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#include "includes.h"
RCSID("$Id: auth2-pam.c,v 1.13 2002/06/26 13:58:00 djm Exp $");
#ifdef USE_PAM
#include <security/pam_appl.h>
#include "ssh.h"
#include "ssh2.h"
#include "auth.h"
#include "auth-pam.h"
#include "packet.h"
#include "xmalloc.h"
#include "dispatch.h"
#include "log.h"
static int do_pam_conversation_kbd_int(int num_msg,
const struct pam_message **msg, struct pam_response **resp,
void *appdata_ptr);
void input_userauth_info_response_pam(int type, u_int32_t seqnr, void *ctxt);
struct {
int finished, num_received, num_expected;
int *prompts;
struct pam_response *responses;
} context_pam2 = {0, 0, 0, NULL};
static struct pam_conv conv2 = {
do_pam_conversation_kbd_int,
NULL,
};
int
auth2_pam(Authctxt *authctxt)
{
int retval = -1;
if (authctxt->user == NULL)
fatal("auth2_pam: internal error: no user");
conv2.appdata_ptr = authctxt;
do_pam_set_conv(&conv2);
dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE,
&input_userauth_info_response_pam);
retval = (do_pam_authenticate(0) == PAM_SUCCESS);
dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, NULL);
return retval;
}
static int
do_pam_conversation_kbd_int(int num_msg, const struct pam_message **msg,
struct pam_response **resp, void *appdata_ptr)
{
int i, j, done;
char *text;
context_pam2.finished = 0;
context_pam2.num_received = 0;
context_pam2.num_expected = 0;
context_pam2.prompts = xmalloc(sizeof(int) * num_msg);
context_pam2.responses = xmalloc(sizeof(struct pam_response) * num_msg);
memset(context_pam2.responses, 0, sizeof(struct pam_response) * num_msg);
text = NULL;
for (i = 0, context_pam2.num_expected = 0; i < num_msg; i++) {
int style = PAM_MSG_MEMBER(msg, i, msg_style);
switch (style) {
case PAM_PROMPT_ECHO_ON:
case PAM_PROMPT_ECHO_OFF:
context_pam2.num_expected++;
break;
case PAM_TEXT_INFO:
case PAM_ERROR_MSG:
default:
/* Capture all these messages to be sent at once */
message_cat(&text, PAM_MSG_MEMBER(msg, i, msg));
break;
}
}
if (context_pam2.num_expected == 0)
return PAM_SUCCESS;
packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
packet_put_cstring(""); /* Name */
packet_put_cstring(""); /* Instructions */
packet_put_cstring(""); /* Language */
packet_put_int(context_pam2.num_expected);
for (i = 0, j = 0; i < num_msg; i++) {
int style = PAM_MSG_MEMBER(msg, i, msg_style);
/* Skip messages which don't need a reply */
if (style != PAM_PROMPT_ECHO_ON && style != PAM_PROMPT_ECHO_OFF)
continue;
context_pam2.prompts[j++] = i;
if (text) {
message_cat(&text, PAM_MSG_MEMBER(msg, i, msg));
packet_put_cstring(text);
text = NULL;
} else
packet_put_cstring(PAM_MSG_MEMBER(msg, i, msg));
packet_put_char(style == PAM_PROMPT_ECHO_ON);
}
packet_send();
packet_write_wait();
/*
* Grabbing control of execution and spinning until we get what
* we want is probably rude, but it seems to work properly, and
* the client *should* be in lock-step with us, so the loop should
* only be traversed once.
*/
while(context_pam2.finished == 0) {
done = 1;
dispatch_run(DISPATCH_BLOCK, &done, appdata_ptr);
if(context_pam2.finished == 0)
debug("extra packet during conversation");
}
if(context_pam2.num_received == context_pam2.num_expected) {
*resp = context_pam2.responses;
return PAM_SUCCESS;
} else
return PAM_CONV_ERR;
}
void
input_userauth_info_response_pam(int type, u_int32_t seqnr, void *ctxt)
{
Authctxt *authctxt = ctxt;
unsigned int nresp = 0, rlen = 0, i = 0;
char *resp;
if (authctxt == NULL)
fatal("input_userauth_info_response_pam: no authentication context");
nresp = packet_get_int(); /* Number of responses. */
debug("got %d responses", nresp);
if (nresp != context_pam2.num_expected)
fatal("%s: Received incorrect number of responses "
"(expected %u, received %u)", __func__, nresp,
context_pam2.num_expected);
if (nresp > 100)
fatal("%s: too many replies", __func__);
for (i = 0; i < nresp; i++) {
int j = context_pam2.prompts[i];
resp = packet_get_string(&rlen);
context_pam2.responses[j].resp_retcode = PAM_SUCCESS;
context_pam2.responses[j].resp = xstrdup(resp);
xfree(resp);
context_pam2.num_received++;
}
context_pam2.finished = 1;
packet_check_eom();
}
#endif
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