source/pam_smbpass/pam_smb_auth.c

   1 /* Unix NT password database implementation, version 0.7.5.
   2  *
   3  * This program is free software; you can redistribute it and/or modify it under
   4  * the terms of the GNU General Public License as published by the Free
   5  * Software Foundation; either version 2 of the License, or (at your option)
   6  * any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 675
  15  * Mass Ave, Cambridge, MA 02139, USA.
  16 */
  17
  18 /* indicate the following groups are defined */
  19 #define PAM_SM_AUTH
  20
  21 #include "includes.h"
  22 #include "debug.h"
  23
  24 #ifndef LINUX
  25
  26 /* This is only used in the Sun implementation. */
  27 #include <security/pam_appl.h>
  28
  29 #endif  /* LINUX */
  30
  31 #include <security/pam_modules.h>
  32
  33 #include "general.h"
  34
  35 #include "support.h"
  36
  37 #define AUTH_RETURN                                             \
  38 do {                                                            \
  39         /* Restore application signal handler */                \
  40         CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);       \
  41         if(ret_data) {                                          \
  42                 *ret_data = retval;                             \
  43                 pam_set_data( pamh, "smb_setcred_return"        \
  44                               , (void *) ret_data, NULL );      \
  45         }                                                       \
  46         return retval;                                          \
  47 } while (0)
  48
  49 static int _smb_add_user(pam_handle_t *pamh, unsigned int ctrl,
  50                          const char *name, struct samu *sampass, BOOL exist);
  51
  52
  53 /*
  54  * pam_sm_authenticate() authenticates users against the samba password file.
  55  *
  56  *      First, obtain the password from the user. Then use a
  57  *      routine in 'support.c' to authenticate the user.
  58  */
  59
  60 #define _SMB_AUTHTOK  "-SMB-PASS"
  61
  62 int pam_sm_authenticate(pam_handle_t *pamh, int flags,
  63                         int argc, const char **argv)
  64 {
  65         unsigned int ctrl;
  66         int retval, *ret_data = NULL;
  67         struct samu *sampass = NULL;
  68         extern BOOL in_client;
  69         const char *name;
  70         void (*oldsig_handler)(int) = NULL;
  71         BOOL found;
  72
  73         /* Points to memory managed by the PAM library. Do not free. */
  74         char *p = NULL;
  75
  76         /* Samba initialization. */
  77         load_case_tables();
  78         setup_logging("pam_smbpass",False);
  79         in_client = True;
  80
  81         ctrl = set_ctrl(flags, argc, argv);
  82
  83         /* Get a few bytes so we can pass our return value to
  84                 pam_sm_setcred(). */
  85         ret_data = SMB_MALLOC_P(int);
  86
  87         /* we need to do this before we call AUTH_RETURN */
  88         /* Getting into places that might use LDAP -- protect the app
  89         from a SIGPIPE it's not expecting */
  90         oldsig_handler = CatchSignal(SIGPIPE, SIGNAL_CAST SIG_IGN);
  91
  92         /* get the username */
  93         retval = pam_get_user( pamh, &name, "Username: " );
  94         if ( retval != PAM_SUCCESS ) {
  95                 if (on( SMB_DEBUG, ctrl )) {
  96                         _log_err(LOG_DEBUG, "auth: could not identify user");
  97                 }
  98                 AUTH_RETURN;
  99         }
 100         if (on( SMB_DEBUG, ctrl )) {
 101                 _log_err( LOG_DEBUG, "username [%s] obtained", name );
 102         }
 103
 104         if (!initialize_password_db(True)) {
 105                 _log_err( LOG_ALERT, "Cannot access samba password database" );
 106                 retval = PAM_AUTHINFO_UNAVAIL;
 107                 AUTH_RETURN;
 108         }
 109
 110         sampass = samu_new( NULL );
 111         if (!sampass) {
 112                 _log_err( LOG_ALERT, "Cannot talloc a samu struct" );
 113                 retval = nt_status_to_pam(NT_STATUS_NO_MEMORY);
 114                 AUTH_RETURN;
 115         }
 116
 117         found = pdb_getsampwnam( sampass, name );
 118
 119         if (on( SMB_MIGRATE, ctrl )) {
 120                 retval = _smb_add_user(pamh, ctrl, name, sampass, found);
 121                 TALLOC_FREE(sampass);
 122                 AUTH_RETURN;
 123         }
 124
 125         if (!found) {
 126                 _log_err(LOG_ALERT, "Failed to find entry for user %s.", name);
 127                 retval = PAM_USER_UNKNOWN;
 128                 TALLOC_FREE(sampass);
 129                 sampass = NULL;
 130                 AUTH_RETURN;
 131         }
 132
 133         /* if this user does not have a password... */
 134
 135         if (_smb_blankpasswd( ctrl, sampass )) {
 136                 TALLOC_FREE(sampass);
 137                 retval = PAM_SUCCESS;
 138                 AUTH_RETURN;
 139         }
 140
 141         /* get this user's authentication token */
 142
 143         retval = _smb_read_password(pamh, ctrl, NULL, "Password: ", NULL, _SMB_AUTHTOK, &p);
 144         if (retval != PAM_SUCCESS ) {
 145                 _log_err(LOG_CRIT, "auth: no password provided for [%s]", name);
 146                 TALLOC_FREE(sampass);
 147                 AUTH_RETURN;
 148         }
 149
 150         /* verify the password of this user */
 151
 152         retval = _smb_verify_password( pamh, sampass, p, ctrl );
 153         TALLOC_FREE(sampass);
 154         p = NULL;
 155         AUTH_RETURN;
 156 }
 157
 158 /*
 159  * This function is for setting samba credentials.  If anyone comes up
 160  * with any credentials they think should be set, let me know.
 161  */
 162
 163 int pam_sm_setcred(pam_handle_t *pamh, int flags,
 164                    int argc, const char **argv)
 165 {
 166     int retval, *pretval = NULL;
 167
 168     retval = PAM_SUCCESS;
 169
 170     pam_get_data(pamh, "smb_setcred_return", (const void **) &pretval);
 171     if(pretval) {
 172         retval = *pretval;
 173         SAFE_FREE(pretval);
 174     }
 175     pam_set_data(pamh, "smb_setcred_return", NULL, NULL);
 176
 177     return retval;
 178 }
 179
 180
 181 /* Helper function for adding a user to the db. */
 182 static int _smb_add_user(pam_handle_t *pamh, unsigned int ctrl,
 183                          const char *name, struct samu *sampass, BOOL exist)
 184 {
 185     pstring err_str;
 186     pstring msg_str;
 187     const char *pass = NULL;
 188     int retval;
 189
 190     err_str[0] = '\0';
 191     msg_str[0] = '\0';
 192
 193     /* Get the authtok; if we don't have one, silently fail. */
 194     retval = pam_get_item( pamh, PAM_AUTHTOK, (const void **) &pass );
 195
 196     if (retval != PAM_SUCCESS) {
 197         _log_err( LOG_ALERT
 198                   , "pam_get_item returned error to pam_sm_authenticate" );
 199         return PAM_AUTHTOK_RECOVER_ERR;
 200     } else if (pass == NULL) {
 201         return PAM_AUTHTOK_RECOVER_ERR;
 202     }
 203
 204     /* Add the user to the db if they aren't already there. */
 205    if (!exist) {
 206         retval = NT_STATUS_IS_OK(local_password_change( name, LOCAL_ADD_USER|LOCAL_SET_PASSWORD,
 207                                          pass, err_str,
 208                                          sizeof(err_str),
 209                                          msg_str, sizeof(msg_str) ));
 210         if (!retval && *err_str)
 211         {
 212             err_str[PSTRING_LEN-1] = '\0';
 213             make_remark( pamh, ctrl, PAM_ERROR_MSG, err_str );
 214         }
 215         else if (*msg_str)
 216         {
 217             msg_str[PSTRING_LEN-1] = '\0';
 218             make_remark( pamh, ctrl, PAM_TEXT_INFO, msg_str );
 219         }
 220         pass = NULL;
 221
 222         return PAM_IGNORE;
 223    }
 224    else {
 225     /* mimick 'update encrypted' as long as the 'no pw req' flag is not set */
 226     if ( pdb_get_acct_ctrl(sampass) & ~ACB_PWNOTREQ )
 227     {
 228         retval = NT_STATUS_IS_OK(local_password_change( name, LOCAL_SET_PASSWORD, pass, err_str, sizeof(err_str),
 229                                          msg_str, sizeof(msg_str) ));
 230         if (!retval && *err_str)
 231         {
 232             err_str[PSTRING_LEN-1] = '\0';
 233             make_remark( pamh, ctrl, PAM_ERROR_MSG, err_str );
 234         }
 235         else if (*msg_str)
 236         {
 237             msg_str[PSTRING_LEN-1] = '\0';
 238             make_remark( pamh, ctrl, PAM_TEXT_INFO, msg_str );
 239         }
 240     }
 241    }
 242
 243     pass = NULL;
 244
 245     return PAM_IGNORE;
 246 }
 247
 248
 249 /* static module data */
 250 #ifdef PAM_STATIC
 251 struct pam_module _pam_smbpass_auth_modstruct = {
 252      "pam_smbpass",
 253      pam_sm_authenticate,
 254      pam_sm_setcred,
 255      NULL,
 256      NULL,
 257      NULL,
 258      NULL
 259 };
 260 #endif