source3/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, SAM_ACCOUNT *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     SAM_ACCOUNT *sampass = NULL;
  68     extern BOOL in_client;
  69     const char *name;
  70     void (*oldsig_handler)(int);
  71     BOOL found;
  72
  73     /* Points to memory managed by the PAM library. Do not free. */
  74     char *p = NULL;
  75
  76
  77     /* Samba initialization. */
  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 = malloc(sizeof(int));
  86
  87     /* get the username */
  88     retval = pam_get_user( pamh, &name, "Username: " );
  89     if ( retval != PAM_SUCCESS ) {
  90         if (on( SMB_DEBUG, ctrl )) {
  91             _log_err(LOG_DEBUG, "auth: could not identify user");
  92         }
  93         AUTH_RETURN;
  94     }
  95     if (on( SMB_DEBUG, ctrl )) {
  96         _log_err( LOG_DEBUG, "username [%s] obtained", name );
  97     }
  98
  99     /* Getting into places that might use LDAP -- protect the app
 100        from a SIGPIPE it's not expecting */
 101     oldsig_handler = CatchSignal(SIGPIPE, SIGNAL_CAST SIG_IGN);
 102
 103     if (!initialize_password_db(True)) {
 104         _log_err( LOG_ALERT, "Cannot access samba password database" );
 105         retval = PAM_AUTHINFO_UNAVAIL;
 106         AUTH_RETURN;
 107     }
 108
 109     pdb_init_sam(&sampass);
 110
 111     found = pdb_getsampwnam( sampass, name );
 112
 113     if (on( SMB_MIGRATE, ctrl )) {
 114         retval = _smb_add_user(pamh, ctrl, name, sampass, found);
 115         pdb_free_sam(&sampass);
 116         AUTH_RETURN;
 117     }
 118
 119     if (!found) {
 120         _log_err(LOG_ALERT, "Failed to find entry for user %s.", name);
 121         retval = PAM_USER_UNKNOWN;
 122         pdb_free_sam(&sampass);
 123         sampass = NULL;
 124         AUTH_RETURN;
 125     }
 126
 127     /* if this user does not have a password... */
 128
 129     if (_smb_blankpasswd( ctrl, sampass )) {
 130         pdb_free_sam(&sampass);
 131         retval = PAM_SUCCESS;
 132         AUTH_RETURN;
 133     }
 134
 135     /* get this user's authentication token */
 136
 137     retval = _smb_read_password(pamh, ctrl, NULL, "Password: ", NULL, _SMB_AUTHTOK, &p);
 138     if (retval != PAM_SUCCESS ) {
 139         _log_err(LOG_CRIT, "auth: no password provided for [%s]"
 140                  , name);
 141         pdb_free_sam(&sampass);
 142         AUTH_RETURN;
 143     }
 144
 145     /* verify the password of this user */
 146
 147     retval = _smb_verify_password( pamh, sampass, p, ctrl );
 148     pdb_free_sam(&sampass);
 149     p = NULL;
 150     AUTH_RETURN;
 151 }
 152
 153 /*
 154  * This function is for setting samba credentials.  If anyone comes up
 155  * with any credentials they think should be set, let me know.
 156  */
 157
 158 int pam_sm_setcred(pam_handle_t *pamh, int flags,
 159                    int argc, const char **argv)
 160 {
 161     int retval, *pretval = NULL;
 162
 163     retval = PAM_SUCCESS;
 164
 165     pam_get_data(pamh, "smb_setcred_return", (const void **) &pretval);
 166     if(pretval) {
 167         retval = *pretval;
 168         SAFE_FREE(pretval);
 169     }
 170     pam_set_data(pamh, "smb_setcred_return", NULL, NULL);
 171
 172     return retval;
 173 }
 174
 175
 176 /* Helper function for adding a user to the db. */
 177 static int _smb_add_user(pam_handle_t *pamh, unsigned int ctrl,
 178                          const char *name, SAM_ACCOUNT *sampass, BOOL exist)
 179 {
 180     pstring err_str;
 181     pstring msg_str;
 182     const char *pass = NULL;
 183     int retval;
 184
 185     err_str[0] = '\0';
 186     msg_str[0] = '\0';
 187
 188     /* Get the authtok; if we don't have one, silently fail. */
 189     retval = pam_get_item( pamh, PAM_AUTHTOK, (const void **) &pass );
 190
 191     if (retval != PAM_SUCCESS) {
 192         _log_err( LOG_ALERT
 193                   , "pam_get_item returned error to pam_sm_authenticate" );
 194         return PAM_AUTHTOK_RECOVER_ERR;
 195     } else if (pass == NULL) {
 196         return PAM_AUTHTOK_RECOVER_ERR;
 197     }
 198
 199     /* Add the user to the db if they aren't already there. */
 200    if (!exist) {
 201         retval = local_password_change( name, LOCAL_ADD_USER,
 202                                          pass, err_str,
 203                                          sizeof(err_str),
 204                                          msg_str, sizeof(msg_str) );
 205         if (!retval && *err_str)
 206         {
 207             err_str[PSTRING_LEN-1] = '\0';
 208             make_remark( pamh, ctrl, PAM_ERROR_MSG, err_str );
 209         }
 210         else if (*msg_str)
 211         {
 212             msg_str[PSTRING_LEN-1] = '\0';
 213             make_remark( pamh, ctrl, PAM_TEXT_INFO, msg_str );
 214         }
 215         pass = NULL;
 216
 217         return PAM_IGNORE;
 218    }
 219    else {
 220     /* Change the user's password IFF it's null. */
 221     if ((pdb_get_lanman_passwd(sampass) == NULL) && (pdb_get_acct_ctrl(sampass) & ACB_PWNOTREQ))
 222     {
 223         retval = local_password_change( name, 0, pass, err_str, sizeof(err_str),
 224                                          msg_str, sizeof(msg_str) );
 225         if (!retval && *err_str)
 226         {
 227             err_str[PSTRING_LEN-1] = '\0';
 228             make_remark( pamh, ctrl, PAM_ERROR_MSG, err_str );
 229         }
 230         else if (*msg_str)
 231         {
 232             msg_str[PSTRING_LEN-1] = '\0';
 233             make_remark( pamh, ctrl, PAM_TEXT_INFO, msg_str );
 234         }
 235     }
 236    }
 237
 238     pass = NULL;
 239
 240     return PAM_IGNORE;
 241 }
 242
 243
 244 /* static module data */
 245 #ifdef PAM_STATIC
 246 struct pam_module _pam_smbpass_auth_modstruct = {
 247      "pam_smbpass",
 248      pam_sm_authenticate,
 249      pam_sm_setcred,
 250      NULL,
 251      NULL,
 252      NULL,
 253      NULL
 254 };
 255 #endif
 256