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authordjm@openbsd.org <djm@openbsd.org>2015-04-13 02:04:08 (GMT)
committerDamien Miller <djm@mindrot.org>2015-04-13 04:37:20 (GMT)
commit318be28cda1fd9108f2e6f2f86b0b7589ba2aed0 (patch)
tree9651309f44099c3027441916c53622a58f34e1a5
parentd8f391caef62378463a0e6b36f940170dadfe605 (diff)
upstream commit
deprecate ancient, pre-RFC4419 and undocumented SSH2_MSG_KEX_DH_GEX_REQUEST_OLD message; ok markus@ deraadt@ "seems reasonable" dtucker@
-rw-r--r--compat.c24
-rw-r--r--kexgexc.c30
-rw-r--r--kexgexs.c49
3 files changed, 38 insertions, 65 deletions
diff --git a/compat.c b/compat.c
index 0934de9..cea63d2 100644
--- a/compat.c
+++ b/compat.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: compat.c,v 1.89 2015/04/10 05:16:50 dtucker Exp $ */
+/* $OpenBSD: compat.c,v 1.90 2015/04/13 02:04:08 djm Exp $ */
/*
* Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
*
@@ -165,6 +165,7 @@ compat_datafellows(const char *version)
"OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD },
{ "*SSH_Version_Mapper*",
SSH_BUG_SCANNER },
+ { "PuTTY*", SSH_OLD_DHGEX },
{ "Probe-*",
SSH_BUG_PROBE },
{ "TeraTerm SSH*,"
@@ -284,15 +285,20 @@ compat_pkalg_proposal(char *pkalg_prop)
}
char *
-compat_kex_proposal(char *kex_prop)
+compat_kex_proposal(char *p)
{
- if (!(datafellows & SSH_BUG_CURVE25519PAD))
- return kex_prop;
- debug2("%s: original KEX proposal: %s", __func__, kex_prop);
- kex_prop = filter_proposal(kex_prop, "curve25519-sha256@libssh.org");
- debug2("%s: compat KEX proposal: %s", __func__, kex_prop);
- if (*kex_prop == '\0')
+ if ((datafellows & (SSH_BUG_CURVE25519PAD|SSH_OLD_DHGEX)) == 0)
+ return p;
+ debug2("%s: original KEX proposal: %s", __func__, p);
+ if ((datafellows & SSH_BUG_CURVE25519PAD) != 0)
+ p = filter_proposal(p, "curve25519-sha256@libssh.org");
+ if ((datafellows & SSH_OLD_DHGEX) != 0) {
+ p = filter_proposal(p, "diffie-hellman-group-exchange-sha256");
+ p = filter_proposal(p, "diffie-hellman-group-exchange-sha1");
+ }
+ debug2("%s: compat KEX proposal: %s", __func__, p);
+ if (*p == '\0')
fatal("No supported key exchange algorithms found");
- return kex_prop;
+ return p;
}
diff --git a/kexgexc.c b/kexgexc.c
index e8e059a..3f20491 100644
--- a/kexgexc.c
+++ b/kexgexc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexgexc.c,v 1.20 2015/01/26 06:10:03 djm Exp $ */
+/* $OpenBSD: kexgexc.c,v 1.21 2015/04/13 02:04:08 djm Exp $ */
/*
* Copyright (c) 2000 Niels Provos. All rights reserved.
* Copyright (c) 2001 Markus Friedl. All rights reserved.
@@ -65,25 +65,15 @@ kexgex_client(struct ssh *ssh)
kex->min = DH_GRP_MIN;
kex->max = DH_GRP_MAX;
kex->nbits = nbits;
- if (ssh->compat & SSH_OLD_DHGEX) {
- /* Old GEX request */
- if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST_OLD))
- != 0 ||
- (r = sshpkt_put_u32(ssh, kex->nbits)) != 0 ||
- (r = sshpkt_send(ssh)) != 0)
- goto out;
- debug("SSH2_MSG_KEX_DH_GEX_REQUEST_OLD(%u) sent", kex->nbits);
- } else {
- /* New GEX request */
- if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST)) != 0 ||
- (r = sshpkt_put_u32(ssh, kex->min)) != 0 ||
- (r = sshpkt_put_u32(ssh, kex->nbits)) != 0 ||
- (r = sshpkt_put_u32(ssh, kex->max)) != 0 ||
- (r = sshpkt_send(ssh)) != 0)
- goto out;
- debug("SSH2_MSG_KEX_DH_GEX_REQUEST(%u<%u<%u) sent",
- kex->min, kex->nbits, kex->max);
- }
+ /* New GEX request */
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST)) != 0 ||
+ (r = sshpkt_put_u32(ssh, kex->min)) != 0 ||
+ (r = sshpkt_put_u32(ssh, kex->nbits)) != 0 ||
+ (r = sshpkt_put_u32(ssh, kex->max)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ goto out;
+ debug("SSH2_MSG_KEX_DH_GEX_REQUEST(%u<%u<%u) sent",
+ kex->min, kex->nbits, kex->max);
#ifdef DEBUG_KEXDH
fprintf(stderr, "\nmin = %d, nbits = %d, max = %d\n",
kex->min, kex->nbits, kex->max);
diff --git a/kexgexs.c b/kexgexs.c
index 9c281d2..ff6c687 100644
--- a/kexgexs.c
+++ b/kexgexs.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexgexs.c,v 1.24 2015/01/26 06:10:03 djm Exp $ */
+/* $OpenBSD: kexgexs.c,v 1.25 2015/04/13 02:04:08 djm Exp $ */
/*
* Copyright (c) 2000 Niels Provos. All rights reserved.
* Copyright (c) 2001 Markus Friedl. All rights reserved.
@@ -60,8 +60,6 @@ static int input_kex_dh_gex_init(int, u_int32_t, void *);
int
kexgex_server(struct ssh *ssh)
{
- ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST_OLD,
- &input_kex_dh_gex_request);
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST,
&input_kex_dh_gex_request);
debug("expecting SSH2_MSG_KEX_DH_GEX_REQUEST");
@@ -76,36 +74,19 @@ input_kex_dh_gex_request(int type, u_int32_t seq, void *ctxt)
int r;
u_int min = 0, max = 0, nbits = 0;
- switch (type) {
- case SSH2_MSG_KEX_DH_GEX_REQUEST:
- debug("SSH2_MSG_KEX_DH_GEX_REQUEST received");
- if ((r = sshpkt_get_u32(ssh, &min)) != 0 ||
- (r = sshpkt_get_u32(ssh, &nbits)) != 0 ||
- (r = sshpkt_get_u32(ssh, &max)) != 0 ||
- (r = sshpkt_get_end(ssh)) != 0)
- goto out;
- kex->nbits = nbits;
- kex->min = min;
- kex->max = max;
- min = MAX(DH_GRP_MIN, min);
- max = MIN(DH_GRP_MAX, max);
- nbits = MAX(DH_GRP_MIN, nbits);
- nbits = MIN(DH_GRP_MAX, nbits);
- break;
- case SSH2_MSG_KEX_DH_GEX_REQUEST_OLD:
- debug("SSH2_MSG_KEX_DH_GEX_REQUEST_OLD received");
- if ((r = sshpkt_get_u32(ssh, &nbits)) != 0 ||
- (r = sshpkt_get_end(ssh)) != 0)
- goto out;
- kex->nbits = nbits;
- /* unused for old GEX */
- kex->min = min = DH_GRP_MIN;
- kex->max = max = DH_GRP_MAX;
- break;
- default:
- r = SSH_ERR_INVALID_ARGUMENT;
+ debug("SSH2_MSG_KEX_DH_GEX_REQUEST received");
+ if ((r = sshpkt_get_u32(ssh, &min)) != 0 ||
+ (r = sshpkt_get_u32(ssh, &nbits)) != 0 ||
+ (r = sshpkt_get_u32(ssh, &max)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
goto out;
- }
+ kex->nbits = nbits;
+ kex->min = min;
+ kex->max = max;
+ min = MAX(DH_GRP_MIN, min);
+ max = MIN(DH_GRP_MAX, max);
+ nbits = MAX(DH_GRP_MIN, nbits);
+ nbits = MIN(DH_GRP_MAX, nbits);
if (kex->max < kex->min || kex->nbits < kex->min ||
kex->max < kex->nbits) {
@@ -131,10 +112,6 @@ input_kex_dh_gex_request(int type, u_int32_t seq, void *ctxt)
if ((r = dh_gen_key(kex->dh, kex->we_need * 8)) != 0)
goto out;
- /* old KEX does not use min/max in kexgex_hash() */
- if (type == SSH2_MSG_KEX_DH_GEX_REQUEST_OLD)
- kex->min = kex->max = -1;
-
debug("expecting SSH2_MSG_KEX_DH_GEX_INIT");
ssh_dispatch_set(ssh, SSH2_MSG_KEX_DH_GEX_INIT, &input_kex_dh_gex_init);
r = 0;