diff options
Diffstat (limited to 'modules/pam_unix/passverify.c')
| -rw-r--r-- | modules/pam_unix/passverify.c | 687 |
1 files changed, 686 insertions, 1 deletions
diff --git a/modules/pam_unix/passverify.c b/modules/pam_unix/passverify.c index 9a3d72e6..e379cf62 100644 --- a/modules/pam_unix/passverify.c +++ b/modules/pam_unix/passverify.c @@ -13,7 +13,12 @@ #include <shadow.h> #include <syslog.h> #include <stdarg.h> +#include <signal.h> +#include <errno.h> #include <time.h> +#include <sys/time.h> +#include <sys/stat.h> +#include <fcntl.h> #include "md5.h" #include "bigcrypt.h" @@ -35,6 +40,10 @@ #include <security/pam_ext.h> #endif +#if defined(USE_LCKPWDF) && !defined(HAVE_LCKPWDF) +# include "./lckpwdf.-c" +#endif + int verify_pwd_hash(const char *p, const char *hash, unsigned int nullok) { @@ -256,6 +265,588 @@ check_shadow_expiry(pam_handle_t *pamh, struct spwd *spent, int *daysleft) } +/* passwd/salt conversion macros */ + +#define PW_TMPFILE "/etc/npasswd" +#define SH_TMPFILE "/etc/nshadow" +#define OPW_TMPFILE "/etc/security/nopasswd" + +/* + * i64c - convert an integer to a radix 64 character + */ +static int +i64c(int i) +{ + if (i < 0) + return ('.'); + else if (i > 63) + return ('z'); + if (i == 0) + return ('.'); + if (i == 1) + return ('/'); + if (i >= 2 && i <= 11) + return ('0' - 2 + i); + if (i >= 12 && i <= 37) + return ('A' - 12 + i); + if (i >= 38 && i <= 63) + return ('a' - 38 + i); + return ('\0'); +} + +char * +crypt_md5_wrapper(const char *pass_new) +{ + /* + * Code lifted from Marek Michalkiewicz's shadow suite. (CG) + * removed use of static variables (AGM) + */ + + struct timeval tv; + MD5_CTX ctx; + unsigned char result[16]; + char *cp = (char *) result; + unsigned char tmp[16]; + int i; + char *x = NULL; + + GoodMD5Init(&ctx); + gettimeofday(&tv, (struct timezone *) 0); + GoodMD5Update(&ctx, (void *) &tv, sizeof tv); + i = getpid(); + GoodMD5Update(&ctx, (void *) &i, sizeof i); + i = clock(); + GoodMD5Update(&ctx, (void *) &i, sizeof i); + GoodMD5Update(&ctx, result, sizeof result); + GoodMD5Final(tmp, &ctx); + strcpy(cp, "$1$"); /* magic for the MD5 */ + cp += strlen(cp); + for (i = 0; i < 8; i++) + *cp++ = i64c(tmp[i] & 077); + *cp = '\0'; + + /* no longer need cleartext */ + x = Goodcrypt_md5(pass_new, (const char *) result); + + return x; +} + +#ifdef WITH_SELINUX +int +unix_selinux_confined(void) +{ + static int confined = -1; + int fd; + char tempfile[]="/etc/.pwdXXXXXX"; + + if (confined != -1) + return confined; + + /* cannot be confined without SELinux enabled */ + if (!SELINUX_ENABLED){ + confined = 0; + return confined; + } + + /* let's try opening shadow read only */ + if ((fd=open("/etc/shadow", O_RDONLY)) != -1) { + close(fd); + confined = 0; + return confined; + } + + if (errno == EACCES) { + confined = 1; + return confined; + } + + /* shadow opening failed because of other reasons let's try + creating a file in /etc */ + if ((fd=mkstemp(tempfile)) != -1) { + unlink(tempfile); + close(fd); + confined = 0; + return confined; + } + + confined = 1; + return confined; +} + +#else +int +unix_selinux_confined(void) +{ + return 0; +} +#endif + +#ifdef USE_LCKPWDF +int +lock_pwdf(void) +{ + int i; + int retval; + +#ifndef HELPER_COMPILE + if (unix_selinux_confined()) { + return PAM_SUCCESS; + } +#endif + /* These values for the number of attempts and the sleep time + are, of course, completely arbitrary. + My reading of the PAM docs is that, once pam_chauthtok() has been + called with PAM_UPDATE_AUTHTOK, we are obliged to take any + reasonable steps to make sure the token is updated; so retrying + for 1/10 sec. isn't overdoing it. */ + i=0; + while((retval = lckpwdf()) != 0 && i < 100) { + usleep(1000); + i++; + } + if(retval != 0) { + return PAM_AUTHTOK_LOCK_BUSY; + } + return PAM_SUCCESS; +} + +void +unlock_pwdf(void) +{ +#ifndef HELPER_COMPILE + if (unix_selinux_confined()) { + return; + } +#endif + ulckpwdf(); +} +#else +int +lock_pwdf(void) +{ + return PAM_SUCCESS; +} + +void +unlock_pwdf(void) +{ + return; +} +#endif + +int +save_old_password(const char *forwho, const char *oldpass, + int howmany) +{ + static char buf[16384]; + static char nbuf[16384]; + char *s_luser, *s_uid, *s_npas, *s_pas, *pass; + int npas; + FILE *pwfile, *opwfile; + int err = 0; + int oldmask; + int found = 0; + struct passwd *pwd = NULL; + struct stat st; + security_context_t prev_context=NULL; + + if (howmany < 0) { + return PAM_SUCCESS; + } + + if (oldpass == NULL) { + return PAM_SUCCESS; + } + + oldmask = umask(077); + +#ifdef WITH_SELINUX + if (SELINUX_ENABLED) { + security_context_t passwd_context=NULL; + if (getfilecon("/etc/passwd",&passwd_context)<0) { + return PAM_AUTHTOK_ERR; + }; + if (getfscreatecon(&prev_context)<0) { + freecon(passwd_context); + return PAM_AUTHTOK_ERR; + } + if (setfscreatecon(passwd_context)) { + freecon(passwd_context); + freecon(prev_context); + return PAM_AUTHTOK_ERR; + } + freecon(passwd_context); + } +#endif + pwfile = fopen(OPW_TMPFILE, "w"); + umask(oldmask); + if (pwfile == NULL) { + err = 1; + goto done; + } + + opwfile = fopen(OLD_PASSWORDS_FILE, "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; + } + + while (fgets(buf, 16380, opwfile)) { + if (!strncmp(buf, forwho, strlen(forwho))) { + char *sptr = NULL; + found = 1; + if (howmany == 0) + continue; + buf[strlen(buf) - 1] = '\0'; + s_luser = strtok_r(buf, ":", &sptr); + s_uid = strtok_r(NULL, ":", &sptr); + s_npas = strtok_r(NULL, ":", &sptr); + s_pas = strtok_r(NULL, ":", &sptr); + npas = strtol(s_npas, NULL, 10) + 1; + while (npas > howmany) { + s_pas = strpbrk(s_pas, ","); + if (s_pas != NULL) + s_pas++; + npas--; + } + pass = crypt_md5_wrapper(oldpass); + if (s_pas == NULL) + snprintf(nbuf, sizeof(nbuf), "%s:%s:%d:%s\n", + s_luser, s_uid, npas, pass); + else + snprintf(nbuf, sizeof(nbuf),"%s:%s:%d:%s,%s\n", + s_luser, s_uid, npas, s_pas, pass); + _pam_delete(pass); + if (fputs(nbuf, pwfile) < 0) { + err = 1; + break; + } + } else if (fputs(buf, pwfile) < 0) { + err = 1; + break; + } + } + fclose(opwfile); + + if (!found) { + pwd = getpwnam(forwho); + if (pwd == NULL) { + err = 1; + } else { + pass = crypt_md5_wrapper(oldpass); + snprintf(nbuf, sizeof(nbuf), "%s:%lu:1:%s\n", + forwho, (unsigned long)pwd->pw_uid, pass); + _pam_delete(pass); + if (fputs(nbuf, pwfile) < 0) { + err = 1; + } + } + } + + if (fclose(pwfile)) { + D(("error writing entries to old passwords file: %m")); + err = 1; + } + +done: + if (!err) { + if (rename(OPW_TMPFILE, OLD_PASSWORDS_FILE)) + 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(OPW_TMPFILE); + return PAM_AUTHTOK_ERR; + } +} + +#ifdef HELPER_COMPILE +int +unix_update_passwd(const char *forwho, const char *towhat) +#else +int +unix_update_passwd(pam_handle_t *pamh, const char *forwho, const char *towhat) +#endif +{ + struct passwd *tmpent = NULL; + struct stat st; + FILE *pwfile, *opwfile; + int err = 1; + int oldmask; + security_context_t prev_context=NULL; + + oldmask = umask(077); +#ifdef WITH_SELINUX + if (SELINUX_ENABLED) { + security_context_t passwd_context=NULL; + if (getfilecon("/etc/passwd",&passwd_context)<0) { + return PAM_AUTHTOK_ERR; + }; + if (getfscreatecon(&prev_context)<0) { + freecon(passwd_context); + return PAM_AUTHTOK_ERR; + } + if (setfscreatecon(passwd_context)) { + freecon(passwd_context); + freecon(prev_context); + return PAM_AUTHTOK_ERR; + } + freecon(passwd_context); + } +#endif + pwfile = fopen(PW_TMPFILE, "w"); + umask(oldmask); + if (pwfile == NULL) { + err = 1; + goto done; + } + + opwfile = fopen("/etc/passwd", "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; + } + + tmpent = fgetpwent(opwfile); + while (tmpent) { + if (!strcmp(tmpent->pw_name, forwho)) { + /* To shut gcc up */ + union { + const char *const_charp; + char *charp; + } assigned_passwd; + assigned_passwd.const_charp = towhat; + + tmpent->pw_passwd = assigned_passwd.charp; + err = 0; + } + if (putpwent(tmpent, pwfile)) { + D(("error writing entry to password file: %m")); + err = 1; + break; + } + tmpent = fgetpwent(opwfile); + } + fclose(opwfile); + + if (fclose(pwfile)) { + D(("error writing entries to password file: %m")); + err = 1; + } + +done: + if (!err) { + if (!rename(PW_TMPFILE, "/etc/passwd")) +#ifdef HELPER_COMPILE + helper_log_err( +#else + pam_syslog(pamh, +#endif + LOG_NOTICE, "password changed for %s", forwho); + else + 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(PW_TMPFILE); + return PAM_AUTHTOK_ERR; + } +} + +#ifdef HELPER_COMPILE +int +unix_update_shadow(const char *forwho, char *towhat) +#else +int +unix_update_shadow(pam_handle_t *pamh, const char *forwho, char *towhat) +#endif +{ + struct spwd *spwdent = NULL, *stmpent = NULL; + struct stat st; + FILE *pwfile, *opwfile; + int err = 1; + int oldmask; + security_context_t prev_context=NULL; + + 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")) +#ifdef HELPER_COMPILE + helper_log_err( +#else + pam_syslog(pamh, +#endif + LOG_NOTICE, "password changed for %s", forwho); + else + 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; + } +} + #ifdef HELPER_COMPILE int @@ -296,13 +887,107 @@ helper_log_err(int err, const char *format, ...) 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) { + _exit(sig); + } +} + +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); +} + +char * +getuidname(uid_t uid) +{ + struct passwd *pw; + static char username[256]; + + pw = getpwuid(uid); + if (pw == NULL) + return NULL; + + strncpy(username, pw->pw_name, sizeof(username)); + username[sizeof(username) - 1] = '\0'; + + return username; +} + +int +read_passwords(int fd, int npass, char **passwords) +{ + int rbytes = 0; + int offset = 0; + int i = 0; + char *pptr; + while (npass > 0) { + rbytes = read(fd, passwords[i]+offset, MAXPASS-offset); + + if (rbytes < 0) { + if (errno == EINTR) continue; + break; + } + if (rbytes == 0) + break; + + while (npass > 0 && (pptr=memchr(passwords[i]+offset, '\0', rbytes)) + != NULL) { + rbytes -= pptr - (passwords[i]+offset) + 1; + i++; + offset = 0; + npass--; + if (rbytes > 0) { + if (npass > 0) + memcpy(passwords[i], pptr+1, rbytes); + memset(pptr+1, '\0', rbytes); + } + } + offset += rbytes; + } + + /* clear up */ + if (offset > 0 && npass > 0) { + memset(passwords[i], '\0', offset); + } + + return i; +} + #endif /* ****************************************************************** * * Copyright (c) Jan Rêkorajski 1999. * Copyright (c) Andrew G. Morgan 1996-8. * Copyright (c) Alex O. Yuriev, 1996. * Copyright (c) Cristian Gafton 1996. - * Copyright (c) Red Hat, Inc. 2007. + * Copyright (c) Red Hat, Inc. 1996, 2007, 2008. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions |