src/pam/afs_password.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 #include <afsconfig.h>
  11 #include <afs/param.h>
  12
  13 #include <roken.h>
  14
  15 #ifdef HAVE_SYS_WAIT_H
  16 #include <sys/wait.h>
  17 #endif
  18
  19 #include <security/pam_appl.h>
  20 #include <security/pam_modules.h>
  21
  22 #include <afs/kautils.h>
  23 #include "afs_message.h"
  24 #include "afs_util.h"
  25 #include "afs_pam_msg.h"
  26
  27 #define RET(x) { retcode = (x); goto out; }
  28
  29 extern int
  30 pam_sm_chauthtok(pam_handle_t * pamh, int flags, int argc, const char **argv)
  31 {
  32     int retcode = PAM_SUCCESS;
  33     int errcode = PAM_SUCCESS;
  34     int code;
  35     int origmask;
  36     int logmask = LOG_UPTO(LOG_INFO);
  37     int nowarn = 0;
  38     int use_first_pass = 0;
  39     int try_first_pass = 0;
  40     int ignore_root = 0;
  41     char *torch_password = NULL;
  42     int i;
  43     char my_password_buf[256];
  44     char instance[256];
  45     char realm[256];
  46     char cell[256];
  47     char *localcell;
  48     PAM_CONST char *user = NULL, *password = NULL;
  49     char *new_password = NULL, *verify_password = NULL;
  50     char *reason = NULL;
  51     struct ktc_encryptionKey oldkey, newkey;
  52     struct ktc_token token;
  53     struct ubik_client *conn = 0;
  54     PAM_CONST struct pam_conv *pam_convp = NULL;
  55     struct passwd *upwd = NULL;
  56 #if !(defined(AFS_LINUX20_ENV) || defined(AFS_FBSD_ENV) || defined(AFS_DFBSD_ENV) || defined(AFS_NBSD_ENV))
  57     char upwd_buf[2048];        /* size is a guess. */
  58     struct passwd unix_pwd;
  59 #endif
  60
  61 #ifndef AFS_SUN5_ENV
  62     openlog(pam_afs_ident, LOG_CONS, LOG_AUTH);
  63 #endif
  64     origmask = setlogmask(logmask);
  65
  66     /*
  67      * Parse the user options.  Log an error for any unknown options.
  68      *
  69      * Todo options: PAM_SILENT
  70      */
  71     for (i = 0; i < argc; i++) {
  72         if (strcasecmp(argv[i], "debug") == 0) {
  73             logmask |= LOG_MASK(LOG_DEBUG);
  74             (void)setlogmask(logmask);
  75         } else if (strcasecmp(argv[i], "nowarn") == 0) {
  76             nowarn = 1;
  77         } else if (strcasecmp(argv[i], "use_first_pass") == 0) {
  78             use_first_pass = 1;
  79         } else if (strcasecmp(argv[i], "try_first_pass") == 0) {
  80             try_first_pass = 1;
  81         } else if (strcasecmp(argv[i], "ignore_root") == 0) {
  82             ignore_root = 1;
  83         } else {
  84             pam_afs_syslog(LOG_ERR, PAMAFS_UNKNOWNOPT, argv[i]);
  85         }
  86     }
  87
  88     if (use_first_pass)
  89         try_first_pass = 0;
  90
  91     if (logmask & LOG_MASK(LOG_DEBUG)) {
  92         pam_afs_syslog(LOG_DEBUG, PAMAFS_OPTIONS, nowarn, use_first_pass,
  93                        try_first_pass);
  94         pam_afs_syslog(LOG_DEBUG, PAMAFS_PAMERROR, flags);
  95     }
  96
  97     /* Try to get the user-interaction info, if available. */
  98     errcode = pam_get_item(pamh, PAM_CONV, (PAM_CONST void **)&pam_convp);
  99     if (errcode != PAM_SUCCESS) {
 100         pam_afs_syslog(LOG_WARNING, PAMAFS_NO_USER_INT);
 101         pam_convp = NULL;
 102     }
 103
 104     /* Who are we trying to authenticate here? */
 105     if ((errcode =
 106          pam_get_user(pamh, &user,
 107                       "AFS username: ")) != PAM_SUCCESS) {
 108         pam_afs_syslog(LOG_ERR, PAMAFS_NOUSER, errcode);
 109         RET(PAM_USER_UNKNOWN);
 110     }
 111
 112     if (logmask & LOG_MASK(LOG_DEBUG))
 113         pam_afs_syslog(LOG_DEBUG, PAMAFS_USERNAMEDEBUG, user);
 114
 115     /*
 116      * If the user has a "local" (or via nss, possibly nss_dce) pwent,
 117      * and its uid==0, and "ignore_root" was given in pam.conf,
 118      * ignore the user.
 119      */
 120 #if     defined(AFS_HPUX_ENV) || defined(AFS_DARWIN100_ENV) || defined(AFS_SUN5_ENV)
 121 #if     defined(AFS_HPUX110_ENV) || defined(AFS_DARWIN100_ENV) || defined(AFS_SUN5_ENV)
 122     i = getpwnam_r(user, &unix_pwd, upwd_buf, sizeof(upwd_buf), &upwd);
 123 #else /* AFS_HPUX110_ENV */
 124     i = getpwnam_r(user, &unix_pwd, upwd_buf, sizeof(upwd_buf));
 125     if (i == 0)                 /* getpwnam_r success */
 126         upwd = &unix_pwd;
 127 #endif /* else AFS_HPUX110_ENV */
 128     if (ignore_root && i == 0 && upwd && upwd->pw_uid == 0) {
 129         pam_afs_syslog(LOG_INFO, PAMAFS_IGNORINGROOT, user);
 130         RET(PAM_AUTH_ERR);
 131     }
 132 #else
 133 #if     defined(AFS_LINUX20_ENV) || defined(AFS_FBSD_ENV) || defined(AFS_DFBSD_ENV) || defined(AFS_NBSD_ENV)
 134     upwd = getpwnam(user);
 135 #else
 136     upwd = getpwnam_r(user, &unix_pwd, upwd_buf, sizeof(upwd_buf));
 137 #endif
 138     if (ignore_root && upwd != NULL && upwd->pw_uid == 0) {
 139         pam_afs_syslog(LOG_INFO, PAMAFS_IGNORINGROOT, user);
 140         RET(PAM_AUTH_ERR);
 141     }
 142 #endif
 143
 144     errcode = pam_get_item(pamh, PAM_AUTHTOK, (PAM_CONST void **)&password);
 145     if (errcode != PAM_SUCCESS || password == NULL) {
 146         if (use_first_pass) {
 147             pam_afs_syslog(LOG_ERR, PAMAFS_PASSWD_REQ, user);
 148             RET(PAM_AUTH_ERR);
 149         }
 150         password = NULL;        /* In case it isn't already NULL */
 151         if (logmask & LOG_MASK(LOG_DEBUG))
 152             pam_afs_syslog(LOG_DEBUG, PAMAFS_NOFIRSTPASS, user);
 153     } else if (password[0] == '\0') {
 154         /* Actually we *did* get one but it was empty. */
 155         pam_afs_syslog(LOG_INFO, PAMAFS_NILPASSWORD, user);
 156         RET(PAM_NEW_AUTHTOK_REQD);
 157     } else {
 158         if (logmask & LOG_MASK(LOG_DEBUG))
 159             pam_afs_syslog(LOG_DEBUG, PAMAFS_GOTPASS, user);
 160     }
 161     if (!(use_first_pass || try_first_pass)) {
 162         password = NULL;
 163     }
 164
 165     if (password == NULL) {
 166         char *prompt_password;
 167         if (use_first_pass)
 168             RET(PAM_AUTH_ERR);  /* shouldn't happen */
 169         if (try_first_pass)
 170             try_first_pass = 0;
 171         if (pam_convp == NULL || pam_convp->conv == NULL) {
 172             pam_afs_syslog(LOG_ERR, PAMAFS_CANNOT_PROMPT);
 173             RET(PAM_AUTH_ERR);
 174         }
 175
 176         errcode = pam_afs_prompt(pam_convp, &prompt_password, 0, PAMAFS_PWD_PROMPT);
 177         if (errcode != PAM_SUCCESS || prompt_password == NULL) {
 178             pam_afs_syslog(LOG_ERR, PAMAFS_GETPASS_FAILED);
 179             RET(PAM_AUTH_ERR);
 180         }
 181         if (prompt_password[0] == '\0') {
 182             pam_afs_syslog(LOG_INFO, PAMAFS_NILPASSWORD, user);
 183             RET(PAM_NEW_AUTHTOK_REQD);
 184         }
 185
 186         /*
 187          * We aren't going to free the password later (we will wipe it,
 188          * though), because the storage for it if we get it from other
 189          * paths may belong to someone else.  Since we do need to free
 190          * this storage, copy it to a buffer that won't need to be freed
 191          * later, and free this storage now.
 192          */
 193         strncpy(my_password_buf, prompt_password, sizeof(my_password_buf));
 194         my_password_buf[sizeof(my_password_buf) - 1] = '\0';
 195         memset(prompt_password, 0, strlen(prompt_password));
 196         free(prompt_password);
 197         password = torch_password = my_password_buf;
 198     }
 199
 200     if ((code = ka_VerifyUserPassword(KA_USERAUTH_VERSION + KA_USERAUTH_DOSETPAG, (char *)user, /* kerberos name */
 201                                       NULL,     /* instance */
 202                                       NULL,     /* realm */
 203                                       (char *)password, /* password */
 204                                       0,        /* spare 2 */
 205                                       &reason /* error string */ )) != 0) {
 206         pam_afs_syslog(LOG_ERR, PAMAFS_LOGIN_FAILED, user, reason);
 207         RET(PAM_AUTH_ERR);
 208     }
 209     torch_password = NULL;
 210     pam_set_item(pamh, PAM_AUTHTOK, password);
 211     pam_set_item(pamh, PAM_OLDAUTHTOK, password);
 212     if (flags & PAM_PRELIM_CHECK) {
 213         /* only auth check was requested, so return success here */
 214         return (PAM_SUCCESS);
 215     }
 216     if (!(flags & PAM_UPDATE_AUTHTOK)) {
 217         /* these lines are never executed ... */
 218         /* UPDATE_AUTHTOK flag is required, return with error */
 219         pam_afs_syslog(LOG_ERR, PAMAFS_FLAGS, "PAM_UPDATE_AUTHTOK");
 220         RET(PAM_AUTH_ERR);
 221     }
 222
 223     /* get the new passwd and verify it */
 224     errcode =
 225         pam_afs_prompt(pam_convp, &new_password, 0, PAMAFS_NEW_PWD_PROMPT);
 226     if (errcode != PAM_SUCCESS || new_password == NULL) {
 227         pam_afs_syslog(LOG_ERR, PAMAFS_GETPASS_FAILED);
 228         RET(PAM_AUTH_ERR);
 229     }
 230     if (new_password[0] == '\0') {
 231         pam_afs_syslog(LOG_INFO, PAMAFS_NILPASSWORD, user);
 232         RET(PAM_AUTH_ERR);
 233     }
 234     errcode =
 235         pam_afs_prompt(pam_convp, &verify_password, 0,
 236                        PAMAFS_VERIFY_PWD_PROMPT);
 237     if (errcode != PAM_SUCCESS || verify_password == NULL) {
 238         pam_afs_syslog(LOG_ERR, PAMAFS_GETPASS_FAILED);
 239         memset(new_password, 0, strlen(new_password));
 240         RET(PAM_AUTH_ERR);
 241     }
 242     if (verify_password[0] == '\0') {
 243         pam_afs_syslog(LOG_INFO, PAMAFS_NILPASSWORD, user);
 244         memset(new_password, 0, strlen(new_password));
 245         RET(PAM_AUTH_ERR);
 246     }
 247     if (strcmp(new_password, verify_password) != 0) {
 248         pam_afs_syslog(LOG_INFO, PAMAFS_NE_PASSWORD);
 249         memset(new_password, 0, strlen(new_password));
 250         memset(verify_password, 0, strlen(verify_password));
 251         RET(PAM_AUTH_ERR);
 252     }
 253     memset(verify_password, 0, strlen(verify_password));
 254     /* checking password length and quality is up to other PAM modules */
 255
 256     /* set the new password */
 257     if ((code = ka_Init(0)) != 0) {
 258         pam_afs_syslog(LOG_ERR, PAMAFS_KAERROR, code);
 259         RET(PAM_AUTH_ERR);
 260     }
 261     if ((code = rx_Init(0)) != 0) {
 262         pam_afs_syslog(LOG_ERR, PAMAFS_KAERROR, code);
 263         RET(PAM_AUTH_ERR);
 264     }
 265     strcpy(instance, "");
 266     if ((localcell = ka_LocalCell()) == NULL) {
 267         pam_afs_syslog(LOG_ERR, PAMAFS_NOCELLNAME);
 268         RET(PAM_AUTH_ERR);
 269     }
 270     strcpy(realm, localcell);
 271     strcpy(cell, realm);
 272     /* oldkey is not used in ka_ChangePassword (only for ka_auth) */
 273     ka_StringToKey((char *)password, realm, &oldkey);
 274     ka_StringToKey(new_password, realm, &newkey);
 275     if ((code =
 276          ka_GetAdminToken((char *)user, instance, realm, &oldkey, 20, &token,
 277                           0)) != 0) {
 278         pam_afs_syslog(LOG_ERR, PAMAFS_KAERROR, code);
 279         RET(PAM_AUTH_ERR);
 280     }
 281     if ((code =
 282          ka_AuthServerConn(realm, KA_MAINTENANCE_SERVICE, &token,
 283                            &conn)) != 0) {
 284         pam_afs_syslog(LOG_ERR, PAMAFS_KAERROR, code);
 285         RET(PAM_AUTH_ERR);
 286     }
 287     if ((code = ka_ChangePassword((char *)user, /* kerberos name */
 288                                   instance,     /* instance */
 289                                   conn, /* conn */
 290                                   0,    /* old password unused */
 291                                   &newkey /* new password */ )) != 0) {
 292         pam_afs_syslog(LOG_ERR, PAMAFS_KAPASS_FAIL);
 293         memset(new_password, 0, strlen(new_password));
 294         RET(PAM_AUTH_ERR);
 295     } else {
 296         pam_set_item(pamh, PAM_AUTHTOK, new_password);
 297         RET(PAM_SUCCESS);
 298     }
 299
 300   out:
 301     if (password && torch_password) {
 302         memset(torch_password, 0, strlen(torch_password));
 303     }
 304     (void)setlogmask(origmask);
 305 #ifndef AFS_SUN5_ENV
 306     closelog();
 307 #endif
 308     return retcode;
 309 }