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/*
* Dropbear - a SSH2 server
*
* Copyright (c) 2002,2003 Matt Johnston
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE. */
/* Validates a user password */
#include "includes.h"
#include "session.h"
#include "buffer.h"
#include "dbutil.h"
#include "auth.h"
#if defined(HAVE_SECURITY_PAM_APPL_H)
#include <security/pam_appl.h>
#elif defined (HAVE_PAM_PAM_APPL_H)
#include <pam/pam_appl.h>
#endif
#ifdef DROPBEAR_PAM_AUTH
struct UserDataS {
char* user;
char* passwd;
};
/* PAM conversation function */
int
pamConvFunc(int num_msg,
const struct pam_message **msg,
struct pam_response **respp,
void *appdata_ptr) {
int rc = PAM_SUCCESS;
struct pam_response* resp = NULL;
struct UserDataS* userDatap = (struct UserDataS*) appdata_ptr;
/* tbd only handles one msg */
switch((*msg)->msg_style) {
case PAM_PROMPT_ECHO_OFF:
dropbear_log(LOG_DEBUG, "pamConvFunc(): PAM_PROMPT_ECHO_OFF: (*msg)->msg=\"%s\"", (*msg)->msg);
if (strcmp((*msg)->msg, "Password:") == 0) {
resp = (struct pam_response*) malloc(sizeof(struct pam_response));
resp->resp = (char*) strdup(userDatap->passwd);
/* dropbear_log(LOG_DEBUG, "pamConvFunc(): PAM_PROMPT_ECHO_ON: userDatap->passwd=\"%s\"", userDatap->passwd); */
resp->resp_retcode = 0;
(*respp) = resp;
}
else {
dropbear_log(LOG_WARNING, "pamConvFunc(): PAM_PROMPT_ECHO_OFF: unrecognized prompt, (*msg)->msg=\"%s\"", (*msg)->msg);
rc = PAM_CONV_ERR;
}
break;
case PAM_PROMPT_ECHO_ON:
dropbear_log(LOG_DEBUG, "pamConvFunc(): PAM_PROMPT_ECHO_ON: (*msg)->msg=\"%s\"", (*msg)->msg);
if ((strcmp((*msg)->msg, "login: " ) == 0) || (strcmp((*msg)->msg, "Please enter username: " ) == 0)) {
resp = (struct pam_response*) malloc(sizeof(struct pam_response));
resp->resp = (char*) strdup(userDatap->user);
dropbear_log(LOG_DEBUG, "pamConvFunc(): PAM_PROMPT_ECHO_ON: userDatap->user=\"%s\"", userDatap->user);
resp->resp_retcode = 0;
(*respp) = resp;
}
else {
dropbear_log(LOG_WARNING, "pamConvFunc(): PAM_PROMPT_ECHO_ON: unrecognized prompt, (*msg)->msg=\"%s\"",
(*msg)->msg);
rc = PAM_CONV_ERR;
}
break;
case PAM_ERROR_MSG:
dropbear_log(LOG_DEBUG, "pamConvFunc(): PAM_ERROR_MSG: (*msg)->msg=\"%s\"", (*msg)->msg);
/* printf("error msg: '%s'\n", (*msg)->msg); */
rc = PAM_CONV_ERR;
break;
case PAM_TEXT_INFO:
dropbear_log(LOG_DEBUG, "pamConvFunc(): PAM_TEXT_INFO: (*msg)->msg=\"%s\"", (*msg)->msg);
/* printf("text info: '%s'\n", (*msg)->msg); */
rc = PAM_CONV_ERR;
break;
case PAM_RADIO_TYPE:
dropbear_log(LOG_DEBUG, "pamConvFunc(): PAM_RADIO_TYPE: (*msg)->msg=\"%s\"", (*msg)->msg);
/* printf("radio type: '%s'\n", (*msg)->msg); */
rc = PAM_CONV_ERR;
break;
case PAM_BINARY_PROMPT:
dropbear_log(LOG_DEBUG, "pamConvFunc(): PAM_BINARY_PROMPT: (*msg)->msg=\"%s\"", (*msg)->msg);
/* printf("binary prompt: '%s'\n", (*msg)->msg); */
rc = PAM_CONV_ERR;
break;
default:
dropbear_log(LOG_DEBUG, "pamConvFunc(): Unknown PAM message");
/* printf("unknown message\n"); */
rc = PAM_CONV_ERR;
break;
}
return rc;
}
/* Process a password auth request, sending success or failure messages as
* appropriate */
void svr_auth_pam() {
// PAM stuff
int rc = PAM_SUCCESS;
struct UserDataS userData;
struct pam_conv pamConv = {
pamConvFunc,
&userData /* submitted to pamvConvFunc as appdata_ptr */
};
pam_handle_t* pamHandlep = NULL;
unsigned char * password = NULL;
unsigned int passwordlen;
unsigned char changepw;
/* check if client wants to change password */
changepw = buf_getbyte(ses.payload);
if (changepw) {
/* not implemented by this server */
send_msg_userauth_failure(0, 1);
return;
}
password = buf_getstring(ses.payload, &passwordlen);
/* clear the buffer containing the password */
buf_incrpos(ses.payload, -passwordlen - 4);
m_burn(buf_getptr(ses.payload, passwordlen + 4), passwordlen + 4);
/* used to pass data to the PAM conversation function */
userData.user = ses.authstate.printableuser;
TRACE(("user is %s\n", userData.user));
userData.passwd = password;
/* Init pam */
if ((rc = pam_start("sshd", NULL, &pamConv, &pamHandlep)) != PAM_SUCCESS) {
dropbear_log(LOG_WARNING, "pam_start() failed, rc=%d, %s\n", rc, pam_strerror(pamHandlep, rc));
/* fprintf(stderr, "pam_start() failed, rc=%d, %s\n", rc, pam_strerror(pamHandlep, rc)); */
goto clean;
}
/*
if ((rc = pam_set_item(pamHandlep, PAM_RHOST, webReqp->ipaddr) != PAM_SUCCESS)) {
dropbear_log(LOG_WARNING, "pam_set_item() failed, rc=%d, %s\n", rc, pam_strerror(pamHandlep, rc));
return;
}
*/
/* just to set it to something */
if ((rc = pam_set_item(pamHandlep, PAM_TTY, "ssh") != PAM_SUCCESS)) {
dropbear_log(LOG_WARNING, "pam_set_item() failed, rc=%d, %s\n", rc, pam_strerror(pamHandlep, rc));
goto clean;
}
(void) pam_fail_delay(pamHandlep, 0 /* musec_delay */);
/* (void) pam_set_item(pamHandlep, PAM_FAIL_DELAY, (void*) pamDelayFunc); */
if ((rc = pam_authenticate(pamHandlep, 0)) != PAM_SUCCESS) {
dropbear_log(LOG_WARNING, "pam_authenticate() failed, rc=%d, %s\n", rc, pam_strerror(pamHandlep, rc));
/* fprintf(stderr, "pam_authenticate() failed, rc=%d, %s\n", rc, pam_strerror(pamHandlep, rc)); */
dropbear_log(LOG_WARNING,
"bad pam password attempt for '%s'",
ses.authstate.printableuser);
send_msg_userauth_failure(0, 1);
goto clean;
}
if ((rc = pam_acct_mgmt(pamHandlep, 0)) != PAM_SUCCESS) {
dropbear_log(LOG_WARNING, "pam_acct_mgmt() failed, rc=%d, %s\n", rc, pam_strerror(pamHandlep, rc));
/* fprintf(stderr, "pam_acct_mgmt() failed, rc=%d, %s\n", rc, pam_strerror(pamHandlep, rc)); */
dropbear_log(LOG_WARNING,
"bad pam password attempt for '%s'",
ses.authstate.printableuser);
send_msg_userauth_failure(0, 1);
goto clean;
}
/* successful authentication */
dropbear_log(LOG_NOTICE,
"password auth succeeded for '%s'",
ses.authstate.printableuser);
send_msg_userauth_success();
clean:
if (password != NULL) {
m_burn(password, passwordlen);
m_free(password);
}
if (pamHandlep != NULL) {
(void) pam_end(pamHandlep, 0 /* pam_status */);
}
}
#endif /* DROPBEAR_PAM_AUTH */
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