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upstream commit 

remove ssh1 server code; ok djm@

Upstream-ID: c24c0c32c49b91740d5a94ae914fb1898ea5f534
This commit is contained in:
markus@openbsd.org 2016-08-13 17:47:40 +00:00 коммит произвёл Damien Miller
Родитель 42d47adc5a
Коммит 6cb6dcffe1
16 изменённых файлов: 83 добавлений и 2762 удалений
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6
Makefile.in
Просмотреть файл

@ -97,11 +97,11 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \
SSHOBJS= ssh.o readconf.o clientloop.o sshtty.o \
sshconnect.o sshconnect1.o sshconnect2.o mux.o
SSHDOBJS=sshd.o auth-rhosts.o auth-passwd.o auth-rsa.o auth-rh-rsa.o \
SSHDOBJS=sshd.o auth-rhosts.o auth-passwd.o \
audit.o audit-bsm.o audit-linux.o platform.o \
sshpty.o sshlogin.o servconf.o serverloop.o \
auth.o auth1.o auth2.o auth-options.o session.o \
auth-chall.o auth2-chall.o groupaccess.o \
auth.o auth2.o auth-options.o session.o \
auth2-chall.o groupaccess.o \
auth-skey.o auth-bsdauth.o auth2-hostbased.o auth2-kbdint.o \
auth2-none.o auth2-passwd.o auth2-pubkey.o \
monitor_mm.o monitor.o monitor_wrap.o auth-krb5.o \

125
auth-chall.c
Просмотреть файл

@ -1,125 +0,0 @@
/* $OpenBSD: auth-chall.c,v 1.14 2014/06/24 01:13:21 djm Exp $ */
/*
* Copyright (c) 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/types.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include "xmalloc.h"
#include "key.h"
#include "hostfile.h"
#include "auth.h"
#include "log.h"
#include "misc.h"
#include "servconf.h"
/* limited protocol v1 interface to kbd-interactive authentication */
extern KbdintDevice *devices[];
static KbdintDevice *device;
extern ServerOptions options;
char *
get_challenge(Authctxt *authctxt)
{
char *challenge, *name, *info, **prompts;
u_int i, numprompts;
u_int *echo_on;
#ifdef USE_PAM
if (!options.use_pam)
remove_kbdint_device("pam");
#endif
device = devices[0]; /* we always use the 1st device for protocol 1 */
if (device == NULL)
return NULL;
if ((authctxt->kbdintctxt = device->init_ctx(authctxt)) == NULL)
return NULL;
if (device->query(authctxt->kbdintctxt, &name, &info,
&numprompts, &prompts, &echo_on)) {
device->free_ctx(authctxt->kbdintctxt);
authctxt->kbdintctxt = NULL;
return NULL;
}
if (numprompts < 1)
fatal("get_challenge: numprompts < 1");
challenge = xstrdup(prompts[0]);
for (i = 0; i < numprompts; i++)
free(prompts[i]);
free(prompts);
free(name);
free(echo_on);
free(info);
return (challenge);
}
int
verify_response(Authctxt *authctxt, const char *response)
{
char *resp[1], *name, *info, **prompts;
u_int i, numprompts, *echo_on;
int authenticated = 0;
if (device == NULL)
return 0;
if (authctxt->kbdintctxt == NULL)
return 0;
resp[0] = (char *)response;
switch (device->respond(authctxt->kbdintctxt, 1, resp)) {
case 0: /* Success */
authenticated = 1;
break;
case 1: /* Postponed - retry with empty query for PAM */
if ((device->query(authctxt->kbdintctxt, &name, &info,
&numprompts, &prompts, &echo_on)) != 0)
break;
if (numprompts == 0 &&
device->respond(authctxt->kbdintctxt, 0, resp) == 0)
authenticated = 1;
for (i = 0; i < numprompts; i++)
free(prompts[i]);
free(prompts);
free(name);
free(echo_on);
free(info);
break;
}
device->free_ctx(authctxt->kbdintctxt);
authctxt->kbdintctxt = NULL;
return authenticated;
}
void
abandon_challenge_response(Authctxt *authctxt)
{
if (authctxt->kbdintctxt != NULL) {
device->free_ctx(authctxt->kbdintctxt);
authctxt->kbdintctxt = NULL;
}
}

109
auth-rh-rsa.c
Просмотреть файл

@ -1,109 +0,0 @@
/* $OpenBSD: auth-rh-rsa.c,v 1.45 2016/03/07 19:02:43 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Rhosts or /etc/hosts.equiv authentication combined with RSA host
* authentication.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
#include "includes.h"
#ifdef WITH_SSH1
#include <sys/types.h>
#include <pwd.h>
#include <stdarg.h>
#include "packet.h"
#include "uidswap.h"
#include "log.h"
#include "buffer.h"
#include "misc.h"
#include "servconf.h"
#include "key.h"
#include "hostfile.h"
#include "pathnames.h"
#include "auth.h"
#include "canohost.h"
#ifdef GSSAPI
#include "ssh-gss.h"
#endif
#include "monitor_wrap.h"
/* import */
extern ServerOptions options;
int
auth_rhosts_rsa_key_allowed(struct passwd *pw, const char *cuser,
const char *chost, Key *client_host_key)
{
HostStatus host_status;
if (auth_key_is_revoked(client_host_key))
return 0;
/* Check if we would accept it using rhosts authentication. */
if (!auth_rhosts(pw, cuser))
return 0;
host_status = check_key_in_hostfiles(pw, client_host_key,
chost, _PATH_SSH_SYSTEM_HOSTFILE,
options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE);
return (host_status == HOST_OK);
}
/*
* Tries to authenticate the user using the .rhosts file and the host using
* its host key. Returns true if authentication succeeds.
*/
int
auth_rhosts_rsa(Authctxt *authctxt, char *cuser, Key *client_host_key)
{
struct ssh *ssh = active_state; /* XXX */
const char *chost;
struct passwd *pw = authctxt->pw;
debug("Trying rhosts with RSA host authentication for client user %.100s",
cuser);
if (!authctxt->valid || client_host_key == NULL ||
client_host_key->rsa == NULL)
return 0;
chost = auth_get_canonical_hostname(ssh, options.use_dns);
debug("Rhosts RSA authentication: canonical host %.900s", chost);
if (!PRIVSEP(auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key))) {
debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
return 0;
}
/* A matching host key was found and is known. */
/* Perform the challenge-response dialog with the client for the host key. */
if (!auth_rsa_challenge_dialog(client_host_key)) {
logit("Client on %.800s failed to respond correctly to host authentication.",
chost);
return 0;
}
/*
* We have authenticated the user using .rhosts or /etc/hosts.equiv,
* and the host using RSA. We accept the authentication.
*/
verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
pw->pw_name, cuser, chost);
packet_send_debug("Rhosts with RSA host authentication accepted.");
return 1;
}
#endif /* WITH_SSH1 */

23
auth-rhosts.c
Просмотреть файл

@ -1,4 +1,4 @@
/* $OpenBSD: auth-rhosts.c,v 1.47 2016/03/07 19:02:43 djm Exp $ */
/* $OpenBSD: auth-rhosts.c,v 1.48 2016/08/13 17:47:41 markus Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -186,20 +186,8 @@ check_rhosts_file(const char *filename, const char *hostname,
* true if authentication succeeds. If ignore_rhosts is true, only
* /etc/hosts.equiv will be considered (.rhosts and .shosts are ignored).
*/
int
auth_rhosts(struct passwd *pw, const char *client_user)
{
struct ssh *ssh = active_state; /* XXX */
const char *hostname, *ipaddr;
hostname = auth_get_canonical_hostname(ssh, options.use_dns);
ipaddr = ssh_remote_ipaddr(ssh);
return auth_rhosts2(pw, client_user, hostname, ipaddr);
}
static int
auth_rhosts2_raw(struct passwd *pw, const char *client_user, const char *hostname,
auth_rhosts2(struct passwd *pw, const char *client_user, const char *hostname,
const char *ipaddr)
{
char buf[1024];
@ -334,10 +322,3 @@ auth_rhosts2_raw(struct passwd *pw, const char *client_user, const char *hostnam
restore_uid();
return 0;
}
int
auth_rhosts2(struct passwd *pw, const char *client_user, const char *hostname,
const char *ipaddr)
{
return auth_rhosts2_raw(pw, client_user, hostname, ipaddr);
}

349
auth-rsa.c
Просмотреть файл

@ -1,349 +0,0 @@
/* $OpenBSD: auth-rsa.c,v 1.90 2015/01/28 22:36:00 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* RSA-based authentication. This code determines whether to admit a login
* based on RSA authentication. This file also contains functions to check
* validity of the host key.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
#include "includes.h"
#ifdef WITH_SSH1
#include <sys/types.h>
#include <sys/stat.h>
#include <openssl/rsa.h>
#include <pwd.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include "xmalloc.h"
#include "rsa.h"
#include "packet.h"
#include "ssh1.h"
#include "uidswap.h"
#include "match.h"
#include "buffer.h"
#include "pathnames.h"
#include "log.h"
#include "misc.h"
#include "servconf.h"
#include "key.h"
#include "auth-options.h"
#include "hostfile.h"
#include "auth.h"
#ifdef GSSAPI
#include "ssh-gss.h"
#endif
#include "monitor_wrap.h"
#include "ssh.h"
#include "digest.h"
/* import */
extern ServerOptions options;
/*
* Session identifier that is used to bind key exchange and authentication
* responses to a particular session.
*/
extern u_char session_id[16];
/*
* The .ssh/authorized_keys file contains public keys, one per line, in the
* following format:
* options bits e n comment
* where bits, e and n are decimal numbers,
* and comment is any string of characters up to newline. The maximum
* length of a line is SSH_MAX_PUBKEY_BYTES characters. See sshd(8) for a
* description of the options.
*/
BIGNUM *
auth_rsa_generate_challenge(Key *key)
{
BIGNUM *challenge;
BN_CTX *ctx;
if ((challenge = BN_new()) == NULL)
fatal("auth_rsa_generate_challenge: BN_new() failed");
/* Generate a random challenge. */
if (BN_rand(challenge, 256, 0, 0) == 0)
fatal("auth_rsa_generate_challenge: BN_rand failed");
if ((ctx = BN_CTX_new()) == NULL)
fatal("auth_rsa_generate_challenge: BN_CTX_new failed");
if (BN_mod(challenge, challenge, key->rsa->n, ctx) == 0)
fatal("auth_rsa_generate_challenge: BN_mod failed");
BN_CTX_free(ctx);
return challenge;
}
int
auth_rsa_verify_response(Key *key, BIGNUM *challenge, u_char response[16])
{
u_char buf[32], mdbuf[16];
struct ssh_digest_ctx *md;
int len;
/* don't allow short keys */
if (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
error("%s: RSA modulus too small: %d < minimum %d bits",
__func__,
BN_num_bits(key->rsa->n), SSH_RSA_MINIMUM_MODULUS_SIZE);
return (0);
}
/* The response is MD5 of decrypted challenge plus session id. */
len = BN_num_bytes(challenge);
if (len <= 0 || len > 32)
fatal("%s: bad challenge length %d", __func__, len);
memset(buf, 0, 32);
BN_bn2bin(challenge, buf + 32 - len);
if ((md = ssh_digest_start(SSH_DIGEST_MD5)) == NULL ||
ssh_digest_update(md, buf, 32) < 0 ||
ssh_digest_update(md, session_id, 16) < 0 ||
ssh_digest_final(md, mdbuf, sizeof(mdbuf)) < 0)
fatal("%s: md5 failed", __func__);
ssh_digest_free(md);
/* Verify that the response is the original challenge. */
if (timingsafe_bcmp(response, mdbuf, 16) != 0) {
/* Wrong answer. */
return (0);
}
/* Correct answer. */
return (1);
}
/*
* Performs the RSA authentication challenge-response dialog with the client,
* and returns true (non-zero) if the client gave the correct answer to
* our challenge; returns zero if the client gives a wrong answer.
*/
int
auth_rsa_challenge_dialog(Key *key)
{
BIGNUM *challenge, *encrypted_challenge;
u_char response[16];
int i, success;
if ((encrypted_challenge = BN_new()) == NULL)
fatal("auth_rsa_challenge_dialog: BN_new() failed");
challenge = PRIVSEP(auth_rsa_generate_challenge(key));
/* Encrypt the challenge with the public key. */
if (rsa_public_encrypt(encrypted_challenge, challenge, key->rsa) != 0)
fatal("%s: rsa_public_encrypt failed", __func__);
/* Send the encrypted challenge to the client. */
packet_start(SSH_SMSG_AUTH_RSA_CHALLENGE);
packet_put_bignum(encrypted_challenge);
packet_send();
BN_clear_free(encrypted_challenge);
packet_write_wait();
/* Wait for a response. */
packet_read_expect(SSH_CMSG_AUTH_RSA_RESPONSE);
for (i = 0; i < 16; i++)
response[i] = (u_char)packet_get_char();
packet_check_eom();
success = PRIVSEP(auth_rsa_verify_response(key, challenge, response));
BN_clear_free(challenge);
return (success);
}
static int
rsa_key_allowed_in_file(struct passwd *pw, char *file,
const BIGNUM *client_n, Key **rkey)
{
char *fp, line[SSH_MAX_PUBKEY_BYTES];
int allowed = 0, bits;
FILE *f;
u_long linenum = 0;
Key *key;
debug("trying public RSA key file %s", file);
if ((f = auth_openkeyfile(file, pw, options.strict_modes)) == NULL)
return 0;
/*
* Go though the accepted keys, looking for the current key. If
* found, perform a challenge-response dialog to verify that the
* user really has the corresponding private key.
*/
key = key_new(KEY_RSA1);
while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
char *cp;
char *key_options;
int keybits;
/* Skip leading whitespace, empty and comment lines. */
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
;
if (!*cp || *cp == '\n' || *cp == '#')
continue;
/*
* Check if there are options for this key, and if so,
* save their starting address and skip the option part
* for now. If there are no options, set the starting
* address to NULL.
*/
if (*cp < '0' || *cp > '9') {
int quoted = 0;
key_options = cp;
for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
if (*cp == '\\' && cp[1] == '"')
cp++; /* Skip both */
else if (*cp == '"')
quoted = !quoted;
}
} else
key_options = NULL;
/* Parse the key from the line. */
if (hostfile_read_key(&cp, &bits, key) == 0) {
debug("%.100s, line %lu: non ssh1 key syntax",
file, linenum);
continue;
}
/* cp now points to the comment part. */
/*
* Check if the we have found the desired key (identified
* by its modulus).
*/
if (BN_cmp(key->rsa->n, client_n) != 0)
continue;
/* check the real bits */
keybits = BN_num_bits(key->rsa->n);
if (keybits < 0 || bits != keybits)
logit("Warning: %s, line %lu: keysize mismatch: "
"actual %d vs. announced %d.",
file, linenum, BN_num_bits(key->rsa->n), bits);
if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
SSH_FP_DEFAULT)) == NULL)
continue;
debug("matching key found: file %s, line %lu %s %s",
file, linenum, key_type(key), fp);
free(fp);
/* Never accept a revoked key */
if (auth_key_is_revoked(key))
break;
/* We have found the desired key. */
/*
* If our options do not allow this key to be used,
* do not send challenge.
*/
if (!auth_parse_options(pw, key_options, file, linenum))
continue;
if (key_is_cert_authority)
continue;
/* break out, this key is allowed */
allowed = 1;
break;
}
/* Close the file. */
fclose(f);
/* return key if allowed */
if (allowed && rkey != NULL)
*rkey = key;
else
key_free(key);
return allowed;
}
/*
* check if there's user key matching client_n,
* return key if login is allowed, NULL otherwise
*/
int
auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
{
char *file;
u_int i, allowed = 0;
temporarily_use_uid(pw);
for (i = 0; !allowed && i < options.num_authkeys_files; i++) {
if (strcasecmp(options.authorized_keys_files[i], "none") == 0)
continue;
file = expand_authorized_keys(
options.authorized_keys_files[i], pw);
allowed = rsa_key_allowed_in_file(pw, file, client_n, rkey);
free(file);
}
restore_uid();
return allowed;
}
/*
* Performs the RSA authentication dialog with the client. This returns
* 0 if the client could not be authenticated, and 1 if authentication was
* successful. This may exit if there is a serious protocol violation.
*/
int
auth_rsa(Authctxt *authctxt, BIGNUM *client_n)
{
Key *key;
struct passwd *pw = authctxt->pw;
/* no user given */
if (!authctxt->valid)
return 0;
if (!PRIVSEP(auth_rsa_key_allowed(pw, client_n, &key))) {
auth_clear_options();
return (0);
}
/* Perform the challenge-response dialog for this key. */
if (!auth_rsa_challenge_dialog(key)) {
/* Wrong response. */
verbose("Wrong response to RSA authentication challenge.");
packet_send_debug("Wrong response to RSA authentication challenge.");
/*
* Break out of the loop. Otherwise we might send
* another challenge and break the protocol.
*/
key_free(key);
return (0);
}
/*
* Correct response. The client has been successfully
* authenticated. Note that we have not yet processed the
* options; this will be reset if the options cause the
* authentication to be rejected.
*/
pubkey_auth_info(authctxt, key, NULL);
packet_send_debug("RSA authentication accepted.");
return (1);
}
#endif /* WITH_SSH1 */

10
auth.c
Просмотреть файл

@ -1,4 +1,4 @@
/* $OpenBSD: auth.c,v 1.115 2016/06/15 00:40:40 dtucker Exp $ */
/* $OpenBSD: auth.c,v 1.116 2016/08/13 17:47:41 markus Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
@ -298,7 +298,7 @@ auth_log(Authctxt *authctxt, int authenticated, int partial,
else
authmsg = authenticated ? "Accepted" : "Failed";
authlog("%s %s%s%s for %s%.100s from %.200s port %d %s%s%s",
authlog("%s %s%s%s for %s%.100s from %.200s port %d ssh2%s%s",
authmsg,
method,
submethod != NULL ? "/" : "", submethod == NULL ? "" : submethod,
@ -306,7 +306,6 @@ auth_log(Authctxt *authctxt, int authenticated, int partial,
authctxt->user,
ssh_remote_ipaddr(ssh),
ssh_remote_port(ssh),
compat20 ? "ssh2" : "ssh1",
authctxt->info != NULL ? ": " : "",
authctxt->info != NULL ? authctxt->info : "");
free(authctxt->info);
@ -339,12 +338,11 @@ auth_maxtries_exceeded(Authctxt *authctxt)
struct ssh *ssh = active_state; /* XXX */
error("maximum authentication attempts exceeded for "
"%s%.100s from %.200s port %d %s",
"%s%.100s from %.200s port %d ssh2",
authctxt->valid ? "" : "invalid user ",
authctxt->user,
ssh_remote_ipaddr(ssh),
ssh_remote_port(ssh),
compat20 ? "ssh2" : "ssh1");
ssh_remote_port(ssh));
packet_disconnect("Too many authentication failures");
/* NOTREACHED */
}

17
auth.h
Просмотреть файл

@ -1,4 +1,4 @@
/* $OpenBSD: auth.h,v 1.88 2016/05/04 14:04:40 markus Exp $ */
/* $OpenBSD: auth.h,v 1.89 2016/08/13 17:47:41 markus Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
@ -112,20 +112,11 @@ struct KbdintDevice
void (*free_ctx)(void *ctx);
};
int auth_rhosts(struct passwd *, const char *);
int
auth_rhosts2(struct passwd *, const char *, const char *, const char *);
int auth_rhosts_rsa(Authctxt *, char *, Key *);
int auth_password(Authctxt *, const char *);
int auth_rsa(Authctxt *, BIGNUM *);
int auth_rsa_challenge_dialog(Key *);
BIGNUM *auth_rsa_generate_challenge(Key *);
int auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
int auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
int auth_rhosts_rsa_key_allowed(struct passwd *, const char *,
const char *, Key *);
int hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
int user_key_allowed(struct passwd *, Key *, int);
void pubkey_auth_info(Authctxt *, const Key *, const char *, ...)
@ -156,7 +147,6 @@ void remove_kbdint_device(const char *);
void disable_forwarding(void);
void do_authentication(Authctxt *);
void do_authentication2(Authctxt *);
void auth_info(Authctxt *authctxt, const char *, ...)
@ -187,10 +177,6 @@ int skey_respond(void *, u_int, char **);
int allowed_user(struct passwd *);
struct passwd * getpwnamallow(const char *user);
char *get_challenge(Authctxt *);
int verify_response(Authctxt *, const char *);
void abandon_challenge_response(Authctxt *);
char *expand_authorized_keys(const char *, struct passwd *pw);
char *authorized_principals_file(struct passwd *);
@ -210,7 +196,6 @@ Key *get_hostkey_public_by_index(int, struct ssh *);
Key *get_hostkey_public_by_type(int, int, struct ssh *);
Key *get_hostkey_private_by_type(int, int, struct ssh *);
int get_hostkey_index(Key *, int, struct ssh *);
int ssh1_session_key(BIGNUM *);
int sshd_hostkey_sign(Key *, Key *, u_char **, size_t *,
const u_char *, size_t, const char *, u_int);

444
auth1.c
Просмотреть файл

@ -1,444 +0,0 @@
/* $OpenBSD: auth1.c,v 1.82 2014/07/15 15:54:14 millert Exp $ */
/*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
#include "includes.h"
#ifdef WITH_SSH1
#include <sys/types.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <pwd.h>
#include "openbsd-compat/sys-queue.h"
#include "xmalloc.h"
#include "rsa.h"
#include "ssh1.h"
#include "packet.h"
#include "buffer.h"
#include "log.h"
#include "misc.h"
#include "servconf.h"
#include "compat.h"
#include "key.h"
#include "hostfile.h"
#include "auth.h"
#include "channels.h"
#include "session.h"
#include "uidswap.h"
#ifdef GSSAPI
#include "ssh-gss.h"
#endif
#include "monitor_wrap.h"
#include "buffer.h"
/* import */
extern ServerOptions options;
extern Buffer loginmsg;
static int auth1_process_password(Authctxt *);
static int auth1_process_rsa(Authctxt *);
static int auth1_process_rhosts_rsa(Authctxt *);
static int auth1_process_tis_challenge(Authctxt *);
static int auth1_process_tis_response(Authctxt *);
static char *client_user = NULL; /* Used to fill in remote user for PAM */
struct AuthMethod1 {
int type;
char *name;
int *enabled;
int (*method)(Authctxt *);
};
const struct AuthMethod1 auth1_methods[] = {
{
SSH_CMSG_AUTH_PASSWORD, "password",
&options.password_authentication, auth1_process_password
},
{
SSH_CMSG_AUTH_RSA, "rsa",
&options.rsa_authentication, auth1_process_rsa
},
{
SSH_CMSG_AUTH_RHOSTS_RSA, "rhosts-rsa",
&options.rhosts_rsa_authentication, auth1_process_rhosts_rsa
},
{
SSH_CMSG_AUTH_TIS, "challenge-response",
&options.challenge_response_authentication,
auth1_process_tis_challenge
},
{
SSH_CMSG_AUTH_TIS_RESPONSE, "challenge-response",
&options.challenge_response_authentication,
auth1_process_tis_response
},
{ -1, NULL, NULL, NULL}
};
static const struct AuthMethod1
*lookup_authmethod1(int type)
{
int i;
for (i = 0; auth1_methods[i].name != NULL; i++)
if (auth1_methods[i].type == type)
return (&(auth1_methods[i]));
return (NULL);
}
static char *
get_authname(int type)
{
const struct AuthMethod1 *a;
static char buf[64];
if ((a = lookup_authmethod1(type)) != NULL)
return (a->name);
snprintf(buf, sizeof(buf), "bad-auth-msg-%d", type);
return (buf);
}
/*ARGSUSED*/
static int
auth1_process_password(Authctxt *authctxt)
{
int authenticated = 0;
char *password;
u_int dlen;
/*
* Read user password. It is in plain text, but was
* transmitted over the encrypted channel so it is
* not visible to an outside observer.
*/
password = packet_get_string(&dlen);
packet_check_eom();
/* Try authentication with the password. */
authenticated = PRIVSEP(auth_password(authctxt, password));
explicit_bzero(password, dlen);
free(password);
return (authenticated);
}
/*ARGSUSED*/
static int
auth1_process_rsa(Authctxt *authctxt)
{
int authenticated = 0;
BIGNUM *n;
/* RSA authentication requested. */
if ((n = BN_new()) == NULL)
fatal("do_authloop: BN_new failed");
packet_get_bignum(n);
packet_check_eom();
authenticated = auth_rsa(authctxt, n);
BN_clear_free(n);
return (authenticated);
}
/*ARGSUSED*/
static int
auth1_process_rhosts_rsa(Authctxt *authctxt)
{
int keybits, authenticated = 0;
u_int bits;
Key *client_host_key;
u_int ulen;
/*
* Get client user name. Note that we just have to
* trust the client; root on the client machine can
* claim to be any user.
*/
client_user = packet_get_cstring(&ulen);
/* Get the client host key. */
client_host_key = key_new(KEY_RSA1);
bits = packet_get_int();
packet_get_bignum(client_host_key->rsa->e);
packet_get_bignum(client_host_key->rsa->n);
keybits = BN_num_bits(client_host_key->rsa->n);
if (keybits < 0 || bits != (u_int)keybits) {
verbose("Warning: keysize mismatch for client_host_key: "
"actual %d, announced %d",
BN_num_bits(client_host_key->rsa->n), bits);
}
packet_check_eom();
authenticated = auth_rhosts_rsa(authctxt, client_user,
client_host_key);
key_free(client_host_key);
auth_info(authctxt, "ruser %.100s", client_user);
return (authenticated);
}
/*ARGSUSED*/
static int
auth1_process_tis_challenge(Authctxt *authctxt)
{
char *challenge;
if ((challenge = get_challenge(authctxt)) == NULL)
return (0);
debug("sending challenge '%s'", challenge);
packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
packet_put_cstring(challenge);
free(challenge);
packet_send();
packet_write_wait();
return (-1);
}
/*ARGSUSED*/
static int
auth1_process_tis_response(Authctxt *authctxt)
{
int authenticated = 0;
char *response;
u_int dlen;
response = packet_get_string(&dlen);
packet_check_eom();
authenticated = verify_response(authctxt, response);
explicit_bzero(response, dlen);
free(response);
return (authenticated);
}
/*
* read packets, try to authenticate the user and
* return only if authentication is successful
*/
static void
do_authloop(Authctxt *authctxt)
{
int authenticated = 0;
int prev = 0, type = 0;
const struct AuthMethod1 *meth;
debug("Attempting authentication for %s%.100s.",
authctxt->valid ? "" : "invalid user ", authctxt->user);
/* If the user has no password, accept authentication immediately. */
if (options.permit_empty_passwd && options.password_authentication &&
#ifdef KRB5
(!options.kerberos_authentication || options.kerberos_or_local_passwd) &&
#endif
PRIVSEP(auth_password(authctxt, ""))) {
#ifdef USE_PAM
if (options.use_pam && (PRIVSEP(do_pam_account())))
#endif
{
auth_log(authctxt, 1, 0, "without authentication",
NULL);
return;
}
}
/* Indicate that authentication is needed. */
packet_start(SSH_SMSG_FAILURE);
packet_send();
packet_write_wait();
for (;;) {
/* default to fail */
authenticated = 0;
/* Get a packet from the client. */
prev = type;
type = packet_read();
/*
* If we started challenge-response authentication but the
* next packet is not a response to our challenge, release
* the resources allocated by get_challenge() (which would
* normally have been released by verify_response() had we
* received such a response)
*/
if (prev == SSH_CMSG_AUTH_TIS &&
type != SSH_CMSG_AUTH_TIS_RESPONSE)
abandon_challenge_response(authctxt);
if (authctxt->failures >= options.max_authtries)
goto skip;
if ((meth = lookup_authmethod1(type)) == NULL) {
logit("Unknown message during authentication: "
"type %d", type);
goto skip;
}
if (!*(meth->enabled)) {
verbose("%s authentication disabled.", meth->name);
goto skip;
}
authenticated = meth->method(authctxt);
if (authenticated == -1)
continue; /* "postponed" */
#ifdef BSD_AUTH
if (authctxt->as) {
auth_close(authctxt->as);
authctxt->as = NULL;
}
#endif
if (!authctxt->valid && authenticated)
fatal("INTERNAL ERROR: authenticated invalid user %s",
authctxt->user);
#ifdef _UNICOS
if (authenticated && cray_access_denied(authctxt->user)) {
authenticated = 0;
fatal("Access denied for user %s.",authctxt->user);
}
#endif /* _UNICOS */
#ifndef HAVE_CYGWIN
/* Special handling for root */
if (authenticated && authctxt->pw->pw_uid == 0 &&
!auth_root_allowed(meth->name)) {
authenticated = 0;
# ifdef SSH_AUDIT_EVENTS
PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED));
# endif
}
#endif
#ifdef USE_PAM
if (options.use_pam && authenticated &&
!PRIVSEP(do_pam_account())) {
char *msg;
size_t len;
error("Access denied for user %s by PAM account "
"configuration", authctxt->user);
len = buffer_len(&loginmsg);
buffer_append(&loginmsg, "\0", 1);
msg = buffer_ptr(&loginmsg);
/* strip trailing newlines */
if (len > 0)
while (len > 0 && msg[--len] == '\n')
msg[len] = '\0';
else
msg = "Access denied.";
packet_disconnect("%s", msg);
}
#endif
skip:
/* Log before sending the reply */
auth_log(authctxt, authenticated, 0, get_authname(type), NULL);
free(client_user);
client_user = NULL;
if (authenticated)
return;
if (++authctxt->failures >= options.max_authtries) {
#ifdef SSH_AUDIT_EVENTS
PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES));
#endif
auth_maxtries_exceeded(authctxt);
}
packet_start(SSH_SMSG_FAILURE);
packet_send();
packet_write_wait();
}
}
/*
* Performs authentication of an incoming connection. Session key has already
* been exchanged and encryption is enabled.
*/
void
do_authentication(Authctxt *authctxt)
{
u_int ulen;
char *user, *style = NULL;
/* Get the name of the user that we wish to log in as. */
packet_read_expect(SSH_CMSG_USER);
/* Get the user name. */
user = packet_get_cstring(&ulen);
packet_check_eom();
if ((style = strchr(user, ':')) != NULL)
*style++ = '\0';
authctxt->user = user;
authctxt->style = style;
/* Verify that the user is a valid user. */
if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL)
authctxt->valid = 1;
else {
debug("do_authentication: invalid user %s", user);
authctxt->pw = fakepw();
}
/* Configuration may have changed as a result of Match */
if (options.num_auth_methods != 0)
fatal("AuthenticationMethods is not supported with SSH "
"protocol 1");
setproctitle("%s%s", authctxt->valid ? user : "unknown",
use_privsep ? " [net]" : "");
#ifdef USE_PAM
if (options.use_pam)
PRIVSEP(start_pam(authctxt));
#endif
/*
* If we are not running as root, the user must have the same uid as
* the server.
*/
#ifndef HAVE_CYGWIN
if (!use_privsep && getuid() != 0 && authctxt->pw &&
authctxt->pw->pw_uid != getuid())
packet_disconnect("Cannot change user when server not running as root.");
#endif
/*
* Loop until the user has been authenticated or the connection is
* closed, do_authloop() returns only if authentication is successful
*/
do_authloop(authctxt);
/* The user has been authenticated and accepted. */
packet_start(SSH_SMSG_SUCCESS);
packet_send();
packet_write_wait();
}
#endif /* WITH_SSH1 */

277
monitor.c
Просмотреть файл

@ -1,4 +1,4 @@
/* $OpenBSD: monitor.c,v 1.161 2016/07/22 03:39:13 djm Exp $ */
/* $OpenBSD: monitor.c,v 1.162 2016/08/13 17:47:41 markus Exp $ */
/*
* Copyright 2002 Niels Provos <provos@citi.umich.edu>
* Copyright 2002 Markus Friedl <markus@openbsd.org>
@ -169,10 +169,6 @@ static int monitor_read_log(struct monitor *);
static Authctxt *authctxt;
#ifdef WITH_SSH1
static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */
#endif
/* local state for key verify */
static u_char *key_blob = NULL;
static u_int key_bloblen = 0;
@ -254,52 +250,6 @@ struct mon_table mon_dispatch_postauth20[] = {
{0, 0, NULL}
};
struct mon_table mon_dispatch_proto15[] = {
#ifdef WITH_SSH1
{MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
{MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
{MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
{MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
{MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed},
{MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed},
{MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
{MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
#ifdef BSD_AUTH
{MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
{MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
#endif
#ifdef SKEY
{MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
{MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
#endif
#ifdef USE_PAM
{MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
{MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
{MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
{MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
{MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
{MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
#endif
#ifdef SSH_AUDIT_EVENTS
{MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
#endif
#endif /* WITH_SSH1 */
{0, 0, NULL}
};
struct mon_table mon_dispatch_postauth15[] = {
#ifdef WITH_SSH1
{MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
{MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
{MONITOR_REQ_TERM, 0, mm_answer_term},
#ifdef SSH_AUDIT_EVENTS
{MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
{MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command},
#endif
#endif /* WITH_SSH1 */
{0, 0, NULL}
};
struct mon_table *mon_dispatch;
/* Specifies if a certain message is allowed at the moment */
@ -348,17 +298,10 @@ monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
authctxt->loginmsg = &loginmsg;
if (compat20) {
mon_dispatch = mon_dispatch_proto20;
/* Permit requests for moduli and signatures */
monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
} else {
mon_dispatch = mon_dispatch_proto15;
monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
}
/* The first few requests do not require asynchronous access */
while (!authenticated) {
@ -369,9 +312,6 @@ monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
/* Special handling for multiple required authentications */
if (options.num_auth_methods != 0) {
if (!compat20)
fatal("AuthenticationMethods is not supported"
"with SSH protocol 1");
if (authenticated &&
!auth2_update_methods_lists(authctxt,
auth_method, auth_submethod)) {
@ -455,17 +395,13 @@ monitor_child_postauth(struct monitor *pmonitor)
signal(SIGXFSZ, SIG_IGN);
#endif
if (compat20) {
mon_dispatch = mon_dispatch_postauth20;
/* Permit requests for moduli and signatures */
monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
} else {
mon_dispatch = mon_dispatch_postauth15;
monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
}
if (!no_pty_flag) {
monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
@ -845,7 +781,7 @@ mm_answer_pwnamallow(int sock, Buffer *m)
#undef M_CP_STRARRAYOPT
/* Create valid auth method lists */
if (compat20 && auth2_setup_methods_lists(authctxt) != 0) {
if (auth2_setup_methods_lists(authctxt) != 0) {
/*
* The monitor will continue long enough to let the child
* run to it's packet_disconnect(), but it must not allow any
@ -857,14 +793,10 @@ mm_answer_pwnamallow(int sock, Buffer *m)
debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed);
mm_request_send(sock, MONITOR_ANS_PWNAM, m);
/* For SSHv1 allow authentication now */
if (!compat20)
monitor_permit_authentications(1);
else {
/* Allow service/style information on the auth context */
monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
}
#ifdef USE_PAM
if (options.use_pam)
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
@ -991,11 +923,8 @@ mm_answer_bsdauthrespond(int sock, Buffer *m)
debug3("%s: sending authenticated: %d", __func__, authok);
mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
if (compat20) {
auth_method = "keyboard-interactive";
auth_submethod = "bsdauth";
} else
auth_method = "bsdauth";
return (authok != 0);
}
@ -1205,10 +1134,6 @@ mm_answer_keyallowed(int sock, Buffer *m)
key = key_from_blob(blob, bloblen);
if ((compat20 && type == MM_RSAHOSTKEY) ||
(!compat20 && type != MM_RSAHOSTKEY))
fatal("%s: key type and protocol mismatch", __func__);
debug3("%s: key_from_blob: %p", __func__, key);
if (key != NULL && authctxt->valid) {
@ -1242,17 +1167,6 @@ mm_answer_keyallowed(int sock, Buffer *m)
cuser, chost);
auth_method = "hostbased";
break;
#ifdef WITH_SSH1
case MM_RSAHOSTKEY:
key->type = KEY_RSA1; /* XXX */
allowed = options.rhosts_rsa_authentication &&
auth_rhosts_rsa_key_allowed(authctxt->pw,
cuser, chost, key);
if (options.rhosts_rsa_authentication && allowed != 1)
auth_clear_options();
auth_method = "rsa";
break;
#endif
default:
fatal("%s: unknown key type %d", __func__, type);
break;
@ -1289,9 +1203,6 @@ mm_answer_keyallowed(int sock, Buffer *m)
mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
if (type == MM_RSAHOSTKEY)
monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
return (0);
}
@ -1600,186 +1511,6 @@ mm_answer_pty_cleanup(int sock, Buffer *m)
return (0);
}
#ifdef WITH_SSH1
int
mm_answer_sesskey(int sock, Buffer *m)
{
BIGNUM *p;
int rsafail;
/* Turn off permissions */
monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0);
if ((p = BN_new()) == NULL)
fatal("%s: BN_new", __func__);
buffer_get_bignum2(m, p);
rsafail = ssh1_session_key(p);
buffer_clear(m);
buffer_put_int(m, rsafail);
buffer_put_bignum2(m, p);
BN_clear_free(p);
mm_request_send(sock, MONITOR_ANS_SESSKEY, m);
/* Turn on permissions for sessid passing */
monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
return (0);
}
int
mm_answer_sessid(int sock, Buffer *m)
{
int i;
debug3("%s entering", __func__);
if (buffer_len(m) != 16)
fatal("%s: bad ssh1 session id", __func__);
for (i = 0; i < 16; i++)
session_id[i] = buffer_get_char(m);
/* Turn on permissions for getpwnam */
monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
return (0);
}
int
mm_answer_rsa_keyallowed(int sock, Buffer *m)
{
BIGNUM *client_n;
Key *key = NULL;
u_char *blob = NULL;
u_int blen = 0;
int allowed = 0;
debug3("%s entering", __func__);
auth_method = "rsa";
if (options.rsa_authentication && authctxt->valid) {
if ((client_n = BN_new()) == NULL)
fatal("%s: BN_new", __func__);
buffer_get_bignum2(m, client_n);
allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
BN_clear_free(client_n);
}
buffer_clear(m);
buffer_put_int(m, allowed);
buffer_put_int(m, forced_command != NULL);
/* clear temporarily storage (used by generate challenge) */
monitor_reset_key_state();
if (allowed && key != NULL) {
key->type = KEY_RSA; /* cheat for key_to_blob */
if (key_to_blob(key, &blob, &blen) == 0)
fatal("%s: key_to_blob failed", __func__);
buffer_put_string(m, blob, blen);
/* Save temporarily for comparison in verify */
key_blob = blob;
key_bloblen = blen;
key_blobtype = MM_RSAUSERKEY;
}
if (key != NULL)
key_free(key);
mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
return (0);
}
int
mm_answer_rsa_challenge(int sock, Buffer *m)
{
Key *key = NULL;
u_char *blob;
u_int blen;
debug3("%s entering", __func__);
if (!authctxt->valid)
fatal("%s: authctxt not valid", __func__);
blob = buffer_get_string(m, &blen);
if (!monitor_allowed_key(blob, blen))
fatal("%s: bad key, not previously allowed", __func__);
if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
fatal("%s: key type mismatch", __func__);
if ((key = key_from_blob(blob, blen)) == NULL)
fatal("%s: received bad key", __func__);
if (key->type != KEY_RSA)
fatal("%s: received bad key type %d", __func__, key->type);
key->type = KEY_RSA1;
if (ssh1_challenge)
BN_clear_free(ssh1_challenge);
ssh1_challenge = auth_rsa_generate_challenge(key);
buffer_clear(m);
buffer_put_bignum2(m, ssh1_challenge);
debug3("%s sending reply", __func__);
mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
free(blob);
key_free(key);
return (0);
}
int
mm_answer_rsa_response(int sock, Buffer *m)
{
Key *key = NULL;
u_char *blob, *response;
u_int blen, len;
int success;
debug3("%s entering", __func__);
if (!authctxt->valid)
fatal("%s: authctxt not valid", __func__);
if (ssh1_challenge == NULL)
fatal("%s: no ssh1_challenge", __func__);
blob = buffer_get_string(m, &blen);
if (!monitor_allowed_key(blob, blen))
fatal("%s: bad key, not previously allowed", __func__);
if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
fatal("%s: key type mismatch: %d", __func__, key_blobtype);
if ((key = key_from_blob(blob, blen)) == NULL)
fatal("%s: received bad key", __func__);
response = buffer_get_string(m, &len);
if (len != 16)
fatal("%s: received bad response to challenge", __func__);
success = auth_rsa_verify_response(key, ssh1_challenge, response);
free(blob);
key_free(key);
free(response);
auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
/* reset state */
BN_clear_free(ssh1_challenge);
ssh1_challenge = NULL;
monitor_reset_key_state();
buffer_clear(m);
buffer_put_int(m, success);
mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
return (success);
}
#endif
int
mm_answer_term(int sock, Buffer *req)
{

151
monitor_wrap.c
Просмотреть файл

@ -1,4 +1,4 @@
/* $OpenBSD: monitor_wrap.c,v 1.88 2016/03/07 19:02:43 djm Exp $ */
/* $OpenBSD: monitor_wrap.c,v 1.89 2016/08/13 17:47:41 markus Exp $ */
/*
* Copyright 2002 Niels Provos <provos@citi.umich.edu>
* Copyright 2002 Markus Friedl <markus@openbsd.org>
@ -85,7 +85,6 @@
#include "ssherr.h"
/* Imports */
extern int compat20;
extern z_stream incoming_stream;
extern z_stream outgoing_stream;
extern struct monitor *pmonitor;
@ -388,18 +387,6 @@ mm_hostbased_key_allowed(struct passwd *pw, const char *user, const char *host,
return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0));
}
int
mm_auth_rhosts_rsa_key_allowed(struct passwd *pw, const char *user,
const char *host, Key *key)
{
int ret;
key->type = KEY_RSA; /* XXX hack for key_to_blob */
ret = mm_key_allowed(MM_RSAHOSTKEY, user, host, key, 0);
key->type = KEY_RSA1;
return (ret);
}
int
mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
Key *key, int pubkey_auth_attempt)
@ -710,28 +697,6 @@ mm_terminate(void)
buffer_free(&m);
}
#ifdef WITH_SSH1
int
mm_ssh1_session_key(BIGNUM *num)
{
int rsafail;
Buffer m;
buffer_init(&m);
buffer_put_bignum2(&m, num);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SESSKEY, &m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SESSKEY, &m);
rsafail = buffer_get_int(&m);
buffer_get_bignum2(&m, num);
buffer_free(&m);
return (rsafail);
}
#endif
static void
mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
char ***prompts, u_int **echo_on)
@ -862,120 +827,6 @@ mm_skey_respond(void *ctx, u_int numresponses, char **responses)
}
#endif /* SKEY */
void
mm_ssh1_session_id(u_char session_id[16])
{
Buffer m;
int i;
debug3("%s entering", __func__);
buffer_init(&m);
for (i = 0; i < 16; i++)
buffer_put_char(&m, session_id[i]);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SESSID, &m);
buffer_free(&m);
}
#ifdef WITH_SSH1
int
mm_auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
{
Buffer m;
Key *key;
u_char *blob;
u_int blen;
int allowed = 0, have_forced = 0;
debug3("%s entering", __func__);
buffer_init(&m);
buffer_put_bignum2(&m, client_n);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSAKEYALLOWED, &m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSAKEYALLOWED, &m);
allowed = buffer_get_int(&m);
/* fake forced command */
auth_clear_options();
have_forced = buffer_get_int(&m);
forced_command = have_forced ? xstrdup("true") : NULL;
if (allowed && rkey != NULL) {
blob = buffer_get_string(&m, &blen);
if ((key = key_from_blob(blob, blen)) == NULL)
fatal("%s: key_from_blob failed", __func__);
*rkey = key;
free(blob);
}
buffer_free(&m);
return (allowed);
}
BIGNUM *
mm_auth_rsa_generate_challenge(Key *key)
{
Buffer m;
BIGNUM *challenge;
u_char *blob;
u_int blen;
debug3("%s entering", __func__);
if ((challenge = BN_new()) == NULL)
fatal("%s: BN_new failed", __func__);
key->type = KEY_RSA; /* XXX cheat for key_to_blob */
if (key_to_blob(key, &blob, &blen) == 0)
fatal("%s: key_to_blob failed", __func__);
key->type = KEY_RSA1;
buffer_init(&m);
buffer_put_string(&m, blob, blen);
free(blob);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSACHALLENGE, &m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSACHALLENGE, &m);
buffer_get_bignum2(&m, challenge);
buffer_free(&m);
return (challenge);
}
int
mm_auth_rsa_verify_response(Key *key, BIGNUM *p, u_char response[16])
{
Buffer m;
u_char *blob;
u_int blen;
int success = 0;
debug3("%s entering", __func__);
key->type = KEY_RSA; /* XXX cheat for key_to_blob */
if (key_to_blob(key, &blob, &blen) == 0)
fatal("%s: key_to_blob failed", __func__);
key->type = KEY_RSA1;
buffer_init(&m);
buffer_put_string(&m, blob, blen);
buffer_put_string(&m, response, 16);
free(blob);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSARESPONSE, &m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSARESPONSE, &m);
success = buffer_get_int(&m);
buffer_free(&m);
return (success);
}
#endif
#ifdef SSH_AUDIT_EVENTS
void
mm_audit_event(ssh_audit_event_t event)

13
monitor_wrap.h
Просмотреть файл

@ -1,4 +1,4 @@
/* $OpenBSD: monitor_wrap.h,v 1.30 2016/03/07 19:02:43 djm Exp $ */
/* $OpenBSD: monitor_wrap.h,v 1.31 2016/08/13 17:47:41 markus Exp $ */
/*
* Copyright 2002 Niels Provos <provos@citi.umich.edu>
@ -31,7 +31,7 @@
extern int use_privsep;
#define PRIVSEP(x) (use_privsep ? mm_##x : x)
enum mm_keytype {MM_NOKEY, MM_HOSTKEY, MM_USERKEY, MM_RSAHOSTKEY, MM_RSAUSERKEY};
enum mm_keytype { MM_NOKEY, MM_HOSTKEY, MM_USERKEY };
struct monitor;
struct mm_master;
@ -49,12 +49,7 @@ int mm_key_allowed(enum mm_keytype, const char *, const char *, Key *, int);
int mm_user_key_allowed(struct passwd *, Key *, int);
int mm_hostbased_key_allowed(struct passwd *, const char *,
const char *, Key *);
int mm_auth_rhosts_rsa_key_allowed(struct passwd *, const char *,
const char *, Key *);
int mm_key_verify(Key *, u_char *, u_int, u_char *, u_int);
int mm_auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
int mm_auth_rsa_verify_response(Key *, BIGNUM *, u_char *);
BIGNUM *mm_auth_rsa_generate_challenge(Key *);
#ifdef GSSAPI
OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
@ -84,10 +79,6 @@ void mm_terminate(void);
int mm_pty_allocate(int *, int *, char *, size_t);
void mm_session_pty_cleanup2(struct Session *);
/* SSHv1 interfaces */
void mm_ssh1_session_id(u_char *);
int mm_ssh1_session_key(BIGNUM *);
/* Key export functions */
struct newkeys *mm_newkeys_from_blob(u_char *, int);
int mm_newkeys_to_blob(int, u_char **, u_int *);

588
serverloop.c
Просмотреть файл

@ -1,4 +1,4 @@
/* $OpenBSD: serverloop.c,v 1.184 2016/03/07 19:02:43 djm Exp $ */
/* $OpenBSD: serverloop.c,v 1.185 2016/08/13 17:47:41 markus Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -67,7 +67,6 @@
#include "sshpty.h"
#include "channels.h"
#include "compat.h"
#include "ssh1.h"
#include "ssh2.h"
#include "key.h"
#include "cipher.h"
@ -86,25 +85,6 @@ extern ServerOptions options;
extern Authctxt *the_authctxt;
extern int use_privsep;
static Buffer stdin_buffer; /* Buffer for stdin data. */
static Buffer stdout_buffer; /* Buffer for stdout data. */
static Buffer stderr_buffer; /* Buffer for stderr data. */
static int fdin; /* Descriptor for stdin (for writing) */
static int fdout; /* Descriptor for stdout (for reading);
May be same number as fdin. */
static int fderr; /* Descriptor for stderr. May be -1. */
static long stdin_bytes = 0; /* Number of bytes written to stdin. */
static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */
static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */
static long fdout_bytes = 0; /* Number of stdout bytes read from program. */
static int stdin_eof = 0; /* EOF message received from client. */
static int fdout_eof = 0; /* EOF encountered reading from fdout. */
static int fderr_eof = 0; /* EOF encountered readung from fderr. */
static int fdin_is_tty = 0; /* fdin points to a tty. */
static int connection_in; /* Connection to client (input). */
static int connection_out; /* Connection to client (output). */
static int connection_closed = 0; /* Connection to client closed. */
static u_int buffer_high; /* "Soft" max buffer size. */
static int no_more_sessions = 0; /* Disallow further sessions. */
/*
@ -185,64 +165,6 @@ sigterm_handler(int sig)
received_sigterm = sig;
}
/*
* Make packets from buffered stderr data, and buffer it for sending
* to the client.
*/
static void
make_packets_from_stderr_data(void)
{
u_int len;
/* Send buffered stderr data to the client. */
while (buffer_len(&stderr_buffer) > 0 &&
packet_not_very_much_data_to_write()) {
len = buffer_len(&stderr_buffer);
if (packet_is_interactive()) {
if (len > 512)
len = 512;
} else {
/* Keep the packets at reasonable size. */
if (len > packet_get_maxsize())
len = packet_get_maxsize();
}
packet_start(SSH_SMSG_STDERR_DATA);
packet_put_string(buffer_ptr(&stderr_buffer), len);
packet_send();
buffer_consume(&stderr_buffer, len);
stderr_bytes += len;
}
}
/*
* Make packets from buffered stdout data, and buffer it for sending to the
* client.
*/
static void
make_packets_from_stdout_data(void)
{
u_int len;
/* Send buffered stdout data to the client. */
while (buffer_len(&stdout_buffer) > 0 &&
packet_not_very_much_data_to_write()) {
len = buffer_len(&stdout_buffer);
if (packet_is_interactive()) {
if (len > 512)
len = 512;
} else {
/* Keep the packets at reasonable size. */
if (len > packet_get_maxsize())
len = packet_get_maxsize();
}
packet_start(SSH_SMSG_STDOUT_DATA);
packet_put_string(buffer_ptr(&stdout_buffer), len);
packet_send();
buffer_consume(&stdout_buffer, len);
stdout_bytes += len;
}
}
static void
client_alive_check(void)
{
@ -275,14 +197,14 @@ client_alive_check(void)
* for the duration of the wait (0 = infinite).
*/
static void
wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
wait_until_can_do_something(int connection_in, int connection_out,
fd_set **readsetp, fd_set **writesetp, int *maxfdp,
u_int *nallocp, u_int64_t max_time_ms)
{
struct timeval tv, *tvp;
int ret;
time_t minwait_secs = 0;
int client_alive_scheduled = 0;
int program_alive_scheduled = 0;
/* Allocate and update select() masks for channel descriptors. */
channel_prepare_select(readsetp, writesetp, maxfdp, nallocp,
@ -300,7 +222,7 @@ wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
* this could be randomized somewhat to make traffic
* analysis more difficult, but we're not doing it yet.
*/
if (compat20 && options.client_alive_interval) {
if (options.client_alive_interval) {
uint64_t keepalive_ms =
(uint64_t)options.client_alive_interval * 1000;
@ -309,38 +231,11 @@ wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
max_time_ms = keepalive_ms;
}
if (compat20) {
#if 0
/* wrong: bad condition XXX */
if (channel_not_very_much_buffered_data())
#endif
FD_SET(connection_in, *readsetp);
} else {
/*
* Read packets from the client unless we have too much
* buffered stdin or channel data.
*/
if (buffer_len(&stdin_buffer) < buffer_high &&
channel_not_very_much_buffered_data())
FD_SET(connection_in, *readsetp);
/*
* If there is not too much data already buffered going to
* the client, try to get some more data from the program.
*/
if (packet_not_very_much_data_to_write()) {
program_alive_scheduled = child_terminated;
if (!fdout_eof)
FD_SET(fdout, *readsetp);
if (!fderr_eof)
FD_SET(fderr, *readsetp);
}
/*
* If we have buffered data, try to write some of that data
* to the program.
*/
if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
FD_SET(fdin, *writesetp);
}
notify_prepare(*readsetp);
/*
@ -374,16 +269,8 @@ wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
memset(*writesetp, 0, *nallocp);
if (errno != EINTR)
error("select: %.100s", strerror(errno));
} else {
if (ret == 0 && client_alive_scheduled)
} else if (ret == 0 && client_alive_scheduled)
client_alive_check();
if (!compat20 && program_alive_scheduled && fdin_is_tty) {
if (!fdout_eof)
FD_SET(fdout, *readsetp);
if (!fderr_eof)
FD_SET(fderr, *readsetp);
}
}
notify_done(*readsetp);
}
@ -392,8 +279,8 @@ wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
* Processes input from the client and the program. Input data is stored
* in buffers and processed later.
*/
static void
process_input(fd_set *readset)
static int
process_input(fd_set *readset, int connection_in)
{
struct ssh *ssh = active_state; /* XXX */
int len;
@ -405,10 +292,7 @@ process_input(fd_set *readset)
if (len == 0) {
verbose("Connection closed by %.100s port %d",
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
connection_closed = 1;
if (compat20)
return;
cleanup_exit(255);
return -1;
} else if (len < 0) {
if (errno != EINTR && errno != EAGAIN &&
errno != EWOULDBLOCK) {
@ -423,381 +307,26 @@ process_input(fd_set *readset)
packet_process_incoming(buf, len);
}
}
if (compat20)
return;
/* Read and buffer any available stdout data from the program. */
if (!fdout_eof && FD_ISSET(fdout, readset)) {
errno = 0;
len = read(fdout, buf, sizeof(buf));
if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
errno == EWOULDBLOCK) && !child_terminated))) {
/* do nothing */
#ifndef PTY_ZEROREAD
} else if (len <= 0) {
#else
} else if ((!isatty(fdout) && len <= 0) ||
(isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) {
#endif
fdout_eof = 1;
} else {
buffer_append(&stdout_buffer, buf, len);
fdout_bytes += len;
}
}
/* Read and buffer any available stderr data from the program. */
if (!fderr_eof && FD_ISSET(fderr, readset)) {
errno = 0;
len = read(fderr, buf, sizeof(buf));
if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
errno == EWOULDBLOCK) && !child_terminated))) {
/* do nothing */
#ifndef PTY_ZEROREAD
} else if (len <= 0) {
#else
} else if ((!isatty(fderr) && len <= 0) ||
(isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) {
#endif
fderr_eof = 1;
} else {
buffer_append(&stderr_buffer, buf, len);
}
}
return 0;
}
/*
* Sends data from internal buffers to client program stdin.
*/
static void
process_output(fd_set *writeset)
process_output(fd_set *writeset, int connection_out)
{
struct termios tio;
u_char *data;
u_int dlen;
int len;
/* Write buffered data to program stdin. */
if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
data = buffer_ptr(&stdin_buffer);
dlen = buffer_len(&stdin_buffer);
len = write(fdin, data, dlen);
if (len < 0 &&
(errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)) {
/* do nothing */
} else if (len <= 0) {
if (fdin != fdout)
close(fdin);
else
shutdown(fdin, SHUT_WR); /* We will no longer send. */
fdin = -1;
} else {
/* Successful write. */
if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
tcgetattr(fdin, &tio) == 0 &&
!(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
/*
* Simulate echo to reduce the impact of
* traffic analysis
*/
packet_send_ignore(len);
packet_send();
}
/* Consume the data from the buffer. */
buffer_consume(&stdin_buffer, len);
/* Update the count of bytes written to the program. */
stdin_bytes += len;
}
}
/* Send any buffered packet data to the client. */
if (FD_ISSET(connection_out, writeset))
packet_write_poll();
}
/*
* Wait until all buffered output has been sent to the client.
* This is used when the program terminates.
*/
static void
drain_output(void)
{
/* Send any buffered stdout data to the client. */
if (buffer_len(&stdout_buffer) > 0) {
packet_start(SSH_SMSG_STDOUT_DATA);
packet_put_string(buffer_ptr(&stdout_buffer),
buffer_len(&stdout_buffer));
packet_send();
/* Update the count of sent bytes. */
stdout_bytes += buffer_len(&stdout_buffer);
}
/* Send any buffered stderr data to the client. */
if (buffer_len(&stderr_buffer) > 0) {
packet_start(SSH_SMSG_STDERR_DATA);
packet_put_string(buffer_ptr(&stderr_buffer),
buffer_len(&stderr_buffer));
packet_send();
/* Update the count of sent bytes. */
stderr_bytes += buffer_len(&stderr_buffer);
}
/* Wait until all buffered data has been written to the client. */
packet_write_wait();
}
static void
process_buffered_input_packets(void)
{
dispatch_run(DISPATCH_NONBLOCK, NULL, active_state);
}
/*
* Performs the interactive session. This handles data transmission between
* the client and the program. Note that the notion of stdin, stdout, and
* stderr in this function is sort of reversed: this function writes to
* stdin (of the child program), and reads from stdout and stderr (of the
* child program).
*/
void
server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
{
fd_set *readset = NULL, *writeset = NULL;
int max_fd = 0;
u_int nalloc = 0;
int wait_status; /* Status returned by wait(). */
pid_t wait_pid; /* pid returned by wait(). */
int waiting_termination = 0; /* Have displayed waiting close message. */
u_int64_t max_time_milliseconds;
u_int previous_stdout_buffer_bytes;
u_int stdout_buffer_bytes;
int type;
debug("Entering interactive session.");
/* Initialize the SIGCHLD kludge. */
child_terminated = 0;
mysignal(SIGCHLD, sigchld_handler);
if (!use_privsep) {
signal(SIGTERM, sigterm_handler);
signal(SIGINT, sigterm_handler);
signal(SIGQUIT, sigterm_handler);
}
/* Initialize our global variables. */
fdin = fdin_arg;
fdout = fdout_arg;
fderr = fderr_arg;
/* nonblocking IO */
set_nonblock(fdin);
set_nonblock(fdout);
/* we don't have stderr for interactive terminal sessions, see below */
if (fderr != -1)
set_nonblock(fderr);
if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
fdin_is_tty = 1;
connection_in = packet_get_connection_in();
connection_out = packet_get_connection_out();
notify_setup();
previous_stdout_buffer_bytes = 0;
/* Set approximate I/O buffer size. */
if (packet_is_interactive())
buffer_high = 4096;
else
buffer_high = 64 * 1024;
#if 0
/* Initialize max_fd to the maximum of the known file descriptors. */
max_fd = MAX(connection_in, connection_out);
max_fd = MAX(max_fd, fdin);
max_fd = MAX(max_fd, fdout);
if (fderr != -1)
max_fd = MAX(max_fd, fderr);
#endif
/* Initialize Initialize buffers. */
buffer_init(&stdin_buffer);
buffer_init(&stdout_buffer);
buffer_init(&stderr_buffer);
/*
* If we have no separate fderr (which is the case when we have a pty
* - there we cannot make difference between data sent to stdout and
* stderr), indicate that we have seen an EOF from stderr. This way
* we don't need to check the descriptor everywhere.
*/
if (fderr == -1)
fderr_eof = 1;
server_init_dispatch();
/* Main loop of the server for the interactive session mode. */
for (;;) {
/* Process buffered packets from the client. */
process_buffered_input_packets();
/*
* If we have received eof, and there is no more pending
* input data, cause a real eof by closing fdin.
*/
if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
if (fdin != fdout)
close(fdin);
else
shutdown(fdin, SHUT_WR); /* We will no longer send. */
fdin = -1;
}
/* Make packets from buffered stderr data to send to the client. */
make_packets_from_stderr_data();
/*
* Make packets from buffered stdout data to send to the
* client. If there is very little to send, this arranges to
* not send them now, but to wait a short while to see if we
* are getting more data. This is necessary, as some systems
* wake up readers from a pty after each separate character.
*/
max_time_milliseconds = 0;
stdout_buffer_bytes = buffer_len(&stdout_buffer);
if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
stdout_buffer_bytes != previous_stdout_buffer_bytes) {
/* try again after a while */
max_time_milliseconds = 10;
} else {
/* Send it now. */
make_packets_from_stdout_data();
}
previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
/* Send channel data to the client. */
if (packet_not_very_much_data_to_write())
channel_output_poll();
/*
* Bail out of the loop if the program has closed its output
* descriptors, and we have no more data to send to the
* client, and there is no pending buffered data.
*/
if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
if (!channel_still_open())
break;
if (!waiting_termination) {
const char *s = "Waiting for forwarded connections to terminate...\r\n";
char *cp;
waiting_termination = 1;
buffer_append(&stderr_buffer, s, strlen(s));
/* Display list of open channels. */
cp = channel_open_message();
buffer_append(&stderr_buffer, cp, strlen(cp));
free(cp);
}
}
max_fd = MAX(connection_in, connection_out);
max_fd = MAX(max_fd, fdin);
max_fd = MAX(max_fd, fdout);
max_fd = MAX(max_fd, fderr);
max_fd = MAX(max_fd, notify_pipe[0]);
/* Sleep in select() until we can do something. */
wait_until_can_do_something(&readset, &writeset, &max_fd,
&nalloc, max_time_milliseconds);
if (received_sigterm) {
logit("Exiting on signal %d", (int)received_sigterm);
/* Clean up sessions, utmp, etc. */
cleanup_exit(255);
}
/* Process any channel events. */
channel_after_select(readset, writeset);
/* Process input from the client and from program stdout/stderr. */
process_input(readset);
/* Process output to the client and to program stdin. */
process_output(writeset);
}
free(readset);
free(writeset);
/* Cleanup and termination code. */
/* Wait until all output has been sent to the client. */
drain_output();
debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
/* Free and clear the buffers. */
buffer_free(&stdin_buffer);
buffer_free(&stdout_buffer);
buffer_free(&stderr_buffer);
/* Close the file descriptors. */
if (fdout != -1)
close(fdout);
fdout = -1;
fdout_eof = 1;
if (fderr != -1)
close(fderr);
fderr = -1;
fderr_eof = 1;
if (fdin != -1)
close(fdin);
fdin = -1;
channel_free_all();
/* We no longer want our SIGCHLD handler to be called. */
mysignal(SIGCHLD, SIG_DFL);
while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
if (errno != EINTR)
packet_disconnect("wait: %.100s", strerror(errno));
if (wait_pid != pid)
error("Strange, wait returned pid %ld, expected %ld",
(long)wait_pid, (long)pid);
/* Check if it exited normally. */
if (WIFEXITED(wait_status)) {
/* Yes, normal exit. Get exit status and send it to the client. */
debug("Command exited with status %d.", WEXITSTATUS(wait_status));
packet_start(SSH_SMSG_EXITSTATUS);
packet_put_int(WEXITSTATUS(wait_status));
packet_send();
packet_write_wait();
/*
* Wait for exit confirmation. Note that there might be
* other packets coming before it; however, the program has
* already died so we just ignore them. The client is
* supposed to respond with the confirmation when it receives
* the exit status.
*/
do {
type = packet_read();
}
while (type != SSH_CMSG_EXIT_CONFIRMATION);
debug("Received exit confirmation.");
return;
}
/* Check if the program terminated due to a signal. */
if (WIFSIGNALED(wait_status))
packet_disconnect("Command terminated on signal %d.",
WTERMSIG(wait_status));
/* Some weird exit cause. Just exit. */
packet_disconnect("wait returned status %04x.", wait_status);
/* NOTREACHED */
}
static void
collect_children(void)
{
@ -825,7 +354,7 @@ server_loop2(Authctxt *authctxt)
{
fd_set *readset = NULL, *writeset = NULL;
int max_fd;
u_int nalloc = 0;
u_int nalloc = 0, connection_in, connection_out;
u_int64_t rekey_timeout_ms = 0;
debug("Entering interactive session for SSH2.");
@ -854,14 +383,14 @@ server_loop2(Authctxt *authctxt)
if (!ssh_packet_is_rekeying(active_state) &&
packet_not_very_much_data_to_write())
channel_output_poll();
if (options.rekey_interval > 0 && compat20 &&
if (options.rekey_interval > 0 &&
!ssh_packet_is_rekeying(active_state))
rekey_timeout_ms = packet_get_rekey_timeout() * 1000;
else
rekey_timeout_ms = 0;
wait_until_can_do_something(&readset, &writeset, &max_fd,
&nalloc, rekey_timeout_ms);
wait_until_can_do_something(connection_in, connection_out,
&readset, &writeset, &max_fd, &nalloc, rekey_timeout_ms);
if (received_sigterm) {
logit("Exiting on signal %d", (int)received_sigterm);
@ -872,10 +401,9 @@ server_loop2(Authctxt *authctxt)
collect_children();
if (!ssh_packet_is_rekeying(active_state))
channel_after_select(readset, writeset);
process_input(readset);
if (connection_closed)
if (process_input(readset, connection_in) < 0)
break;
process_output(writeset);
process_output(writeset, connection_out);
}
collect_children();
@ -902,53 +430,6 @@ server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
return 0;
}
static int
server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
{
char *data;
u_int data_len;
/* Stdin data from the client. Append it to the buffer. */
/* Ignore any data if the client has closed stdin. */
if (fdin == -1)
return 0;
data = packet_get_string(&data_len);
packet_check_eom();
buffer_append(&stdin_buffer, data, data_len);
explicit_bzero(data, data_len);
free(data);
return 0;
}
static int
server_input_eof(int type, u_int32_t seq, void *ctxt)
{
/*
* Eof from the client. The stdin descriptor to the
* program will be closed when all buffered data has
* drained.
*/
debug("EOF received for stdin.");
packet_check_eom();
stdin_eof = 1;
return 0;
}
static int
server_input_window_size(int type, u_int32_t seq, void *ctxt)
{
u_int row = packet_get_int();
u_int col = packet_get_int();
u_int xpixel = packet_get_int();
u_int ypixel = packet_get_int();
debug("Window change received.");
packet_check_eom();
if (fdin != -1)
pty_change_window_size(fdin, row, col, xpixel, ypixel);
return 0;
}
static Channel *
server_request_direct_tcpip(void)
{
@ -1353,9 +834,9 @@ server_input_channel_req(int type, u_int32_t seq, void *ctxt)
}
static void
server_init_dispatch_20(void)
server_init_dispatch(void)
{
debug("server_init_dispatch_20");
debug("server_init_dispatch");
dispatch_init(&dispatch_protocol_error);
dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
@ -1375,36 +856,3 @@ server_init_dispatch_20(void)
/* rekeying */
dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
}
static void
server_init_dispatch_13(void)
{
debug("server_init_dispatch_13");
dispatch_init(NULL);
dispatch_set(SSH_CMSG_EOF, &server_input_eof);
dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
}
static void
server_init_dispatch_15(void)
{
server_init_dispatch_13();
debug("server_init_dispatch_15");
dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
}
static void
server_init_dispatch(void)
{
if (compat20)
server_init_dispatch_20();
else if (compat13)
server_init_dispatch_13();
else
server_init_dispatch_15();
}

3
serverloop.h
Просмотреть файл

@ -1,4 +1,4 @@
/* $OpenBSD: serverloop.h,v 1.6 2006/03/25 22:22:43 djm Exp $ */
/* $OpenBSD: serverloop.h,v 1.7 2016/08/13 17:47:41 markus Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
@ -21,7 +21,6 @@
#ifndef SERVERLOOP_H
#define SERVERLOOP_H
void server_loop(pid_t, int, int, int);
void server_loop2(Authctxt *);
#endif

194
session.c
Просмотреть файл

@ -1,4 +1,4 @@
/* $OpenBSD: session.c,v 1.282 2016/03/10 11:47:57 djm Exp $ */
/* $OpenBSD: session.c,v 1.283 2016/08/13 17:47:41 markus Exp $ */
/*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
@ -66,7 +66,6 @@
#include "openbsd-compat/sys-queue.h"
#include "xmalloc.h"
#include "ssh.h"
#include "ssh1.h"
#include "ssh2.h"
#include "sshpty.h"
#include "packet.h"
@ -128,7 +127,6 @@ void do_child(Session *, const char *);
void do_motd(void);
int check_quietlogin(Session *, const char *);
static void do_authenticated1(Authctxt *);
static void do_authenticated2(Authctxt *);
static int session_pty_req(Session *);
@ -267,11 +265,7 @@ do_authenticated(Authctxt *authctxt)
auth_debug_send();
if (compat20)
do_authenticated2(authctxt);
else
do_authenticated1(authctxt);
do_cleanup(authctxt);
}
@ -290,164 +284,6 @@ xauth_valid_string(const char *s)
return 1;
}
/*
* Prepares for an interactive session. This is called after the user has
* been successfully authenticated. During this message exchange, pseudo
* terminals are allocated, X11, TCP/IP, and authentication agent forwardings
* are requested, etc.
*/
static void
do_authenticated1(Authctxt *authctxt)
{
Session *s;
char *command;
int success, type, screen_flag;
int enable_compression_after_reply = 0;
u_int proto_len, data_len, dlen, compression_level = 0;
s = session_new();
if (s == NULL) {
error("no more sessions");
return;
}
s->authctxt = authctxt;
s->pw = authctxt->pw;
/*
* We stay in this loop until the client requests to execute a shell
* or a command.
*/
for (;;) {
success = 0;
/* Get a packet from the client. */
type = packet_read();
/* Process the packet. */
switch (type) {
case SSH_CMSG_REQUEST_COMPRESSION:
compression_level = packet_get_int();
packet_check_eom();
if (compression_level < 1 || compression_level > 9) {
packet_send_debug("Received invalid compression level %d.",
compression_level);
break;
}
if (options.compression == COMP_NONE) {
debug2("compression disabled");
break;
}
/* Enable compression after we have responded with SUCCESS. */
enable_compression_after_reply = 1;
success = 1;
break;
case SSH_CMSG_REQUEST_PTY:
success = session_pty_req(s);
break;
case SSH_CMSG_X11_REQUEST_FORWARDING:
s->auth_proto = packet_get_string(&proto_len);
s->auth_data = packet_get_string(&data_len);
screen_flag = packet_get_protocol_flags() &
SSH_PROTOFLAG_SCREEN_NUMBER;
debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag);
if (packet_remaining() == 4) {
if (!screen_flag)
debug2("Buggy client: "
"X11 screen flag missing");
s->screen = packet_get_int();
} else {
s->screen = 0;
}
packet_check_eom();
if (xauth_valid_string(s->auth_proto) &&
xauth_valid_string(s->auth_data))
success = session_setup_x11fwd(s);
else {
success = 0;
error("Invalid X11 forwarding data");
}
if (!success) {
free(s->auth_proto);
free(s->auth_data);
s->auth_proto = NULL;
s->auth_data = NULL;
}
break;
case SSH_CMSG_AGENT_REQUEST_FORWARDING:
if (!options.allow_agent_forwarding ||
no_agent_forwarding_flag || compat13) {
debug("Authentication agent forwarding not permitted for this authentication.");
break;
}
debug("Received authentication agent forwarding request.");
success = auth_input_request_forwarding(s->pw);
break;
case SSH_CMSG_PORT_FORWARD_REQUEST:
if (no_port_forwarding_flag) {
debug("Port forwarding not permitted for this authentication.");
break;
}
if (!(options.allow_tcp_forwarding & FORWARD_REMOTE)) {
debug("Port forwarding not permitted.");
break;
}
debug("Received TCP/IP port forwarding request.");
if (channel_input_port_forward_request(s->pw->pw_uid == 0,
&options.fwd_opts) < 0) {
debug("Port forwarding failed.");
break;
}
success = 1;
break;
case SSH_CMSG_MAX_PACKET_SIZE:
if (packet_set_maxsize(packet_get_int()) > 0)
success = 1;
break;
case SSH_CMSG_EXEC_SHELL:
case SSH_CMSG_EXEC_CMD:
if (type == SSH_CMSG_EXEC_CMD) {
command = packet_get_string(&dlen);
debug("Exec command '%.500s'", command);
if (do_exec(s, command) != 0)
packet_disconnect(
"command execution failed");
free(command);
} else {
if (do_exec(s, NULL) != 0)
packet_disconnect(
"shell execution failed");
}
packet_check_eom();
session_close(s);
return;
default:
/*
* Any unknown messages in this phase are ignored,
* and a failure message is returned.
*/
logit("Unknown packet type received after authentication: %d", type);
}
packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE);
packet_send();
packet_write_wait();
/* Enable compression now that we have replied if appropriate. */
if (enable_compression_after_reply) {
enable_compression_after_reply = 0;
packet_start_compression(compression_level);
}
}
}
#define USE_PIPES 1
/*
* This is called to fork and execute a command when we have no tty. This
@ -615,14 +451,8 @@ do_exec_no_pty(Session *s, const char *command)
close(pout[1]);
close(perr[1]);
if (compat20) {
session_set_fds(s, pin[1], pout[0], perr[0],
s->is_subsystem, 0);
} else {
/* Enter the interactive session. */
server_loop(pid, pin[1], pout[0], perr[0]);
/* server_loop has closed pin[1], pout[0], and perr[0]. */
}
#else
/* We are the parent. Close the child sides of the socket pairs. */
close(inout[0]);
@ -632,13 +462,8 @@ do_exec_no_pty(Session *s, const char *command)
* Enter the interactive session. Note: server_loop must be able to
* handle the case that fdin and fdout are the same.
*/
if (compat20) {
session_set_fds(s, inout[1], inout[1], err[1],
s->is_subsystem, 0);
} else {
server_loop(pid, inout[1], inout[1], err[1]);
/* server_loop has closed inout[1] and err[1]. */
}
#endif
return 0;
}
@ -756,12 +581,7 @@ do_exec_pty(Session *s, const char *command)
s->ptymaster = ptymaster;
packet_set_interactive(1,
options.ip_qos_interactive, options.ip_qos_bulk);
if (compat20) {
session_set_fds(s, ptyfd, fdout, -1, 1, 1);
} else {
server_loop(pid, ptyfd, fdout, -1);
/* server_loop _has_ closed ptyfd and fdout. */
}
return 0;
}
@ -2106,14 +1926,8 @@ session_pty_req(Session *s)
}
s->term = packet_get_string(&len);
if (compat20) {
s->col = packet_get_int();
s->row = packet_get_int();
} else {
s->row = packet_get_int();
s->col = packet_get_int();
}
s->xpixel = packet_get_int();
s->ypixel = packet_get_int();
@ -2135,8 +1949,6 @@ session_pty_req(Session *s)
}
debug("session_pty_req: session %d alloc %s", s->self, s->tty);
/* for SSH1 the tty modes length is not given */
if (!compat20)
n_bytes = packet_remaining();
tty_parse_modes(s->ttyfd, &n_bytes);
@ -2353,8 +2165,6 @@ void
session_set_fds(Session *s, int fdin, int fdout, int fderr, int ignore_fderr,
int is_tty)
{
if (!compat20)
fatal("session_set_fds: called for proto != 2.0");
/*
* now that have a child and a pipe to the child,
* we can activate our channel and register the fd's
@ -2794,7 +2604,7 @@ do_cleanup(Authctxt *authctxt)
#endif
#ifdef GSSAPI
if (compat20 && options.gss_cleanup_creds)
if (options.gss_cleanup_creds)
ssh_gssapi_cleanup_creds();
#endif

3
session.h
Просмотреть файл

@ -1,4 +1,4 @@
/* $OpenBSD: session.h,v 1.32 2016/03/07 19:02:43 djm Exp $ */
/* $OpenBSD: session.h,v 1.33 2016/08/13 17:47:41 markus Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
@ -51,7 +51,6 @@ struct Session {
char *auth_data;
int single_connection;
/* proto 2 */
int chanid;
int *x11_chanids;
int is_subsystem;

473
sshd.c
Просмотреть файл

@ -1,4 +1,4 @@
/* $OpenBSD: sshd.c,v 1.471 2016/08/03 04:23:55 dtucker Exp $ */
/* $OpenBSD: sshd.c,v 1.472 2016/08/13 17:47:41 markus Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -87,7 +87,6 @@
#include "xmalloc.h"
#include "ssh.h"
#include "ssh1.h"
#include "ssh2.h"
#include "rsa.h"
#include "sshpty.h"
@ -201,22 +200,12 @@ int have_agent = 0;
* not very useful. Currently, memory locking is not implemented.
*/
struct {
Key *server_key; /* ephemeral server key */
Key *ssh1_host_key; /* ssh1 host key */
Key **host_keys; /* all private host keys */
Key **host_pubkeys; /* all public host keys */
Key **host_certificates; /* all public host certificates */
int have_ssh1_key;
int have_ssh2_key;
u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH];
} sensitive_data;
/*
* Flag indicating whether the RSA server key needs to be regenerated.
* Is set in the SIGALRM handler and cleared when the key is regenerated.
*/
static volatile sig_atomic_t key_do_regen = 0;
/* This is set to true when a signal is received. */
static volatile sig_atomic_t received_sighup = 0;
static volatile sig_atomic_t received_sigterm = 0;
@ -255,10 +244,6 @@ struct passwd *privsep_pw = NULL;
/* Prototypes for various functions defined later in this file. */
void destroy_sensitive_data(void);
void demote_sensitive_data(void);
#ifdef WITH_SSH1
static void do_ssh1_kex(void);
#endif
static void do_ssh2_kex(void);
/*
@ -375,43 +360,10 @@ grace_alarm_handler(int sig)
ssh_remote_ipaddr(active_state), ssh_remote_port(active_state));
}
/*
* Signal handler for the key regeneration alarm. Note that this
* alarm only occurs in the daemon waiting for connections, and it does not
* do anything with the private key or random state before forking.
* Thus there should be no concurrency control/asynchronous execution
* problems.
*/
static void
generate_ephemeral_server_key(void)
{
verbose("Generating %s%d bit RSA key.",
sensitive_data.server_key ? "new " : "", options.server_key_bits);
if (sensitive_data.server_key != NULL)
key_free(sensitive_data.server_key);
sensitive_data.server_key = key_generate(KEY_RSA1,
options.server_key_bits);
verbose("RSA key generation complete.");
arc4random_buf(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
}
/*ARGSUSED*/
static void
key_regeneration_alarm(int sig)
{
int save_errno = errno;
signal(SIGALRM, SIG_DFL);
errno = save_errno;
key_do_regen = 1;
}
static void
sshd_exchange_identification(struct ssh *ssh, int sock_in, int sock_out)
{
u_int i;
int mismatch;
int remote_major, remote_minor;
int major, minor;
char *s, *newline = "\n";
@ -511,42 +463,13 @@ sshd_exchange_identification(struct ssh *ssh, int sock_in, int sock_out)
"refusing connection", remote_version);
}
mismatch = 0;
switch (remote_major) {
case 1:
if (remote_minor == 99) {
if (options.protocol & SSH_PROTO_2)
enable_compat20();
else
mismatch = 1;
break;
}
if (!(options.protocol & SSH_PROTO_1)) {
mismatch = 1;
break;
}
if (remote_minor < 3) {
packet_disconnect("Your ssh version is too old and "
"is no longer supported. Please install a newer version.");
} else if (remote_minor == 3) {
/* note that this disables agent-forwarding */
enable_compat13();
}
break;
case 2:
if (options.protocol & SSH_PROTO_2) {
enable_compat20();
break;
}
/* FALLTHROUGH */
default:
mismatch = 1;
break;
}
chop(server_version_string);
debug("Local version string %.200s", server_version_string);
if (mismatch) {
if (remote_major == 2 ||
(remote_major == 1 && remote_minor == 99)) {
enable_compat20();
} else {
s = "Protocol major versions differ.\n";
(void) atomicio(vwrite, sock_out, s, strlen(s));
close(sock_in);
@ -565,10 +488,6 @@ destroy_sensitive_data(void)
{
int i;
if (sensitive_data.server_key) {
key_free(sensitive_data.server_key);
sensitive_data.server_key = NULL;
}
for (i = 0; i < options.num_host_key_files; i++) {
if (sensitive_data.host_keys[i]) {
key_free(sensitive_data.host_keys[i]);
@ -579,8 +498,6 @@ destroy_sensitive_data(void)
sensitive_data.host_certificates[i] = NULL;
}
}
sensitive_data.ssh1_host_key = NULL;
explicit_bzero(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
}
/* Demote private to public keys for network child */
@ -590,24 +507,14 @@ demote_sensitive_data(void)
Key *tmp;
int i;
if (sensitive_data.server_key) {
tmp = key_demote(sensitive_data.server_key);
key_free(sensitive_data.server_key);
sensitive_data.server_key = tmp;
}
for (i = 0; i < options.num_host_key_files; i++) {
if (sensitive_data.host_keys[i]) {
tmp = key_demote(sensitive_data.host_keys[i]);
key_free(sensitive_data.host_keys[i]);
sensitive_data.host_keys[i] = tmp;
if (tmp->type == KEY_RSA1)
sensitive_data.ssh1_host_key = tmp;
}
/* Certs do not need demotion */
}
/* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */
}
static void
@ -803,7 +710,7 @@ list_hostkey_types(void)
key = sensitive_data.host_keys[i];
if (key == NULL)
key = sensitive_data.host_pubkeys[i];
if (key == NULL || key->type == KEY_RSA1)
if (key == NULL)
continue;
/* Check that the key is accepted in HostkeyAlgorithms */
if (match_pattern_list(sshkey_ssh_name(key),
@ -952,7 +859,7 @@ notify_hostkeys(struct ssh *ssh)
for (i = nkeys = 0; i < options.num_host_key_files; i++) {
key = get_hostkey_public_by_index(i, ssh);
if (key == NULL || key->type == KEY_UNSPEC ||
key->type == KEY_RSA1 || sshkey_is_cert(key))
sshkey_is_cert(key))
continue;
fp = sshkey_fingerprint(key, options.fingerprint_hash,
SSH_FP_DEFAULT);
@ -1038,13 +945,6 @@ send_rexec_state(int fd, struct sshbuf *conf)
/*
* Protocol from reexec master to child:
* string configuration
* u_int ephemeral_key_follows
* bignum e (only if ephemeral_key_follows == 1)
* bignum n "
* bignum d "
* bignum iqmp "
* bignum p "
* bignum q "
* string rngseed (only if OpenSSL is not self-seeded)
*/
if ((m = sshbuf_new()) == NULL)
@ -1052,28 +952,6 @@ send_rexec_state(int fd, struct sshbuf *conf)
if ((r = sshbuf_put_stringb(m, conf)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
#ifdef WITH_SSH1
if (sensitive_data.server_key != NULL &&
sensitive_data.server_key->type == KEY_RSA1) {
if ((r = sshbuf_put_u32(m, 1)) != 0 ||
(r = sshbuf_put_bignum1(m,
sensitive_data.server_key->rsa->e)) != 0 ||
(r = sshbuf_put_bignum1(m,
sensitive_data.server_key->rsa->n)) != 0 ||
(r = sshbuf_put_bignum1(m,
sensitive_data.server_key->rsa->d)) != 0 ||
(r = sshbuf_put_bignum1(m,
sensitive_data.server_key->rsa->iqmp)) != 0 ||
(r = sshbuf_put_bignum1(m,
sensitive_data.server_key->rsa->p)) != 0 ||
(r = sshbuf_put_bignum1(m,
sensitive_data.server_key->rsa->q)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
} else
#endif
if ((r = sshbuf_put_u32(m, 0)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
#if defined(WITH_OPENSSL) && !defined(OPENSSL_PRNG_ONLY)
rexec_send_rng_seed(m);
#endif
@ -1107,24 +985,6 @@ recv_rexec_state(int fd, Buffer *conf)
buffer_append(conf, cp, len);
free(cp);
if (buffer_get_int(&m)) {
#ifdef WITH_SSH1
if (sensitive_data.server_key != NULL)
key_free(sensitive_data.server_key);
sensitive_data.server_key = key_new_private(KEY_RSA1);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->e);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->n);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->d);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->p);
buffer_get_bignum(&m, sensitive_data.server_key->rsa->q);
if (rsa_generate_additional_parameters(
sensitive_data.server_key->rsa) != 0)
fatal("%s: rsa_generate_additional_parameters "
"error", __func__);
#endif
}
#if defined(WITH_OPENSSL) && !defined(OPENSSL_PRNG_ONLY)
rexec_recv_rng_seed(&m);
#endif
@ -1248,7 +1108,7 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
{
fd_set *fdset;
int i, j, ret, maxfd;
int key_used = 0, startups = 0;
int startups = 0;
int startup_p[2] = { -1 , -1 };
struct sockaddr_storage from;
socklen_t fromlen;
@ -1295,11 +1155,6 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
unlink(options.pid_file);
exit(received_sigterm == SIGTERM ? 0 : 255);
}
if (key_used && key_do_regen) {
generate_ephemeral_server_key();
key_used = 0;
key_do_regen = 0;
}
if (ret < 0)
continue;
@ -1434,19 +1289,6 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
close(config_s[0]);
close(config_s[1]);
}
/*
* Mark that the key has been used (it
* was "given" to the child).
*/
if ((options.protocol & SSH_PROTO_1) &&
key_used == 0) {
/* Schedule server key regeneration alarm. */
signal(SIGALRM, key_regeneration_alarm);
alarm(options.key_regeneration_time);
key_used = 1;
}
close(*newsock);
/*
@ -1619,8 +1461,7 @@ main(int ac, char **av)
options.log_level = SYSLOG_LEVEL_QUIET;
break;
case 'b':
options.server_key_bits = (int)strtonum(optarg, 256,
32768, NULL);
/* ignored */
break;
case 'p':
options.ports_from_cmdline = 1;
@ -1726,9 +1567,6 @@ main(int ac, char **av)
drop_cray_privs();
#endif
sensitive_data.server_key = NULL;
sensitive_data.ssh1_host_key = NULL;
sensitive_data.have_ssh1_key = 0;
sensitive_data.have_ssh2_key = 0;
/*
@ -1852,8 +1690,7 @@ main(int ac, char **av)
sensitive_data.host_keys[i] = key;
sensitive_data.host_pubkeys[i] = pubkey;
if (key == NULL && pubkey != NULL && pubkey->type != KEY_RSA1 &&
have_agent) {
if (key == NULL && pubkey != NULL && have_agent) {
debug("will rely on agent for hostkey %s",
options.host_key_files[i]);
keytype = pubkey->type;
@ -1868,10 +1705,6 @@ main(int ac, char **av)
}
switch (keytype) {
case KEY_RSA1:
sensitive_data.ssh1_host_key = key;
sensitive_data.have_ssh1_key = 1;
break;
case KEY_RSA:
case KEY_DSA:
case KEY_ECDSA:
@ -1884,19 +1717,10 @@ main(int ac, char **av)
SSH_FP_DEFAULT)) == NULL)
fatal("sshkey_fingerprint failed");
debug("%s host key #%d: %s %s",
key ? "private" : "agent", i, keytype == KEY_RSA1 ?
sshkey_type(pubkey) : sshkey_ssh_name(pubkey), fp);
key ? "private" : "agent", i, sshkey_ssh_name(pubkey), fp);
free(fp);
}
if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
logit("Disabling protocol version 1. Could not load host key");
options.protocol &= ~SSH_PROTO_1;
}
if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
logit("Disabling protocol version 2. Could not load host key");
options.protocol &= ~SSH_PROTO_2;
}
if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
if (!sensitive_data.have_ssh2_key) {
logit("sshd: no hostkeys available -- exiting.");
exit(1);
}
@ -1944,33 +1768,6 @@ main(int ac, char **av)
key_type(key));
}
#ifdef WITH_SSH1
/* Check certain values for sanity. */
if (options.protocol & SSH_PROTO_1) {
if (options.server_key_bits < SSH_RSA_MINIMUM_MODULUS_SIZE ||
options.server_key_bits > OPENSSL_RSA_MAX_MODULUS_BITS) {
fprintf(stderr, "Bad server key size.\n");
exit(1);
}
/*
* Check that server and host key lengths differ sufficiently. This
* is necessary to make double encryption work with rsaref. Oh, I
* hate software patents. I dont know if this can go? Niels
*/
if (options.server_key_bits >
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) -
SSH_KEY_BITS_RESERVED && options.server_key_bits <
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
SSH_KEY_BITS_RESERVED) {
options.server_key_bits =
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
SSH_KEY_BITS_RESERVED;
debug("Forcing server key to %d bits to make it differ from host key.",
options.server_key_bits);
}
}
#endif
if (use_privsep) {
struct stat st;
@ -2068,9 +1865,6 @@ main(int ac, char **av)
platform_pre_listen();
server_listen();
if (options.protocol & SSH_PROTO_1)
generate_ephemeral_server_key();
signal(SIGHUP, sighup_handler);
signal(SIGCHLD, main_sigchld_handler);
signal(SIGTERM, sigterm_handler);
@ -2220,11 +2014,6 @@ main(int ac, char **av)
alarm(options.login_grace_time);
sshd_exchange_identification(ssh, sock_in, sock_out);
/* In inetd mode, generate ephemeral key only for proto 1 connections */
if (!compat20 && inetd_flag && sensitive_data.server_key == NULL)
generate_ephemeral_server_key();
packet_set_nonblocking();
/* allocate authentication context */
@ -2242,7 +2031,7 @@ main(int ac, char **av)
if (use_privsep) {
if (privsep_preauth(authctxt) == 1)
goto authenticated;
} else if (compat20 && have_agent) {
} else if (have_agent) {
if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) {
error("Unable to get agent socket: %s", ssh_err(r));
have_agent = 0;
@ -2251,17 +2040,9 @@ main(int ac, char **av)
/* perform the key exchange */
/* authenticate user and start session */
if (compat20) {
do_ssh2_kex();
do_authentication2(authctxt);
} else {
#ifdef WITH_SSH1
do_ssh1_kex();
do_authentication(authctxt);
#else
fatal("ssh1 not supported");
#endif
}
/*
* If we use privilege separation, the unprivileged child transfers
* the current keystate and exits
@ -2309,15 +2090,12 @@ main(int ac, char **av)
if (use_privsep) {
privsep_postauth(authctxt);
/* the monitor process [priv] will not return */
if (!compat20)
destroy_sensitive_data();
}
packet_set_timeout(options.client_alive_interval,
options.client_alive_count_max);
/* Try to send all our hostkeys to the client */
if (compat20)
notify_hostkeys(active_state);
/* Start session. */
@ -2347,229 +2125,6 @@ main(int ac, char **av)
exit(0);
}
#ifdef WITH_SSH1
/*
* Decrypt session_key_int using our private server key and private host key
* (key with larger modulus first).
*/
int
ssh1_session_key(BIGNUM *session_key_int)
{
struct ssh *ssh = active_state; /* XXX */
int rsafail = 0;
if (BN_cmp(sensitive_data.server_key->rsa->n,
sensitive_data.ssh1_host_key->rsa->n) > 0) {
/* Server key has bigger modulus. */
if (BN_num_bits(sensitive_data.server_key->rsa->n) <
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
SSH_KEY_BITS_RESERVED) {
fatal("do_connection: %s port %d: "
"server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
BN_num_bits(sensitive_data.server_key->rsa->n),
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
SSH_KEY_BITS_RESERVED);
}
if (rsa_private_decrypt(session_key_int, session_key_int,
sensitive_data.server_key->rsa) != 0)
rsafail++;
if (rsa_private_decrypt(session_key_int, session_key_int,
sensitive_data.ssh1_host_key->rsa) != 0)
rsafail++;
} else {
/* Host key has bigger modulus (or they are equal). */
if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
BN_num_bits(sensitive_data.server_key->rsa->n) +
SSH_KEY_BITS_RESERVED) {
fatal("do_connection: %s port %d: "
"host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
BN_num_bits(sensitive_data.server_key->rsa->n),
SSH_KEY_BITS_RESERVED);
}
if (rsa_private_decrypt(session_key_int, session_key_int,
sensitive_data.ssh1_host_key->rsa) != 0)
rsafail++;
if (rsa_private_decrypt(session_key_int, session_key_int,
sensitive_data.server_key->rsa) != 0)
rsafail++;
}
return (rsafail);
}
/*
* SSH1 key exchange
*/
static void
do_ssh1_kex(void)
{
struct ssh *ssh = active_state; /* XXX */
int i, len;
int rsafail = 0;
BIGNUM *session_key_int, *fake_key_int, *real_key_int;
u_char session_key[SSH_SESSION_KEY_LENGTH];
u_char fake_key_bytes[4096 / 8];
size_t fake_key_len;
u_char cookie[8];
u_int cipher_type, auth_mask, protocol_flags;
/*
* Generate check bytes that the client must send back in the user
* packet in order for it to be accepted; this is used to defy ip
* spoofing attacks. Note that this only works against somebody
* doing IP spoofing from a remote machine; any machine on the local
* network can still see outgoing packets and catch the random
* cookie. This only affects rhosts authentication, and this is one
* of the reasons why it is inherently insecure.
*/
arc4random_buf(cookie, sizeof(cookie));
/*
* Send our public key. We include in the packet 64 bits of random
* data that must be matched in the reply in order to prevent IP
* spoofing.
*/
packet_start(SSH_SMSG_PUBLIC_KEY);
for (i = 0; i < 8; i++)
packet_put_char(cookie[i]);
/* Store our public server RSA key. */
packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n));
packet_put_bignum(sensitive_data.server_key->rsa->e);
packet_put_bignum(sensitive_data.server_key->rsa->n);
/* Store our public host RSA key. */
packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e);
packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n);
/* Put protocol flags. */
packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN);
/* Declare which ciphers we support. */
packet_put_int(cipher_mask_ssh1(0));
/* Declare supported authentication types. */
auth_mask = 0;
if (options.rhosts_rsa_authentication)
auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
if (options.rsa_authentication)
auth_mask |= 1 << SSH_AUTH_RSA;
if (options.challenge_response_authentication == 1)
auth_mask |= 1 << SSH_AUTH_TIS;
if (options.password_authentication)
auth_mask |= 1 << SSH_AUTH_PASSWORD;
packet_put_int(auth_mask);
/* Send the packet and wait for it to be sent. */
packet_send();
packet_write_wait();
debug("Sent %d bit server key and %d bit host key.",
BN_num_bits(sensitive_data.server_key->rsa->n),
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
/* Read clients reply (cipher type and session key). */
packet_read_expect(SSH_CMSG_SESSION_KEY);
/* Get cipher type and check whether we accept this. */
cipher_type = packet_get_char();
if (!(cipher_mask_ssh1(0) & (1 << cipher_type)))
packet_disconnect("Warning: client selects unsupported cipher.");
/* Get check bytes from the packet. These must match those we
sent earlier with the public key packet. */
for (i = 0; i < 8; i++)
if (cookie[i] != packet_get_char())
packet_disconnect("IP Spoofing check bytes do not match.");
debug("Encryption type: %.200s", cipher_name(cipher_type));
/* Get the encrypted integer. */
if ((real_key_int = BN_new()) == NULL)
fatal("do_ssh1_kex: BN_new failed");
packet_get_bignum(real_key_int);
protocol_flags = packet_get_int();
packet_set_protocol_flags(protocol_flags);
packet_check_eom();
/* Setup a fake key in case RSA decryption fails */
if ((fake_key_int = BN_new()) == NULL)
fatal("do_ssh1_kex: BN_new failed");
fake_key_len = BN_num_bytes(real_key_int);
if (fake_key_len > sizeof(fake_key_bytes))
fake_key_len = sizeof(fake_key_bytes);
arc4random_buf(fake_key_bytes, fake_key_len);
if (BN_bin2bn(fake_key_bytes, fake_key_len, fake_key_int) == NULL)
fatal("do_ssh1_kex: BN_bin2bn failed");
/* Decrypt real_key_int using host/server keys */
rsafail = PRIVSEP(ssh1_session_key(real_key_int));
/* If decryption failed, use the fake key. Else, the real key. */
if (rsafail)
session_key_int = fake_key_int;
else
session_key_int = real_key_int;
/*
* Extract session key from the decrypted integer. The key is in the
* least significant 256 bits of the integer; the first byte of the
* key is in the highest bits.
*/
(void) BN_mask_bits(session_key_int, sizeof(session_key) * 8);
len = BN_num_bytes(session_key_int);
if (len < 0 || (u_int)len > sizeof(session_key)) {
error("%s: bad session key len from %s port %d: "
"session_key_int %d > sizeof(session_key) %lu", __func__,
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
len, (u_long)sizeof(session_key));
rsafail++;
} else {
explicit_bzero(session_key, sizeof(session_key));
BN_bn2bin(session_key_int,
session_key + sizeof(session_key) - len);
derive_ssh1_session_id(
sensitive_data.ssh1_host_key->rsa->n,
sensitive_data.server_key->rsa->n,
cookie, session_id);
/*
* Xor the first 16 bytes of the session key with the
* session id.
*/
for (i = 0; i < 16; i++)
session_key[i] ^= session_id[i];
}
/* Destroy the private and public keys. No longer. */
destroy_sensitive_data();
if (use_privsep)
mm_ssh1_session_id(session_id);
/* Destroy the decrypted integer. It is no longer needed. */
BN_clear_free(real_key_int);
BN_clear_free(fake_key_int);
/* Set the session key. From this on all communications will be encrypted. */
packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
/* Destroy our copy of the session key. It is no longer needed. */
explicit_bzero(session_key, sizeof(session_key));
debug("Received session key; encryption turned on.");
/* Send an acknowledgment packet. Note that this packet is sent encrypted. */
packet_start(SSH_SMSG_SUCCESS);
packet_send();
packet_write_wait();
}
#endif
int
sshd_hostkey_sign(Key *privkey, Key *pubkey, u_char **signature, size_t *slen,
const u_char *data, size_t dlen, const char *alg, u_int flag)