- sshd fails to set TERM correctly. - privilege separation may break PAM and is currently turned off. - man pages have not yet been updated I will have these issues resolved, and privilege separation turned on by default, in time for DP2. Sponsored by: DARPA, NAI Labs
333 lines
8.3 KiB
C
333 lines
8.3 KiB
C
/*
|
|
* Copyright (c) 2001 Markus Friedl. All rights reserved.
|
|
* Copyright (c) 2001 Per Allansson. 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"
|
|
RCSID("$OpenBSD: auth2-chall.c,v 1.18 2002/06/19 00:27:55 deraadt Exp $");
|
|
RCSID("$FreeBSD$");
|
|
|
|
#include "ssh2.h"
|
|
#include "auth.h"
|
|
#include "buffer.h"
|
|
#include "packet.h"
|
|
#include "xmalloc.h"
|
|
#include "dispatch.h"
|
|
#include "auth.h"
|
|
#include "log.h"
|
|
|
|
static int auth2_challenge_start(Authctxt *);
|
|
static int send_userauth_info_request(Authctxt *);
|
|
static void input_userauth_info_response(int, u_int32_t, void *);
|
|
|
|
#ifdef BSD_AUTH
|
|
extern KbdintDevice bsdauth_device;
|
|
#elif defined(USE_PAM)
|
|
extern KbdintDevice pam_device;
|
|
#elif defined(SKEY)
|
|
extern KbdintDevice skey_device;
|
|
#endif
|
|
|
|
KbdintDevice *devices[] = {
|
|
#ifdef BSD_AUTH
|
|
&bsdauth_device,
|
|
#elif defined(USE_PAM)
|
|
&pam_device,
|
|
#elif defined(SKEY)
|
|
&skey_device,
|
|
#endif
|
|
NULL
|
|
};
|
|
|
|
typedef struct KbdintAuthctxt KbdintAuthctxt;
|
|
struct KbdintAuthctxt
|
|
{
|
|
char *devices;
|
|
void *ctxt;
|
|
KbdintDevice *device;
|
|
};
|
|
|
|
static KbdintAuthctxt *
|
|
kbdint_alloc(const char *devs)
|
|
{
|
|
KbdintAuthctxt *kbdintctxt;
|
|
Buffer b;
|
|
int i;
|
|
|
|
kbdintctxt = xmalloc(sizeof(KbdintAuthctxt));
|
|
if (strcmp(devs, "") == 0) {
|
|
buffer_init(&b);
|
|
for (i = 0; devices[i]; i++) {
|
|
if (buffer_len(&b) > 0)
|
|
buffer_append(&b, ",", 1);
|
|
buffer_append(&b, devices[i]->name,
|
|
strlen(devices[i]->name));
|
|
}
|
|
buffer_append(&b, "\0", 1);
|
|
kbdintctxt->devices = xstrdup(buffer_ptr(&b));
|
|
buffer_free(&b);
|
|
} else {
|
|
kbdintctxt->devices = xstrdup(devs);
|
|
}
|
|
debug("kbdint_alloc: devices '%s'", kbdintctxt->devices);
|
|
kbdintctxt->ctxt = NULL;
|
|
kbdintctxt->device = NULL;
|
|
|
|
return kbdintctxt;
|
|
}
|
|
static void
|
|
kbdint_reset_device(KbdintAuthctxt *kbdintctxt)
|
|
{
|
|
if (kbdintctxt->ctxt) {
|
|
kbdintctxt->device->free_ctx(kbdintctxt->ctxt);
|
|
kbdintctxt->ctxt = NULL;
|
|
}
|
|
kbdintctxt->device = NULL;
|
|
}
|
|
static void
|
|
kbdint_free(KbdintAuthctxt *kbdintctxt)
|
|
{
|
|
if (kbdintctxt->device)
|
|
kbdint_reset_device(kbdintctxt);
|
|
if (kbdintctxt->devices) {
|
|
xfree(kbdintctxt->devices);
|
|
kbdintctxt->devices = NULL;
|
|
}
|
|
xfree(kbdintctxt);
|
|
}
|
|
/* get next device */
|
|
static int
|
|
kbdint_next_device(KbdintAuthctxt *kbdintctxt)
|
|
{
|
|
size_t len;
|
|
char *t;
|
|
int i;
|
|
|
|
if (kbdintctxt->device)
|
|
kbdint_reset_device(kbdintctxt);
|
|
do {
|
|
len = kbdintctxt->devices ?
|
|
strcspn(kbdintctxt->devices, ",") : 0;
|
|
|
|
if (len == 0)
|
|
break;
|
|
for (i = 0; devices[i]; i++)
|
|
if (strncmp(kbdintctxt->devices, devices[i]->name, len) == 0)
|
|
kbdintctxt->device = devices[i];
|
|
t = kbdintctxt->devices;
|
|
kbdintctxt->devices = t[len] ? xstrdup(t+len+1) : NULL;
|
|
xfree(t);
|
|
debug2("kbdint_next_device: devices %s", kbdintctxt->devices ?
|
|
kbdintctxt->devices : "<empty>");
|
|
} while (kbdintctxt->devices && !kbdintctxt->device);
|
|
|
|
return kbdintctxt->device ? 1 : 0;
|
|
}
|
|
|
|
/*
|
|
* try challenge-response, set authctxt->postponed if we have to
|
|
* wait for the response.
|
|
*/
|
|
int
|
|
auth2_challenge(Authctxt *authctxt, char *devs)
|
|
{
|
|
debug("auth2_challenge: user=%s devs=%s",
|
|
authctxt->user ? authctxt->user : "<nouser>",
|
|
devs ? devs : "<no devs>");
|
|
|
|
if (authctxt->user == NULL || !devs)
|
|
return 0;
|
|
if (authctxt->kbdintctxt == NULL)
|
|
authctxt->kbdintctxt = kbdint_alloc(devs);
|
|
return auth2_challenge_start(authctxt);
|
|
}
|
|
|
|
/* unregister kbd-int callbacks and context */
|
|
void
|
|
auth2_challenge_stop(Authctxt *authctxt)
|
|
{
|
|
/* unregister callback */
|
|
dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL);
|
|
if (authctxt->kbdintctxt != NULL) {
|
|
kbdint_free(authctxt->kbdintctxt);
|
|
authctxt->kbdintctxt = NULL;
|
|
}
|
|
}
|
|
|
|
/* side effect: sets authctxt->postponed if a reply was sent*/
|
|
static int
|
|
auth2_challenge_start(Authctxt *authctxt)
|
|
{
|
|
KbdintAuthctxt *kbdintctxt = authctxt->kbdintctxt;
|
|
|
|
debug2("auth2_challenge_start: devices %s",
|
|
kbdintctxt->devices ? kbdintctxt->devices : "<empty>");
|
|
|
|
if (kbdint_next_device(kbdintctxt) == 0) {
|
|
auth2_challenge_stop(authctxt);
|
|
return 0;
|
|
}
|
|
debug("auth2_challenge_start: trying authentication method '%s'",
|
|
kbdintctxt->device->name);
|
|
|
|
if ((kbdintctxt->ctxt = kbdintctxt->device->init_ctx(authctxt)) == NULL) {
|
|
auth2_challenge_stop(authctxt);
|
|
return 0;
|
|
}
|
|
if (send_userauth_info_request(authctxt) == 0) {
|
|
auth2_challenge_stop(authctxt);
|
|
return 0;
|
|
}
|
|
dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE,
|
|
&input_userauth_info_response);
|
|
|
|
authctxt->postponed = 1;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
send_userauth_info_request(Authctxt *authctxt)
|
|
{
|
|
KbdintAuthctxt *kbdintctxt;
|
|
char *name, *instr, **prompts;
|
|
int i;
|
|
u_int numprompts, *echo_on;
|
|
|
|
kbdintctxt = authctxt->kbdintctxt;
|
|
if (kbdintctxt->device->query(kbdintctxt->ctxt,
|
|
&name, &instr, &numprompts, &prompts, &echo_on))
|
|
return 0;
|
|
|
|
packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
|
|
packet_put_cstring(name);
|
|
packet_put_cstring(instr);
|
|
packet_put_cstring(""); /* language not used */
|
|
packet_put_int(numprompts);
|
|
for (i = 0; i < numprompts; i++) {
|
|
packet_put_cstring(prompts[i]);
|
|
packet_put_char(echo_on[i]);
|
|
}
|
|
packet_send();
|
|
packet_write_wait();
|
|
|
|
for (i = 0; i < numprompts; i++)
|
|
xfree(prompts[i]);
|
|
xfree(prompts);
|
|
xfree(echo_on);
|
|
xfree(name);
|
|
xfree(instr);
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
input_userauth_info_response(int type, u_int32_t seq, void *ctxt)
|
|
{
|
|
Authctxt *authctxt = ctxt;
|
|
KbdintAuthctxt *kbdintctxt;
|
|
int i, authenticated = 0, res, len;
|
|
u_int nresp;
|
|
char **response = NULL, *method;
|
|
|
|
if (authctxt == NULL)
|
|
fatal("input_userauth_info_response: no authctxt");
|
|
kbdintctxt = authctxt->kbdintctxt;
|
|
if (kbdintctxt == NULL || kbdintctxt->ctxt == NULL)
|
|
fatal("input_userauth_info_response: no kbdintctxt");
|
|
if (kbdintctxt->device == NULL)
|
|
fatal("input_userauth_info_response: no device");
|
|
|
|
authctxt->postponed = 0; /* reset */
|
|
nresp = packet_get_int();
|
|
if (nresp > 0) {
|
|
response = xmalloc(nresp * sizeof(char*));
|
|
for (i = 0; i < nresp; i++)
|
|
response[i] = packet_get_string(NULL);
|
|
}
|
|
packet_check_eom();
|
|
|
|
if (authctxt->valid) {
|
|
res = kbdintctxt->device->respond(kbdintctxt->ctxt,
|
|
nresp, response);
|
|
} else {
|
|
res = -1;
|
|
}
|
|
|
|
for (i = 0; i < nresp; i++) {
|
|
memset(response[i], 'r', strlen(response[i]));
|
|
xfree(response[i]);
|
|
}
|
|
if (response)
|
|
xfree(response);
|
|
|
|
switch (res) {
|
|
case 0:
|
|
/* Success! */
|
|
authenticated = 1;
|
|
break;
|
|
case 1:
|
|
/* Authentication needs further interaction */
|
|
if (send_userauth_info_request(authctxt) == 1)
|
|
authctxt->postponed = 1;
|
|
break;
|
|
default:
|
|
/* Failure! */
|
|
break;
|
|
}
|
|
|
|
len = strlen("keyboard-interactive") + 2 +
|
|
strlen(kbdintctxt->device->name);
|
|
method = xmalloc(len);
|
|
snprintf(method, len, "keyboard-interactive/%s",
|
|
kbdintctxt->device->name);
|
|
|
|
if (!authctxt->postponed) {
|
|
if (authenticated) {
|
|
auth2_challenge_stop(authctxt);
|
|
} else {
|
|
/* start next device */
|
|
/* may set authctxt->postponed */
|
|
auth2_challenge_start(authctxt);
|
|
}
|
|
}
|
|
userauth_finish(authctxt, authenticated, method);
|
|
xfree(method);
|
|
}
|
|
|
|
void
|
|
privsep_challenge_enable(void)
|
|
{
|
|
#ifdef BSD_AUTH
|
|
extern KbdintDevice mm_bsdauth_device;
|
|
#endif
|
|
#ifdef SKEY
|
|
extern KbdintDevice mm_skey_device;
|
|
#endif
|
|
/* As long as SSHv1 has devices[0] hard coded this is fine */
|
|
#ifdef BSD_AUTH
|
|
devices[0] = &mm_bsdauth_device;
|
|
#else
|
|
#ifdef SKEY
|
|
devices[0] = &mm_skey_device;
|
|
#endif
|
|
#endif
|
|
}
|