openssh/kex.c

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/* $OpenBSD: kex.c,v 1.103 2015/01/20 23:14:00 deraadt Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
#include <sys/param.h> /* MAX roundup */
- deraadt@cvs.openbsd.org 2006/08/03 03:34:42 [OVERVIEW atomicio.c atomicio.h auth-bsdauth.c auth-chall.c auth-krb5.c] [auth-options.c auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c] [auth-rsa.c auth-skey.c auth.c auth.h auth1.c auth2-chall.c auth2-gss.c] [auth2-hostbased.c auth2-kbdint.c auth2-none.c auth2-passwd.c ] [auth2-pubkey.c auth2.c authfd.c authfd.h authfile.c bufaux.c bufbn.c] [buffer.c buffer.h canohost.c channels.c channels.h cipher-3des1.c] [cipher-bf1.c cipher-ctr.c cipher.c cleanup.c clientloop.c compat.c] [compress.c deattack.c dh.c dispatch.c dns.c dns.h fatal.c groupaccess.c] [groupaccess.h gss-genr.c gss-serv-krb5.c gss-serv.c hostfile.c kex.c] [kex.h kexdh.c kexdhc.c kexdhs.c kexgex.c kexgexc.c kexgexs.c key.c] [key.h log.c log.h mac.c match.c md-sha256.c misc.c misc.h moduli.c] [monitor.c monitor_fdpass.c monitor_mm.c monitor_mm.h monitor_wrap.c] [monitor_wrap.h msg.c nchan.c packet.c progressmeter.c readconf.c] [readconf.h readpass.c rsa.c scard.c scard.h scp.c servconf.c servconf.h] [serverloop.c session.c session.h sftp-client.c sftp-common.c] [sftp-common.h sftp-glob.c sftp-server.c sftp.c ssh-add.c ssh-agent.c] [ssh-dss.c ssh-gss.h ssh-keygen.c ssh-keyscan.c ssh-keysign.c ssh-rsa.c] [ssh.c ssh.h sshconnect.c sshconnect.h sshconnect1.c sshconnect2.c] [sshd.c sshlogin.c sshlogin.h sshpty.c sshpty.h sshtty.c ttymodes.c] [uidswap.c uidswap.h uuencode.c uuencode.h xmalloc.c xmalloc.h] [loginrec.c loginrec.h openbsd-compat/port-aix.c openbsd-compat/port-tun.h] almost entirely get rid of the culture of ".h files that include .h files" ok djm, sort of ok stevesk makes the pain stop in one easy step NB. portable commit contains everything *except* removing includes.h, as that will take a fair bit more work as we move headers that are required for portability workarounds to defines.h. (also, this step wasn't "easy")
2006-08-05 02:39:39 +00:00
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef WITH_OPENSSL
- deraadt@cvs.openbsd.org 2006/08/03 03:34:42 [OVERVIEW atomicio.c atomicio.h auth-bsdauth.c auth-chall.c auth-krb5.c] [auth-options.c auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c] [auth-rsa.c auth-skey.c auth.c auth.h auth1.c auth2-chall.c auth2-gss.c] [auth2-hostbased.c auth2-kbdint.c auth2-none.c auth2-passwd.c ] [auth2-pubkey.c auth2.c authfd.c authfd.h authfile.c bufaux.c bufbn.c] [buffer.c buffer.h canohost.c channels.c channels.h cipher-3des1.c] [cipher-bf1.c cipher-ctr.c cipher.c cleanup.c clientloop.c compat.c] [compress.c deattack.c dh.c dispatch.c dns.c dns.h fatal.c groupaccess.c] [groupaccess.h gss-genr.c gss-serv-krb5.c gss-serv.c hostfile.c kex.c] [kex.h kexdh.c kexdhc.c kexdhs.c kexgex.c kexgexc.c kexgexs.c key.c] [key.h log.c log.h mac.c match.c md-sha256.c misc.c misc.h moduli.c] [monitor.c monitor_fdpass.c monitor_mm.c monitor_mm.h monitor_wrap.c] [monitor_wrap.h msg.c nchan.c packet.c progressmeter.c readconf.c] [readconf.h readpass.c rsa.c scard.c scard.h scp.c servconf.c servconf.h] [serverloop.c session.c session.h sftp-client.c sftp-common.c] [sftp-common.h sftp-glob.c sftp-server.c sftp.c ssh-add.c ssh-agent.c] [ssh-dss.c ssh-gss.h ssh-keygen.c ssh-keyscan.c ssh-keysign.c ssh-rsa.c] [ssh.c ssh.h sshconnect.c sshconnect.h sshconnect1.c sshconnect2.c] [sshd.c sshlogin.c sshlogin.h sshpty.c sshpty.h sshtty.c ttymodes.c] [uidswap.c uidswap.h uuencode.c uuencode.h xmalloc.c xmalloc.h] [loginrec.c loginrec.h openbsd-compat/port-aix.c openbsd-compat/port-tun.h] almost entirely get rid of the culture of ".h files that include .h files" ok djm, sort of ok stevesk makes the pain stop in one easy step NB. portable commit contains everything *except* removing includes.h, as that will take a fair bit more work as we move headers that are required for portability workarounds to defines.h. (also, this step wasn't "easy")
2006-08-05 02:39:39 +00:00
#include <openssl/crypto.h>
#endif
- deraadt@cvs.openbsd.org 2006/08/03 03:34:42 [OVERVIEW atomicio.c atomicio.h auth-bsdauth.c auth-chall.c auth-krb5.c] [auth-options.c auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c] [auth-rsa.c auth-skey.c auth.c auth.h auth1.c auth2-chall.c auth2-gss.c] [auth2-hostbased.c auth2-kbdint.c auth2-none.c auth2-passwd.c ] [auth2-pubkey.c auth2.c authfd.c authfd.h authfile.c bufaux.c bufbn.c] [buffer.c buffer.h canohost.c channels.c channels.h cipher-3des1.c] [cipher-bf1.c cipher-ctr.c cipher.c cleanup.c clientloop.c compat.c] [compress.c deattack.c dh.c dispatch.c dns.c dns.h fatal.c groupaccess.c] [groupaccess.h gss-genr.c gss-serv-krb5.c gss-serv.c hostfile.c kex.c] [kex.h kexdh.c kexdhc.c kexdhs.c kexgex.c kexgexc.c kexgexs.c key.c] [key.h log.c log.h mac.c match.c md-sha256.c misc.c misc.h moduli.c] [monitor.c monitor_fdpass.c monitor_mm.c monitor_mm.h monitor_wrap.c] [monitor_wrap.h msg.c nchan.c packet.c progressmeter.c readconf.c] [readconf.h readpass.c rsa.c scard.c scard.h scp.c servconf.c servconf.h] [serverloop.c session.c session.h sftp-client.c sftp-common.c] [sftp-common.h sftp-glob.c sftp-server.c sftp.c ssh-add.c ssh-agent.c] [ssh-dss.c ssh-gss.h ssh-keygen.c ssh-keyscan.c ssh-keysign.c ssh-rsa.c] [ssh.c ssh.h sshconnect.c sshconnect.h sshconnect1.c sshconnect2.c] [sshd.c sshlogin.c sshlogin.h sshpty.c sshpty.h sshtty.c ttymodes.c] [uidswap.c uidswap.h uuencode.c uuencode.h xmalloc.c xmalloc.h] [loginrec.c loginrec.h openbsd-compat/port-aix.c openbsd-compat/port-tun.h] almost entirely get rid of the culture of ".h files that include .h files" ok djm, sort of ok stevesk makes the pain stop in one easy step NB. portable commit contains everything *except* removing includes.h, as that will take a fair bit more work as we move headers that are required for portability workarounds to defines.h. (also, this step wasn't "easy")
2006-08-05 02:39:39 +00:00
#include "ssh2.h"
Hopefully things did not get mixed around too much. It compiles under Linux and works. So that is at least a good sign. =) 20010122 - (bal) OpenBSD Resync - markus@cvs.openbsd.org 2001/01/19 12:45:26 GMT 2001 by markus [servconf.c ssh.h sshd.c] only auth-chall.c needs #ifdef SKEY - markus@cvs.openbsd.org 2001/01/19 15:55:10 GMT 2001 by markus [auth-krb4.c auth-options.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c auth2.c channels.c clientloop.c dh.c dispatch.c nchan.c packet.c pathname.h readconf.c scp.c servconf.c serverloop.c session.c ssh-add.c ssh-keygen.c ssh-keyscan.c ssh.c ssh.h ssh1.h sshconnect1.c sshd.c ttymodes.c] move ssh1 definitions to ssh1.h, pathnames to pathnames.h - markus@cvs.openbsd.org 2001/01/19 16:48:14 [sshd.8] fix typo; from stevesk@ - markus@cvs.openbsd.org 2001/01/19 16:50:58 [ssh-dss.c] clear and free digest, make consistent with other code (use dlen); from stevesk@ - markus@cvs.openbsd.org 2001/01/20 15:55:20 GMT 2001 by markus [auth-options.c auth-options.h auth-rsa.c auth2.c] pass the filename to auth_parse_options() - markus@cvs.openbsd.org 2001/01/20 17:59:40 GMT 2001 [readconf.c] fix SIGSEGV from -o ""; problem noted by jehsom@togetherweb.com - stevesk@cvs.openbsd.org 2001/01/20 18:20:29 [sshconnect2.c] dh_new_group() does not return NULL. ok markus@ - markus@cvs.openbsd.org 2001/01/20 21:33:42 [ssh-add.c] do not loop forever if askpass does not exist; from andrew@pimlott.ne.mediaone.net - djm@cvs.openbsd.org 2001/01/20 23:00:56 [servconf.c] Check for NULL return from strdelim; ok markus - djm@cvs.openbsd.org 2001/01/20 23:02:07 [readconf.c] KNF; ok markus - jakob@cvs.openbsd.org 2001/01/21 9:00:33 [ssh-keygen.1] remove -R flag; ok markus@ - markus@cvs.openbsd.org 2001/01/21 19:05:40 [atomicio.c automicio.h auth-chall.c auth-krb4.c auth-options.c auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth.c auth.h auth1.c auth2-chall.c auth2.c authfd.c authfile.c bufaux.c bufaux.h buffer.c canahost.c canahost.h channels.c cipher.c cli.c clientloop.c clientloop.h compat.c compress.c deattack.c dh.c dispatch.c groupaccess.c hmac.c hostfile.c kex.c key.c key.h log-client.c log-server.c log.c log.h login.c login.h match.c misc.c misc.h nchan.c packet.c pty.c radix.h readconf.c readpass.c readpass.h rsa.c scp.c servconf.c serverloop.c serverloop.h session.c sftp-server.c ssh-add.c ssh-agent.c ssh-dss.c ssh-keygen.c ssh-keyscan.c ssh-rsa.c ssh.c ssh.h sshconnect.c sshconnect.h sshconnect1.c sshconnect2.c sshd.c tildexpand.c tildexpand.h ttysmodes.c uidswap.c xmalloc.c] split ssh.h and try to cleanup the #include mess. remove unnecessary #includes. rename util.[ch] -> misc.[ch] - (bal) renamed 'PIDDIR' to '_PATH_SSH_PIDDIR' to match OpenBSD tree - (bal) Moved #ifdef KRB4 in auth-krb4.c above the #include to resolve conflict when compiling for non-kerb install - (bal) removed the #ifdef SKEY in auth1.c to match Markus' changes on 1/19.
2001-01-22 05:34:40 +00:00
#include "packet.h"
#include "compat.h"
#include "cipher.h"
#include "sshkey.h"
- deraadt@cvs.openbsd.org 2006/08/03 03:34:42 [OVERVIEW atomicio.c atomicio.h auth-bsdauth.c auth-chall.c auth-krb5.c] [auth-options.c auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c] [auth-rsa.c auth-skey.c auth.c auth.h auth1.c auth2-chall.c auth2-gss.c] [auth2-hostbased.c auth2-kbdint.c auth2-none.c auth2-passwd.c ] [auth2-pubkey.c auth2.c authfd.c authfd.h authfile.c bufaux.c bufbn.c] [buffer.c buffer.h canohost.c channels.c channels.h cipher-3des1.c] [cipher-bf1.c cipher-ctr.c cipher.c cleanup.c clientloop.c compat.c] [compress.c deattack.c dh.c dispatch.c dns.c dns.h fatal.c groupaccess.c] [groupaccess.h gss-genr.c gss-serv-krb5.c gss-serv.c hostfile.c kex.c] [kex.h kexdh.c kexdhc.c kexdhs.c kexgex.c kexgexc.c kexgexs.c key.c] [key.h log.c log.h mac.c match.c md-sha256.c misc.c misc.h moduli.c] [monitor.c monitor_fdpass.c monitor_mm.c monitor_mm.h monitor_wrap.c] [monitor_wrap.h msg.c nchan.c packet.c progressmeter.c readconf.c] [readconf.h readpass.c rsa.c scard.c scard.h scp.c servconf.c servconf.h] [serverloop.c session.c session.h sftp-client.c sftp-common.c] [sftp-common.h sftp-glob.c sftp-server.c sftp.c ssh-add.c ssh-agent.c] [ssh-dss.c ssh-gss.h ssh-keygen.c ssh-keyscan.c ssh-keysign.c ssh-rsa.c] [ssh.c ssh.h sshconnect.c sshconnect.h sshconnect1.c sshconnect2.c] [sshd.c sshlogin.c sshlogin.h sshpty.c sshpty.h sshtty.c ttymodes.c] [uidswap.c uidswap.h uuencode.c uuencode.h xmalloc.c xmalloc.h] [loginrec.c loginrec.h openbsd-compat/port-aix.c openbsd-compat/port-tun.h] almost entirely get rid of the culture of ".h files that include .h files" ok djm, sort of ok stevesk makes the pain stop in one easy step NB. portable commit contains everything *except* removing includes.h, as that will take a fair bit more work as we move headers that are required for portability workarounds to defines.h. (also, this step wasn't "easy")
2006-08-05 02:39:39 +00:00
#include "kex.h"
Hopefully things did not get mixed around too much. It compiles under Linux and works. So that is at least a good sign. =) 20010122 - (bal) OpenBSD Resync - markus@cvs.openbsd.org 2001/01/19 12:45:26 GMT 2001 by markus [servconf.c ssh.h sshd.c] only auth-chall.c needs #ifdef SKEY - markus@cvs.openbsd.org 2001/01/19 15:55:10 GMT 2001 by markus [auth-krb4.c auth-options.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c auth2.c channels.c clientloop.c dh.c dispatch.c nchan.c packet.c pathname.h readconf.c scp.c servconf.c serverloop.c session.c ssh-add.c ssh-keygen.c ssh-keyscan.c ssh.c ssh.h ssh1.h sshconnect1.c sshd.c ttymodes.c] move ssh1 definitions to ssh1.h, pathnames to pathnames.h - markus@cvs.openbsd.org 2001/01/19 16:48:14 [sshd.8] fix typo; from stevesk@ - markus@cvs.openbsd.org 2001/01/19 16:50:58 [ssh-dss.c] clear and free digest, make consistent with other code (use dlen); from stevesk@ - markus@cvs.openbsd.org 2001/01/20 15:55:20 GMT 2001 by markus [auth-options.c auth-options.h auth-rsa.c auth2.c] pass the filename to auth_parse_options() - markus@cvs.openbsd.org 2001/01/20 17:59:40 GMT 2001 [readconf.c] fix SIGSEGV from -o ""; problem noted by jehsom@togetherweb.com - stevesk@cvs.openbsd.org 2001/01/20 18:20:29 [sshconnect2.c] dh_new_group() does not return NULL. ok markus@ - markus@cvs.openbsd.org 2001/01/20 21:33:42 [ssh-add.c] do not loop forever if askpass does not exist; from andrew@pimlott.ne.mediaone.net - djm@cvs.openbsd.org 2001/01/20 23:00:56 [servconf.c] Check for NULL return from strdelim; ok markus - djm@cvs.openbsd.org 2001/01/20 23:02:07 [readconf.c] KNF; ok markus - jakob@cvs.openbsd.org 2001/01/21 9:00:33 [ssh-keygen.1] remove -R flag; ok markus@ - markus@cvs.openbsd.org 2001/01/21 19:05:40 [atomicio.c automicio.h auth-chall.c auth-krb4.c auth-options.c auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth.c auth.h auth1.c auth2-chall.c auth2.c authfd.c authfile.c bufaux.c bufaux.h buffer.c canahost.c canahost.h channels.c cipher.c cli.c clientloop.c clientloop.h compat.c compress.c deattack.c dh.c dispatch.c groupaccess.c hmac.c hostfile.c kex.c key.c key.h log-client.c log-server.c log.c log.h login.c login.h match.c misc.c misc.h nchan.c packet.c pty.c radix.h readconf.c readpass.c readpass.h rsa.c scp.c servconf.c serverloop.c serverloop.h session.c sftp-server.c ssh-add.c ssh-agent.c ssh-dss.c ssh-keygen.c ssh-keyscan.c ssh-rsa.c ssh.c ssh.h sshconnect.c sshconnect.h sshconnect1.c sshconnect2.c sshd.c tildexpand.c tildexpand.h ttysmodes.c uidswap.c xmalloc.c] split ssh.h and try to cleanup the #include mess. remove unnecessary #includes. rename util.[ch] -> misc.[ch] - (bal) renamed 'PIDDIR' to '_PATH_SSH_PIDDIR' to match OpenBSD tree - (bal) Moved #ifdef KRB4 in auth-krb4.c above the #include to resolve conflict when compiling for non-kerb install - (bal) removed the #ifdef SKEY in auth1.c to match Markus' changes on 1/19.
2001-01-22 05:34:40 +00:00
#include "log.h"
#include "mac.h"
#include "match.h"
#include "misc.h"
#include "dispatch.h"
#include "monitor.h"
#include "roaming.h"
#include "ssherr.h"
#include "sshbuf.h"
#include "digest.h"
#if OPENSSL_VERSION_NUMBER >= 0x00907000L
# if defined(HAVE_EVP_SHA256)
# define evp_ssh_sha256 EVP_sha256
# else
extern const EVP_MD *evp_ssh_sha256(void);
# endif
#endif
/* prototype */
static int kex_choose_conf(struct ssh *);
static int kex_input_newkeys(int, u_int32_t, void *);
struct kexalg {
char *name;
u_int type;
int ec_nid;
int hash_alg;
};
static const struct kexalg kexalgs[] = {
#ifdef WITH_OPENSSL
{ KEX_DH1, KEX_DH_GRP1_SHA1, 0, SSH_DIGEST_SHA1 },
{ KEX_DH14, KEX_DH_GRP14_SHA1, 0, SSH_DIGEST_SHA1 },
{ KEX_DHGEX_SHA1, KEX_DH_GEX_SHA1, 0, SSH_DIGEST_SHA1 },
#ifdef HAVE_EVP_SHA256
{ KEX_DHGEX_SHA256, KEX_DH_GEX_SHA256, 0, SSH_DIGEST_SHA256 },
#endif /* HAVE_EVP_SHA256 */
#ifdef OPENSSL_HAS_ECC
{ KEX_ECDH_SHA2_NISTP256, KEX_ECDH_SHA2,
NID_X9_62_prime256v1, SSH_DIGEST_SHA256 },
{ KEX_ECDH_SHA2_NISTP384, KEX_ECDH_SHA2, NID_secp384r1,
SSH_DIGEST_SHA384 },
# ifdef OPENSSL_HAS_NISTP521
{ KEX_ECDH_SHA2_NISTP521, KEX_ECDH_SHA2, NID_secp521r1,
SSH_DIGEST_SHA512 },
# endif /* OPENSSL_HAS_NISTP521 */
#endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
#if defined(HAVE_EVP_SHA256) || !defined(WITH_OPENSSL)
{ KEX_CURVE25519_SHA256, KEX_C25519_SHA256, 0, SSH_DIGEST_SHA256 },
#endif /* HAVE_EVP_SHA256 || !WITH_OPENSSL */
{ NULL, -1, -1, -1},
};
char *
kex_alg_list(char sep)
{
char *ret = NULL, *tmp;
size_t nlen, rlen = 0;
const struct kexalg *k;
for (k = kexalgs; k->name != NULL; k++) {
if (ret != NULL)
ret[rlen++] = sep;
nlen = strlen(k->name);
if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) {
free(ret);
return NULL;
}
ret = tmp;
memcpy(ret + rlen, k->name, nlen + 1);
rlen += nlen;
}
return ret;
}
static const struct kexalg *
kex_alg_by_name(const char *name)
{
const struct kexalg *k;
for (k = kexalgs; k->name != NULL; k++) {
if (strcmp(k->name, name) == 0)
return k;
}
return NULL;
}
/* Validate KEX method name list */
int
kex_names_valid(const char *names)
{
char *s, *cp, *p;
if (names == NULL || strcmp(names, "") == 0)
return 0;
if ((s = cp = strdup(names)) == NULL)
return 0;
for ((p = strsep(&cp, ",")); p && *p != '\0';
(p = strsep(&cp, ","))) {
if (kex_alg_by_name(p) == NULL) {
error("Unsupported KEX algorithm \"%.100s\"", p);
free(s);
return 0;
}
}
debug3("kex names ok: [%s]", names);
free(s);
return 1;
}
/* put algorithm proposal into buffer */
int
kex_prop2buf(struct sshbuf *b, char *proposal[PROPOSAL_MAX])
{
u_int i;
int r;
sshbuf_reset(b);
/*
* add a dummy cookie, the cookie will be overwritten by
* kex_send_kexinit(), each time a kexinit is set
*/
for (i = 0; i < KEX_COOKIE_LEN; i++) {
if ((r = sshbuf_put_u8(b, 0)) != 0)
return r;
}
for (i = 0; i < PROPOSAL_MAX; i++) {
if ((r = sshbuf_put_cstring(b, proposal[i])) != 0)
return r;
}
if ((r = sshbuf_put_u8(b, 0)) != 0 || /* first_kex_packet_follows */
(r = sshbuf_put_u32(b, 0)) != 0) /* uint32 reserved */
return r;
return 0;
}
/* parse buffer and return algorithm proposal */
int
kex_buf2prop(struct sshbuf *raw, int *first_kex_follows, char ***propp)
{
struct sshbuf *b = NULL;
u_char v;
u_int i;
char **proposal = NULL;
int r;
*propp = NULL;
if ((proposal = calloc(PROPOSAL_MAX, sizeof(char *))) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((b = sshbuf_fromb(raw)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((r = sshbuf_consume(b, KEX_COOKIE_LEN)) != 0) /* skip cookie */
goto out;
/* extract kex init proposal strings */
for (i = 0; i < PROPOSAL_MAX; i++) {
if ((r = sshbuf_get_cstring(b, &(proposal[i]), NULL)) != 0)
goto out;
debug2("kex_parse_kexinit: %s", proposal[i]);
}
/* first kex follows / reserved */
if ((r = sshbuf_get_u8(b, &v)) != 0 ||
(r = sshbuf_get_u32(b, &i)) != 0)
goto out;
if (first_kex_follows != NULL)
*first_kex_follows = i;
debug2("kex_parse_kexinit: first_kex_follows %d ", v);
debug2("kex_parse_kexinit: reserved %u ", i);
r = 0;
*propp = proposal;
out:
if (r != 0 && proposal != NULL)
kex_prop_free(proposal);
sshbuf_free(b);
return r;
}
void
kex_prop_free(char **proposal)
{
u_int i;
for (i = 0; i < PROPOSAL_MAX; i++)
free(proposal[i]);
free(proposal);
}
/* ARGSUSED */
static int
kex_protocol_error(int type, u_int32_t seq, void *ctxt)
{
error("Hm, kex protocol error: type %d seq %u", type, seq);
return 0;
}
static void
kex_reset_dispatch(struct ssh *ssh)
{
ssh_dispatch_range(ssh, SSH2_MSG_TRANSPORT_MIN,
SSH2_MSG_TRANSPORT_MAX, &kex_protocol_error);
ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit);
}
int
kex_send_newkeys(struct ssh *ssh)
{
int r;
kex_reset_dispatch(ssh);
if ((r = sshpkt_start(ssh, SSH2_MSG_NEWKEYS)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
return r;
debug("SSH2_MSG_NEWKEYS sent");
debug("expecting SSH2_MSG_NEWKEYS");
ssh_dispatch_set(ssh, SSH2_MSG_NEWKEYS, &kex_input_newkeys);
return 0;
}
static int
kex_input_newkeys(int type, u_int32_t seq, void *ctxt)
{
struct ssh *ssh = ctxt;
struct kex *kex = ssh->kex;
int r;
debug("SSH2_MSG_NEWKEYS received");
ssh_dispatch_set(ssh, SSH2_MSG_NEWKEYS, &kex_protocol_error);
if ((r = sshpkt_get_end(ssh)) != 0)
return r;
kex->done = 1;
sshbuf_reset(kex->peer);
/* sshbuf_reset(kex->my); */
kex->flags &= ~KEX_INIT_SENT;
free(kex->name);
kex->name = NULL;
return 0;
}
int
kex_send_kexinit(struct ssh *ssh)
- (djm) Big OpenBSD sync: - markus@cvs.openbsd.org 2000/09/30 10:27:44 [log.c] allow loglevel debug - markus@cvs.openbsd.org 2000/10/03 11:59:57 [packet.c] hmac->mac - markus@cvs.openbsd.org 2000/10/03 12:03:03 [auth-krb4.c auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c] move fake-auth from auth1.c to individual auth methods, disables s/key in debug-msg - markus@cvs.openbsd.org 2000/10/03 12:16:48 ssh.c do not resolve canonname, i have no idea why this was added oin ossh - markus@cvs.openbsd.org 2000/10/09 15:30:44 ssh-keygen.1 ssh-keygen.c -X now reads private ssh.com DSA keys, too. - markus@cvs.openbsd.org 2000/10/09 15:32:34 auth-options.c clear options on every call. - markus@cvs.openbsd.org 2000/10/09 15:51:00 authfd.c authfd.h interop with ssh-agent2, from <res@shore.net> - markus@cvs.openbsd.org 2000/10/10 14:20:45 compat.c use rexexp for version string matching - provos@cvs.openbsd.org 2000/10/10 22:02:18 [kex.c kex.h myproposal.h ssh.h ssh2.h sshconnect2.c sshd.c dh.c dh.h] First rough implementation of the diffie-hellman group exchange. The client can ask the server for bigger groups to perform the diffie-hellman in, thus increasing the attack complexity when using ciphers with longer keys. University of Windsor provided network, T the company. - markus@cvs.openbsd.org 2000/10/11 13:59:52 [auth-rsa.c auth2.c] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:00:27 [auth-options.h] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:03:27 [scp.1 scp.c] support 'scp -o' with help from mouring@pconline.com - markus@cvs.openbsd.org 2000/10/11 14:11:35 [dh.c] Wall - markus@cvs.openbsd.org 2000/10/11 14:14:40 [auth.h auth2.c readconf.c readconf.h readpass.c servconf.c servconf.h] [ssh.h sshconnect2.c sshd_config auth2-skey.c cli.c cli.h] add support for s/key (kbd-interactive) to ssh2, based on work by mkiernan@avantgo.com and me - markus@cvs.openbsd.org 2000/10/11 14:27:24 [auth.c auth1.c auth2.c authfile.c cipher.c cipher.h kex.c kex.h] [myproposal.h packet.c readconf.c session.c ssh.c ssh.h sshconnect1.c] [sshconnect2.c sshd.c] new cipher framework - markus@cvs.openbsd.org 2000/10/11 14:45:21 [cipher.c] remove DES - markus@cvs.openbsd.org 2000/10/12 03:59:20 [cipher.c cipher.h sshconnect1.c sshconnect2.c sshd.c] enable DES in SSH-1 clients only - markus@cvs.openbsd.org 2000/10/12 08:21:13 [kex.h packet.c] remove unused - markus@cvs.openbsd.org 2000/10/13 12:34:46 [sshd.c] Kludge for F-Secure Macintosh < 1.0.2; appro@fy.chalmers.se - markus@cvs.openbsd.org 2000/10/13 12:59:15 [cipher.c cipher.h myproposal.h rijndael.c rijndael.h] rijndael/aes support - markus@cvs.openbsd.org 2000/10/13 13:10:54 [sshd.8] more info about -V - markus@cvs.openbsd.org 2000/10/13 13:12:02 [myproposal.h] prefer no compression
2000-10-14 05:23:11 +00:00
{
u_char *cookie;
struct kex *kex = ssh->kex;
int r;
if (kex == NULL)
return SSH_ERR_INTERNAL_ERROR;
if (kex->flags & KEX_INIT_SENT)
return 0;
kex->done = 0;
/* generate a random cookie */
if (sshbuf_len(kex->my) < KEX_COOKIE_LEN)
return SSH_ERR_INVALID_FORMAT;
if ((cookie = sshbuf_mutable_ptr(kex->my)) == NULL)
return SSH_ERR_INTERNAL_ERROR;
arc4random_buf(cookie, KEX_COOKIE_LEN);
if ((r = sshpkt_start(ssh, SSH2_MSG_KEXINIT)) != 0 ||
(r = sshpkt_putb(ssh, kex->my)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
return r;
debug("SSH2_MSG_KEXINIT sent");
kex->flags |= KEX_INIT_SENT;
return 0;
}
/* ARGSUSED */
int
kex_input_kexinit(int type, u_int32_t seq, void *ctxt)
{
struct ssh *ssh = ctxt;
struct kex *kex = ssh->kex;
const u_char *ptr;
u_int i;
size_t dlen;
int r;
- (djm) Big OpenBSD sync: - markus@cvs.openbsd.org 2000/09/30 10:27:44 [log.c] allow loglevel debug - markus@cvs.openbsd.org 2000/10/03 11:59:57 [packet.c] hmac->mac - markus@cvs.openbsd.org 2000/10/03 12:03:03 [auth-krb4.c auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c] move fake-auth from auth1.c to individual auth methods, disables s/key in debug-msg - markus@cvs.openbsd.org 2000/10/03 12:16:48 ssh.c do not resolve canonname, i have no idea why this was added oin ossh - markus@cvs.openbsd.org 2000/10/09 15:30:44 ssh-keygen.1 ssh-keygen.c -X now reads private ssh.com DSA keys, too. - markus@cvs.openbsd.org 2000/10/09 15:32:34 auth-options.c clear options on every call. - markus@cvs.openbsd.org 2000/10/09 15:51:00 authfd.c authfd.h interop with ssh-agent2, from <res@shore.net> - markus@cvs.openbsd.org 2000/10/10 14:20:45 compat.c use rexexp for version string matching - provos@cvs.openbsd.org 2000/10/10 22:02:18 [kex.c kex.h myproposal.h ssh.h ssh2.h sshconnect2.c sshd.c dh.c dh.h] First rough implementation of the diffie-hellman group exchange. The client can ask the server for bigger groups to perform the diffie-hellman in, thus increasing the attack complexity when using ciphers with longer keys. University of Windsor provided network, T the company. - markus@cvs.openbsd.org 2000/10/11 13:59:52 [auth-rsa.c auth2.c] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:00:27 [auth-options.h] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:03:27 [scp.1 scp.c] support 'scp -o' with help from mouring@pconline.com - markus@cvs.openbsd.org 2000/10/11 14:11:35 [dh.c] Wall - markus@cvs.openbsd.org 2000/10/11 14:14:40 [auth.h auth2.c readconf.c readconf.h readpass.c servconf.c servconf.h] [ssh.h sshconnect2.c sshd_config auth2-skey.c cli.c cli.h] add support for s/key (kbd-interactive) to ssh2, based on work by mkiernan@avantgo.com and me - markus@cvs.openbsd.org 2000/10/11 14:27:24 [auth.c auth1.c auth2.c authfile.c cipher.c cipher.h kex.c kex.h] [myproposal.h packet.c readconf.c session.c ssh.c ssh.h sshconnect1.c] [sshconnect2.c sshd.c] new cipher framework - markus@cvs.openbsd.org 2000/10/11 14:45:21 [cipher.c] remove DES - markus@cvs.openbsd.org 2000/10/12 03:59:20 [cipher.c cipher.h sshconnect1.c sshconnect2.c sshd.c] enable DES in SSH-1 clients only - markus@cvs.openbsd.org 2000/10/12 08:21:13 [kex.h packet.c] remove unused - markus@cvs.openbsd.org 2000/10/13 12:34:46 [sshd.c] Kludge for F-Secure Macintosh < 1.0.2; appro@fy.chalmers.se - markus@cvs.openbsd.org 2000/10/13 12:59:15 [cipher.c cipher.h myproposal.h rijndael.c rijndael.h] rijndael/aes support - markus@cvs.openbsd.org 2000/10/13 13:10:54 [sshd.8] more info about -V - markus@cvs.openbsd.org 2000/10/13 13:12:02 [myproposal.h] prefer no compression
2000-10-14 05:23:11 +00:00
debug("SSH2_MSG_KEXINIT received");
if (kex == NULL)
return SSH_ERR_INVALID_ARGUMENT;
- (djm) Big OpenBSD sync: - markus@cvs.openbsd.org 2000/09/30 10:27:44 [log.c] allow loglevel debug - markus@cvs.openbsd.org 2000/10/03 11:59:57 [packet.c] hmac->mac - markus@cvs.openbsd.org 2000/10/03 12:03:03 [auth-krb4.c auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c] move fake-auth from auth1.c to individual auth methods, disables s/key in debug-msg - markus@cvs.openbsd.org 2000/10/03 12:16:48 ssh.c do not resolve canonname, i have no idea why this was added oin ossh - markus@cvs.openbsd.org 2000/10/09 15:30:44 ssh-keygen.1 ssh-keygen.c -X now reads private ssh.com DSA keys, too. - markus@cvs.openbsd.org 2000/10/09 15:32:34 auth-options.c clear options on every call. - markus@cvs.openbsd.org 2000/10/09 15:51:00 authfd.c authfd.h interop with ssh-agent2, from <res@shore.net> - markus@cvs.openbsd.org 2000/10/10 14:20:45 compat.c use rexexp for version string matching - provos@cvs.openbsd.org 2000/10/10 22:02:18 [kex.c kex.h myproposal.h ssh.h ssh2.h sshconnect2.c sshd.c dh.c dh.h] First rough implementation of the diffie-hellman group exchange. The client can ask the server for bigger groups to perform the diffie-hellman in, thus increasing the attack complexity when using ciphers with longer keys. University of Windsor provided network, T the company. - markus@cvs.openbsd.org 2000/10/11 13:59:52 [auth-rsa.c auth2.c] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:00:27 [auth-options.h] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:03:27 [scp.1 scp.c] support 'scp -o' with help from mouring@pconline.com - markus@cvs.openbsd.org 2000/10/11 14:11:35 [dh.c] Wall - markus@cvs.openbsd.org 2000/10/11 14:14:40 [auth.h auth2.c readconf.c readconf.h readpass.c servconf.c servconf.h] [ssh.h sshconnect2.c sshd_config auth2-skey.c cli.c cli.h] add support for s/key (kbd-interactive) to ssh2, based on work by mkiernan@avantgo.com and me - markus@cvs.openbsd.org 2000/10/11 14:27:24 [auth.c auth1.c auth2.c authfile.c cipher.c cipher.h kex.c kex.h] [myproposal.h packet.c readconf.c session.c ssh.c ssh.h sshconnect1.c] [sshconnect2.c sshd.c] new cipher framework - markus@cvs.openbsd.org 2000/10/11 14:45:21 [cipher.c] remove DES - markus@cvs.openbsd.org 2000/10/12 03:59:20 [cipher.c cipher.h sshconnect1.c sshconnect2.c sshd.c] enable DES in SSH-1 clients only - markus@cvs.openbsd.org 2000/10/12 08:21:13 [kex.h packet.c] remove unused - markus@cvs.openbsd.org 2000/10/13 12:34:46 [sshd.c] Kludge for F-Secure Macintosh < 1.0.2; appro@fy.chalmers.se - markus@cvs.openbsd.org 2000/10/13 12:59:15 [cipher.c cipher.h myproposal.h rijndael.c rijndael.h] rijndael/aes support - markus@cvs.openbsd.org 2000/10/13 13:10:54 [sshd.8] more info about -V - markus@cvs.openbsd.org 2000/10/13 13:12:02 [myproposal.h] prefer no compression
2000-10-14 05:23:11 +00:00
ptr = sshpkt_ptr(ssh, &dlen);
if ((r = sshbuf_put(kex->peer, ptr, dlen)) != 0)
return r;
- (djm) Big OpenBSD sync: - markus@cvs.openbsd.org 2000/09/30 10:27:44 [log.c] allow loglevel debug - markus@cvs.openbsd.org 2000/10/03 11:59:57 [packet.c] hmac->mac - markus@cvs.openbsd.org 2000/10/03 12:03:03 [auth-krb4.c auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c] move fake-auth from auth1.c to individual auth methods, disables s/key in debug-msg - markus@cvs.openbsd.org 2000/10/03 12:16:48 ssh.c do not resolve canonname, i have no idea why this was added oin ossh - markus@cvs.openbsd.org 2000/10/09 15:30:44 ssh-keygen.1 ssh-keygen.c -X now reads private ssh.com DSA keys, too. - markus@cvs.openbsd.org 2000/10/09 15:32:34 auth-options.c clear options on every call. - markus@cvs.openbsd.org 2000/10/09 15:51:00 authfd.c authfd.h interop with ssh-agent2, from <res@shore.net> - markus@cvs.openbsd.org 2000/10/10 14:20:45 compat.c use rexexp for version string matching - provos@cvs.openbsd.org 2000/10/10 22:02:18 [kex.c kex.h myproposal.h ssh.h ssh2.h sshconnect2.c sshd.c dh.c dh.h] First rough implementation of the diffie-hellman group exchange. The client can ask the server for bigger groups to perform the diffie-hellman in, thus increasing the attack complexity when using ciphers with longer keys. University of Windsor provided network, T the company. - markus@cvs.openbsd.org 2000/10/11 13:59:52 [auth-rsa.c auth2.c] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:00:27 [auth-options.h] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:03:27 [scp.1 scp.c] support 'scp -o' with help from mouring@pconline.com - markus@cvs.openbsd.org 2000/10/11 14:11:35 [dh.c] Wall - markus@cvs.openbsd.org 2000/10/11 14:14:40 [auth.h auth2.c readconf.c readconf.h readpass.c servconf.c servconf.h] [ssh.h sshconnect2.c sshd_config auth2-skey.c cli.c cli.h] add support for s/key (kbd-interactive) to ssh2, based on work by mkiernan@avantgo.com and me - markus@cvs.openbsd.org 2000/10/11 14:27:24 [auth.c auth1.c auth2.c authfile.c cipher.c cipher.h kex.c kex.h] [myproposal.h packet.c readconf.c session.c ssh.c ssh.h sshconnect1.c] [sshconnect2.c sshd.c] new cipher framework - markus@cvs.openbsd.org 2000/10/11 14:45:21 [cipher.c] remove DES - markus@cvs.openbsd.org 2000/10/12 03:59:20 [cipher.c cipher.h sshconnect1.c sshconnect2.c sshd.c] enable DES in SSH-1 clients only - markus@cvs.openbsd.org 2000/10/12 08:21:13 [kex.h packet.c] remove unused - markus@cvs.openbsd.org 2000/10/13 12:34:46 [sshd.c] Kludge for F-Secure Macintosh < 1.0.2; appro@fy.chalmers.se - markus@cvs.openbsd.org 2000/10/13 12:59:15 [cipher.c cipher.h myproposal.h rijndael.c rijndael.h] rijndael/aes support - markus@cvs.openbsd.org 2000/10/13 13:10:54 [sshd.8] more info about -V - markus@cvs.openbsd.org 2000/10/13 13:12:02 [myproposal.h] prefer no compression
2000-10-14 05:23:11 +00:00
/* discard packet */
for (i = 0; i < KEX_COOKIE_LEN; i++)
if ((r = sshpkt_get_u8(ssh, NULL)) != 0)
return r;
for (i = 0; i < PROPOSAL_MAX; i++)
if ((r = sshpkt_get_string(ssh, NULL, NULL)) != 0)
return r;
/*
* 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.
*/
if ((r = sshpkt_get_u8(ssh, NULL)) != 0 || /* first_kex_follows */
(r = sshpkt_get_u32(ssh, NULL)) != 0 || /* reserved */
(r = sshpkt_get_end(ssh)) != 0)
return r;
if (!(kex->flags & KEX_INIT_SENT))
if ((r = kex_send_kexinit(ssh)) != 0)
return r;
if ((r = kex_choose_conf(ssh)) != 0)
return r;
if (kex->kex_type < KEX_MAX && kex->kex[kex->kex_type] != NULL)
return (kex->kex[kex->kex_type])(ssh);
return SSH_ERR_INTERNAL_ERROR;
}
int
kex_new(struct ssh *ssh, char *proposal[PROPOSAL_MAX], struct kex **kexp)
{
struct kex *kex;
int r;
*kexp = NULL;
if ((kex = calloc(1, sizeof(*kex))) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((kex->peer = sshbuf_new()) == NULL ||
(kex->my = sshbuf_new()) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((r = kex_prop2buf(kex->my, proposal)) != 0)
goto out;
kex->done = 0;
kex_reset_dispatch(ssh);
r = 0;
*kexp = kex;
out:
if (r != 0)
kex_free(kex);
return r;
- (djm) Big OpenBSD sync: - markus@cvs.openbsd.org 2000/09/30 10:27:44 [log.c] allow loglevel debug - markus@cvs.openbsd.org 2000/10/03 11:59:57 [packet.c] hmac->mac - markus@cvs.openbsd.org 2000/10/03 12:03:03 [auth-krb4.c auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c] move fake-auth from auth1.c to individual auth methods, disables s/key in debug-msg - markus@cvs.openbsd.org 2000/10/03 12:16:48 ssh.c do not resolve canonname, i have no idea why this was added oin ossh - markus@cvs.openbsd.org 2000/10/09 15:30:44 ssh-keygen.1 ssh-keygen.c -X now reads private ssh.com DSA keys, too. - markus@cvs.openbsd.org 2000/10/09 15:32:34 auth-options.c clear options on every call. - markus@cvs.openbsd.org 2000/10/09 15:51:00 authfd.c authfd.h interop with ssh-agent2, from <res@shore.net> - markus@cvs.openbsd.org 2000/10/10 14:20:45 compat.c use rexexp for version string matching - provos@cvs.openbsd.org 2000/10/10 22:02:18 [kex.c kex.h myproposal.h ssh.h ssh2.h sshconnect2.c sshd.c dh.c dh.h] First rough implementation of the diffie-hellman group exchange. The client can ask the server for bigger groups to perform the diffie-hellman in, thus increasing the attack complexity when using ciphers with longer keys. University of Windsor provided network, T the company. - markus@cvs.openbsd.org 2000/10/11 13:59:52 [auth-rsa.c auth2.c] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:00:27 [auth-options.h] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:03:27 [scp.1 scp.c] support 'scp -o' with help from mouring@pconline.com - markus@cvs.openbsd.org 2000/10/11 14:11:35 [dh.c] Wall - markus@cvs.openbsd.org 2000/10/11 14:14:40 [auth.h auth2.c readconf.c readconf.h readpass.c servconf.c servconf.h] [ssh.h sshconnect2.c sshd_config auth2-skey.c cli.c cli.h] add support for s/key (kbd-interactive) to ssh2, based on work by mkiernan@avantgo.com and me - markus@cvs.openbsd.org 2000/10/11 14:27:24 [auth.c auth1.c auth2.c authfile.c cipher.c cipher.h kex.c kex.h] [myproposal.h packet.c readconf.c session.c ssh.c ssh.h sshconnect1.c] [sshconnect2.c sshd.c] new cipher framework - markus@cvs.openbsd.org 2000/10/11 14:45:21 [cipher.c] remove DES - markus@cvs.openbsd.org 2000/10/12 03:59:20 [cipher.c cipher.h sshconnect1.c sshconnect2.c sshd.c] enable DES in SSH-1 clients only - markus@cvs.openbsd.org 2000/10/12 08:21:13 [kex.h packet.c] remove unused - markus@cvs.openbsd.org 2000/10/13 12:34:46 [sshd.c] Kludge for F-Secure Macintosh < 1.0.2; appro@fy.chalmers.se - markus@cvs.openbsd.org 2000/10/13 12:59:15 [cipher.c cipher.h myproposal.h rijndael.c rijndael.h] rijndael/aes support - markus@cvs.openbsd.org 2000/10/13 13:10:54 [sshd.8] more info about -V - markus@cvs.openbsd.org 2000/10/13 13:12:02 [myproposal.h] prefer no compression
2000-10-14 05:23:11 +00:00
}
void
kex_free_newkeys(struct newkeys *newkeys)
{
if (newkeys == NULL)
return;
if (newkeys->enc.key) {
explicit_bzero(newkeys->enc.key, newkeys->enc.key_len);
free(newkeys->enc.key);
newkeys->enc.key = NULL;
}
if (newkeys->enc.iv) {
explicit_bzero(newkeys->enc.iv, newkeys->enc.block_size);
free(newkeys->enc.iv);
newkeys->enc.iv = NULL;
}
free(newkeys->enc.name);
explicit_bzero(&newkeys->enc, sizeof(newkeys->enc));
free(newkeys->comp.name);
explicit_bzero(&newkeys->comp, sizeof(newkeys->comp));
mac_clear(&newkeys->mac);
if (newkeys->mac.key) {
explicit_bzero(newkeys->mac.key, newkeys->mac.key_len);
free(newkeys->mac.key);
newkeys->mac.key = NULL;
}
free(newkeys->mac.name);
explicit_bzero(&newkeys->mac, sizeof(newkeys->mac));
explicit_bzero(newkeys, sizeof(*newkeys));
free(newkeys);
}
void
kex_free(struct kex *kex)
{
u_int mode;
#ifdef WITH_OPENSSL
if (kex->dh)
DH_free(kex->dh);
if (kex->ec_client_key)
EC_KEY_free(kex->ec_client_key);
#endif
for (mode = 0; mode < MODE_MAX; mode++) {
kex_free_newkeys(kex->newkeys[mode]);
kex->newkeys[mode] = NULL;
}
sshbuf_free(kex->peer);
sshbuf_free(kex->my);
free(kex->session_id);
free(kex->client_version_string);
free(kex->server_version_string);
free(kex);
}
int
kex_setup(struct ssh *ssh, char *proposal[PROPOSAL_MAX])
{
int r;
if ((r = kex_new(ssh, proposal, &ssh->kex)) != 0)
return r;
if ((r = kex_send_kexinit(ssh)) != 0) { /* we start */
kex_free(ssh->kex);
ssh->kex = NULL;
return r;
}
return 0;
}
static int
choose_enc(struct sshenc *enc, char *client, char *server)
{
char *name = match_list(client, server, NULL);
if (name == NULL)
return SSH_ERR_NO_CIPHER_ALG_MATCH;
if ((enc->cipher = cipher_by_name(name)) == NULL)
return SSH_ERR_INTERNAL_ERROR;
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);
return 0;
}
static int
choose_mac(struct ssh *ssh, struct sshmac *mac, char *client, char *server)
{
char *name = match_list(client, server, NULL);
if (name == NULL)
return SSH_ERR_NO_MAC_ALG_MATCH;
if (mac_setup(mac, name) < 0)
return SSH_ERR_INTERNAL_ERROR;
/* truncate the key */
if (ssh->compat & SSH_BUG_HMAC)
mac->key_len = 16;
mac->name = name;
mac->key = NULL;
mac->enabled = 0;
return 0;
}
static int
choose_comp(struct sshcomp *comp, char *client, char *server)
{
char *name = match_list(client, server, NULL);
if (name == NULL)
return SSH_ERR_NO_COMPRESS_ALG_MATCH;
if (strcmp(name, "zlib@openssh.com") == 0) {
comp->type = COMP_DELAYED;
} else if (strcmp(name, "zlib") == 0) {
comp->type = COMP_ZLIB;
} else if (strcmp(name, "none") == 0) {
comp->type = COMP_NONE;
} else {
return SSH_ERR_INTERNAL_ERROR;
}
comp->name = name;
return 0;
}
static int
choose_kex(struct kex *k, char *client, char *server)
{
const struct kexalg *kexalg;
k->name = match_list(client, server, NULL);
if (k->name == NULL)
return SSH_ERR_NO_KEX_ALG_MATCH;
if ((kexalg = kex_alg_by_name(k->name)) == NULL)
return SSH_ERR_INTERNAL_ERROR;
k->kex_type = kexalg->type;
k->hash_alg = kexalg->hash_alg;
k->ec_nid = kexalg->ec_nid;
return 0;
}
static int
choose_hostkeyalg(struct kex *k, char *client, char *server)
{
char *hostkeyalg = match_list(client, server, NULL);
- (djm) Merge OpenBSD changes: - markus@cvs.openbsd.org 2000/11/06 16:04:56 [channels.c channels.h clientloop.c nchan.c serverloop.c] [session.c ssh.c] agent forwarding and -R for ssh2, based on work from jhuuskon@messi.uku.fi - markus@cvs.openbsd.org 2000/11/06 16:13:27 [ssh.c sshconnect.c sshd.c] do not disabled rhosts(rsa) if server port > 1024; from pekkas@netcore.fi - markus@cvs.openbsd.org 2000/11/06 16:16:35 [sshconnect.c] downgrade client to 1.3 if server is 1.4; help from mdb@juniper.net - markus@cvs.openbsd.org 2000/11/09 18:04:40 [auth1.c] typo; from mouring@pconline.com - markus@cvs.openbsd.org 2000/11/12 12:03:28 [ssh-agent.c] off-by-one when removing a key from the agent - markus@cvs.openbsd.org 2000/11/12 12:50:39 [auth-rh-rsa.c auth2.c authfd.c authfd.h] [authfile.c hostfile.c kex.c kex.h key.c key.h myproposal.h] [readconf.c readconf.h rsa.c rsa.h servconf.c servconf.h ssh-add.c] [ssh-agent.c ssh-keygen.1 ssh-keygen.c ssh.1 ssh.c ssh_config] [sshconnect1.c sshconnect2.c sshd.8 sshd.c sshd_config ssh-dss.c] [ssh-dss.h ssh-rsa.c ssh-rsa.h dsa.c dsa.h] add support for RSA to SSH2. please test. there are now 3 types of keys: RSA1 is used by ssh-1 only, RSA and DSA are used by SSH2. you can use 'ssh-keygen -t rsa -f ssh2_rsa_file' to generate RSA keys for SSH2 and use the RSA keys for hostkeys or for user keys. SSH2 RSA or DSA keys are added to .ssh/authorised_keys2 as before. - (djm) Fix up Makefile and Redhat init script to create RSA host keys - (djm) Change to interim version
2000-11-13 11:57:25 +00:00
if (hostkeyalg == NULL)
return SSH_ERR_NO_HOSTKEY_ALG_MATCH;
k->hostkey_type = sshkey_type_from_name(hostkeyalg);
- (djm) Merge OpenBSD changes: - markus@cvs.openbsd.org 2000/11/06 16:04:56 [channels.c channels.h clientloop.c nchan.c serverloop.c] [session.c ssh.c] agent forwarding and -R for ssh2, based on work from jhuuskon@messi.uku.fi - markus@cvs.openbsd.org 2000/11/06 16:13:27 [ssh.c sshconnect.c sshd.c] do not disabled rhosts(rsa) if server port > 1024; from pekkas@netcore.fi - markus@cvs.openbsd.org 2000/11/06 16:16:35 [sshconnect.c] downgrade client to 1.3 if server is 1.4; help from mdb@juniper.net - markus@cvs.openbsd.org 2000/11/09 18:04:40 [auth1.c] typo; from mouring@pconline.com - markus@cvs.openbsd.org 2000/11/12 12:03:28 [ssh-agent.c] off-by-one when removing a key from the agent - markus@cvs.openbsd.org 2000/11/12 12:50:39 [auth-rh-rsa.c auth2.c authfd.c authfd.h] [authfile.c hostfile.c kex.c kex.h key.c key.h myproposal.h] [readconf.c readconf.h rsa.c rsa.h servconf.c servconf.h ssh-add.c] [ssh-agent.c ssh-keygen.1 ssh-keygen.c ssh.1 ssh.c ssh_config] [sshconnect1.c sshconnect2.c sshd.8 sshd.c sshd_config ssh-dss.c] [ssh-dss.h ssh-rsa.c ssh-rsa.h dsa.c dsa.h] add support for RSA to SSH2. please test. there are now 3 types of keys: RSA1 is used by ssh-1 only, RSA and DSA are used by SSH2. you can use 'ssh-keygen -t rsa -f ssh2_rsa_file' to generate RSA keys for SSH2 and use the RSA keys for hostkeys or for user keys. SSH2 RSA or DSA keys are added to .ssh/authorised_keys2 as before. - (djm) Fix up Makefile and Redhat init script to create RSA host keys - (djm) Change to interim version
2000-11-13 11:57:25 +00:00
if (k->hostkey_type == KEY_UNSPEC)
return SSH_ERR_INTERNAL_ERROR;
free(hostkeyalg);
return 0;
}
static int
proposals_match(char *my[PROPOSAL_MAX], char *peer[PROPOSAL_MAX])
{
static int check[] = {
PROPOSAL_KEX_ALGS, PROPOSAL_SERVER_HOST_KEY_ALGS, -1
};
int *idx;
char *p;
for (idx = &check[0]; *idx != -1; idx++) {
if ((p = strchr(my[*idx], ',')) != NULL)
*p = '\0';
if ((p = strchr(peer[*idx], ',')) != NULL)
*p = '\0';
if (strcmp(my[*idx], peer[*idx]) != 0) {
debug2("proposal mismatch: my %s peer %s",
my[*idx], peer[*idx]);
return (0);
}
}
debug2("proposals match");
return (1);
}
static int
kex_choose_conf(struct ssh *ssh)
{
struct kex *kex = ssh->kex;
struct newkeys *newkeys;
char **my = NULL, **peer = NULL;
char **cprop, **sprop;
int nenc, nmac, ncomp;
u_int mode, ctos, need, dh_need, authlen;
int r, first_kex_follows;
if ((r = kex_buf2prop(kex->my, NULL, &my)) != 0 ||
(r = kex_buf2prop(kex->peer, &first_kex_follows, &peer)) != 0)
goto out;
if (kex->server) {
cprop=peer;
sprop=my;
} else {
cprop=my;
sprop=peer;
}
/* Check whether server offers roaming */
if (!kex->server) {
char *roaming = match_list(KEX_RESUME,
peer[PROPOSAL_KEX_ALGS], NULL);
if (roaming) {
kex->roaming = 1;
free(roaming);
}
}
/* Algorithm Negotiation */
for (mode = 0; mode < MODE_MAX; mode++) {
if ((newkeys = calloc(1, sizeof(*newkeys))) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
kex->newkeys[mode] = newkeys;
ctos = (!kex->server && mode == MODE_OUT) ||
(kex->server && mode == MODE_IN);
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;
if ((r = choose_enc(&newkeys->enc, cprop[nenc],
sprop[nenc])) != 0)
goto out;
authlen = cipher_authlen(newkeys->enc.cipher);
/* ignore mac for authenticated encryption */
if (authlen == 0 &&
(r = choose_mac(ssh, &newkeys->mac, cprop[nmac],
sprop[nmac])) != 0)
goto out;
if ((r = choose_comp(&newkeys->comp, cprop[ncomp],
sprop[ncomp])) != 0)
goto out;
debug("kex: %s %s %s %s",
ctos ? "client->server" : "server->client",
newkeys->enc.name,
authlen == 0 ? newkeys->mac.name : "<implicit>",
newkeys->comp.name);
}
if ((r = choose_kex(kex, cprop[PROPOSAL_KEX_ALGS],
sprop[PROPOSAL_KEX_ALGS])) != 0 ||
(r = choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
sprop[PROPOSAL_SERVER_HOST_KEY_ALGS])) != 0)
goto out;
need = dh_need = 0;
for (mode = 0; mode < MODE_MAX; mode++) {
newkeys = kex->newkeys[mode];
need = MAX(need, newkeys->enc.key_len);
need = MAX(need, newkeys->enc.block_size);
need = MAX(need, newkeys->enc.iv_len);
need = MAX(need, newkeys->mac.key_len);
dh_need = MAX(dh_need, cipher_seclen(newkeys->enc.cipher));
dh_need = MAX(dh_need, newkeys->enc.block_size);
dh_need = MAX(dh_need, newkeys->enc.iv_len);
dh_need = MAX(dh_need, newkeys->mac.key_len);
}
/* XXX need runden? */
kex->we_need = need;
kex->dh_need = dh_need;
/* ignore the next message if the proposals do not match */
if (first_kex_follows && !proposals_match(my, peer) &&
!(ssh->compat & SSH_BUG_FIRSTKEX))
ssh->dispatch_skip_packets = 1;
r = 0;
out:
kex_prop_free(my);
kex_prop_free(peer);
return r;
}
static int
derive_key(struct ssh *ssh, int id, u_int need, u_char *hash, u_int hashlen,
const struct sshbuf *shared_secret, u_char **keyp)
{
struct kex *kex = ssh->kex;
struct ssh_digest_ctx *hashctx = NULL;
char c = id;
u_int have;
size_t mdsz;
u_char *digest;
int r;
if ((mdsz = ssh_digest_bytes(kex->hash_alg)) == 0)
return SSH_ERR_INVALID_ARGUMENT;
if ((digest = calloc(1, roundup(need, mdsz))) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
/* K1 = HASH(K || H || "A" || session_id) */
if ((hashctx = ssh_digest_start(kex->hash_alg)) == NULL ||
ssh_digest_update_buffer(hashctx, shared_secret) != 0 ||
ssh_digest_update(hashctx, hash, hashlen) != 0 ||
ssh_digest_update(hashctx, &c, 1) != 0 ||
ssh_digest_update(hashctx, kex->session_id,
kex->session_id_len) != 0 ||
ssh_digest_final(hashctx, digest, mdsz) != 0) {
r = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
ssh_digest_free(hashctx);
hashctx = NULL;
/*
* expand key:
* Kn = HASH(K || H || K1 || K2 || ... || Kn-1)
* Key = K1 || K2 || ... || Kn
*/
for (have = mdsz; need > have; have += mdsz) {
if ((hashctx = ssh_digest_start(kex->hash_alg)) == NULL ||
ssh_digest_update_buffer(hashctx, shared_secret) != 0 ||
ssh_digest_update(hashctx, hash, hashlen) != 0 ||
ssh_digest_update(hashctx, digest, have) != 0 ||
ssh_digest_final(hashctx, digest + have, mdsz) != 0) {
r = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
ssh_digest_free(hashctx);
hashctx = NULL;
}
#ifdef DEBUG_KEX
fprintf(stderr, "key '%c'== ", c);
dump_digest("key", digest, need);
#endif
*keyp = digest;
digest = NULL;
r = 0;
out:
if (digest)
free(digest);
ssh_digest_free(hashctx);
return r;
}
#define NKEYS 6
int
kex_derive_keys(struct ssh *ssh, u_char *hash, u_int hashlen,
const struct sshbuf *shared_secret)
{
struct kex *kex = ssh->kex;
u_char *keys[NKEYS];
u_int i, j, mode, ctos;
int r;
for (i = 0; i < NKEYS; i++) {
if ((r = derive_key(ssh, 'A'+i, kex->we_need, hash, hashlen,
shared_secret, &keys[i])) != 0) {
for (j = 0; j < i; j++)
free(keys[j]);
return r;
}
}
for (mode = 0; mode < MODE_MAX; mode++) {
ctos = (!kex->server && mode == MODE_OUT) ||
(kex->server && mode == MODE_IN);
kex->newkeys[mode]->enc.iv = keys[ctos ? 0 : 1];
kex->newkeys[mode]->enc.key = keys[ctos ? 2 : 3];
kex->newkeys[mode]->mac.key = keys[ctos ? 4 : 5];
}
return 0;
}
#ifdef WITH_OPENSSL
int
kex_derive_keys_bn(struct ssh *ssh, u_char *hash, u_int hashlen,
const BIGNUM *secret)
{
struct sshbuf *shared_secret;
int r;
if ((shared_secret = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshbuf_put_bignum2(shared_secret, secret)) == 0)
r = kex_derive_keys(ssh, hash, hashlen, shared_secret);
sshbuf_free(shared_secret);
return r;
}
#endif
#ifdef WITH_SSH1
int
derive_ssh1_session_id(BIGNUM *host_modulus, BIGNUM *server_modulus,
u_int8_t cookie[8], u_int8_t id[16])
{
u_int8_t nbuf[2048], obuf[SSH_DIGEST_MAX_LENGTH];
struct ssh_digest_ctx *hashctx = NULL;
size_t len;
int r;
len = BN_num_bytes(host_modulus);
if (len < (512 / 8) || (u_int)len > sizeof(nbuf))
return SSH_ERR_KEY_BITS_MISMATCH;
if (BN_bn2bin(host_modulus, nbuf) <= 0 ||
(hashctx = ssh_digest_start(SSH_DIGEST_MD5)) == NULL ||
ssh_digest_update(hashctx, nbuf, len) != 0 ||
ssh_digest_update(hashctx, cookie, 8) != 0 ||
ssh_digest_final(hashctx, obuf, sizeof(obuf)) != 0) {
r = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
memcpy(id, obuf, ssh_digest_bytes(SSH_DIGEST_MD5));
r = 0;
out:
ssh_digest_free(hashctx);
explicit_bzero(nbuf, sizeof(nbuf));
explicit_bzero(obuf, sizeof(obuf));
return r;
}
#endif
#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
void
dump_digest(char *msg, u_char *digest, int len)
{
fprintf(stderr, "%s\n", msg);
sshbuf_dump_data(digest, len, stderr);
}
#endif