diff options
Diffstat (limited to 'crypto/heimdal/appl/su/su.c')
| -rw-r--r-- | crypto/heimdal/appl/su/su.c | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/crypto/heimdal/appl/su/su.c b/crypto/heimdal/appl/su/su.c new file mode 100644 index 0000000..049a4d7 --- /dev/null +++ b/crypto/heimdal/appl/su/su.c @@ -0,0 +1,418 @@ +/* + * Copyright (c) 1999 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * 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. Neither the name of KTH nor the names of its contributors may be + * used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY KTH AND ITS 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 KTH OR ITS 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 <config.h> + +RCSID("$Id: su.c,v 1.10 1999/09/28 02:34:17 assar Exp $"); + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <syslog.h> + +#ifdef HAVE_PATHS_H +#include <paths.h> +#endif + +#ifdef HAVE_SHADOW_H +#include <shadow.h> +#endif + +#include <pwd.h> + +#include <krb5.h> +#include <kafs.h> +#include <err.h> +#include <roken.h> +#include <getarg.h> +#include <kafs.h> + +#ifndef _PATH_DEFPATH +#define _PATH_DEFPATH "/usr/bin:/bin" +#endif + +#ifndef _PATH_BSHELL +#define _PATH_BSHELL "/bin/sh" +#endif + +int kerberos_flag = 1; +int csh_f_flag; +int full_login; +int env_flag; +char *kerberos_instance = "root"; +int help_flag; +int version_flag; +char *cmd; + +struct getargs args[] = { + { "kerberos", 'K', arg_negative_flag, &kerberos_flag, + "don't use kerberos" }, + { NULL, 'f', arg_flag, &csh_f_flag, + "don't read .cshrc" }, + { "full", 'l', arg_flag, &full_login, + "simulate full login" }, + { NULL, 'm', arg_flag, &env_flag, + "leave environment unmodified" }, + { "instance", 'i', arg_string, &kerberos_instance, + "root instance to use" }, + { "command", 'c', arg_string, &cmd, + "command to execute" }, + { "help", 'h', arg_flag, &help_flag }, + { "version", 0, arg_flag, &version_flag }, +}; + + +static void +usage (int ret) +{ + arg_printusage (args, + sizeof(args)/sizeof(*args), + NULL, + "[login [shell arguments]]"); + exit (ret); +} + +static struct passwd* +make_info(struct passwd *pwd) +{ + struct passwd *info; + info = malloc(sizeof(*info)); + if(info == NULL) + return NULL; + info->pw_name = strdup(pwd->pw_name); + info->pw_passwd = strdup(pwd->pw_passwd); + info->pw_uid = pwd->pw_uid; + info->pw_gid = pwd->pw_gid; + info->pw_dir = strdup(pwd->pw_dir); + info->pw_shell = strdup(pwd->pw_shell); + if(info->pw_name == NULL || info->pw_passwd == NULL || + info->pw_dir == NULL || info->pw_shell == NULL) + return NULL; + return info; +} + +#ifdef KRB5 +static krb5_context context; +static krb5_ccache ccache; +#endif + +static int +krb5_verify(struct passwd *login_info, struct passwd *su_info, + const char *kerberos_instance) +{ +#ifdef KRB5 + krb5_error_code ret; + krb5_principal p; + + ret = krb5_init_context (&context); + if (ret) { +#if 0 + warnx("krb5_init_context failed: %u", ret); +#endif + return 1; + } + + if (strcmp (su_info->pw_name, "root") == 0) + ret = krb5_make_principal(context, &p, NULL, + login_info->pw_name, + kerberos_instance, + NULL); + else + ret = krb5_make_principal(context, &p, NULL, + su_info->pw_name, + NULL); + if(ret) + return 1; + + if(su_info->pw_uid != 0 || krb5_kuserok(context, p, su_info->pw_name)) { + ret = krb5_cc_gen_new(context, &krb5_mcc_ops, &ccache); + if(ret) { +#if 1 + krb5_warn(context, ret, "krb5_cc_gen_new"); +#endif + return 1; + } + ret = krb5_verify_user_lrealm(context, p, ccache, NULL, TRUE, NULL); + if(ret) { + krb5_free_principal (context, p); + krb5_cc_destroy(context, ccache); + switch (ret) { + case KRB5KRB_AP_ERR_BAD_INTEGRITY: + case KRB5KRB_AP_ERR_MODIFIED: + krb5_warnx(context, "Password incorrect"); + break; + default : + krb5_warn(context, ret, "krb5_verify_user"); + break; + } + return 1; + } + return 0; + } +#endif + return 1; +} + +#ifdef KRB5 +static int +krb5_start_session(void) +{ + krb5_ccache ccache2; + char *cc_name; + int ret; + + ret = krb5_cc_gen_new(context, &krb5_fcc_ops, &ccache2); + if (ret) { + krb5_cc_destroy(context, ccache); + return 1; + } + + ret = krb5_cc_copy_cache(context, ccache, ccache2); + + asprintf(&cc_name, "%s:%s", krb5_cc_get_type(context, ccache2), + krb5_cc_get_name(context, ccache2)); + setenv("KRB5CCNAME", cc_name, 1); + +#ifdef KRB4 + if(k_hasafs()) { + if (k_setpag() == 0) + krb5_afslog(context, ccache2, NULL, NULL); + } +#endif + + krb5_cc_close(context, ccache2); + krb5_cc_destroy(context, ccache); + return 0; +} +#endif + +static int +verify_unix(struct passwd *su) +{ + char prompt[128]; + char pw_buf[1024]; + char *pw; + int r; + if(su->pw_passwd != NULL && *su->pw_passwd != '\0') { + sprintf(prompt, "%s's password: ", su->pw_name); + r = des_read_pw_string(pw_buf, sizeof(pw_buf), prompt, 0); + if(r != 0) + exit(0); + pw = crypt(pw_buf, su->pw_passwd); + memset(pw_buf, 0, sizeof(pw_buf)); + if(strcmp(pw, su->pw_passwd) != 0) + return 1; + } + return 0; +} + +int +main(int argc, char **argv) +{ + int i, optind = 0; + char *su_user; + struct passwd *su_info; + char *login_user = NULL; + struct passwd *login_info; + + struct passwd *pwd; + + char *shell; + + int ok = 0; + int kerberos_error=1; + + set_progname (argv[0]); + + if(getarg(args, sizeof(args) / sizeof(args[0]), argc, argv, &optind)) + usage(1); + + for (i=0; i < optind; i++) + if (strcmp(argv[i], "-") == 0) { + full_login = 1; + break; + } + + if(help_flag) + usage(0); + if(version_flag) { + print_version(NULL); + exit(0); + } + if(optind >= argc) + su_user = "root"; + else + su_user = argv[optind++]; + + pwd = k_getpwnam(su_user); + if(pwd == NULL) + errx (1, "unknown login %s", su_user); + if (pwd->pw_uid == 0 && strcmp ("root", su_user) != 0) { + syslog (LOG_ALERT, "NIS attack, user %s has uid 0", su_user); + errx (1, "unknown login %s", su_user); + } + su_info = make_info(pwd); + +#if defined(HAVE_GETLOGIN) && !defined(POSIX_GETLOGIN) + login_user = getlogin(); +#endif + if(login_user == NULL || (pwd = getpwnam(login_user)) == NULL) + pwd = getpwuid(getuid()); + if(pwd == NULL) + errx(1, "who are you?"); + login_info = make_info(pwd); + if(env_flag) + shell = login_info->pw_shell; + else + shell = su_info->pw_shell; + if(shell == NULL || *shell == '\0') + shell = _PATH_BSHELL; + + if(kerberos_flag && ok == 0 && + (kerberos_error=krb5_verify(login_info, su_info, kerberos_instance)) == 0) + ok++; + + if(ok == 0 && login_info->pw_uid && verify_unix(su_info) != 0) { + printf("Sorry!\n"); + exit(1); + } + +#ifdef HAVE_GETSPNAM + { struct spwd *sp; + long today; + + sp=getspnam(su_info->pw_name); + if (sp==NULL) + errx(1,"Have not rights to read shadow passwords!"); + today = time(0)/(24L * 60 * 60); + if (sp->sp_expire > 0) { + if (today >= sp->sp_expire) { + if (login_info->pw_uid) + errx(1,"Your account has expired."); + else + printf("Your account has expired."); + } + else if (sp->sp_expire - today < 14) + printf("Your account will expire in %d days.\n", + (int)(sp->sp_expire - today)); + } + if (sp->sp_max > 0) { + if (today >= sp->sp_lstchg + sp->sp_max) { + if (login_info->pw_uid) + errx(1,"Your password has expired. Choose a new one."); + else + printf("Your password has expired. Choose a new one."); + } + else if (today >= sp->sp_lstchg + sp->sp_max - sp->sp_warn) + printf("Your account will expire in %d days.\n", + (int)(sp->sp_lstchg + sp->sp_max -today)); + } + } +#endif + { + char *tty = ttyname (STDERR_FILENO); + syslog (LOG_NOTICE | LOG_AUTH, tty ? "%s to %s" : "%s to %s on %s", + login_info->pw_name, su_info->pw_name, tty); + } + + + if(!env_flag) { + if(full_login) { + char *t = getenv ("TERM"); + + environ = malloc (10 * sizeof (char *)); + if (environ == NULL) + err (1, "malloc"); + environ[0] = NULL; + setenv ("PATH", _PATH_DEFPATH, 1); + if (t) + setenv ("TERM", t, 1); + if (chdir (su_info->pw_dir) < 0) + errx (1, "no directory"); + } + if (full_login || su_info->pw_uid) + setenv ("USER", su_info->pw_name, 1); + setenv("HOME", su_info->pw_dir, 1); + setenv("SHELL", shell, 1); + } + + { + int i; + char **args; + char *p; + + p = strrchr(shell, '/'); + if(p) + p++; + else + p = shell; + + if (strcmp(p, "csh") != 0) + csh_f_flag = 0; + + args = malloc(((cmd ? 2 : 0) + 1 + argc - optind + 1 + csh_f_flag) * sizeof(*args)); + if (args == NULL) + err (1, "malloc"); + i = 0; + if(full_login) + asprintf(&args[i++], "-%s", p); + else + args[i++] = p; + if (cmd) { + args[i++] = "-c"; + args[i++] = cmd; + } + + if (csh_f_flag) + args[i++] = "-f"; + + for (argv += optind; *argv; ++argv) + args[i++] = *argv; + args[i] = NULL; + + if(setgid(su_info->pw_gid) < 0) + err(1, "setgid"); + if (initgroups (su_info->pw_name, su_info->pw_gid) < 0) + err (1, "initgroups"); + if(setuid(su_info->pw_uid) < 0) + err(1, "setuid"); + +#ifdef KRB5 + if (!kerberos_error) + krb5_start_session(); +#endif + execv(shell, args); + } + + exit(1); +} |
