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 a3e2065..11056c7 100644 (file)
--- 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;