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-rw-r--r--plugins/sample/sample_plugin.c500
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diff --git a/plugins/sample/sample_plugin.c b/plugins/sample/sample_plugin.c
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+++ b/plugins/sample/sample_plugin.c
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+/*
+ * Copyright (c) 2010-2016 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_STDBOOL_H
+# include <stdbool.h>
+#else
+# include "compat/stdbool.h"
+#endif /* HAVE_STDBOOL_H */
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#include <unistd.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <grp.h>
+#include <pwd.h>
+#include <stdarg.h>
+
+#include <pathnames.h>
+#include "sudo_compat.h"
+#include "sudo_plugin.h"
+#include "sudo_util.h"
+
+/*
+ * Sample plugin module that allows any user who knows the password
+ * ("test") to run any command as root. Since there is no credential
+ * caching the validate and invalidate functions are NULL.
+ */
+
+#ifdef __TANDEM
+# define ROOT_UID 65535
+#else
+# define ROOT_UID 0
+#endif
+
+static struct plugin_state {
+ char **envp;
+ char * const *settings;
+ char * const *user_info;
+} plugin_state;
+static sudo_conv_t sudo_conv;
+static sudo_printf_t sudo_log;
+static FILE *input, *output;
+static uid_t runas_uid = ROOT_UID;
+static gid_t runas_gid = -1;
+static int use_sudoedit = false;
+
+/*
+ * Plugin policy open function.
+ */
+static int
+policy_open(unsigned int version, sudo_conv_t conversation,
+ sudo_printf_t sudo_printf, char * const settings[],
+ char * const user_info[], char * const user_env[], char * const args[])
+{
+ char * const *ui;
+ struct passwd *pw;
+ const char *runas_user = NULL;
+ struct group *gr;
+ const char *runas_group = NULL;
+
+ if (!sudo_conv)
+ sudo_conv = conversation;
+ if (!sudo_log)
+ sudo_log = sudo_printf;
+
+ if (SUDO_API_VERSION_GET_MAJOR(version) != SUDO_API_VERSION_MAJOR) {
+ sudo_log(SUDO_CONV_ERROR_MSG,
+ "the sample plugin requires API version %d.x\n",
+ SUDO_API_VERSION_MAJOR);
+ return -1;
+ }
+
+ /* Only allow commands to be run as root. */
+ for (ui = settings; *ui != NULL; ui++) {
+ if (strncmp(*ui, "runas_user=", sizeof("runas_user=") - 1) == 0) {
+ runas_user = *ui + sizeof("runas_user=") - 1;
+ }
+ if (strncmp(*ui, "runas_group=", sizeof("runas_group=") - 1) == 0) {
+ runas_group = *ui + sizeof("runas_group=") - 1;
+ }
+ if (strncmp(*ui, "progname=", sizeof("progname=") - 1) == 0) {
+ initprogname(*ui + sizeof("progname=") - 1);
+ }
+ /* Check to see if sudo was called as sudoedit or with -e flag. */
+ if (strncmp(*ui, "sudoedit=", sizeof("sudoedit=") - 1) == 0) {
+ if (strcasecmp(*ui + sizeof("sudoedit=") - 1, "true") == 0)
+ use_sudoedit = true;
+ }
+ /* This plugin doesn't support running sudo with no arguments. */
+ if (strncmp(*ui, "implied_shell=", sizeof("implied_shell=") - 1) == 0) {
+ if (strcasecmp(*ui + sizeof("implied_shell=") - 1, "true") == 0)
+ return -2; /* usage error */
+ }
+ }
+ if (runas_user != NULL) {
+ if ((pw = getpwnam(runas_user)) == NULL) {
+ sudo_log(SUDO_CONV_ERROR_MSG, "unknown user %s\n", runas_user);
+ return 0;
+ }
+ runas_uid = pw->pw_uid;
+ }
+ if (runas_group != NULL) {
+ if ((gr = getgrnam(runas_group)) == NULL) {
+ sudo_log(SUDO_CONV_ERROR_MSG, "unknown group %s\n", runas_group);
+ return 0;
+ }
+ runas_gid = gr->gr_gid;
+ }
+
+ /* Plugin state. */
+ plugin_state.envp = (char **)user_env;
+ plugin_state.settings = settings;
+ plugin_state.user_info = user_info;
+
+ return 1;
+}
+
+static char *
+find_in_path(char *command, char **envp)
+{
+ struct stat sb;
+ char *path, *path0, **ep, *cp;
+ char pathbuf[PATH_MAX], *qualified = NULL;
+
+ if (strchr(command, '/') != NULL)
+ return command;
+
+ path = _PATH_DEFPATH;
+ for (ep = plugin_state.envp; *ep != NULL; ep++) {
+ if (strncmp(*ep, "PATH=", 5) == 0) {
+ path = *ep + 5;
+ break;
+ }
+ }
+ path = path0 = strdup(path);
+ do {
+ if ((cp = strchr(path, ':')))
+ *cp = '\0';
+ snprintf(pathbuf, sizeof(pathbuf), "%s/%s", *path ? path : ".",
+ command);
+ if (stat(pathbuf, &sb) == 0) {
+ if (S_ISREG(sb.st_mode) && (sb.st_mode & 0000111)) {
+ qualified = pathbuf;
+ break;
+ }
+ }
+ path = cp + 1;
+ } while (cp != NULL);
+ free(path0);
+ return qualified ? strdup(qualified) : NULL;
+}
+
+static int
+check_passwd(void)
+{
+ struct sudo_conv_message msg;
+ struct sudo_conv_reply repl;
+
+ /* Prompt user for password via conversation function. */
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_type = SUDO_CONV_PROMPT_ECHO_OFF;
+ msg.msg = "Password: ";
+ memset(&repl, 0, sizeof(repl));
+ sudo_conv(1, &msg, &repl, NULL);
+ if (repl.reply == NULL) {
+ sudo_log(SUDO_CONV_ERROR_MSG, "missing password\n");
+ return false;
+ }
+ if (strcmp(repl.reply, "test") != 0) {
+ sudo_log(SUDO_CONV_ERROR_MSG, "incorrect password\n");
+ return false;
+ }
+ return true;
+}
+
+static char **
+build_command_info(const char *command)
+{
+ static char **command_info;
+ int i = 0;
+
+ /* Setup command info. */
+ command_info = calloc(32, sizeof(char *));
+ if (command_info == NULL)
+ return NULL;
+ if ((command_info[i++] = sudo_new_key_val("command", command)) == NULL ||
+ asprintf(&command_info[i++], "runas_euid=%ld", (long)runas_uid) == -1 ||
+ asprintf(&command_info[i++], "runas_uid=%ld", (long)runas_uid) == -1) {
+ return NULL;
+ }
+ if (runas_gid != (gid_t)-1) {
+ if (asprintf(&command_info[i++], "runas_gid=%ld", (long)runas_gid) == -1 ||
+ asprintf(&command_info[i++], "runas_egid=%ld", (long)runas_gid) == -1) {
+ return NULL;
+ }
+ }
+ if (use_sudoedit) {
+ command_info[i] = strdup("sudoedit=true");
+ if (command_info[i++] == NULL)
+ return NULL;
+ }
+#ifdef USE_TIMEOUT
+ command_info[i++] = "timeout=30";
+#endif
+ return command_info;
+}
+
+static char *
+find_editor(int nfiles, char * const files[], char **argv_out[])
+{
+ char *cp, *last, **ep, **nargv, *editor, *editor_path;
+ int ac, i, nargc, wasblank;
+
+ /* Lookup EDITOR in user's environment. */
+ editor = _PATH_VI;
+ for (ep = plugin_state.envp; *ep != NULL; ep++) {
+ if (strncmp(*ep, "EDITOR=", 7) == 0) {
+ editor = *ep + 7;
+ break;
+ }
+ }
+ editor = strdup(editor);
+ if (editor == NULL) {
+ sudo_log(SUDO_CONV_ERROR_MSG, "unable to allocate memory\n");
+ return NULL;
+ }
+
+ /*
+ * Split editor into an argument vector; editor is reused (do not free).
+ * The EDITOR environment variables may contain command
+ * line args so look for those and alloc space for them too.
+ */
+ nargc = 1;
+ for (wasblank = 0, cp = editor; *cp != '\0'; cp++) {
+ if (isblank((unsigned char) *cp))
+ wasblank = 1;
+ else if (wasblank) {
+ wasblank = 0;
+ nargc++;
+ }
+ }
+ /* If we can't find the editor in the user's PATH, give up. */
+ cp = strtok_r(editor, " \t", &last);
+ if (cp == NULL ||
+ (editor_path = find_in_path(editor, plugin_state.envp)) == NULL) {
+ free(editor);
+ return NULL;
+ }
+ if (editor_path != editor)
+ free(editor);
+ nargv = malloc((nargc + 1 + nfiles + 1) * sizeof(char *));
+ if (nargv == NULL) {
+ sudo_log(SUDO_CONV_ERROR_MSG, "unable to allocate memory\n");
+ free(editor_path);
+ return NULL;
+ }
+ for (ac = 0; cp != NULL && ac < nargc; ac++) {
+ nargv[ac] = cp;
+ cp = strtok_r(NULL, " \t", &last);
+ }
+ nargv[ac++] = "--";
+ for (i = 0; i < nfiles; )
+ nargv[ac++] = files[i++];
+ nargv[ac] = NULL;
+
+ *argv_out = nargv;
+ return editor_path;
+}
+
+/*
+ * Plugin policy check function.
+ * Simple example that prompts for a password, hard-coded to "test".
+ */
+static int
+policy_check(int argc, char * const argv[],
+ char *env_add[], char **command_info_out[],
+ char **argv_out[], char **user_env_out[])
+{
+ char *command;
+
+ if (!argc || argv[0] == NULL) {
+ sudo_log(SUDO_CONV_ERROR_MSG, "no command specified\n");
+ return false;
+ }
+
+ if (!check_passwd())
+ return false;
+
+ command = find_in_path(argv[0], plugin_state.envp);
+ if (command == NULL) {
+ sudo_log(SUDO_CONV_ERROR_MSG, "%s: command not found\n", argv[0]);
+ return false;
+ }
+
+ /* If "sudo vi" is run, auto-convert to sudoedit. */
+ if (strcmp(command, _PATH_VI) == 0)
+ use_sudoedit = true;
+
+ if (use_sudoedit) {
+ /* Rebuild argv using editor */
+ free(command);
+ command = find_editor(argc - 1, argv + 1, argv_out);
+ if (command == NULL) {
+ sudo_log(SUDO_CONV_ERROR_MSG, "unable to find valid editor\n");
+ return -1;
+ }
+ use_sudoedit = true;
+ } else {
+ /* No changes needd to argv */
+ *argv_out = (char **)argv;
+ }
+
+ /* No changes to envp */
+ *user_env_out = plugin_state.envp;
+
+ /* Setup command info. */
+ *command_info_out = build_command_info(command);
+ free(command);
+ if (*command_info_out == NULL) {
+ sudo_log(SUDO_CONV_ERROR_MSG, "out of memory\n");
+ return -1;
+ }
+
+ return true;
+}
+
+static int
+policy_list(int argc, char * const argv[], int verbose, const char *list_user)
+{
+ /*
+ * List user's capabilities.
+ */
+ sudo_log(SUDO_CONV_INFO_MSG, "Validated users may run any command\n");
+ return true;
+}
+
+static int
+policy_version(int verbose)
+{
+ sudo_log(SUDO_CONV_INFO_MSG, "Sample policy plugin version %s\n", PACKAGE_VERSION);
+ return true;
+}
+
+static void
+policy_close(int exit_status, int error)
+{
+ /*
+ * The policy might log the command exit status here.
+ * In this example, we just print a message.
+ */
+ if (error) {
+ sudo_log(SUDO_CONV_ERROR_MSG, "Command error: %s\n", strerror(error));
+ } else {
+ if (WIFEXITED(exit_status)) {
+ sudo_log(SUDO_CONV_INFO_MSG, "Command exited with status %d\n",
+ WEXITSTATUS(exit_status));
+ } else if (WIFSIGNALED(exit_status)) {
+ sudo_log(SUDO_CONV_INFO_MSG, "Command killed by signal %d\n",
+ WTERMSIG(exit_status));
+ }
+ }
+}
+
+static int
+io_open(unsigned int version, sudo_conv_t conversation,
+ sudo_printf_t sudo_printf, char * const settings[],
+ char * const user_info[], char * const command_info[],
+ int argc, char * const argv[], char * const user_env[], char * const args[])
+{
+ int fd;
+ char path[PATH_MAX];
+
+ if (!sudo_conv)
+ sudo_conv = conversation;
+ if (!sudo_log)
+ sudo_log = sudo_printf;
+
+ /* Open input and output files. */
+ snprintf(path, sizeof(path), "/var/tmp/sample-%u.output",
+ (unsigned int)getpid());
+ fd = open(path, O_WRONLY|O_CREAT|O_EXCL, 0644);
+ if (fd == -1)
+ return false;
+ output = fdopen(fd, "w");
+
+ snprintf(path, sizeof(path), "/var/tmp/sample-%u.input",
+ (unsigned int)getpid());
+ fd = open(path, O_WRONLY|O_CREAT|O_EXCL, 0644);
+ if (fd == -1)
+ return false;
+ input = fdopen(fd, "w");
+
+ return true;
+}
+
+static void
+io_close(int exit_status, int error)
+{
+ fclose(input);
+ fclose(output);
+}
+
+static int
+io_version(int verbose)
+{
+ sudo_log(SUDO_CONV_INFO_MSG, "Sample I/O plugin version %s\n",
+ PACKAGE_VERSION);
+ return true;
+}
+
+static int
+io_log_input(const char *buf, unsigned int len)
+{
+ ignore_result(fwrite(buf, len, 1, input));
+ return true;
+}
+
+static int
+io_log_output(const char *buf, unsigned int len)
+{
+ const char *cp, *ep;
+ bool ret = true;
+
+ ignore_result(fwrite(buf, len, 1, output));
+ /*
+ * If we find the string "honk!" in the buffer, reject it.
+ * In practice we'd want to be able to detect the word
+ * broken across two buffers.
+ */
+ for (cp = buf, ep = buf + len; cp < ep; cp++) {
+ if (cp + 5 < ep && memcmp(cp, "honk!", 5) == 0) {
+ ret = false;
+ break;
+ }
+ }
+ return ret;
+}
+
+__dso_public struct policy_plugin sample_policy = {
+ SUDO_POLICY_PLUGIN,
+ SUDO_API_VERSION,
+ policy_open,
+ policy_close,
+ policy_version,
+ policy_check,
+ policy_list,
+ NULL, /* validate */
+ NULL, /* invalidate */
+ NULL, /* init_session */
+ NULL, /* register_hooks */
+ NULL /* deregister_hooks */
+};
+
+/*
+ * Note: This plugin does not differentiate between tty and pipe I/O.
+ * It all gets logged to the same file.
+ */
+__dso_public struct io_plugin sample_io = {
+ SUDO_IO_PLUGIN,
+ SUDO_API_VERSION,
+ io_open,
+ io_close,
+ io_version,
+ io_log_input, /* tty input */
+ io_log_output, /* tty output */
+ io_log_input, /* command stdin if not tty */
+ io_log_output, /* command stdout if not tty */
+ io_log_output /* command stderr if not tty */
+};
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