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-rw-r--r--plugins/sudoers/env.c1419
1 files changed, 1419 insertions, 0 deletions
diff --git a/plugins/sudoers/env.c b/plugins/sudoers/env.c
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index 0000000..73f017a
--- /dev/null
+++ b/plugins/sudoers/env.c
@@ -0,0 +1,1419 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2000-2005, 2007-2019
+ * 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.
+ *
+ * Sponsored in part by the Defense Advanced Research Projects
+ * Agency (DARPA) and Air Force Research Laboratory, Air Force
+ * Materiel Command, USAF, under agreement number F39502-99-1-0512.
+ */
+
+/*
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#if defined(HAVE_STDINT_H)
+# include <stdint.h>
+#elif defined(HAVE_INTTYPES_H)
+# include <inttypes.h>
+#endif
+#ifdef HAVE_LOGIN_CAP_H
+# include <login_cap.h>
+# ifndef LOGIN_SETENV
+# define LOGIN_SETENV 0
+# endif
+#endif /* HAVE_LOGIN_CAP_H */
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <pwd.h>
+
+#include "sudoers.h"
+
+/*
+ * Flags used in rebuild_env()
+ */
+#undef DID_TERM
+#define DID_TERM 0x00000001
+#undef DID_PATH
+#define DID_PATH 0x00000002
+#undef DID_HOME
+#define DID_HOME 0x00000004
+#undef DID_SHELL
+#define DID_SHELL 0x00000008
+#undef DID_LOGNAME
+#define DID_LOGNAME 0x00000010
+#undef DID_USER
+#define DID_USER 0x00000020
+#undef DID_LOGIN
+#define DID_LOGIN 0x00000040
+#undef DID_MAIL
+#define DID_MAIL 0x00000080
+#undef DID_MAX
+#define DID_MAX 0x0000ffff
+
+#undef KEPT_TERM
+#define KEPT_TERM 0x00010000
+#undef KEPT_PATH
+#define KEPT_PATH 0x00020000
+#undef KEPT_HOME
+#define KEPT_HOME 0x00040000
+#undef KEPT_SHELL
+#define KEPT_SHELL 0x00080000
+#undef KEPT_LOGNAME
+#define KEPT_LOGNAME 0x00100000
+#undef KEPT_USER
+#define KEPT_USER 0x00200000
+#undef KEPT_LOGIN
+#define KEPT_LOGIN 0x00400000
+#undef KEPT_MAIL
+#define KEPT_MAIL 0x00800000
+#undef KEPT_MAX
+#define KEPT_MAX 0xffff0000
+
+/*
+ * AIX sets the LOGIN environment variable too.
+ */
+#ifdef _AIX
+# define KEPT_USER_VARIABLES (KEPT_LOGIN|KEPT_LOGNAME|KEPT_USER)
+#else
+# define KEPT_USER_VARIABLES (KEPT_LOGNAME|KEPT_USER)
+#endif
+
+/*
+ * Functions to open, close and parse an environment file, either
+ * a system file such as /etc/environment or one specified in sudoers.
+ */
+struct sudoers_env_file {
+ void * (*open)(const char *);
+ void (*close)(void *);
+ char * (*next)(void *, int *);
+};
+
+/*
+ * State for a local environment file.
+ */
+struct env_file_local {
+ FILE *fp;
+ char *line;
+ size_t linesize;
+};
+
+struct environment {
+ char **envp; /* pointer to the new environment */
+ char **old_envp; /* pointer the old environment we allocated */
+ size_t env_size; /* size of new_environ in char **'s */
+ size_t env_len; /* number of slots used, not counting NULL */
+};
+
+/*
+ * Copy of the sudo-managed environment.
+ */
+static struct environment env;
+
+/*
+ * Default table of "bad" variables to remove from the environment.
+ * XXX - how to omit TERMCAP if it starts with '/'?
+ */
+static const char *initial_badenv_table[] = {
+ "IFS",
+ "CDPATH",
+ "LOCALDOMAIN",
+ "RES_OPTIONS",
+ "HOSTALIASES",
+ "NLSPATH",
+ "PATH_LOCALE",
+ "LD_*",
+ "_RLD*",
+#ifdef __hpux
+ "SHLIB_PATH",
+#endif /* __hpux */
+#ifdef _AIX
+ "LDR_*",
+ "LIBPATH",
+ "AUTHSTATE",
+#endif
+#ifdef __APPLE__
+ "DYLD_*",
+#endif
+#ifdef HAVE_KERB5
+ "KRB5_CONFIG*",
+ "KRB5_KTNAME",
+#endif /* HAVE_KERB5 */
+#ifdef HAVE_SECURID
+ "VAR_ACE",
+ "USR_ACE",
+ "DLC_ACE",
+#endif /* HAVE_SECURID */
+ "TERMINFO", /* terminfo, exclusive path to terminfo files */
+ "TERMINFO_DIRS", /* terminfo, path(s) to terminfo files */
+ "TERMPATH", /* termcap, path(s) to termcap files */
+ "TERMCAP", /* XXX - only if it starts with '/' */
+ "ENV", /* ksh, file to source before script runs */
+ "BASH_ENV", /* bash, file to source before script runs */
+ "PS4", /* bash, prefix for lines in xtrace mode */
+ "GLOBIGNORE", /* bash, globbing patterns to ignore */
+ "BASHOPTS", /* bash, initial "shopt -s" options */
+ "SHELLOPTS", /* bash, initial "set -o" options */
+ "JAVA_TOOL_OPTIONS", /* java, extra command line options */
+ "PERLIO_DEBUG", /* perl, debugging output file */
+ "PERLLIB", /* perl, search path for modules/includes */
+ "PERL5LIB", /* perl 5, search path for modules/includes */
+ "PERL5OPT", /* perl 5, extra command line options */
+ "PERL5DB", /* perl 5, command used to load debugger */
+ "FPATH", /* ksh, search path for functions */
+ "NULLCMD", /* zsh, command for null file redirection */
+ "READNULLCMD", /* zsh, command for null file redirection */
+ "ZDOTDIR", /* zsh, search path for dot files */
+ "TMPPREFIX", /* zsh, prefix for temporary files */
+ "PYTHONHOME", /* python, module search path */
+ "PYTHONPATH", /* python, search path */
+ "PYTHONINSPECT", /* python, allow inspection */
+ "PYTHONUSERBASE", /* python, per user site-packages directory */
+ "RUBYLIB", /* ruby, library load path */
+ "RUBYOPT", /* ruby, extra command line options */
+ "*=()*", /* bash functions */
+ NULL
+};
+
+/*
+ * Default table of variables to check for '%' and '/' characters.
+ */
+static const char *initial_checkenv_table[] = {
+ "COLORTERM",
+ "LANG",
+ "LANGUAGE",
+ "LC_*",
+ "LINGUAS",
+ "TERM",
+ "TZ",
+ NULL
+};
+
+/*
+ * Default table of variables to preserve in the environment.
+ */
+static const char *initial_keepenv_table[] = {
+ "COLORS",
+ "DISPLAY",
+ "HOSTNAME",
+ "KRB5CCNAME",
+ "LS_COLORS",
+ "PATH",
+ "PS1",
+ "PS2",
+ "XAUTHORITY",
+ "XAUTHORIZATION",
+ "XDG_CURRENT_DESKTOP",
+ NULL
+};
+
+/*
+ * Initialize env based on envp.
+ */
+bool
+env_init(char * const envp[])
+{
+ char * const *ep;
+ size_t len;
+ debug_decl(env_init, SUDOERS_DEBUG_ENV);
+
+ if (envp == NULL) {
+ /* Free the old envp we allocated, if any. */
+ sudoers_gc_remove(GC_PTR, env.old_envp);
+ free(env.old_envp);
+
+ /* Reset to initial state but keep a pointer to what we allocated. */
+ env.old_envp = env.envp;
+ env.envp = NULL;
+ env.env_size = 0;
+ env.env_len = 0;
+ } else {
+ /* Make private copy of envp. */
+ for (ep = envp; *ep != NULL; ep++)
+ continue;
+ len = (size_t)(ep - envp);
+
+ env.env_len = len;
+ env.env_size = len + 1 + 128;
+ env.envp = reallocarray(NULL, env.env_size, sizeof(char *));
+ if (env.envp == NULL) {
+ env.env_size = 0;
+ env.env_len = 0;
+ sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+ debug_return_bool(false);
+ }
+ sudoers_gc_add(GC_PTR, env.envp);
+#ifdef ENV_DEBUG
+ memset(env.envp, 0, env.env_size * sizeof(char *));
+#endif
+ memcpy(env.envp, envp, len * sizeof(char *));
+ env.envp[len] = NULL;
+
+ /* Free the old envp we allocated, if any. */
+ sudoers_gc_remove(GC_PTR, env.old_envp);
+ free(env.old_envp);
+ env.old_envp = NULL;
+ }
+
+ debug_return_bool(true);
+}
+
+/*
+ * Getter for private copy of the environment.
+ */
+char **
+env_get(void)
+{
+ return env.envp;
+}
+
+/*
+ * Swap the old and new copies of the environment.
+ */
+bool
+env_swap_old(void)
+{
+ char **old_envp;
+
+ if (env.old_envp == NULL)
+ return false;
+ old_envp = env.old_envp;
+ env.old_envp = env.envp;
+ env.envp = old_envp;
+ return true;
+}
+
+/*
+ * Similar to putenv(3) but operates on sudo's private copy of the
+ * environment (not environ) and it always overwrites. The dupcheck param
+ * determines whether we need to verify that the variable is not already set.
+ * Will only overwrite an existing variable if overwrite is set.
+ * Does not include warnings or debugging to avoid recursive calls.
+ */
+int
+sudo_putenv_nodebug(char *str, bool dupcheck, bool overwrite)
+{
+ char **ep;
+ const char *equal;
+ bool found = false;
+
+ /* Some putenv(3) implementations check for NULL. */
+ if (str == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ /* The string must contain a '=' char but not start with one. */
+ equal = strchr(str, '=');
+ if (equal == NULL || equal == str) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ /* Make sure there is room for the new entry plus a NULL. */
+ if (env.env_size > 2 && env.env_len > env.env_size - 2) {
+ char **nenvp;
+ size_t nsize;
+
+ if (env.env_size > SIZE_MAX - 128) {
+ sudo_warnx_nodebug(U_("internal error, %s overflow"),
+ "sudo_putenv_nodebug");
+ errno = EOVERFLOW;
+ return -1;
+ }
+ nsize = env.env_size + 128;
+ if (nsize > SIZE_MAX / sizeof(char *)) {
+ sudo_warnx_nodebug(U_("internal error, %s overflow"),
+ "sudo_putenv_nodebug");
+ errno = EOVERFLOW;
+ return -1;
+ }
+ sudoers_gc_remove(GC_PTR, env.envp);
+ nenvp = reallocarray(env.envp, nsize, sizeof(char *));
+ if (nenvp == NULL) {
+ sudoers_gc_add(GC_PTR, env.envp);
+ return -1;
+ }
+ sudoers_gc_add(GC_PTR, nenvp);
+ env.envp = nenvp;
+ env.env_size = nsize;
+#ifdef ENV_DEBUG
+ memset(env.envp + env.env_len, 0,
+ (env.env_size - env.env_len) * sizeof(char *));
+#endif
+ }
+
+#ifdef ENV_DEBUG
+ if (env.envp[env.env_len] != NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+#endif
+
+ if (dupcheck) {
+ size_t len = (size_t)(equal - str) + 1;
+ for (ep = env.envp; *ep != NULL; ep++) {
+ if (strncmp(str, *ep, len) == 0) {
+ if (overwrite)
+ *ep = str;
+ found = true;
+ break;
+ }
+ }
+ /* Prune out extra instances of the variable we just overwrote. */
+ if (found && overwrite) {
+ while (*++ep != NULL) {
+ if (strncmp(str, *ep, len) == 0) {
+ char **cur = ep;
+ while ((*cur = *(cur + 1)) != NULL)
+ cur++;
+ ep--;
+ }
+ }
+ env.env_len = ep - env.envp;
+ }
+ }
+
+ if (!found) {
+ ep = env.envp + env.env_len;
+ env.env_len++;
+ *ep++ = str;
+ *ep = NULL;
+ }
+ return 0;
+}
+
+/*
+ * Similar to putenv(3) but operates on sudo's private copy of the
+ * environment (not environ) and it always overwrites. The dupcheck param
+ * determines whether we need to verify that the variable is not already set.
+ * Will only overwrite an existing variable if overwrite is set.
+ */
+static int
+sudo_putenv(char *str, bool dupcheck, bool overwrite)
+{
+ int ret;
+ debug_decl(sudo_putenv, SUDOERS_DEBUG_ENV);
+
+ sudo_debug_printf(SUDO_DEBUG_INFO, "sudo_putenv: %s", str);
+
+ ret = sudo_putenv_nodebug(str, dupcheck, overwrite);
+ if (ret == -1) {
+#ifdef ENV_DEBUG
+ if (env.envp[env.env_len] != NULL) {
+ sudo_warnx("%s",
+ U_("sudo_putenv: corrupted envp, length mismatch"));
+ }
+#endif
+ }
+ debug_return_int(ret);
+}
+
+/*
+ * Similar to setenv(3) but operates on a private copy of the environment.
+ * The dupcheck param determines whether we need to verify that the variable
+ * is not already set.
+ */
+static int
+sudo_setenv2(const char *var, const char *val, bool dupcheck, bool overwrite)
+{
+ char *estring;
+ size_t esize;
+ int ret = -1;
+ debug_decl(sudo_setenv2, SUDOERS_DEBUG_ENV);
+
+ esize = strlen(var) + 1 + strlen(val) + 1;
+ if ((estring = malloc(esize)) == NULL) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "unable to allocate memory");
+ debug_return_int(-1);
+ }
+
+ /* Build environment string and insert it. */
+ if (strlcpy(estring, var, esize) >= esize ||
+ strlcat(estring, "=", esize) >= esize ||
+ strlcat(estring, val, esize) >= esize) {
+
+ sudo_warnx(U_("internal error, %s overflow"), __func__);
+ errno = EOVERFLOW;
+ } else {
+ ret = sudo_putenv(estring, dupcheck, overwrite);
+ }
+ if (ret == -1)
+ free(estring);
+ else
+ sudoers_gc_add(GC_PTR, estring);
+ debug_return_int(ret);
+}
+
+/*
+ * Similar to setenv(3) but operates on a private copy of the environment.
+ */
+int
+sudo_setenv(const char *var, const char *val, int overwrite)
+{
+ return sudo_setenv2(var, val, true, (bool)overwrite);
+}
+
+/*
+ * Similar to unsetenv(3) but operates on a private copy of the environment.
+ * Does not include warnings or debugging to avoid recursive calls.
+ */
+int
+sudo_unsetenv_nodebug(const char *var)
+{
+ char **ep = env.envp;
+ size_t len;
+
+ if (ep == NULL || var == NULL || *var == '\0' || strchr(var, '=') != NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ len = strlen(var);
+ while (*ep != NULL) {
+ if (strncmp(var, *ep, len) == 0 && (*ep)[len] == '=') {
+ /* Found it; shift remainder + NULL over by one. */
+ char **cur = ep;
+ while ((*cur = *(cur + 1)) != NULL)
+ cur++;
+ env.env_len--;
+ /* Keep going, could be multiple instances of the var. */
+ } else {
+ ep++;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Similar to unsetenv(3) but operates on a private copy of the environment.
+ */
+int
+sudo_unsetenv(const char *name)
+{
+ int ret;
+ debug_decl(sudo_unsetenv, SUDOERS_DEBUG_ENV);
+
+ sudo_debug_printf(SUDO_DEBUG_INFO, "sudo_unsetenv: %s", name);
+
+ ret = sudo_unsetenv_nodebug(name);
+
+ debug_return_int(ret);
+}
+
+/*
+ * Similar to getenv(3) but operates on a private copy of the environment.
+ * Does not include warnings or debugging to avoid recursive calls.
+ */
+char *
+sudo_getenv_nodebug(const char *name)
+{
+ char **ep, *val = NULL;
+ size_t namelen = 0;
+
+ if (env.env_len != 0) {
+ /* For BSD compatibility, treat '=' in name like end of string. */
+ while (name[namelen] != '\0' && name[namelen] != '=')
+ namelen++;
+ for (ep = env.envp; *ep != NULL; ep++) {
+ if (strncmp(*ep, name, namelen) == 0 && (*ep)[namelen] == '=') {
+ val = *ep + namelen + 1;
+ break;
+ }
+ }
+ }
+ return val;
+}
+
+/*
+ * Similar to getenv(3) but operates on a private copy of the environment.
+ */
+char *
+sudo_getenv(const char *name)
+{
+ char *val;
+ debug_decl(sudo_getenv, SUDOERS_DEBUG_ENV);
+
+ sudo_debug_printf(SUDO_DEBUG_INFO, "sudo_getenv: %s", name);
+
+ val = sudo_getenv_nodebug(name);
+
+ debug_return_str(val);
+}
+
+/*
+ * Check for var against patterns in the specified environment list.
+ * Returns true if the variable was found, else false.
+ */
+static bool
+matches_env_list(const char *var, struct list_members *list, bool *full_match)
+{
+ struct list_member *cur;
+ bool is_logname = false;
+ debug_decl(matches_env_list, SUDOERS_DEBUG_ENV);
+
+ switch (*var) {
+ case 'L':
+ if (strncmp(var, "LOGNAME=", 8) == 0)
+ is_logname = true;
+#ifdef _AIX
+ else if (strncmp(var, "LOGIN=", 6) == 0)
+ is_logname = true;
+#endif
+ break;
+ case 'U':
+ if (strncmp(var, "USER=", 5) == 0)
+ is_logname = true;
+ break;
+ }
+
+ if (is_logname) {
+ /*
+ * We treat LOGIN, LOGNAME and USER specially.
+ * If one is preserved/deleted we want to preserve/delete them all.
+ */
+ SLIST_FOREACH(cur, list, entries) {
+ if (matches_env_pattern(cur->value, "LOGNAME", full_match) ||
+#ifdef _AIX
+ matches_env_pattern(cur->value, "LOGIN", full_match) ||
+#endif
+ matches_env_pattern(cur->value, "USER", full_match))
+ debug_return_bool(true);
+ }
+ } else {
+ SLIST_FOREACH(cur, list, entries) {
+ if (matches_env_pattern(cur->value, var, full_match))
+ debug_return_bool(true);
+ }
+ }
+ debug_return_bool(false);
+}
+
+/*
+ * Check the env_delete blocklist.
+ * Returns true if the variable was found, else false.
+ */
+static bool
+matches_env_delete(const char *var)
+{
+ bool full_match; /* unused */
+ debug_decl(matches_env_delete, SUDOERS_DEBUG_ENV);
+
+ /* Skip anything listed in env_delete. */
+ debug_return_bool(matches_env_list(var, &def_env_delete, &full_match));
+}
+
+/*
+ * Verify the TZ environment variable is safe.
+ * On many systems it is possible to set this to a pathname.
+ */
+static bool
+tz_is_safe(const char *tzval)
+{
+ const char *cp;
+ char lastch;
+ debug_decl(tz_is_safe, SUDOERS_DEBUG_ENV);
+
+ /* tzcode treats a value beginning with a ':' as a path. */
+ if (tzval[0] == ':')
+ tzval++;
+
+ /* Reject fully-qualified TZ that doesn't being with the zoneinfo dir. */
+ if (tzval[0] == '/') {
+#ifdef _PATH_ZONEINFO
+ if (strncmp(tzval, _PATH_ZONEINFO, sizeof(_PATH_ZONEINFO) - 1) != 0 ||
+ tzval[sizeof(_PATH_ZONEINFO) - 1] != '/')
+ debug_return_bool(false);
+#else
+ /* Assume the worst. */
+ debug_return_bool(false);
+#endif
+ }
+
+ /*
+ * Make sure TZ only contains printable non-space characters
+ * and does not contain a '..' path element.
+ */
+ lastch = '/';
+ for (cp = tzval; *cp != '\0'; cp++) {
+ if (isspace((unsigned char)*cp) || !isprint((unsigned char)*cp))
+ debug_return_bool(false);
+ if (lastch == '/' && cp[0] == '.' && cp[1] == '.' &&
+ (cp[2] == '/' || cp[2] == '\0'))
+ debug_return_bool(false);
+ lastch = *cp;
+ }
+
+ /* Reject extra long TZ values (even if not a path). */
+ if ((size_t)(cp - tzval) >= PATH_MAX)
+ debug_return_bool(false);
+
+ debug_return_bool(true);
+}
+
+/*
+ * Apply the env_check list.
+ * Returns true if the variable is allowed, false if denied
+ * or -1 if no match.
+ */
+static int
+matches_env_check(const char *var, bool *full_match)
+{
+ int keepit = -1;
+ debug_decl(matches_env_check, SUDOERS_DEBUG_ENV);
+
+ /* Skip anything listed in env_check that includes '/' or '%'. */
+ if (matches_env_list(var, &def_env_check, full_match)) {
+ if (strncmp(var, "TZ=", 3) == 0) {
+ /* Special case for TZ */
+ keepit = tz_is_safe(var + 3);
+ } else {
+ const char *val = strchr(var, '=');
+ if (val != NULL)
+ keepit = !strpbrk(val + 1, "/%");
+ }
+ }
+ debug_return_int(keepit);
+}
+
+/*
+ * Check the env_keep list.
+ * Returns true if the variable is allowed else false.
+ */
+static bool
+matches_env_keep(const char *var, bool *full_match)
+{
+ bool keepit = false;
+ debug_decl(matches_env_keep, SUDOERS_DEBUG_ENV);
+
+ /* Preserve SHELL variable for "sudo -s". */
+ if (ISSET(sudo_mode, MODE_SHELL) && strncmp(var, "SHELL=", 6) == 0) {
+ keepit = true;
+ } else if (matches_env_list(var, &def_env_keep, full_match)) {
+ keepit = true;
+ }
+ debug_return_bool(keepit);
+}
+
+/*
+ * Look up var in the env_delete and env_check.
+ * Returns true if we should delete the variable, else false.
+ */
+static bool
+env_should_delete(const char *var)
+{
+ int delete_it;
+ bool full_match = false;
+ debug_decl(env_should_delete, SUDOERS_DEBUG_ENV);
+
+ delete_it = matches_env_delete(var);
+ if (!delete_it)
+ delete_it = matches_env_check(var, &full_match) == false;
+
+ sudo_debug_printf(SUDO_DEBUG_INFO, "delete %s: %s",
+ var, delete_it ? "YES" : "NO");
+ debug_return_bool(delete_it);
+}
+
+/*
+ * Lookup var in the env_check and env_keep lists.
+ * Returns true if the variable is allowed else false.
+ */
+static bool
+env_should_keep(const char *var)
+{
+ int keepit;
+ bool full_match = false;
+ const char *cp;
+ debug_decl(env_should_keep, SUDOERS_DEBUG_ENV);
+
+ keepit = matches_env_check(var, &full_match);
+ if (keepit == -1)
+ keepit = matches_env_keep(var, &full_match);
+
+ /* Skip bash functions unless we matched on the value as well as name. */
+ if (keepit && !full_match) {
+ if ((cp = strchr(var, '=')) != NULL) {
+ if (strncmp(cp, "=() ", 4) == 0)
+ keepit = false;
+ }
+ }
+ sudo_debug_printf(SUDO_DEBUG_INFO, "keep %s: %s",
+ var, keepit == true ? "YES" : "NO");
+ debug_return_bool(keepit == true);
+}
+
+#ifdef HAVE_PAM
+/*
+ * Merge another environment with our private copy.
+ * Only overwrite an existing variable if it is not
+ * being preserved from the user's environment.
+ * Returns true on success or false on failure.
+ */
+bool
+env_merge(char * const envp[])
+{
+ char * const *ep;
+ bool ret = true;
+ debug_decl(env_merge, SUDOERS_DEBUG_ENV);
+
+ for (ep = envp; *ep != NULL; ep++) {
+ /* XXX - avoid checking value here, should only check name */
+ bool overwrite = def_env_reset ? !env_should_keep(*ep) : env_should_delete(*ep);
+ if (sudo_putenv(*ep, true, overwrite) == -1) {
+ /* XXX cannot undo on failure */
+ ret = false;
+ break;
+ }
+ }
+ debug_return_bool(ret);
+}
+#endif /* HAVE_PAM */
+
+static void
+env_update_didvar(const char *ep, unsigned int *didvar)
+{
+ switch (*ep) {
+ case 'H':
+ if (strncmp(ep, "HOME=", 5) == 0)
+ SET(*didvar, DID_HOME);
+ break;
+ case 'L':
+#ifdef _AIX
+ if (strncmp(ep, "LOGIN=", 8) == 0)
+ SET(*didvar, DID_LOGIN);
+#endif
+ if (strncmp(ep, "LOGNAME=", 8) == 0)
+ SET(*didvar, DID_LOGNAME);
+ break;
+ case 'M':
+ if (strncmp(ep, "MAIL=", 5) == 0)
+ SET(*didvar, DID_MAIL);
+ break;
+ case 'P':
+ if (strncmp(ep, "PATH=", 5) == 0)
+ SET(*didvar, DID_PATH);
+ break;
+ case 'S':
+ if (strncmp(ep, "SHELL=", 6) == 0)
+ SET(*didvar, DID_SHELL);
+ break;
+ case 'T':
+ if (strncmp(ep, "TERM=", 5) == 0)
+ SET(*didvar, DID_TERM);
+ break;
+ case 'U':
+ if (strncmp(ep, "USER=", 5) == 0)
+ SET(*didvar, DID_USER);
+ break;
+ }
+}
+
+#define CHECK_PUTENV(a, b, c) do { \
+ if (sudo_putenv((char *)(a), (b), (c)) == -1) { \
+ goto bad; \
+ } \
+} while (0)
+
+#define CHECK_SETENV2(a, b, c, d) do { \
+ if (sudo_setenv2((char *)(a), (b), (c), (d)) == -1) { \
+ goto bad; \
+ } \
+} while (0)
+
+/*
+ * Build a new environment and either clear potentially dangerous
+ * variables from the old one or start with a clean slate.
+ * Also adds sudo-specific variables (SUDO_*).
+ * Returns true on success or false on failure.
+ */
+bool
+rebuild_env(void)
+{
+ char **ep, *cp, *ps1;
+ char idbuf[MAX_UID_T_LEN + 1];
+ unsigned int didvar;
+ bool reset_home = false;
+ debug_decl(rebuild_env, SUDOERS_DEBUG_ENV);
+
+ /*
+ * Either clean out the environment or reset to a safe default.
+ */
+ ps1 = NULL;
+ didvar = 0;
+ env.env_len = 0;
+ env.env_size = 128;
+ sudoers_gc_remove(GC_PTR, env.old_envp);
+ free(env.old_envp);
+ env.old_envp = env.envp;
+ env.envp = reallocarray(NULL, env.env_size, sizeof(char *));
+ if (env.envp == NULL) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "unable to allocate memory");
+ env.env_size = 0;
+ goto bad;
+ }
+ sudoers_gc_add(GC_PTR, env.envp);
+#ifdef ENV_DEBUG
+ memset(env.envp, 0, env.env_size * sizeof(char *));
+#else
+ env.envp[0] = NULL;
+#endif
+
+ /* Reset HOME based on target user if configured to. */
+ if (ISSET(sudo_mode, MODE_RUN)) {
+ if (def_always_set_home ||
+ ISSET(sudo_mode, MODE_RESET_HOME | MODE_LOGIN_SHELL) ||
+ (ISSET(sudo_mode, MODE_SHELL) && def_set_home))
+ reset_home = true;
+ }
+
+ if (def_env_reset || ISSET(sudo_mode, MODE_LOGIN_SHELL)) {
+ /*
+ * If starting with a fresh environment, initialize it based on
+ * /etc/environment or login.conf. For "sudo -i" we want those
+ * variables to override the invoking user's environment, so we
+ * defer reading them until later.
+ */
+ if (!ISSET(sudo_mode, MODE_LOGIN_SHELL)) {
+#ifdef HAVE_LOGIN_CAP_H
+ /* Insert login class environment variables. */
+ if (login_class) {
+ login_cap_t *lc = login_getclass(login_class);
+ if (lc != NULL) {
+ setusercontext(lc, runas_pw, runas_pw->pw_uid,
+ LOGIN_SETPATH|LOGIN_SETENV);
+ login_close(lc);
+ }
+ }
+#endif /* HAVE_LOGIN_CAP_H */
+#if defined(_AIX) || (defined(__linux__) && !defined(HAVE_PAM))
+ /* Insert system-wide environment variables. */
+ if (!read_env_file(_PATH_ENVIRONMENT, true, false))
+ sudo_warn("%s", _PATH_ENVIRONMENT);
+#endif
+ for (ep = env.envp; *ep; ep++)
+ env_update_didvar(*ep, &didvar);
+ }
+
+ /* Pull in vars we want to keep from the old environment. */
+ if (env.old_envp != NULL) {
+ for (ep = env.old_envp; *ep; ep++) {
+ bool keepit;
+
+ /*
+ * Look up the variable in the env_check and env_keep lists.
+ */
+ keepit = env_should_keep(*ep);
+
+ /*
+ * Do SUDO_PS1 -> PS1 conversion.
+ * This must happen *after* env_should_keep() is called.
+ */
+ if (strncmp(*ep, "SUDO_PS1=", 9) == 0)
+ ps1 = *ep + 5;
+
+ if (keepit) {
+ /* Preserve variable. */
+ CHECK_PUTENV(*ep, true, false);
+ env_update_didvar(*ep, &didvar);
+ }
+ }
+ }
+ didvar |= didvar << 16; /* convert DID_* to KEPT_* */
+
+ /*
+ * Add in defaults. In -i mode these come from the runas user,
+ * otherwise they may be from the user's environment (depends
+ * on sudoers options).
+ */
+ if (ISSET(sudo_mode, MODE_LOGIN_SHELL)) {
+ CHECK_SETENV2("SHELL", runas_pw->pw_shell,
+ ISSET(didvar, DID_SHELL), true);
+#ifdef _AIX
+ CHECK_SETENV2("LOGIN", runas_pw->pw_name,
+ ISSET(didvar, DID_LOGIN), true);
+#endif
+ CHECK_SETENV2("LOGNAME", runas_pw->pw_name,
+ ISSET(didvar, DID_LOGNAME), true);
+ CHECK_SETENV2("USER", runas_pw->pw_name,
+ ISSET(didvar, DID_USER), true);
+ } else {
+ /* We will set LOGNAME later in the def_set_logname case. */
+ if (!def_set_logname) {
+#ifdef _AIX
+ if (!ISSET(didvar, DID_LOGIN))
+ CHECK_SETENV2("LOGIN", user_name, false, true);
+#endif
+ if (!ISSET(didvar, DID_LOGNAME))
+ CHECK_SETENV2("LOGNAME", user_name, false, true);
+ if (!ISSET(didvar, DID_USER))
+ CHECK_SETENV2("USER", user_name, false, true);
+ }
+ }
+
+ /* If we didn't keep HOME, reset it based on target user. */
+ if (!ISSET(didvar, KEPT_HOME))
+ reset_home = true;
+
+ /*
+ * Set MAIL to target user in -i mode or if MAIL is not preserved
+ * from user's environment.
+ */
+ if (ISSET(sudo_mode, MODE_LOGIN_SHELL) || !ISSET(didvar, KEPT_MAIL)) {
+ if (_PATH_MAILDIR[sizeof(_PATH_MAILDIR) - 2] == '/') {
+ if (asprintf(&cp, "MAIL=%s%s", _PATH_MAILDIR, runas_pw->pw_name) == -1)
+ goto bad;
+ } else {
+ if (asprintf(&cp, "MAIL=%s/%s", _PATH_MAILDIR, runas_pw->pw_name) == -1)
+ goto bad;
+ }
+ if (sudo_putenv(cp, ISSET(didvar, DID_MAIL), true) == -1) {
+ free(cp);
+ goto bad;
+ }
+ sudoers_gc_add(GC_PTR, cp);
+ }
+ } else {
+ /*
+ * Copy environ entries as long as they don't match env_delete or
+ * env_check.
+ */
+ if (env.old_envp != NULL) {
+ for (ep = env.old_envp; *ep; ep++) {
+ /* Add variable unless it matches a blocklist. */
+ if (!env_should_delete(*ep)) {
+ if (strncmp(*ep, "SUDO_PS1=", 9) == 0)
+ ps1 = *ep + 5;
+ else if (strncmp(*ep, "SHELL=", 6) == 0)
+ SET(didvar, DID_SHELL);
+ else if (strncmp(*ep, "PATH=", 5) == 0)
+ SET(didvar, DID_PATH);
+ else if (strncmp(*ep, "TERM=", 5) == 0)
+ SET(didvar, DID_TERM);
+ CHECK_PUTENV(*ep, true, false);
+ }
+ }
+ }
+ }
+ /* Replace the PATH envariable with a secure one? */
+ if (def_secure_path && !user_is_exempt()) {
+ CHECK_SETENV2("PATH", def_secure_path, true, true);
+ SET(didvar, DID_PATH);
+ }
+
+ /*
+ * Set LOGIN, LOGNAME, and USER to target if "set_logname" is not
+ * disabled. We skip this if we are running a login shell (because
+ * they have already been set).
+ */
+ if (def_set_logname && !ISSET(sudo_mode, MODE_LOGIN_SHELL)) {
+ if ((didvar & KEPT_USER_VARIABLES) == 0) {
+ /* Nothing preserved, set them all. */
+#ifdef _AIX
+ CHECK_SETENV2("LOGIN", runas_pw->pw_name, true, true);
+#endif
+ CHECK_SETENV2("LOGNAME", runas_pw->pw_name, true, true);
+ CHECK_SETENV2("USER", runas_pw->pw_name, true, true);
+ } else if ((didvar & KEPT_USER_VARIABLES) != KEPT_USER_VARIABLES) {
+ /*
+ * Preserved some of LOGIN, LOGNAME, USER but not all.
+ * Make the unset ones match so we don't end up with some
+ * set to the invoking user and others set to the runas user.
+ */
+ if (ISSET(didvar, KEPT_LOGNAME))
+ cp = sudo_getenv("LOGNAME");
+#ifdef _AIX
+ else if (ISSET(didvar, KEPT_LOGIN))
+ cp = sudo_getenv("LOGIN");
+#endif
+ else if (ISSET(didvar, KEPT_USER))
+ cp = sudo_getenv("USER");
+ else
+ cp = NULL;
+ if (cp != NULL) {
+#ifdef _AIX
+ if (!ISSET(didvar, KEPT_LOGIN))
+ CHECK_SETENV2("LOGIN", cp, true, true);
+#endif
+ if (!ISSET(didvar, KEPT_LOGNAME))
+ CHECK_SETENV2("LOGNAME", cp, true, true);
+ if (!ISSET(didvar, KEPT_USER))
+ CHECK_SETENV2("USER", cp, true, true);
+ }
+ }
+ }
+
+ /* Set $HOME to target user if not preserving user's value. */
+ if (reset_home)
+ CHECK_SETENV2("HOME", runas_pw->pw_dir, true, true);
+
+ /* Provide default values for $SHELL, $TERM and $PATH if not set. */
+ if (!ISSET(didvar, DID_SHELL))
+ CHECK_SETENV2("SHELL", runas_pw->pw_shell, false, false);
+ if (!ISSET(didvar, DID_TERM))
+ CHECK_PUTENV("TERM=unknown", false, false);
+ if (!ISSET(didvar, DID_PATH))
+ CHECK_SETENV2("PATH", _PATH_STDPATH, false, true);
+
+ /* Set PS1 if SUDO_PS1 is set. */
+ if (ps1 != NULL)
+ CHECK_PUTENV(ps1, true, true);
+
+ /* Add the SUDO_COMMAND envariable (cmnd + args). */
+ if (user_args) {
+ /*
+ * We limit user_args to 4096 bytes to avoid an execve() failure
+ * for very long argument vectors. The command's environment also
+ * counts against the ARG_MAX limit.
+ */
+ if (asprintf(&cp, "SUDO_COMMAND=%s %.*s", user_cmnd, 4096, user_args) == -1)
+ goto bad;
+ if (sudo_putenv(cp, true, true) == -1) {
+ free(cp);
+ goto bad;
+ }
+ sudoers_gc_add(GC_PTR, cp);
+ } else {
+ CHECK_SETENV2("SUDO_COMMAND", user_cmnd, true, true);
+ }
+
+ /* Add the SUDO_USER, SUDO_UID, SUDO_GID environment variables. */
+ CHECK_SETENV2("SUDO_USER", user_name, true, true);
+ (void)snprintf(idbuf, sizeof(idbuf), "%u", (unsigned int) user_uid);
+ CHECK_SETENV2("SUDO_UID", idbuf, true, true);
+ (void)snprintf(idbuf, sizeof(idbuf), "%u", (unsigned int) user_gid);
+ CHECK_SETENV2("SUDO_GID", idbuf, true, true);
+
+ debug_return_bool(true);
+
+bad:
+ sudo_warn("%s", U_("unable to rebuild the environment"));
+ debug_return_bool(false);
+}
+
+/*
+ * Insert all environment variables in envp into the private copy
+ * of the environment.
+ * Returns true on success or false on failure.
+ */
+bool
+insert_env_vars(char * const envp[])
+{
+ char * const *ep;
+ bool ret = true;
+ debug_decl(insert_env_vars, SUDOERS_DEBUG_ENV);
+
+ /* Add user-specified environment variables. */
+ if (envp != NULL) {
+ for (ep = envp; *ep != NULL; ep++) {
+ /* XXX - no undo on failure */
+ if (sudo_putenv(*ep, true, true) == -1) {
+ ret = false;
+ break;
+ }
+ }
+ }
+ debug_return_bool(ret);
+}
+
+/*
+ * Validate the list of environment variables passed in on the command
+ * line against env_delete, env_check, and env_keep.
+ * Calls log_warning() if any specified variables are not allowed.
+ * Returns true if allowed, else false.
+ */
+bool
+validate_env_vars(char * const env_vars[])
+{
+ char * const *ep;
+ char errbuf[4096];
+ char *errpos = errbuf;
+ bool okvar, ret = true;
+ debug_decl(validate_env_vars, SUDOERS_DEBUG_ENV);
+
+ if (env_vars == NULL)
+ debug_return_bool(true); /* nothing to do */
+
+ /* Add user-specified environment variables. */
+ for (ep = env_vars; *ep != NULL; ep++) {
+ char *eq = strchr(*ep, '=');
+ if (eq == NULL || eq == *ep) {
+ /* Must be in the form var=val. */
+ okvar = false;
+ } else if (def_secure_path && !user_is_exempt() &&
+ strncmp(*ep, "PATH=", 5) == 0) {
+ okvar = false;
+ } else if (def_env_reset) {
+ okvar = env_should_keep(*ep);
+ } else {
+ okvar = !env_should_delete(*ep);
+ }
+ if (okvar == false) {
+ /* Not allowed, append to error buffer if space remains. */
+ if (errpos < &errbuf[sizeof(errbuf)]) {
+ size_t varlen = strcspn(*ep, "=");
+ int len = snprintf(errpos, sizeof(errbuf) - (errpos - errbuf),
+ "%s%.*s", errpos != errbuf ? ", " : "", (int)varlen, *ep);
+ if (len >= ssizeof(errbuf) - (errpos - errbuf)) {
+ memcpy(&errbuf[sizeof(errbuf) - 4], "...", 4);
+ errpos = &errbuf[sizeof(errbuf)];
+ } else {
+ errpos += len;
+ }
+ }
+ }
+ }
+ if (errpos != errbuf) {
+ /* XXX - audit? */
+ log_warningx(0,
+ N_("sorry, you are not allowed to set the following environment variables: %s"), errbuf);
+ ret = false;
+ }
+ debug_return_bool(ret);
+}
+
+static void *
+env_file_open_local(const char *path)
+{
+ struct env_file_local *efl;
+ debug_decl(env_file_open_local, SUDOERS_DEBUG_ENV);
+
+ efl = calloc(1, sizeof(*efl));
+ if (efl != NULL) {
+ if ((efl->fp = fopen(path, "r")) == NULL) {
+ if (errno != ENOENT) {
+ free(efl);
+ efl = NULL;
+ }
+ }
+ }
+ debug_return_ptr(efl);
+}
+
+static void
+env_file_close_local(void *cookie)
+{
+ struct env_file_local *efl = cookie;
+ debug_decl(env_file_close_local, SUDOERS_DEBUG_ENV);
+
+ if (efl != NULL) {
+ if (efl->fp != NULL)
+ fclose(efl->fp);
+ free(efl->line);
+ free(efl);
+ }
+ debug_return;
+}
+
+/*
+ * Parse /etc/environment lines ala AIX and Linux.
+ * Lines may be in either of three formats:
+ * NAME=VALUE
+ * NAME="VALUE"
+ * NAME='VALUE'
+ * with an optional "export" prefix so the shell can source the file.
+ * Invalid lines, blank lines, or lines consisting solely of a comment
+ * character are skipped.
+ */
+static char *
+env_file_next_local(void *cookie, int *errnum)
+{
+ struct env_file_local *efl = cookie;
+ char *var, *val, *ret = NULL;
+ size_t var_len, val_len;
+ debug_decl(env_file_next_local, SUDOERS_DEBUG_ENV);
+
+ *errnum = 0;
+ if (efl->fp == NULL)
+ debug_return_ptr(NULL);
+
+ for (;;) {
+ if (sudo_parseln(&efl->line, &efl->linesize, NULL, efl->fp, PARSELN_CONT_IGN) == -1) {
+ if (!feof(efl->fp))
+ *errnum = errno;
+ break;
+ }
+
+ /* Skip blank or comment lines */
+ if (*(var = efl->line) == '\0')
+ continue;
+
+ /* Skip optional "export " */
+ if (strncmp(var, "export", 6) == 0 && isspace((unsigned char) var[6])) {
+ var += 7;
+ while (isspace((unsigned char) *var)) {
+ var++;
+ }
+ }
+
+ /* Must be of the form name=["']value['"] */
+ for (val = var; *val != '\0' && *val != '='; val++)
+ continue;
+ if (var == val || *val != '=')
+ continue;
+ var_len = (size_t)(val - var);
+ val_len = strlen(++val);
+
+ /* Strip leading and trailing single/double quotes */
+ if ((val[0] == '\'' || val[0] == '\"') && val_len > 1 && val[0] == val[val_len - 1]) {
+ val[val_len - 1] = '\0';
+ val++;
+ val_len -= 2;
+ }
+
+ if ((ret = malloc(var_len + 1 + val_len + 1)) == NULL) {
+ *errnum = errno;
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "unable to allocate memory");
+ } else {
+ memcpy(ret, var, var_len + 1); /* includes '=' */
+ memcpy(ret + var_len + 1, val, val_len + 1); /* includes NUL */
+ sudoers_gc_add(GC_PTR, ret);
+ }
+ break;
+ }
+ debug_return_str(ret);
+}
+
+static struct sudoers_env_file env_file_sudoers = {
+ env_file_open_local,
+ env_file_close_local,
+ env_file_next_local
+};
+
+static struct sudoers_env_file env_file_system = {
+ env_file_open_local,
+ env_file_close_local,
+ env_file_next_local
+};
+
+void
+register_env_file(void * (*ef_open)(const char *), void (*ef_close)(void *),
+ char * (*ef_next)(void *, int *), bool sys)
+{
+ struct sudoers_env_file *ef = sys ? &env_file_system : &env_file_sudoers;
+
+ ef->open = ef_open;
+ ef->close = ef_close;
+ ef->next = ef_next;
+}
+
+bool
+read_env_file(const char *path, bool overwrite, bool restricted)
+{
+ struct sudoers_env_file *ef;
+ bool ret = true;
+ char *envstr;
+ void *cookie;
+ int errnum;
+ debug_decl(read_env_file, SUDOERS_DEBUG_ENV);
+
+ /*
+ * The environment file may be handled differently depending on
+ * whether it is specified in sudoers or the system.
+ */
+ if (path == def_env_file || path == def_restricted_env_file)
+ ef = &env_file_sudoers;
+ else
+ ef = &env_file_system;
+
+ cookie = ef->open(path);
+ if (cookie == NULL)
+ debug_return_bool(false);
+
+ for (;;) {
+ /* Keep reading until EOF or error. */
+ if ((envstr = ef->next(cookie, &errnum)) == NULL) {
+ if (errnum != 0)
+ ret = false;
+ break;
+ }
+
+ /*
+ * If the env file is restricted, apply env_check and env_keep
+ * when env_reset is set or env_delete when it is not.
+ */
+ if (restricted) {
+ if (def_env_reset ? !env_should_keep(envstr) : env_should_delete(envstr)) {
+ free(envstr);
+ continue;
+ }
+ }
+ if (sudo_putenv(envstr, true, overwrite) == -1) {
+ /* XXX - no undo on failure */
+ ret = false;
+ break;
+ }
+ }
+ ef->close(cookie);
+
+ debug_return_bool(ret);
+}
+
+bool
+init_envtables(void)
+{
+ struct list_member *cur;
+ const char **p;
+ debug_decl(init_envtables, SUDOERS_DEBUG_ENV);
+
+ /* Fill in the "env_delete" list. */
+ for (p = initial_badenv_table; *p; p++) {
+ cur = calloc(1, sizeof(struct list_member));
+ if (cur == NULL || (cur->value = strdup(*p)) == NULL) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "unable to allocate memory");
+ free(cur);
+ debug_return_bool(false);
+ }
+ SLIST_INSERT_HEAD(&def_env_delete, cur, entries);
+ }
+
+ /* Fill in the "env_check" list. */
+ for (p = initial_checkenv_table; *p; p++) {
+ cur = calloc(1, sizeof(struct list_member));
+ if (cur == NULL || (cur->value = strdup(*p)) == NULL) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "unable to allocate memory");
+ free(cur);
+ debug_return_bool(false);
+ }
+ SLIST_INSERT_HEAD(&def_env_check, cur, entries);
+ }
+
+ /* Fill in the "env_keep" list. */
+ for (p = initial_keepenv_table; *p; p++) {
+ cur = calloc(1, sizeof(struct list_member));
+ if (cur == NULL || (cur->value = strdup(*p)) == NULL) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "unable to allocate memory");
+ free(cur);
+ debug_return_bool(false);
+ }
+ SLIST_INSERT_HEAD(&def_env_keep, cur, entries);
+ }
+ debug_return_bool(true);
+}