diff options
| author | Damien Miller <djm@cvs.openbsd.org> | 2009-01-01 21:17:37 +0000 |
|---|---|---|
| committer | Damien Miller <djm@cvs.openbsd.org> | 2009-01-01 21:17:37 +0000 |
| commit | fcf2e1c6b894f59d64e4ef11f5c5d4ab2b694ccd (patch) | |
| tree | 8dd90278265cbf436dba237666daebe652632c36 /usr.bin/ssh | |
| parent | 41c64ddb3502c0ccfd3f8d9dafd9328582a795f5 (diff) | |
fix hash calculation for KEXGEX: hash over the original client-supplied
values and not the sanity checked versions that we acutally use;
bz#1540 reported by john.smith AT arrows.demon.co.uk
ok markus@
Diffstat (limited to 'usr.bin/ssh')
| -rw-r--r-- | usr.bin/ssh/kexgexs.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/usr.bin/ssh/kexgexs.c b/usr.bin/ssh/kexgexs.c index 592d35e0688..9263399c4e5 100644 --- a/usr.bin/ssh/kexgexs.c +++ b/usr.bin/ssh/kexgexs.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kexgexs.c,v 1.10 2006/11/06 21:25:28 markus Exp $ */ +/* $OpenBSD: kexgexs.c,v 1.11 2009/01/01 21:17:36 djm Exp $ */ /* * Copyright (c) 2000 Niels Provos. All rights reserved. * Copyright (c) 2001 Markus Friedl. All rights reserved. @@ -53,7 +53,8 @@ kexgex_server(Kex *kex) DH *dh; u_char *kbuf, *hash, *signature = NULL, *server_host_key_blob = NULL; u_int sbloblen, klen, slen, hashlen; - int min = -1, max = -1, nbits = -1, type, kout; + int omin = -1, min = -1, omax = -1, max = -1, onbits = -1, nbits = -1; + int type, kout; if (kex->load_host_key == NULL) fatal("Cannot load hostkey"); @@ -65,27 +66,29 @@ kexgex_server(Kex *kex) switch (type) { case SSH2_MSG_KEX_DH_GEX_REQUEST: debug("SSH2_MSG_KEX_DH_GEX_REQUEST received"); - min = packet_get_int(); - nbits = packet_get_int(); - max = packet_get_int(); + omin = min = packet_get_int(); + onbits = nbits = packet_get_int(); + omax = max = packet_get_int(); 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"); - nbits = packet_get_int(); - min = DH_GRP_MIN; - max = DH_GRP_MAX; + onbits = nbits = packet_get_int(); /* unused for old GEX */ + omin = min = DH_GRP_MIN; + omax = max = DH_GRP_MAX; break; default: fatal("protocol error during kex, no DH_GEX_REQUEST: %d", type); } packet_check_eom(); - if (max < min || nbits < min || max < nbits) + if (omax < omin || onbits < omin || omax < onbits) fatal("DH_GEX_REQUEST, bad parameters: %d !< %d !< %d", - min, nbits, max); + omin, onbits, omax); /* Contact privileged parent */ dh = PRIVSEP(choose_dh(min, nbits, max)); @@ -146,7 +149,7 @@ kexgex_server(Kex *kex) key_to_blob(server_host_key, &server_host_key_blob, &sbloblen); if (type == SSH2_MSG_KEX_DH_GEX_REQUEST_OLD) - min = max = -1; + omin = min = omax = max = -1; /* calc H */ kexgex_hash( @@ -156,7 +159,7 @@ kexgex_server(Kex *kex) buffer_ptr(&kex->peer), buffer_len(&kex->peer), buffer_ptr(&kex->my), buffer_len(&kex->my), server_host_key_blob, sbloblen, - min, nbits, max, + omin, onbits, omax, dh->p, dh->g, dh_client_pub, dh->pub_key, |