diff options
| -rw-r--r-- | ChangeLog | 10 | ||||
| -rw-r--r-- | compat.c | 18 | ||||
| -rw-r--r-- | compat.h | 4 | ||||
| -rw-r--r-- | sshconnect2.c | 4 | ||||
| -rw-r--r-- | sshd.c | 5 | ||||
| -rw-r--r-- | version.h | 4 |
6 files changed, 38 insertions, 7 deletions
@@ -98,6 +98,16 @@ remove the identity files from this manpage - ssh-agent doesn't deal with them at all and the same information is duplicated in ssh-add.1 (which does deal with them); prodded by deraadt@ + - djm@cvs.openbsd.org 2014/04/18 23:52:25 + [compat.c compat.h sshconnect2.c sshd.c version.h] + OpenSSH 6.5 and 6.6 have a bug that causes ~0.2% of connections + using the curve25519-sha256@libssh.org KEX exchange method to fail + when connecting with something that implements the spec properly. + + Disable this KEX method when speaking to one of the affected + versions. + + reported by Aris Adamantiadis; ok markus@ 20140401 - (djm) On platforms that support it, use prctl() to prevent sftp-server @@ -1,4 +1,4 @@ -/* $OpenBSD: compat.c,v 1.82 2013/12/30 23:52:27 djm Exp $ */ +/* $OpenBSD: compat.c,v 1.83 2014/04/18 23:52:25 djm Exp $ */ /* * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. * @@ -95,6 +95,8 @@ compat_datafellows(const char *version) { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, { "OpenSSH_4*", 0 }, { "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT}, + { "OpenSSH_6.5*," + "OpenSSH_6.6", SSH_NEW_OPENSSH|SSH_BUG_CURVE25519PAD}, { "OpenSSH*", SSH_NEW_OPENSSH }, { "*MindTerm*", 0 }, { "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC| @@ -251,7 +253,6 @@ compat_cipher_proposal(char *cipher_prop) return cipher_prop; } - char * compat_pkalg_proposal(char *pkalg_prop) { @@ -265,3 +266,16 @@ compat_pkalg_proposal(char *pkalg_prop) return pkalg_prop; } +char * +compat_kex_proposal(char *kex_prop) +{ + 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') + fatal("No supported key exchange algorithms found"); + return kex_prop; +} + @@ -1,4 +1,4 @@ -/* $OpenBSD: compat.h,v 1.44 2013/12/30 23:52:27 djm Exp $ */ +/* $OpenBSD: compat.h,v 1.45 2014/04/18 23:52:25 djm Exp $ */ /* * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved. @@ -59,6 +59,7 @@ #define SSH_BUG_RFWD_ADDR 0x02000000 #define SSH_NEW_OPENSSH 0x04000000 #define SSH_BUG_DYNAMIC_RPORT 0x08000000 +#define SSH_BUG_CURVE25519PAD 0x10000000 void enable_compat13(void); void enable_compat20(void); @@ -66,6 +67,7 @@ void compat_datafellows(const char *); int proto_spec(const char *); char *compat_cipher_proposal(char *); char *compat_pkalg_proposal(char *); +char *compat_kex_proposal(char *); extern int compat13; extern int compat20; diff --git a/sshconnect2.c b/sshconnect2.c index f123194b..b1aa69c2 100644 --- a/sshconnect2.c +++ b/sshconnect2.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshconnect2.c,v 1.205 2014/03/27 23:01:27 markus Exp $ */ +/* $OpenBSD: sshconnect2.c,v 1.206 2014/04/18 23:52:25 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * Copyright (c) 2008 Damien Miller. All rights reserved. @@ -196,6 +196,8 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port) } if (options.kex_algorithms != NULL) myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms; + myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal( + myproposal[PROPOSAL_KEX_ALGS]); if (options.rekey_limit || options.rekey_interval) packet_set_rekey_limits((u_int32_t)options.rekey_limit, @@ -1,4 +1,4 @@ -/* $OpenBSD: sshd.c,v 1.423 2014/04/12 04:55:53 djm Exp $ */ +/* $OpenBSD: sshd.c,v 1.424 2014/04/18 23:52:25 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -2438,6 +2438,9 @@ do_ssh2_kex(void) if (options.kex_algorithms != NULL) myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms; + myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal( + myproposal[PROPOSAL_KEX_ALGS]); + if (options.rekey_limit || options.rekey_interval) packet_set_rekey_limits((u_int32_t)options.rekey_limit, (time_t)options.rekey_interval); @@ -1,6 +1,6 @@ -/* $OpenBSD: version.h,v 1.70 2014/02/27 22:57:40 djm Exp $ */ +/* $OpenBSD: version.h,v 1.71 2014/04/18 23:52:25 djm Exp $ */ -#define SSH_VERSION "OpenSSH_6.6" +#define SSH_VERSION "OpenSSH_6.7" #define SSH_PORTABLE "p1" #define SSH_RELEASE SSH_VERSION SSH_PORTABLE |