/* Unix NT password database implementation, version 0.6. * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 675 * Mass Ave, Cambridge, MA 02139, USA. */ #include "includes.h" #include "general.h" #include "support.h" #define _pam_overwrite(x) \ do { \ register char *__xx__; \ if ((__xx__=(x))) \ while (*__xx__) \ *__xx__++ = '\0'; \ } while (0) /* * Don't just free it, forget it too. */ #define _pam_drop(X) \ do { \ if (X) { \ free(X); \ X=NULL; \ } \ } while (0) #define _pam_drop_reply(/* struct pam_response * */ reply, /* int */ replies) \ do { \ int reply_i; \ \ for (reply_i=0; reply_i<replies; ++reply_i) { \ if (reply[reply_i].resp) { \ _pam_overwrite(reply[reply_i].resp); \ free(reply[reply_i].resp); \ } \ } \ if (reply) \ free(reply); \ } while (0) int converse(pam_handle_t *, int, int, struct pam_message **, struct pam_response **); int make_remark(pam_handle_t *, unsigned int, int, const char *); void _cleanup(pam_handle_t *, void *, int); char *_pam_delete(register char *); /* syslogging function for errors and other information */ void _log_err( int err, const char *format, ... ) { va_list args; va_start( args, format ); openlog( "PAM_smbpass", LOG_CONS | LOG_PID, LOG_AUTH ); vsyslog( err, format, args ); va_end( args ); closelog(); } /* this is a front-end for module-application conversations */ int converse( pam_handle_t * pamh, int ctrl, int nargs , struct pam_message **message , struct pam_response **response ) { int retval; struct pam_conv *conv; retval = pam_get_item(pamh, PAM_CONV, (const void **) &conv); if (retval == PAM_SUCCESS) { retval = conv->conv(nargs, (const struct pam_message **) message ,response, conv->appdata_ptr); if (retval != PAM_SUCCESS && on(SMB_DEBUG, ctrl)) { _log_err(LOG_DEBUG, "conversation failure [%s]" ,pam_strerror(pamh, retval)); } } else { _log_err(LOG_ERR, "couldn't obtain coversation function [%s]" ,pam_strerror(pamh, retval)); } return retval; /* propagate error status */ } int make_remark( pam_handle_t * pamh, unsigned int ctrl , int type, const char *text ) { if (off(SMB__QUIET, ctrl)) { struct pam_message *pmsg[1], msg[1]; struct pam_response *resp; pmsg[0] = &msg[0]; msg[0].msg = text; msg[0].msg_style = type; resp = NULL; return converse(pamh, ctrl, 1, pmsg, &resp); } return PAM_SUCCESS; } /* set the control flags for the SMB module. */ int set_ctrl( int flags, int argc, const char **argv ) { int i = 0; static pstring servicesf = CONFIGFILE; const char *service_file = servicesf; unsigned int ctrl; ctrl = SMB_DEFAULTS; /* the default selection of options */ /* set some flags manually */ /* A good, sane default (matches Samba's behavior). */ set( SMB__NONULL, ctrl ); if (flags & PAM_SILENT) { set( SMB__QUIET, ctrl ); } /* Run through the arguments once, looking for an alternate smb config file location */ while (i < argc) { int j; for (j = 0; j < SMB_CTRLS_; ++j) { if (smb_args[j].token && !strncmp(argv[i], smb_args[j].token, strlen(smb_args[j].token))) { break; } } if (j == SMB_CONF_FILE) { service_file = argv[i] + 8; } i++; } /* Read some options from the Samba config. Can be overridden by the PAM config. */ if(lp_load(service_file,True,False,False) == False) { _log_err( LOG_ERR, "Error loading service file %s", service_file ); } if (lp_null_passwords()) { set( SMB__NULLOK, ctrl ); } /* now parse the rest of the arguments to this module */ while (argc-- > 0) { int j; for (j = 0; j < SMB_CTRLS_; ++j) { if (smb_args[j].token && !strncmp(*argv, smb_args[j].token, strlen(smb_args[j].token))) { break; } } if (j >= SMB_CTRLS_) { _log_err( LOG_ERR, "unrecognized option [%s]", *argv ); } else { ctrl &= smb_args[j].mask; /* for turning things off */ ctrl |= smb_args[j].flag; /* for turning things on */ } ++argv; /* step to next argument */ } /* auditing is a more sensitive version of debug */ if (on( SMB_AUDIT, ctrl )) { set( SMB_DEBUG, ctrl ); } /* return the set of flags */ return ctrl; } /* use this to free strings. ESPECIALLY password strings */ char * _pam_delete( register char *xx ) { _pam_overwrite( xx ); _pam_drop( xx ); return NULL; } void _cleanup( pam_handle_t * pamh, void *x, int error_status ) { x = _pam_delete( (char *) x ); } /* * Safe duplication of character strings. "Paranoid"; don't leave * evidence of old token around for later stack analysis. */ char * xstrdup( const char *x ) { register char *new = NULL; if (x != NULL) { register int i; for (i = 0; x[i]; ++i); /* length of string */ if ((new = malloc(++i)) == NULL) { i = 0; _log_err( LOG_CRIT, "out of memory in xstrdup" ); } else { while (i-- > 0) { new[i] = x[i]; } } x = NULL; } return new; /* return the duplicate or NULL on error */ } /* ************************************************************** * * Useful non-trivial functions * * ************************************************************** */ void _cleanup_failures( pam_handle_t * pamh, void *fl, int err ) { int quiet; const char *service = NULL; struct _pam_failed_auth *failure; #ifdef PAM_DATA_SILENT quiet = err & PAM_DATA_SILENT; /* should we log something? */ #else quiet = 0; #endif #ifdef PAM_DATA_REPLACE err &= PAM_DATA_REPLACE; /* are we just replacing data? */ #endif failure = (struct _pam_failed_auth *) fl; if (failure != NULL) { #ifdef PAM_DATA_SILENT if (!quiet && !err) { /* under advisement from Sun,may go away */ #else if (!quiet) { /* under advisement from Sun,may go away */ #endif /* log the number of authentication failures */ if (failure->count != 0) { pam_get_item( pamh, PAM_SERVICE, (const void **) &service ); _log_err( LOG_NOTICE , "%d authentication %s " "from %s for service %s as %s(%d)" , failure->count , failure->count == 1 ? "failure" : "failures" , failure->agent , service == NULL ? "**unknown**" : service , failure->user, failure->id ); if (failure->count > SMB_MAX_RETRIES) { _log_err( LOG_ALERT , "service(%s) ignoring max retries; %d > %d" , service == NULL ? "**unknown**" : service , failure->count , SMB_MAX_RETRIES ); } } } _pam_delete( failure->agent ); /* tidy up */ _pam_delete( failure->user ); /* tidy up */ free( failure ); } } int _smb_verify_password( pam_handle_t * pamh , const struct smb_passwd *smb_pwent , const char *p, unsigned int ctrl ) { uchar hash_pass[16]; uchar lm_pw[16]; uchar nt_pw[16]; int retval; char *data_name; const char *name; if (!smb_pwent) return PAM_ABORT; name = smb_pwent->smb_name; #ifdef HAVE_PAM_FAIL_DELAY if (off( SMB_NODELAY, ctrl )) { (void) pam_fail_delay( pamh, 1000000 ); /* 1 sec delay for on failure */ } #endif if (!smb_pwent->smb_passwd) { _log_err( LOG_DEBUG, "user %s has null SMB password" , name ); if (off( SMB__NONULL, ctrl ) && (smb_pwent->acct_ctrl & ACB_PWNOTREQ)) { /* this means we've succeeded */ return PAM_SUCCESS; } else { const char *service; pam_get_item( pamh, PAM_SERVICE, (const void **)&service ); _log_err( LOG_NOTICE , "failed auth request by %s for service %s as %s(%d)" , uidtoname( getuid() ) , service ? service : "**unknown**", name , smb_pwent->smb_userid ); return PAM_AUTH_ERR; } } data_name = (char *) malloc( sizeof(FAIL_PREFIX) + strlen( name )); if (data_name == NULL) { _log_err( LOG_CRIT, "no memory for data-name" ); } strncpy( data_name, FAIL_PREFIX, sizeof(FAIL_PREFIX) ); strncpy( data_name + sizeof(FAIL_PREFIX) - 1, name, strlen( name ) + 1 ); /* First we check whether we've been given the password in already encrypted form. */ if (strlen( p ) == 16 || (strlen( p ) == 32 && pdb_gethexpwd( p, (char *) hash_pass ))) { if (!memcmp( hash_pass, smb_pwent->smb_passwd, 16 ) || (smb_pwent->smb_nt_passwd && !memcmp( hash_pass, smb_pwent->smb_nt_passwd, 16 ))) { retval = PAM_SUCCESS; if (data_name) { /* reset failures */ pam_set_data( pamh, data_name, NULL, _cleanup_failures ); } _pam_delete( data_name ); memset( hash_pass, '\0', 16 ); smb_pwent = NULL; return retval; } } /* * The password we were given wasn't an encrypted password, or it * didn't match the one we have. We encrypt the password now and try * again. */ nt_lm_owf_gen(p, nt_pw, lm_pw); /* the moment of truth -- do we agree with the password? */ if (!memcmp( nt_pw, smb_pwent->smb_nt_passwd, 16 )) { retval = PAM_SUCCESS; if (data_name) { /* reset failures */ pam_set_data(pamh, data_name, NULL, _cleanup_failures); } } else { const char *service; pam_get_item( pamh, PAM_SERVICE, (const void **)&service ); if (data_name != NULL) { struct _pam_failed_auth *new = NULL; const struct _pam_failed_auth *old = NULL; /* get a failure recorder */ new = (struct _pam_failed_auth *) malloc( sizeof(struct _pam_failed_auth) ); if (new != NULL) { /* any previous failures for this user ? */ pam_get_data(pamh, data_name, (const void **) &old); if (old != NULL) { new->count = old->count + 1; if (new->count >= SMB_MAX_RETRIES) { retval = PAM_MAXTRIES; } } else { _log_err( LOG_NOTICE , "failed auth request by %s for service %s as %s(%d)" , uidtoname( getuid() ) , service ? service : "**unknown**", name , smb_pwent->smb_userid ); new->count = 1; } new->user = xstrdup( name ); new->id = smb_pwent->smb_userid; new->agent = xstrdup( uidtoname( getuid() ) ); pam_set_data( pamh, data_name, new, _cleanup_failures ); } else { _log_err( LOG_CRIT, "no memory for failure recorder" ); _log_err( LOG_NOTICE , "failed auth request by %s for service %s as %s(%d)" , uidtoname( getuid() ) , service ? service : "**unknown**", name , smb_pwent->smb_userid ); } } else { _log_err( LOG_NOTICE , "failed auth request by %s for service %s as %s(%d)" , uidtoname( getuid() ) , service ? service : "**unknown**", name , smb_pwent->smb_userid ); retval = PAM_AUTH_ERR; } } _pam_delete( data_name ); smb_pwent = NULL; return retval; } /* * _smb_blankpasswd() is a quick check for a blank password * * returns TRUE if user does not have a password * - to avoid prompting for one in such cases (CG) */ int _smb_blankpasswd( unsigned int ctrl, const struct smb_passwd *smb_pwent ) { int retval; /* * This function does not have to be too smart if something goes * wrong, return FALSE and let this case to be treated somewhere * else (CG) */ if (on( SMB__NONULL, ctrl )) return 0; /* will fail but don't let on yet */ if (smb_pwent->smb_passwd == NULL) retval = 1; else retval = 0; return retval; } /* * obtain a password from the user */ int _smb_read_password( pam_handle_t * pamh, unsigned int ctrl , const char *comment, const char *prompt1 , const char *prompt2, const char *data_name , const char **pass ) { int authtok_flag; int retval; const char *item = NULL; char *token; struct pam_message msg[3], *pmsg[3]; struct pam_response *resp; int i, expect; /* make sure nothing inappropriate gets returned */ *pass = token = NULL; /* which authentication token are we getting? */ authtok_flag = on(SMB__OLD_PASSWD, ctrl) ? PAM_OLDAUTHTOK : PAM_AUTHTOK; /* should we obtain the password from a PAM item ? */ if (on(SMB_TRY_FIRST_PASS, ctrl) || on(SMB_USE_FIRST_PASS, ctrl)) { retval = pam_get_item( pamh, authtok_flag, (const void **) &item ); if (retval != PAM_SUCCESS) { /* very strange. */ _log_err( LOG_ALERT , "pam_get_item returned error to smb_read_password" ); return retval; } else if (item != NULL) { /* we have a password! */ *pass = item; item = NULL; return PAM_SUCCESS; } else if (on( SMB_USE_FIRST_PASS, ctrl )) { return PAM_AUTHTOK_RECOVER_ERR; /* didn't work */ } else if (on( SMB_USE_AUTHTOK, ctrl ) && off( SMB__OLD_PASSWD, ctrl )) { return PAM_AUTHTOK_RECOVER_ERR; } } /* * getting here implies we will have to get the password from the * user directly. */ /* prepare to converse */ if (comment != NULL && off(SMB__QUIET, ctrl)) { pmsg[0] = &msg[0]; msg[0].msg_style = PAM_TEXT_INFO; msg[0].msg = comment; i = 1; } else { i = 0; } pmsg[i] = &msg[i]; msg[i].msg_style = PAM_PROMPT_ECHO_OFF; msg[i++].msg = prompt1; if (prompt2 != NULL) { pmsg[i] = &msg[i]; msg[i].msg_style = PAM_PROMPT_ECHO_OFF; msg[i++].msg = prompt2; expect = 2; } else expect = 1; resp = NULL; retval = converse( pamh, ctrl, i, pmsg, &resp ); if (resp != NULL) { int j = comment ? 1 : 0; /* interpret the response */ if (retval == PAM_SUCCESS) { /* a good conversation */ token = xstrdup(resp[j++].resp); if (token != NULL) { if (expect == 2) { /* verify that password entered correctly */ if (!resp[j].resp || strcmp( token, resp[j].resp )) { _pam_delete( token ); retval = PAM_AUTHTOK_RECOVER_ERR; make_remark( pamh, ctrl, PAM_ERROR_MSG , MISTYPED_PASS ); } } } else { _log_err(LOG_NOTICE, "could not recover authentication token"); } } /* tidy up */ _pam_drop_reply( resp, expect ); } else { retval = (retval == PAM_SUCCESS) ? PAM_AUTHTOK_RECOVER_ERR : retval; } if (retval != PAM_SUCCESS) { if (on( SMB_DEBUG, ctrl )) _log_err( LOG_DEBUG, "unable to obtain a password" ); return retval; } /* 'token' is the entered password */ if (off( SMB_NOT_SET_PASS, ctrl )) { /* we store this password as an item */ retval = pam_set_item( pamh, authtok_flag, (const void *)token ); _pam_delete( token ); /* clean it up */ if (retval != PAM_SUCCESS || (retval = pam_get_item( pamh, authtok_flag ,(const void **)&item )) != PAM_SUCCESS) { _log_err( LOG_CRIT, "error manipulating password" ); return retval; } } else { /* * then store it as data specific to this module. pam_end() * will arrange to clean it up. */ retval = pam_set_data( pamh, data_name, (void *) token, _cleanup ); if (retval != PAM_SUCCESS || (retval = pam_get_data( pamh, data_name, (const void **)&item )) != PAM_SUCCESS) { _log_err( LOG_CRIT, "error manipulating password data [%s]" , pam_strerror( pamh, retval )); _pam_delete( token ); item = NULL; return retval; } token = NULL; /* break link to password */ } *pass = item; item = NULL; /* break link to password */ return PAM_SUCCESS; } int _pam_smb_approve_pass(pam_handle_t * pamh ,unsigned int ctrl ,const char *pass_old ,const char *pass_new) { /* Further checks should be handled through module stacking. -SRL */ if (pass_new == NULL || (pass_old && !strcmp( pass_old, pass_new ))) { if (on(SMB_DEBUG, ctrl)) { _log_err( LOG_DEBUG, "passwd: bad authentication token (null or unchanged)" ); } make_remark( pamh, ctrl, PAM_ERROR_MSG, pass_new == NULL ? "No password supplied" : "Password unchanged" ); return PAM_AUTHTOK_ERR; } return PAM_SUCCESS; }