diff options
Diffstat (limited to 'lib/libpam/modules/pam_unix/pam_unix.c')
| -rw-r--r-- | lib/libpam/modules/pam_unix/pam_unix.c | 731 |
1 files changed, 731 insertions, 0 deletions
diff --git a/lib/libpam/modules/pam_unix/pam_unix.c b/lib/libpam/modules/pam_unix/pam_unix.c new file mode 100644 index 0000000..09910a6 --- /dev/null +++ b/lib/libpam/modules/pam_unix/pam_unix.c @@ -0,0 +1,731 @@ +/*- + * Copyright 1998 Juniper Networks, Inc. + * All rights reserved. + * Copyright (c) 2002 Networks Associates Technology, Inc. + * All rights reserved. + * + * Portions of this software was developed for the FreeBSD Project by + * ThinkSec AS and NAI Labs, the Security Research Division of Network + * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 + * ("CBOSS"), as part of the DARPA CHATS research program. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/socket.h> +#include <sys/time.h> +#include <netinet/in.h> +#include <arpa/inet.h> + +#ifdef YP +#include <rpc/rpc.h> +#include <rpcsvc/yp_prot.h> +#include <rpcsvc/ypclnt.h> +#include <rpcsvc/yppasswd.h> +#endif + +#include <login_cap.h> +#include <netdb.h> +#include <pwd.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <syslog.h> +#include <unistd.h> + +#include <pw_copy.h> +#include <pw_util.h> + +#ifdef YP +#include <pw_yp.h> +#include "yppasswd_private.h" +#endif + +#define PAM_SM_AUTH +#define PAM_SM_ACCOUNT +#define PAM_SM_SESSION +#define PAM_SM_PASSWORD + +#include <security/pam_appl.h> +#include <security/pam_modules.h> +#include <security/pam_mod_misc.h> + +#define USER_PROMPT "Username: " +#define PASSWORD_PROMPT "Password:" +#define PASSWORD_PROMPT_EXPIRED "\nPassword expired\nOld Password:" +#define NEW_PASSWORD_PROMPT_1 "New Password:" +#define NEW_PASSWORD_PROMPT_2 "New Password (again):" +#define PASSWORD_HASH "md5" +#define DEFAULT_WARN (2L * 7L * 86400L) /* Two weeks */ +#define MAX_TRIES 3 +#define SALTSIZE 32 + +static void makesalt(char []); + +static char password_prompt_def[] = PASSWORD_PROMPT; +static char password_hash[] = PASSWORD_HASH; +static char blank[] = ""; +static char colon[] = ":"; + +enum { + PAM_OPT_AUTH_AS_SELF = PAM_OPT_STD_MAX, + PAM_OPT_NULLOK, + PAM_OPT_LOCAL_PASS, + PAM_OPT_NIS_PASS +}; + +static struct opttab other_options[] = { + { "auth_as_self", PAM_OPT_AUTH_AS_SELF }, + { "nullok", PAM_OPT_NULLOK }, + { "local_pass", PAM_OPT_LOCAL_PASS }, + { "nis_pass", PAM_OPT_NIS_PASS }, + { NULL, 0 } +}; + +#ifdef YP +int pam_use_yp = 0; +int yp_errno = YP_TRUE; +#endif + +char *tempname = NULL; +static int local_passwd(const char *user, const char *pass); +#ifdef YP +static int yp_passwd(const char *user, const char *pass); +#endif + +/* + * authentication management + */ +PAM_EXTERN int +pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, int argc, const char **argv) +{ + login_cap_t *lc; + struct options options; + struct passwd *pwd; + int retval; + const char *pass, *user; + char *encrypted, *password_prompt; + + pam_std_option(&options, other_options, argc, argv); + + PAM_LOG("Options processed"); + + if (pam_test_option(&options, PAM_OPT_AUTH_AS_SELF, NULL)) + pwd = getpwnam(getlogin()); + else { + retval = pam_get_user(pamh, &user, NULL); + if (retval != PAM_SUCCESS) + PAM_RETURN(retval); + pwd = getpwnam(user); + } + + PAM_LOG("Got user: %s", user); + + lc = login_getclass(NULL); + password_prompt = login_getcapstr(lc, "passwd_prompt", + password_prompt_def, password_prompt_def); + login_close(lc); + lc = NULL; + + if (pwd != NULL) { + + PAM_LOG("Doing real authentication"); + + if (pwd->pw_passwd[0] == '\0' + && pam_test_option(&options, PAM_OPT_NULLOK, NULL)) { + /* + * No password case. XXX Are we giving too much away + * by not prompting for a password? + */ + PAM_LOG("No password, and null password OK"); + PAM_RETURN(PAM_SUCCESS); + } + else { + retval = pam_get_authtok(pamh, &pass, password_prompt); + if (retval != PAM_SUCCESS) + PAM_RETURN(retval); + PAM_LOG("Got password"); + } + encrypted = crypt(pass, pwd->pw_passwd); + if (pass[0] == '\0' && pwd->pw_passwd[0] != '\0') + encrypted = colon; + + PAM_LOG("Encrypted password 1 is: %s", encrypted); + PAM_LOG("Encrypted password 2 is: %s", pwd->pw_passwd); + + retval = strcmp(encrypted, pwd->pw_passwd) == 0 ? + PAM_SUCCESS : PAM_AUTH_ERR; + } + else { + + PAM_LOG("Doing dummy authentication"); + + /* + * User unknown. + * Encrypt a dummy password so as to not give away too much. + */ + retval = pam_get_authtok(pamh, &pass, password_prompt); + if (retval != PAM_SUCCESS) + PAM_RETURN(retval); + PAM_LOG("Got password"); + crypt(pass, "xx"); + retval = PAM_AUTH_ERR; + } + + /* + * The PAM infrastructure will obliterate the cleartext + * password before returning to the application. + */ + if (retval != PAM_SUCCESS) + PAM_VERBOSE_ERROR("UNIX authentication refused"); + + PAM_RETURN(retval); +} + +PAM_EXTERN int +pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, int argc, const char **argv) +{ + struct options options; + + pam_std_option(&options, other_options, argc, argv); + + PAM_LOG("Options processed"); + + PAM_RETURN(PAM_SUCCESS); +} + +/* + * account management + */ +PAM_EXTERN int +pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused, int argc, const char **argv) +{ + struct addrinfo hints, *res; + struct options options; + struct passwd *pwd; + struct timeval tp; + login_cap_t *lc; + time_t warntime; + int retval; + const char *rhost, *tty, *user; + char rhostip[MAXHOSTNAMELEN]; + + pam_std_option(&options, other_options, argc, argv); + + PAM_LOG("Options processed"); + + retval = pam_get_item(pamh, PAM_USER, (const void **)&user); + if (retval != PAM_SUCCESS) + PAM_RETURN(retval); + + if (user == NULL || (pwd = getpwnam(user)) == NULL) + PAM_RETURN(PAM_SERVICE_ERR); + + PAM_LOG("Got user: %s", user); + + retval = pam_get_item(pamh, PAM_RHOST, (const void **)&rhost); + if (retval != PAM_SUCCESS) + PAM_RETURN(retval); + + retval = pam_get_item(pamh, PAM_TTY, (const void **)&tty); + if (retval != PAM_SUCCESS) + PAM_RETURN(retval); + + if (*pwd->pw_passwd == '\0' && + (flags & PAM_DISALLOW_NULL_AUTHTOK) != 0) + return (PAM_NEW_AUTHTOK_REQD); + + lc = login_getpwclass(pwd); + if (lc == NULL) { + PAM_LOG("Unable to get login class for user %s", user); + return (PAM_SERVICE_ERR); + } + + PAM_LOG("Got login_cap"); + + if (pwd->pw_change || pwd->pw_expire) + gettimeofday(&tp, NULL); + + /* + * Check pw_expire before pw_change - no point in letting the + * user change the password on an expired account. + */ + + if (pwd->pw_expire) { + warntime = login_getcaptime(lc, "warnexpire", + DEFAULT_WARN, DEFAULT_WARN); + if (tp.tv_sec >= pwd->pw_expire) { + login_close(lc); + PAM_RETURN(PAM_ACCT_EXPIRED); + } else if (pwd->pw_expire - tp.tv_sec < warntime && + (flags & PAM_SILENT) == 0) { + pam_error(pamh, "Warning: your account expires on %s", + ctime(&pwd->pw_expire)); + } + } + + retval = PAM_SUCCESS; + if (pwd->pw_change) { + warntime = login_getcaptime(lc, "warnpassword", + DEFAULT_WARN, DEFAULT_WARN); + if (tp.tv_sec >= pwd->pw_change) { + retval = PAM_NEW_AUTHTOK_REQD; + } else if (pwd->pw_change - tp.tv_sec < warntime && + (flags & PAM_SILENT) == 0) { + pam_error(pamh, "Warning: your password expires on %s", + ctime(&pwd->pw_change)); + } + } + + /* + * From here on, we must leave retval untouched (unless we + * know we're going to fail), because we need to remember + * whether we're supposed to return PAM_SUCCESS or + * PAM_NEW_AUTHTOK_REQD. + */ + + if (rhost) { + memset(&hints, 0, sizeof(hints)); + hints.ai_family = AF_UNSPEC; + if (getaddrinfo(rhost, NULL, &hints, &res) == 0) { + getnameinfo(res->ai_addr, res->ai_addrlen, + rhostip, sizeof(rhostip), NULL, 0, + NI_NUMERICHOST|NI_WITHSCOPEID); + } + if (res != NULL) + freeaddrinfo(res); + } + + /* + * Check host / tty / time-of-day restrictions + */ + + if (!auth_hostok(lc, rhost, rhostip) || + !auth_ttyok(lc, tty) || + !auth_timeok(lc, time(NULL))) + retval = PAM_AUTH_ERR; + + login_close(lc); + + PAM_RETURN(retval); +} + +/* + * session management + * + * logging only + */ +PAM_EXTERN int +pam_sm_open_session(pam_handle_t *pamh __unused, int flags __unused, int argc, const char **argv) +{ + struct options options; + + pam_std_option(&options, other_options, argc, argv); + + PAM_LOG("Options processed"); + + PAM_RETURN(PAM_SUCCESS); +} + +PAM_EXTERN int +pam_sm_close_session(pam_handle_t *pamh __unused, int flags __unused, int argc, const char **argv) +{ + struct options options; + + pam_std_option(&options, other_options, argc, argv); + + PAM_LOG("Options processed"); + + PAM_RETURN(PAM_SUCCESS); +} + +/* + * password management + * + * standard Unix and NIS password changing + */ +PAM_EXTERN int +pam_sm_chauthtok(pam_handle_t *pamh, int flags, int argc, const char **argv) +{ + struct options options; + struct passwd *pwd; + int retval, retry, res, got; + const char *user, *pass; + char *new_pass, *new_pass_, *encrypted, *usrdup; + + pam_std_option(&options, other_options, argc, argv); + + PAM_LOG("Options processed"); + + if (pam_test_option(&options, PAM_OPT_AUTH_AS_SELF, NULL)) + pwd = getpwnam(getlogin()); + else { + retval = pam_get_user(pamh, &user, NULL); + if (retval != PAM_SUCCESS) + PAM_RETURN(retval); + pwd = getpwnam(user); + } + + PAM_LOG("Got user: %s", user); + + if (flags & PAM_PRELIM_CHECK) { + + PAM_LOG("PRELIM round; checking user password"); + + if (pwd->pw_passwd[0] == '\0' + && pam_test_option(&options, PAM_OPT_NULLOK, NULL)) { + /* + * No password case. XXX Are we giving too much away + * by not prompting for a password? + */ + PAM_LOG("No password, and null password OK"); + PAM_RETURN(PAM_SUCCESS); + } + else { + retval = pam_get_authtok(pamh, &pass, + PASSWORD_PROMPT_EXPIRED); + if (retval != PAM_SUCCESS) + PAM_RETURN(retval); + PAM_LOG("Got password: %s", pass); + } + encrypted = crypt(pass, pwd->pw_passwd); + if (pass[0] == '\0' && pwd->pw_passwd[0] != '\0') + encrypted = colon; + + PAM_LOG("Encrypted password 1 is: %s", encrypted); + PAM_LOG("Encrypted password 2 is: %s", pwd->pw_passwd); + + if (strcmp(encrypted, pwd->pw_passwd) != 0) + PAM_RETURN(PAM_AUTH_ERR); + + retval = pam_set_item(pamh, PAM_OLDAUTHTOK, (const void *)pass); + pass = NULL; + if (retval != PAM_SUCCESS) + PAM_RETURN(retval); + + PAM_LOG("Stashed old password"); + + retval = pam_set_item(pamh, PAM_AUTHTOK, (const void *)pass); + if (retval != PAM_SUCCESS) + PAM_RETURN(retval); + + PAM_LOG("Voided old password"); + + PAM_RETURN(PAM_SUCCESS); + } + else if (flags & PAM_UPDATE_AUTHTOK) { + PAM_LOG("UPDATE round; checking user password"); + + retval = pam_get_item(pamh, PAM_OLDAUTHTOK, + (const void **)&pass); + if (retval != PAM_SUCCESS) + PAM_RETURN(retval); + + PAM_LOG("Got old password: %s", pass); + + got = 0; + retry = 0; + while (retry++ < MAX_TRIES) { + new_pass = NULL; + retval = pam_prompt(pamh, PAM_PROMPT_ECHO_OFF, + &new_pass, "%s", NEW_PASSWORD_PROMPT_1); + + if (new_pass == NULL) + new_pass = blank; + + if (retval == PAM_SUCCESS) { + new_pass_ = NULL; + retval = pam_prompt(pamh, PAM_PROMPT_ECHO_OFF, + &new_pass_, "%s", NEW_PASSWORD_PROMPT_2); + + if (new_pass_ == NULL) + new_pass_ = blank; + + if (retval == PAM_SUCCESS) { + if (strcmp(new_pass, new_pass_) == 0) { + got = 1; + break; + } + else + PAM_VERBOSE_ERROR("Password mismatch"); + } + } + } + + if (!got) { + PAM_VERBOSE_ERROR("Unable to get valid password"); + PAM_RETURN(PAM_PERM_DENIED); + } + + PAM_LOG("Got new password: %s", new_pass); + +#ifdef YP + /* If NIS is set in the passwd database, use it */ + if ((usrdup = strdup(user)) == NULL) + PAM_RETURN(PAM_BUF_ERR); + res = use_yp(usrdup, 0, 0); + free(usrdup); + if (res == USER_YP_ONLY) { + if (!pam_test_option(&options, PAM_OPT_LOCAL_PASS, + NULL)) + retval = yp_passwd(user, new_pass); + else { + /* Reject 'local' flag if NIS is on and the user + * is not local + */ + retval = PAM_PERM_DENIED; + PAM_LOG("Unknown local user: %s", user); + } + } + else if (res == USER_LOCAL_ONLY) { + if (!pam_test_option(&options, PAM_OPT_NIS_PASS, NULL)) + retval = local_passwd(user, new_pass); + else { + /* Reject 'nis' flag if user is only local */ + retval = PAM_PERM_DENIED; + PAM_LOG("Unknown NIS user: %s", user); + } + } + else if (res == USER_YP_AND_LOCAL) { + if (pam_test_option(&options, PAM_OPT_NIS_PASS, NULL)) + retval = yp_passwd(user, new_pass); + else + retval = local_passwd(user, new_pass); + } + else + retval = PAM_SERVICE_ERR; /* Bad juju */ +#else + retval = local_passwd(user, new_pass); +#endif + + /* XXX wipe the mem as well */ + pass = NULL; + new_pass = NULL; + } + else { + /* Very bad juju */ + retval = PAM_ABORT; + PAM_LOG("Illegal 'flags'"); + } + + PAM_RETURN(retval); +} + +/* Mostly stolen from passwd(1)'s local_passwd.c - markm */ + +static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */ + "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; + +static void +to64(char *s, long v, int n) +{ + while (--n >= 0) { + *s++ = itoa64[v&0x3f]; + v >>= 6; + } +} + +static int +local_passwd(const char *user, const char *pass) +{ + login_cap_t * lc; + struct passwd *pwd; + struct timeval tv; + int pfd, tfd; + char *crypt_type, salt[SALTSIZE + 1]; + + pwd = getpwnam(user); + if (pwd == NULL) + return(PAM_SERVICE_ERR); /* Really bad things */ + +#ifdef YP + pwd = (struct passwd *)&local_password; +#endif + pw_init(); + + pwd->pw_change = 0; + lc = login_getclass(NULL); + crypt_type = login_getcapstr(lc, "passwd_format", + password_hash, password_hash); + if (login_setcryptfmt(lc, crypt_type, NULL) == NULL) + syslog(LOG_ERR, "cannot set password cipher"); + login_close(lc); + makesalt(salt); + pwd->pw_passwd = crypt(pass, salt); + + pfd = pw_lock(); + tfd = pw_tmp(); + pw_copy(pfd, tfd, pwd, NULL); + + if (!pw_mkdb(user)) + pw_error((char *)NULL, 0, 1); + + return (PAM_SUCCESS); +} + +#ifdef YP +/* Stolen from src/usr.bin/passwd/yp_passwd.c, carrying copyrights of: + * Copyright (c) 1992/3 Theo de Raadt <deraadt@fsa.ca> + * Copyright (c) 1994 Olaf Kirch <okir@monad.swb.de> + * Copyright (c) 1995 Bill Paul <wpaul@ctr.columbia.edu> + */ +int +yp_passwd(const char *user __unused, const char *pass) +{ + struct master_yppasswd master_yppwd; + struct passwd *pwd; + struct rpc_err err; + struct timeval tv; + struct yppasswd yppwd; + CLIENT *clnt; + login_cap_t *lc; + int *status; + gid_t gid; + pid_t pid; + uid_t uid; + char *master, sockname[] = YP_SOCKNAME, salt[SALTSIZE + 1]; + + _use_yp = 1; + + uid = getuid(); + + master = get_yp_master(1); + if (master == NULL) + return (PAM_SERVICE_ERR); /* Major disaster */ + + /* + * It is presumed that by the time we get here, use_yp() + * has been called and that we have verified that the user + * actually exists. This being the case, the yp_password + * stucture has already been filled in for us. + */ + + /* Use the correct password */ + pwd = (struct passwd *)&yp_password; + + pwd->pw_change = 0; + + /* Initialize password information */ + if (suser_override) { + master_yppwd.newpw.pw_passwd = strdup(pwd->pw_passwd); + master_yppwd.newpw.pw_name = strdup(pwd->pw_name); + master_yppwd.newpw.pw_uid = pwd->pw_uid; + master_yppwd.newpw.pw_gid = pwd->pw_gid; + master_yppwd.newpw.pw_expire = pwd->pw_expire; + master_yppwd.newpw.pw_change = pwd->pw_change; + master_yppwd.newpw.pw_fields = pwd->pw_fields; + master_yppwd.newpw.pw_gecos = strdup(pwd->pw_gecos); + master_yppwd.newpw.pw_dir = strdup(pwd->pw_dir); + master_yppwd.newpw.pw_shell = strdup(pwd->pw_shell); + master_yppwd.newpw.pw_class = pwd->pw_class != NULL ? + strdup(pwd->pw_class) : strdup(""); + master_yppwd.oldpass = strdup(""); + master_yppwd.domain = yp_domain; + } else { + yppwd.newpw.pw_passwd = strdup(pwd->pw_passwd); + yppwd.newpw.pw_name = strdup(pwd->pw_name); + yppwd.newpw.pw_uid = pwd->pw_uid; + yppwd.newpw.pw_gid = pwd->pw_gid; + yppwd.newpw.pw_gecos = strdup(pwd->pw_gecos); + yppwd.newpw.pw_dir = strdup(pwd->pw_dir); + yppwd.newpw.pw_shell = strdup(pwd->pw_shell); + yppwd.oldpass = strdup(""); + } + + if (login_setcryptfmt(lc, "md5", NULL) == NULL) + syslog(LOG_ERR, "cannot set password cipher"); + login_close(lc); + + makesalt(salt); + if (suser_override) + master_yppwd.newpw.pw_passwd = crypt(pass, salt); + else + yppwd.newpw.pw_passwd = crypt(pass, salt); + + if (suser_override) { + if ((clnt = clnt_create(sockname, MASTER_YPPASSWDPROG, + MASTER_YPPASSWDVERS, "unix")) == NULL) { + syslog(LOG_ERR, + "Cannot contact rpc.yppasswdd on host %s: %s", + master, clnt_spcreateerror("")); + return (PAM_SERVICE_ERR); + } + } + else { + if ((clnt = clnt_create(master, YPPASSWDPROG, + YPPASSWDVERS, "udp")) == NULL) { + syslog(LOG_ERR, + "Cannot contact rpc.yppasswdd on host %s: %s", + master, clnt_spcreateerror("")); + return (PAM_SERVICE_ERR); + } + } + /* + * The yppasswd.x file said `unix authentication required', + * so I added it. This is the only reason it is in here. + * My yppasswdd doesn't use it, but maybe some others out there + * do. --okir + */ + clnt->cl_auth = authunix_create_default(); + + if (suser_override) + status = yppasswdproc_update_master_1(&master_yppwd, clnt); + else + status = yppasswdproc_update_1(&yppwd, clnt); + + clnt_geterr(clnt, &err); + + auth_destroy(clnt->cl_auth); + clnt_destroy(clnt); + + if (err.re_status != RPC_SUCCESS || status == NULL || *status) + return (PAM_SERVICE_ERR); + + if (err.re_status || status == NULL || *status) + return (PAM_SERVICE_ERR); + return (PAM_SUCCESS); +} +#endif /* YP */ + +/* Salt suitable for traditional DES and MD5 */ +void +makesalt(char salt[SALTSIZE]) +{ + int i; + + /* These are not really random numbers, they are just + * numbers that change to thwart construction of a + * dictionary. This is exposed to the public. + */ + for (i = 0; i < SALTSIZE; i += 4) + to64(&salt[i], arc4random(), 4); + salt[SALTSIZE] = '\0'; +} + +PAM_MODULE_ENTRY("pam_unix"); |
