diff options
Diffstat (limited to 'crypto/openssh/kex.c')
| -rw-r--r-- | crypto/openssh/kex.c | 30 |
1 files changed, 23 insertions, 7 deletions
diff --git a/crypto/openssh/kex.c b/crypto/openssh/kex.c index 3a30b9b..2814060 100644 --- a/crypto/openssh/kex.c +++ b/crypto/openssh/kex.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kex.c,v 1.86 2010/09/22 05:01:29 djm Exp $ */ +/* $OpenBSD: kex.c,v 1.88 2013/01/08 18:49:04 markus Exp $ */ /* $FreeBSD$ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. @@ -248,8 +248,18 @@ kex_input_kexinit(int type, u_int32_t seq, void *ctxt) packet_get_char(); for (i = 0; i < PROPOSAL_MAX; i++) xfree(packet_get_string(NULL)); - (void) packet_get_char(); - (void) packet_get_int(); + /* + * XXX RFC4253 sec 7: "each side MAY guess" - currently no supported + * KEX method has the server move first, but a server might be using + * a custom method or one that we otherwise don't support. We should + * be prepared to remember first_kex_follows here so we can eat a + * packet later. + * XXX2 - RFC4253 is kind of ambiguous on what first_kex_follows means + * for cases where the server *doesn't* go first. I guess we should + * ignore it when it is set for these cases, which is what we do now. + */ + (void) packet_get_char(); /* first_kex_follows */ + (void) packet_get_int(); /* reserved */ packet_check_eom(); kex_kexinit_finish(kex); @@ -300,6 +310,7 @@ choose_enc(Enc *enc, char *client, char *server) enc->name = name; enc->enabled = 0; enc->iv = NULL; + enc->iv_len = cipher_ivlen(enc->cipher); enc->key = NULL; enc->key_len = cipher_keylen(enc->cipher); enc->block_size = cipher_blocksize(enc->cipher); @@ -411,7 +422,7 @@ kex_choose_conf(Kex *kex) char **my, **peer; char **cprop, **sprop; int nenc, nmac, ncomp; - u_int mode, ctos, need; + u_int mode, ctos, need, authlen; int first_kex_follows, type; #ifdef NONE_CIPHER_ENABLED int auth_flag; @@ -451,8 +462,11 @@ kex_choose_conf(Kex *kex) nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC; nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC; ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC; - choose_enc (&newkeys->enc, cprop[nenc], sprop[nenc]); - choose_mac (&newkeys->mac, cprop[nmac], sprop[nmac]); + choose_enc(&newkeys->enc, cprop[nenc], sprop[nenc]); + /* ignore mac for authenticated encryption */ + authlen = cipher_authlen(newkeys->enc.cipher); + if (authlen == 0) + choose_mac(&newkeys->mac, cprop[nmac], sprop[nmac]); choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]); #ifdef NONE_CIPHER_ENABLED debug("REQUESTED ENC.NAME is '%s'", newkeys->enc.name); @@ -468,7 +482,7 @@ kex_choose_conf(Kex *kex) debug("kex: %s %s %s %s", ctos ? "client->server" : "server->client", newkeys->enc.name, - newkeys->mac.name, + authlen == 0 ? newkeys->mac.name : "<implicit>", newkeys->comp.name); } choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]); @@ -481,6 +495,8 @@ kex_choose_conf(Kex *kex) need = newkeys->enc.key_len; if (need < newkeys->enc.block_size) need = newkeys->enc.block_size; + if (need < newkeys->enc.iv_len) + need = newkeys->enc.iv_len; if (need < newkeys->mac.key_len) need = newkeys->mac.key_len; } |
