pam_keystore/pam_keystore.c

//  Copyright 2007-2010 Mir Calculate Ltd. http://www.calculate-linux.org
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
// 
//      http://www.apache.org/licenses/LICENSE-2.0
// 
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.

#include <security/pam_modules.h>

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <ctype.h>

#include <asm/unistd.h>
#include "keyutils.h"


#define PAM_SM_AUTH
#define MAX_V 30

// 		if (strcmp(arg, "@t" ) == 0) return KEY_SPEC_THREAD_KEYRING;
// 		if (strcmp(arg, "@p" ) == 0) return KEY_SPEC_PROCESS_KEYRING;
// 		if (strcmp(arg, "@s" ) == 0) return KEY_SPEC_SESSION_KEYRING;
// 		if (strcmp(arg, "@u" ) == 0) return KEY_SPEC_USER_KEYRING;
// 		if (strcmp(arg, "@us") == 0) return KEY_SPEC_USER_SESSION_KEYRING;
// 		if (strcmp(arg, "@g" ) == 0) return KEY_SPEC_GROUP_KEYRING;
// 		if (strcmp(arg, "@a" ) == 0) return KEY_SPEC_REQKEY_AUTH_KEY;


// Authentication function
PAM_EXTERN int pam_sm_authenticate(pam_handle_t * pamh, int flags
                                   ,int argc, const char **argv)
{
unsigned int ctrl;
int retval;
const char *name, *p;
char *token;


// Get username
retval = pam_get_user(pamh, &name, "login: ");
if (retval!=PAM_SUCCESS) {return PAM_AUTH_ERR;};

// Structure for pam-functions
struct pam_conv *conv;
// Structure for pam-messages
struct pam_message *pmsg[3],msg[3];
// Structure for pam-pesponse
struct pam_response *response;
// Get the function to obtain a password
retval = pam_get_item( pamh, PAM_CONV, (const void **) &conv );

if (retval!=PAM_SUCCESS) {return PAM_AUTH_ERR;}

int flag = 0;
     for (ctrl=0; argc-- > 0; ++argv) 
     {
       if (!strcmp(*argv,"use_first_pass"))
       {
         retval = pam_get_item(pamh,PAM_AUTHTOK,(const void **)&p);
         if (retval!=PAM_SUCCESS) {return PAM_AUTH_ERR;};
         flag = 1;
       };
     };
if (flag == 0){

  // Initialize the structure for pam-messages
  pmsg[0] = &msg[0];
  msg[0].msg_style = PAM_PROMPT_ECHO_OFF;
  msg[0].msg="Password:";
  // Get a pointer to the answer pam
  retval = conv->conv(1, ( const struct pam_message ** ) pmsg, &response, conv->appdata_ptr);

  if (retval!=PAM_SUCCESS) {return PAM_AUTH_ERR;};
  // Get Password
  p = response->resp;
 };

// Ignore the root user
if (strcmp(name,"root")){
  key_serial_t dest;
  int ret;
  // User id and gid
  uid_t uid, gid;
  // Get user id and gid
  uid = getuid();
  gid = getgid();
  if (uid==0 && gid==0){
    // Get id (user key)
    dest = KEY_SPEC_USER_SESSION_KEYRING;

    // Write the key in the keystore kernel (space of root)
    ret = add_key("user", name, p, strlen(p), dest);
    };
  }

 if (p) {
   // Copy password for send to next module
   token = strdup(p);
   p=NULL;
   // Send password to next module
   retval = pam_set_item (pamh, PAM_AUTHTOK, (const void *) token);
   if (retval == PAM_SUCCESS) {return PAM_SUCCESS;}
 }
 return PAM_AUTH_ERR;
}


// Empty function, necessary for pam-module
PAM_EXTERN int pam_sm_setcred(pam_handle_t * pamh, int flags
                              ,int argc, const char **argv)
{
 return PAM_SUCCESS;
}

#ifdef PAM_STATIC
struct pam_module _pam_unix_auth_modstruct = {
    "pam_permit",
    pam_sm_authenticate,
    pam_sm_setcred,
    NULL,
    NULL,
    NULL,
    NULL,
};
#endif