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author | Tomas Mraz <tm@t8m.info> | 2008-01-23 15:35:12 +0000 |
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committer | Tomas Mraz <tm@t8m.info> | 2008-01-23 15:35:12 +0000 |
commit | 459e97431e99fa2c32e30e957993f95794b98dd0 (patch) | |
tree | dcf013e6644eba5ee5bdbaf6b2f78999bf43dc9b /modules/pam_unix/unix_chkpwd.c | |
parent | ca2cb12dd3165ab006c674d673a2d596d642c875 (diff) | |
download | pam-459e97431e99fa2c32e30e957993f95794b98dd0.tar.gz pam-459e97431e99fa2c32e30e957993f95794b98dd0.tar.bz2 pam-459e97431e99fa2c32e30e957993f95794b98dd0.zip |
Relevant BUGIDs:
Purpose of commit: cleanup, new feature
Commit summary:
---------------
Merging the the refactorization pam_unix_ref branch into the trunk.
Added support for sha256 and sha512 password hashes to pam_unix
when the libcrypt supports them.
Diffstat (limited to 'modules/pam_unix/unix_chkpwd.c')
-rw-r--r-- | modules/pam_unix/unix_chkpwd.c | 395 |
1 files changed, 42 insertions, 353 deletions
diff --git a/modules/pam_unix/unix_chkpwd.c b/modules/pam_unix/unix_chkpwd.c index 1e8944e9..11ac3aac 100644 --- a/modules/pam_unix/unix_chkpwd.c +++ b/modules/pam_unix/unix_chkpwd.c @@ -13,7 +13,6 @@ #include "config.h" -#include <stdarg.h> #include <stdio.h> #include <stdlib.h> #include <string.h> @@ -25,329 +24,34 @@ #include <shadow.h> #include <signal.h> #include <time.h> -#ifdef WITH_SELINUX -#include <selinux/selinux.h> -#define SELINUX_ENABLED (selinux_enabled!=-1 ? selinux_enabled : (selinux_enabled=is_selinux_enabled()>0)) -static security_context_t prev_context=NULL; -static int selinux_enabled=-1; -#else -#define SELINUX_ENABLED 0 -#endif - -#define MAXPASS 200 /* the maximum length of a password */ #include <security/_pam_types.h> #include <security/_pam_macros.h> #include "passverify.h" -/* syslogging function for errors and other information */ - -static void _log_err(int err, const char *format,...) -{ - va_list args; - - va_start(args, format); - openlog("unix_chkpwd", LOG_CONS | LOG_PID, LOG_AUTHPRIV); - vsyslog(err, format, args); - va_end(args); - closelog(); -} - -static void su_sighandler(int sig) -{ -#ifndef SA_RESETHAND - /* emulate the behaviour of the SA_RESETHAND flag */ - if ( sig == SIGILL || sig == SIGTRAP || sig == SIGBUS || sig = SIGSERV ) - signal(sig, SIG_DFL); -#endif - if (sig > 0) { - _log_err(LOG_NOTICE, "caught signal %d.", sig); - exit(sig); - } -} - -static void setup_signals(void) -{ - struct sigaction action; /* posix signal structure */ - - /* - * Setup signal handlers - */ - (void) memset((void *) &action, 0, sizeof(action)); - action.sa_handler = su_sighandler; -#ifdef SA_RESETHAND - action.sa_flags = SA_RESETHAND; -#endif - (void) sigaction(SIGILL, &action, NULL); - (void) sigaction(SIGTRAP, &action, NULL); - (void) sigaction(SIGBUS, &action, NULL); - (void) sigaction(SIGSEGV, &action, NULL); - action.sa_handler = SIG_IGN; - action.sa_flags = 0; - (void) sigaction(SIGTERM, &action, NULL); - (void) sigaction(SIGHUP, &action, NULL); - (void) sigaction(SIGINT, &action, NULL); - (void) sigaction(SIGQUIT, &action, NULL); -} - -static int _verify_account(const char * const uname) +static int _check_expiry(const char *uname) { struct spwd *spent; struct passwd *pwent; - - pwent = getpwnam(uname); - if (!pwent) { - _log_err(LOG_ALERT, "could not identify user (from getpwnam(%s))", uname); - return PAM_USER_UNKNOWN; - } - - spent = getspnam( uname ); - if (!spent) { - _log_err(LOG_ALERT, "could not get username from shadow (%s))", uname); - return PAM_AUTHINFO_UNAVAIL; /* Couldn't get username from shadow */ - } - printf("%ld:%ld:%ld:%ld:%ld:%ld", - spent->sp_lstchg, /* last password change */ - spent->sp_min, /* days until change allowed. */ - spent->sp_max, /* days before change required */ - spent->sp_warn, /* days warning for expiration */ - spent->sp_inact, /* days before account inactive */ - spent->sp_expire); /* date when account expires */ - - return PAM_SUCCESS; -} - -static int _unix_verify_password(const char *name, const char *p, int nullok) -{ - struct passwd *pwd = NULL; - struct spwd *spwdent = NULL; - char *salt = NULL; - int retval = PAM_AUTH_ERR; - - /* UNIX passwords area */ - setpwent(); - pwd = getpwnam(name); /* Get password file entry... */ - endpwent(); - if (pwd != NULL) { - if (_unix_shadowed(pwd)) { - /* - * ...and shadow password file entry for this user, - * if shadowing is enabled - */ - setspent(); - spwdent = getspnam(name); - endspent(); - if (spwdent != NULL) - salt = x_strdup(spwdent->sp_pwdp); - else - pwd = NULL; - } else { - if (strcmp(pwd->pw_passwd, "*NP*") == 0) { /* NIS+ */ - uid_t save_uid; - - save_uid = geteuid(); - seteuid(pwd->pw_uid); - spwdent = getspnam(name); - seteuid(save_uid); - - salt = x_strdup(spwdent->sp_pwdp); - } else { - salt = x_strdup(pwd->pw_passwd); - } - } + int retval; + int daysleft; + + retval = get_account_info(uname, &pwent, &spent); + if (retval != PAM_SUCCESS) { + helper_log_err(LOG_ALERT, "could not obtain user info (%s)", uname); + printf("-1\n"); + return retval; } - if (pwd == NULL || salt == NULL) { - _log_err(LOG_WARNING, "check pass; user unknown"); - retval = PAM_USER_UNKNOWN; - } else { - retval = verify_pwd_hash(p, salt, nullok); - } - - if (salt) { - _pam_overwrite(salt); - _pam_drop(salt); + + if (spent == NULL) { + printf("-1\n"); + return retval; } - p = NULL; /* no longer needed here */ - - return retval; -} - -static char *getuidname(uid_t uid) -{ - struct passwd *pw; - static char username[32]; - - pw = getpwuid(uid); - if (pw == NULL) - return NULL; - - strncpy(username, pw->pw_name, sizeof(username)); - username[sizeof(username) - 1] = '\0'; - - return username; -} - -#define SH_TMPFILE "/etc/nshadow" -static int _update_shadow(const char *forwho) -{ - struct spwd *spwdent = NULL, *stmpent = NULL; - FILE *pwfile, *opwfile; - int err = 1; - int oldmask; - struct stat st; - char pass[MAXPASS + 1]; - char towhat[MAXPASS + 1]; - int npass=0; - - /* read the password from stdin (a pipe from the pam_unix module) */ - - npass = read(STDIN_FILENO, pass, MAXPASS); - - if (npass < 0) { /* is it a valid password? */ - - _log_err(LOG_DEBUG, "no password supplied"); - return PAM_AUTHTOK_ERR; - - } else if (npass >= MAXPASS) { - - _log_err(LOG_DEBUG, "password too long"); - return PAM_AUTHTOK_ERR; - - } else { - /* does pass agree with the official one? */ - int retval=0; - pass[npass] = '\0'; /* NUL terminate */ - retval = _unix_verify_password(forwho, pass, 0); - if (retval != PAM_SUCCESS) { + retval = check_shadow_expiry(spent, &daysleft); + printf("%d\n", daysleft); return retval; - } - } - - /* read the password from stdin (a pipe from the pam_unix module) */ - - npass = read(STDIN_FILENO, towhat, MAXPASS); - - if (npass < 0) { /* is it a valid password? */ - - _log_err(LOG_DEBUG, "no new password supplied"); - return PAM_AUTHTOK_ERR; - - } else if (npass >= MAXPASS) { - - _log_err(LOG_DEBUG, "new password too long"); - return PAM_AUTHTOK_ERR; - - } - - towhat[npass] = '\0'; /* NUL terminate */ - spwdent = getspnam(forwho); - if (spwdent == NULL) { - return PAM_USER_UNKNOWN; - } - oldmask = umask(077); - -#ifdef WITH_SELINUX - if (SELINUX_ENABLED) { - security_context_t shadow_context=NULL; - if (getfilecon("/etc/shadow",&shadow_context)<0) { - return PAM_AUTHTOK_ERR; - }; - if (getfscreatecon(&prev_context)<0) { - freecon(shadow_context); - return PAM_AUTHTOK_ERR; - } - if (setfscreatecon(shadow_context)) { - freecon(shadow_context); - freecon(prev_context); - return PAM_AUTHTOK_ERR; - } - freecon(shadow_context); - } -#endif - pwfile = fopen(SH_TMPFILE, "w"); - umask(oldmask); - if (pwfile == NULL) { - err = 1; - goto done; - } - - opwfile = fopen("/etc/shadow", "r"); - if (opwfile == NULL) { - fclose(pwfile); - err = 1; - goto done; - } - - if (fstat(fileno(opwfile), &st) == -1) { - fclose(opwfile); - fclose(pwfile); - err = 1; - goto done; - } - - if (fchown(fileno(pwfile), st.st_uid, st.st_gid) == -1) { - fclose(opwfile); - fclose(pwfile); - err = 1; - goto done; - } - if (fchmod(fileno(pwfile), st.st_mode) == -1) { - fclose(opwfile); - fclose(pwfile); - err = 1; - goto done; - } - - stmpent = fgetspent(opwfile); - while (stmpent) { - - if (!strcmp(stmpent->sp_namp, forwho)) { - stmpent->sp_pwdp = towhat; - stmpent->sp_lstchg = time(NULL) / (60 * 60 * 24); - err = 0; - D(("Set password %s for %s", stmpent->sp_pwdp, forwho)); - } - - if (putspent(stmpent, pwfile)) { - D(("error writing entry to shadow file: %m")); - err = 1; - break; - } - - stmpent = fgetspent(opwfile); - } - fclose(opwfile); - - if (fclose(pwfile)) { - D(("error writing entries to shadow file: %m")); - err = 1; - } - - done: - if (!err) { - if (rename(SH_TMPFILE, "/etc/shadow")) - err = 1; - } - -#ifdef WITH_SELINUX - if (SELINUX_ENABLED) { - if (setfscreatecon(prev_context)) { - err = 1; - } - if (prev_context) - freecon(prev_context); - prev_context=NULL; - } -#endif - - if (!err) { - return PAM_SUCCESS; - } else { - unlink(SH_TMPFILE); - return PAM_AUTHTOK_ERR; - } } int main(int argc, char *argv[]) @@ -355,9 +59,10 @@ int main(int argc, char *argv[]) char pass[MAXPASS + 1]; char *option; int npass, nullok; - int force_failure = 0; + int blankpass = 0; int retval = PAM_AUTH_ERR; char *user; + char *passwords[] = { pass }; /* * Catch or ignore as many signal as possible. @@ -374,7 +79,7 @@ int main(int argc, char *argv[]) */ if (isatty(STDIN_FILENO) || argc != 3 ) { - _log_err(LOG_NOTICE + helper_log_err(LOG_NOTICE ,"inappropriate use of Unix helper binary [UID=%d]" ,getuid()); fprintf(stderr @@ -386,11 +91,9 @@ int main(int argc, char *argv[]) /* * Determine what the current user's name is. - * On a SELinux enabled system with a strict policy leaving the - * existing check prevents shadow password authentication from working. * We must thus skip the check if the real uid is 0. */ - if (SELINUX_ENABLED && getuid() == 0) { + if (getuid() == 0) { user=argv[1]; } else { @@ -404,63 +107,49 @@ int main(int argc, char *argv[]) option=argv[2]; - if (strncmp(argv[2], "verify", 8) == 0) { - /* Get the account information from the shadow file */ - return _verify_account(argv[1]); - } - - if (strncmp(option, "shadow", 8) == 0) { - /* Attempting to change the password */ - return _update_shadow(argv[1]); - } - + if (strcmp(option, "chkexpiry") == 0) + /* Check account information from the shadow file */ + return _check_expiry(argv[1]); /* read the nullok/nonull option */ - if (strncmp(option, "nullok", 8) == 0) + else if (strcmp(option, "nullok") == 0) nullok = 1; - else + else if (strcmp(option, "nonull") == 0) nullok = 0; + else + return PAM_SYSTEM_ERR; /* read the password from stdin (a pipe from the pam_unix module) */ - npass = read(STDIN_FILENO, pass, MAXPASS); + npass = read_passwords(STDIN_FILENO, 1, passwords); - if (npass < 0) { /* is it a valid password? */ - - _log_err(LOG_DEBUG, "no password supplied"); - - } else if (npass >= MAXPASS) { - - _log_err(LOG_DEBUG, "password too long"); - - } else { - if (npass == 0) { - /* the password is NULL */ - - retval = _unix_verify_password(user, NULL, nullok); - - } else { - /* does pass agree with the official one? */ - - pass[npass] = '\0'; /* NUL terminate */ - retval = _unix_verify_password(user, pass, nullok); + if (npass != 1) { /* is it a valid password? */ + helper_log_err(LOG_DEBUG, "no password supplied"); + *pass = '\0'; + } - } + if (*pass == '\0') { + blankpass = 1; } + retval = helper_verify_password(user, pass, nullok); + memset(pass, '\0', MAXPASS); /* clear memory of the password */ /* return pass or fail */ - if ((retval != PAM_SUCCESS) || force_failure) { - _log_err(LOG_NOTICE, "password check failed for user (%s)", user); - return PAM_AUTH_ERR; + if (retval != PAM_SUCCESS) { + if (!nullok || !blankpass) + /* no need to log blank pass test */ + helper_log_err(LOG_NOTICE, "password check failed for user (%s)", user); + return PAM_AUTH_ERR; } else { - return PAM_SUCCESS; + return PAM_SUCCESS; } } /* * Copyright (c) Andrew G. Morgan, 1996. All rights reserved + * Copyright (c) Red Hat, Inc., 2007,2008. All rights reserved * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions |