type) != KEY_RSA ||
-	    BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE)
+	    sshkey_type_plain(key->type) != KEY_RSA)
 		return SSH_ERR_INVALID_ARGUMENT;
+	if (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE)
+		return SSH_ERR_KEY_LENGTH;
 	slen = RSA_size(key->rsa);
 	if (slen <= 0 || slen > SSHBUF_MAX_BIGNUM)
 		return SSH_ERR_INVALID_ARGUMENT;
@@ -172,9 +173,10 @@
 
 	if (key == NULL || key->rsa == NULL ||
 	    sshkey_type_plain(key->type) != KEY_RSA ||
-	    BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE ||
 	    sig == NULL || siglen == 0)
 		return SSH_ERR_INVALID_ARGUMENT;
+	if (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE)
+		return SSH_ERR_KEY_LENGTH;
 
 	if ((b = sshbuf_from(sig, siglen)) == NULL)
 		return SSH_ERR_ALLOC_FAIL;