--- /dev/null
+/* Copyright 1999-2004 The Apache Software Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * suexec.c -- "Wrapper" support program for suEXEC behaviour for Apache
+ *
+ ***********************************************************************
+ *
+ * NOTE! : DO NOT edit this code!!! Unless you know what you are doing,
+ * editing this code might open up your system in unexpected
+ * ways to would-be crackers. Every precaution has been taken
+ * to make this code as safe as possible; alter it at your own
+ * risk.
+ *
+ ***********************************************************************
+ *
+ *
+ */
+
+#include "apr.h"
+#include "ap_config.h"
+#include "gsexec.h"
+
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <string.h>
+#include <time.h>
+#if APR_HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+
+#ifdef HAVE_PWD_H
+#include <pwd.h>
+#endif
+
+#ifdef HAVE_GRP_H
+#include <grp.h>
+#endif
+
+/*
+ ***********************************************************************
+ * There is no initgroups() in QNX, so I believe this is safe :-)
+ * Use cc -osuexec -3 -O -mf -DQNX suexec.c to compile.
+ *
+ * May 17, 1997.
+ * Igor N. Kovalenko -- infoh mail.wplus.net
+ ***********************************************************************
+ */
+
+#if defined(NEED_INITGROUPS)
+int initgroups(const char *name, gid_t basegid)
+{
+ /* QNX and MPE do not appear to support supplementary groups. */
+ return 0;
+}
+#endif
+
+#if defined(SUNOS4)
+extern char *sys_errlist[];
+#define strerror(x) sys_errlist[(x)]
+#endif
+
+#if defined(PATH_MAX)
+#define AP_MAXPATH PATH_MAX
+#elif defined(MAXPATHLEN)
+#define AP_MAXPATH MAXPATHLEN
+#else
+#define AP_MAXPATH 8192
+#endif
+
+#define AP_ENVBUF 256
+
+extern char **environ;
+static FILE *log = NULL;
+
+char *safe_env_lst[] =
+{
+ /* variable name starts with */
+ "HTTP_",
+ "SSL_",
+
+ /* variable name is */
+ "AUTH_TYPE=",
+ "CONTENT_LENGTH=",
+ "CONTENT_TYPE=",
+ "DATE_GMT=",
+ "DATE_LOCAL=",
+ "DOCUMENT_NAME=",
+ "DOCUMENT_PATH_INFO=",
+ "DOCUMENT_ROOT=",
+ "DOCUMENT_URI=",
+ "GATEWAY_INTERFACE=",
+ "HTTPS=",
+ "LAST_MODIFIED=",
+ "PATH_INFO=",
+ "PATH_TRANSLATED=",
+ "QUERY_STRING=",
+ "QUERY_STRING_UNESCAPED=",
+ "REMOTE_ADDR=",
+ "REMOTE_HOST=",
+ "REMOTE_IDENT=",
+ "REMOTE_PORT=",
+ "REMOTE_USER=",
+ "REDIRECT_HANDLER=",
+ "REDIRECT_QUERY_STRING=",
+ "REDIRECT_REMOTE_USER=",
+ "REDIRECT_STATUS=",
+ "REDIRECT_URL=",
+ "REQUEST_METHOD=",
+ "REQUEST_URI=",
+ "SCRIPT_FILENAME=",
+ "SCRIPT_NAME=",
+ "SCRIPT_URI=",
+ "SCRIPT_URL=",
+ "SERVER_ADMIN=",
+ "SERVER_NAME=",
+ "SERVER_ADDR=",
+ "SERVER_PORT=",
+ "SERVER_PROTOCOL=",
+ "SERVER_SIGNATURE=",
+ "SERVER_SOFTWARE=",
+ "UNIQUE_ID=",
+ "USER_NAME=",
+ "TZ=",
+ NULL
+};
+
+
+static void err_output(int is_error, const char *fmt, va_list ap)
+{
+#ifdef AP_LOG_EXEC
+ time_t timevar;
+ struct tm *lt;
+
+ if (!log) {
+ if ((log = fopen(AP_LOG_EXEC, "a")) == NULL) {
+ fprintf(stderr, "suexec failure: could not open log file\n");
+ perror("fopen");
+ exit(1);
+ }
+ }
+
+ if (is_error) {
+ fprintf(stderr, "suexec policy violation: see suexec log for more "
+ "details\n");
+ }
+
+ time(&timevar);
+ lt = localtime(&timevar);
+
+ fprintf(log, "[%d-%.2d-%.2d %.2d:%.2d:%.2d]: ",
+ lt->tm_year + 1900, lt->tm_mon + 1, lt->tm_mday,
+ lt->tm_hour, lt->tm_min, lt->tm_sec);
+
+ vfprintf(log, fmt, ap);
+
+ fflush(log);
+#endif /* AP_LOG_EXEC */
+ return;
+}
+
+static void log_err(const char *fmt,...)
+{
+#ifdef AP_LOG_EXEC
+ va_list ap;
+
+ va_start(ap, fmt);
+ err_output(1, fmt, ap); /* 1 == is_error */
+ va_end(ap);
+#endif /* AP_LOG_EXEC */
+ return;
+}
+
+static void log_no_err(const char *fmt,...)
+{
+#ifdef AP_LOG_EXEC
+ va_list ap;
+
+ va_start(ap, fmt);
+ err_output(0, fmt, ap); /* 0 == !is_error */
+ va_end(ap);
+#endif /* AP_LOG_EXEC */
+ return;
+}
+
+static void clean_env(void)
+{
+ char pathbuf[512];
+ char **cleanenv;
+ char **ep;
+ int cidx = 0;
+ int idx;
+
+ /* While cleaning the environment, the environment should be clean.
+ * (e.g. malloc() may get the name of a file for writing debugging info.
+ * Bad news if MALLOC_DEBUG_FILE is set to /etc/passwd. Sprintf() may be
+ * susceptible to bad locale settings....)
+ * (from PR 2790)
+ */
+ char **envp = environ;
+ char *empty_ptr = NULL;
+
+ environ = &empty_ptr; /* VERY safe environment */
+
+ if ((cleanenv = (char **) calloc(AP_ENVBUF, sizeof(char *))) == NULL) {
+ log_err("failed to malloc memory for environment\n");
+ exit(120);
+ }
+
+ sprintf(pathbuf, "PATH=%s", AP_SAFE_PATH);
+ cleanenv[cidx] = strdup(pathbuf);
+ cidx++;
+
+ for (ep = envp; *ep && cidx < AP_ENVBUF-1; ep++) {
+ for (idx = 0; safe_env_lst[idx]; idx++) {
+ if (!strncmp(*ep, safe_env_lst[idx],
+ strlen(safe_env_lst[idx]))) {
+ cleanenv[cidx] = *ep;
+ cidx++;
+ break;
+ }
+ }
+ }
+
+ cleanenv[cidx] = NULL;
+
+ environ = cleanenv;
+}
+
+int main(int argc, char *argv[])
+{
+ int userdir = 0; /* ~userdir flag */
+ uid_t uid; /* user information */
+ gid_t gid; /* target group placeholder */
+ char *target_uname; /* target user name */
+ char *target_gname; /* target group name */
+ char *target_homedir; /* target home directory */
+ char *actual_uname; /* actual user name */
+ char *actual_gname; /* actual group name */
+ char *prog; /* name of this program */
+ char *cmd; /* command to be executed */
+ char cwd[AP_MAXPATH]; /* current working directory */
+ char dwd[AP_MAXPATH]; /* docroot working directory */
+ struct passwd *pw; /* password entry holder */
+ struct group *gr; /* group entry holder */
+ struct stat dir_info; /* directory info holder */
+ struct stat prg_info; /* program info holder */
+
+ /*
+ * Start with a "clean" environment
+ */
+ clean_env();
+
+ prog = argv[0];
+ /*
+ * Check existence/validity of the UID of the user
+ * running this program. Error out if invalid.
+ */
+ uid = getuid();
+ if ((pw = getpwuid(uid)) == NULL) {
+ log_err("crit: invalid uid: (%ld)\n", uid);
+ exit(102);
+ }
+ /*
+ * See if this is a 'how were you compiled' request, and
+ * comply if so.
+ */
+ if ((argc > 1)
+ && (! strcmp(argv[1], "-V"))
+ && ((uid == 0)
+#ifdef _OSD_POSIX
+ /* User name comparisons are case insensitive on BS2000/OSD */
+ || (! strcasecmp(AP_HTTPD_USER, pw->pw_name)))
+#else /* _OSD_POSIX */
+ || (! strcmp(AP_HTTPD_USER, pw->pw_name)))
+#endif /* _OSD_POSIX */
+ ) {
+#ifdef AP_DOC_ROOT
+ fprintf(stderr, " -D AP_DOC_ROOT=\"%s\"\n", AP_DOC_ROOT);
+#endif
+#ifdef AP_GID_MIN
+ fprintf(stderr, " -D AP_GID_MIN=%d\n", AP_GID_MIN);
+#endif
+#ifdef AP_HTTPD_USER
+ fprintf(stderr, " -D AP_HTTPD_USER=\"%s\"\n", AP_HTTPD_USER);
+#endif
+#ifdef AP_LOG_EXEC
+ fprintf(stderr, " -D AP_LOG_EXEC=\"%s\"\n", AP_LOG_EXEC);
+#endif
+#ifdef AP_SAFE_PATH
+ fprintf(stderr, " -D AP_SAFE_PATH=\"%s\"\n", AP_SAFE_PATH);
+#endif
+#ifdef AP_SUEXEC_UMASK
+ fprintf(stderr, " -D AP_SUEXEC_UMASK=%03o\n", AP_SUEXEC_UMASK);
+#endif
+#ifdef AP_UID_MIN
+ fprintf(stderr, " -D AP_UID_MIN=%d\n", AP_UID_MIN);
+#endif
+#ifdef AP_USERDIR_SUFFIX
+ fprintf(stderr, " -D AP_USERDIR_SUFFIX=\"%s\"\n", AP_USERDIR_SUFFIX);
+#endif
+ exit(0);
+ }
+ /*
+ * If there are a proper number of arguments, set
+ * all of them to variables. Otherwise, error out.
+ */
+ if (argc < 4) {
+ log_err("too few arguments\n");
+ exit(101);
+ }
+ target_uname = argv[1];
+ target_gname = argv[2];
+ cmd = argv[3];
+
+ /*
+ * Check to see if the user running this program
+ * is the user allowed to do so as defined in
+ * suexec.h. If not the allowed user, error out.
+ */
+#ifdef _OSD_POSIX
+ /* User name comparisons are case insensitive on BS2000/OSD */
+ if (strcasecmp(AP_HTTPD_USER, pw->pw_name)) {
+ log_err("user mismatch (%s instead of %s)\n", pw->pw_name, AP_HTTPD_USER);
+ exit(103);
+ }
+#else /*_OSD_POSIX*/
+ if (strcmp(AP_HTTPD_USER, pw->pw_name)) {
+ log_err("user mismatch (%s instead of %s)\n", pw->pw_name, AP_HTTPD_USER);
+ exit(103);
+ }
+#endif /*_OSD_POSIX*/
+
+ /*
+ * Check for a leading '/' (absolute path) in the command to be executed,
+ * or attempts to back up out of the current directory,
+ * to protect against attacks. If any are
+ * found, error out. Naughty naughty crackers.
+ */
+ if ((cmd[0] == '/') || (!strncmp(cmd, "../", 3))
+ || (strstr(cmd, "/../") != NULL)) {
+ log_err("invalid command (%s)\n", cmd);
+ exit(104);
+ }
+
+ /*
+ * Check to see if this is a ~userdir request. If
+ * so, set the flag, and remove the '~' from the
+ * target username.
+ */
+ if (!strncmp("~", target_uname, 1)) {
+ target_uname++;
+ userdir = 1;
+ }
+
+ /*
+ * Error out if the target username is invalid.
+ */
+ if (strspn(target_uname, "1234567890") != strlen(target_uname)) {
+ if ((pw = getpwnam(target_uname)) == NULL) {
+ log_err("invalid target user name: (%s)\n", target_uname);
+ exit(105);
+ }
+ }
+ else {
+ if ((pw = getpwuid(atoi(target_uname))) == NULL) {
+ log_err("invalid target user id: (%s)\n", target_uname);
+ exit(121);
+ }
+ }
+
+ /*
+ * Error out if the target group name is invalid.
+ */
+ if (strspn(target_gname, "1234567890") != strlen(target_gname)) {
+ if ((gr = getgrnam(target_gname)) == NULL) {
+ log_err("invalid target group name: (%s)\n", target_gname);
+ exit(106);
+ }
+ gid = gr->gr_gid;
+ actual_gname = strdup(gr->gr_name);
+ }
+ else {
+ gid = atoi(target_gname);
+ actual_gname = strdup(target_gname);
+ }
+
+#ifdef _OSD_POSIX
+ /*
+ * Initialize BS2000 user environment
+ */
+ {
+ pid_t pid;
+ int status;
+
+ switch (pid = ufork(target_uname)) {
+ case -1: /* Error */
+ log_err("failed to setup bs2000 environment for user %s: %s\n",
+ target_uname, strerror(errno));
+ exit(150);
+ case 0: /* Child */
+ break;
+ default: /* Father */
+ while (pid != waitpid(pid, &status, 0))
+ ;
+ /* @@@ FIXME: should we deal with STOP signals as well? */
+ if (WIFSIGNALED(status)) {
+ kill (getpid(), WTERMSIG(status));
+ }
+ exit(WEXITSTATUS(status));
+ }
+ }
+#endif /*_OSD_POSIX*/
+
+ /*
+ * Save these for later since initgroups will hose the struct
+ */
+ uid = pw->pw_uid;
+ actual_uname = strdup(pw->pw_name);
+ target_homedir = strdup(pw->pw_dir);
+
+ /*
+ * Log the transaction here to be sure we have an open log
+ * before we setuid().
+ */
+ log_no_err("uid: (%s/%s) gid: (%s/%s) cmd: %s\n",
+ target_uname, actual_uname,
+ target_gname, actual_gname,
+ cmd);
+
+ /*
+ * Error out if attempt is made to execute as root or as
+ * a UID less than AP_UID_MIN. Tsk tsk.
+ */
+ if ((uid == 0) || (uid < AP_UID_MIN)) {
+ log_err("cannot run as forbidden uid (%d/%s)\n", uid, cmd);
+ exit(107);
+ }
+
+ /*
+ * Error out if attempt is made to execute as root group
+ * or as a GID less than AP_GID_MIN. Tsk tsk.
+ */
+ if ((gid == 0) || (gid < AP_GID_MIN)) {
+ log_err("cannot run as forbidden gid (%d/%s)\n", gid, cmd);
+ exit(108);
+ }
+
+ /*
+ * Change UID/GID here so that the following tests work over NFS.
+ *
+ * Initialize the group access list for the target user,
+ * and setgid() to the target group. If unsuccessful, error out.
+ */
+ if (((setgid(gid)) != 0) || (initgroups(actual_uname, gid) != 0)) {
+ log_err("failed to setgid (%ld: %s)\n", gid, cmd);
+ exit(109);
+ }
+
+ /*
+ * setuid() to the target user. Error out on fail.
+ */
+ if ((setuid(uid)) != 0) {
+ log_err("failed to setuid (%ld: %s)\n", uid, cmd);
+ exit(110);
+ }
+
+ /*
+ * Get the current working directory, as well as the proper
+ * document root (dependant upon whether or not it is a
+ * ~userdir request). Error out if we cannot get either one,
+ * or if the current working directory is not in the docroot.
+ * Use chdir()s and getcwd()s to avoid problems with symlinked
+ * directories. Yuck.
+ */
+ if (getcwd(cwd, AP_MAXPATH) == NULL) {
+ log_err("cannot get current working directory\n");
+ exit(111);
+ }
+
+ if (userdir) {
+ if (((chdir(target_homedir)) != 0) ||
+ ((chdir(AP_USERDIR_SUFFIX)) != 0) ||
+ ((getcwd(dwd, AP_MAXPATH)) == NULL) ||
+ ((chdir(cwd)) != 0)) {
+ log_err("cannot get docroot information (%s)\n", target_homedir);
+ exit(112);
+ }
+ }
+ else {
+ if (((chdir(AP_DOC_ROOT)) != 0) ||
+ ((getcwd(dwd, AP_MAXPATH)) == NULL) ||
+ ((chdir(cwd)) != 0)) {
+ log_err("cannot get docroot information (%s)\n", AP_DOC_ROOT);
+ exit(113);
+ }
+ }
+
+ if ((strncmp(cwd, dwd, strlen(dwd))) != 0) {
+ log_err("command not in docroot (%s/%s)\n", cwd, cmd);
+ exit(114);
+ }
+
+ /*
+ * Stat the cwd and verify it is a directory, or error out.
+ */
+ if (((lstat(cwd, &dir_info)) != 0) || !(S_ISDIR(dir_info.st_mode))) {
+ log_err("cannot stat directory: (%s)\n", cwd);
+ exit(115);
+ }
+
+ /*
+ * Error out if cwd is writable by others.
+ */
+ if ((dir_info.st_mode & S_IWOTH) || (dir_info.st_mode & S_IWGRP)) {
+ log_err("directory is writable by others: (%s)\n", cwd);
+ exit(116);
+ }
+
+ /*
+ * Error out if we cannot stat the program.
+ */
+ if (((lstat(cmd, &prg_info)) != 0) || (S_ISLNK(prg_info.st_mode))) {
+ log_err("cannot stat program: (%s)\n", cmd);
+ exit(117);
+ }
+
+ /*
+ * Error out if the program is writable by others.
+ */
+ if ((prg_info.st_mode & S_IWOTH) || (prg_info.st_mode & S_IWGRP)) {
+ log_err("file is writable by others: (%s/%s)\n", cwd, cmd);
+ exit(118);
+ }
+
+ /*
+ * Error out if the file is setuid or setgid.
+ */
+ if ((prg_info.st_mode & S_ISUID) || (prg_info.st_mode & S_ISGID)) {
+ log_err("file is either setuid or setgid: (%s/%s)\n", cwd, cmd);
+ exit(119);
+ }
+
+ /*
+ * Error out if the target name/group is different from
+ * the name/group of the cwd or the program.
+ */
+ if ((uid != dir_info.st_uid) ||
+ (gid != dir_info.st_gid) ||
+ (uid != prg_info.st_uid) ||
+ (gid != prg_info.st_gid)) {
+ log_err("target uid/gid (%ld/%ld) mismatch "
+ "with directory (%ld/%ld) or program (%ld/%ld)\n",
+ uid, gid,
+ dir_info.st_uid, dir_info.st_gid,
+ prg_info.st_uid, prg_info.st_gid);
+ exit(120);
+ }
+ /*
+ * Error out if the program is not executable for the user.
+ * Otherwise, she won't find any error in the logs except for
+ * "[error] Premature end of script headers: ..."
+ */
+ if (!(prg_info.st_mode & S_IXUSR)) {
+ log_err("file has no execute permission: (%s/%s)\n", cwd, cmd);
+ exit(121);
+ }
+
+#ifdef AP_SUEXEC_UMASK
+ /*
+ * umask() uses inverse logic; bits are CLEAR for allowed access.
+ */
+ if ((~AP_SUEXEC_UMASK) & 0022) {
+ log_err("notice: AP_SUEXEC_UMASK of %03o allows "
+ "write permission to group and/or other\n", AP_SUEXEC_UMASK);
+ }
+ umask(AP_SUEXEC_UMASK);
+#endif /* AP_SUEXEC_UMASK */
+
+ /*
+ * Be sure to close the log file so the CGI can't
+ * mess with it. If the exec fails, it will be reopened
+ * automatically when log_err is called. Note that the log
+ * might not actually be open if AP_LOG_EXEC isn't defined.
+ * However, the "log" cell isn't ifdef'd so let's be defensive
+ * and assume someone might have done something with it
+ * outside an ifdef'd AP_LOG_EXEC block.
+ */
+ if (log != NULL) {
+ fclose(log);
+ log = NULL;
+ }
+
+ /*
+ * Execute the command, replacing our image with its own.
+ */
+#ifdef NEED_HASHBANG_EMUL
+ /* We need the #! emulation when we want to execute scripts */
+ {
+ extern char **environ;
+
+ ap_execve(cmd, &argv[3], environ);
+ }
+#else /*NEED_HASHBANG_EMUL*/
+ execv(cmd, &argv[3]);
+#endif /*NEED_HASHBANG_EMUL*/
+
+ /*
+ * (I can't help myself...sorry.)
+ *
+ * Uh oh. Still here. Where's the kaboom? There was supposed to be an
+ * EARTH-shattering kaboom!
+ *
+ * Oh well, log the failure and error out.
+ */
+ log_err("(%d)%s: exec failed (%s)\n", errno, strerror(errno), cmd);
+ exit(255);
+}
git://scientific.zcu.cz / jra1mw.git / commitdiff