From: djm <djm@openbsd.org>
Date: Sat, 24 Jun 2017 06:38:11 +0000 (+0000)
Subject: don't pass pointer to struct sshcipher between privsep processes,
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=253a922e815618d1730434aacecbb81a40d6eea5;p=openbsd

don't pass pointer to struct sshcipher between privsep processes,
just redo the lookup in each using the already-passed cipher name.
bz#2704 based on patch from Brooks Davis; ok markus dtucker
---

diff --git a/usr.bin/ssh/packet.c b/usr.bin/ssh/packet.c
index a3e20652b55..11056c7d3dd 100644
--- a/usr.bin/ssh/packet.c
+++ b/usr.bin/ssh/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.261 2017/06/09 04:40:04 dtucker Exp $ */
+/* $OpenBSD: packet.c,v 1.262 2017/06/24 06:38:11 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2202,9 +2202,7 @@ newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
 		return r;
 	if ((b = sshbuf_new()) == NULL)
 		return SSH_ERR_ALLOC_FAIL;
-	/* The cipher struct is constant and shared, you export pointer */
 	if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
-	    (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
 	    (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
 	    (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
 	    (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
@@ -2278,12 +2276,15 @@ newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
 	comp = &newkey->comp;
 
 	if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
-	    (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
 	    (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
 	    (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
 	    (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
 	    (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
 		goto out;
+	if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
 	if (cipher_authlen(enc->cipher) == 0) {
 		if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
 			goto out;
@@ -2301,11 +2302,6 @@ newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
 	if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
 	    (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
 		goto out;
-	if (enc->name == NULL ||
-	    cipher_by_name(enc->name) != enc->cipher) {
-		r = SSH_ERR_INVALID_FORMAT;
-		goto out;
-	}
 	if (sshbuf_len(b) != 0) {
 		r = SSH_ERR_INVALID_FORMAT;
 		goto out;