/*
* Copyright (c) 2000-2005, 2007-2011
* Todd C. Miller <Todd.Miller@courtesan.com>
*
* 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.
*/
#include <config.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
# include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#include <ctype.h>
#include <errno.h>
#include <pwd.h>
#include "sudoers.h"
/*
* Flags used in rebuild_env()
*/
#undef DID_TERM
#define DID_TERM 0x0001
#undef DID_PATH
#define DID_PATH 0x0002
#undef DID_HOME
#define DID_HOME 0x0004
#undef DID_SHELL
#define DID_SHELL 0x0008
#undef DID_LOGNAME
#define DID_LOGNAME 0x0010
#undef DID_USER
#define DID_USER 0x0020
#undef DID_USERNAME
#define DID_USERNAME 0x0040
#undef DID_MAIL
#define DID_MAIL 0x0080
#undef DID_MAX
#define DID_MAX 0x00ff
#undef KEPT_TERM
#define KEPT_TERM 0x0100
#undef KEPT_PATH
#define KEPT_PATH 0x0200
#undef KEPT_HOME
#define KEPT_HOME 0x0400
#undef KEPT_SHELL
#define KEPT_SHELL 0x0800
#undef KEPT_LOGNAME
#define KEPT_LOGNAME 0x1000
#undef KEPT_USER
#define KEPT_USER 0x2000
#undef KEPT_USERNAME
#define KEPT_USERNAME 0x4000
#undef KEPT_MAIL
#define KEPT_MAIL 0x8000
#undef KEPT_MAX
#define KEPT_MAX 0xff00
struct environment {
char **envp; /* pointer to the new environment */
size_t env_size; /* size of new_environ in char **'s */
size_t env_len; /* number of slots used, not counting NULL */
};
/*
* Prototypes
*/
static void sudo_setenv(const char *, const char *, int);
static void sudo_putenv(char *, int, int);
/*
* 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_KERB4
"KRB_CONF*",
"KRBCONFDIR",
"KRBTKFILE",
#endif /* HAVE_KERB4 */
#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 */
"SHELLOPTS", /* bash, extra command line 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 */
NULL
};
/*
* Default table of variables to check for '%' and '/' characters.
*/
static const char *initial_checkenv_table[] = {
"COLORTERM",
"LANG",
"LANGUAGE",
"LC_*",
"LINGUAS",
"TERM",
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",
"TZ",
"XAUTHORITY",
"XAUTHORIZATION",
#ifdef _AIX
"ODMDIR",
#endif
NULL
};
/*
* Initialize env based on envp.
*/
void
env_init(char * const envp[])
{
char * const *ep;
size_t len;
for (ep = envp; *ep != NULL; ep++)
continue;
len = (size_t)(ep - envp);
env.env_len = len;
env.env_size = len + 1 + 128;
env.envp = emalloc2(env.env_size, sizeof(char *));
#ifdef ENV_DEBUG
memset(env.envp, 0, env.env_size * sizeof(char *));
#endif
memcpy(env.envp, envp, len * sizeof(char *));
env.envp[len] = '\0';
}
char **
env_get(void)
{
return env.envp;
}
/*
* Similar to setenv(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.
*/
static void
sudo_setenv(const char *var, const char *val, int dupcheck)
{
char *estring;
size_t esize;
esize = strlen(var) + 1 + strlen(val) + 1;
estring = emalloc(esize);
/* Build environment string and insert it. */
if (strlcpy(estring, var, esize) >= esize ||
strlcat(estring, "=", esize) >= esize ||
strlcat(estring, val, esize) >= esize) {
errorx(1, _("internal error, sudo_setenv() overflow"));
}
sudo_putenv(estring, dupcheck, 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.
*/
static void
sudo_putenv(char *str, int dupcheck, int overwrite)
{
char **ep;
size_t len;
int found = FALSE;
/* Make sure there is room for the new entry plus a NULL. */
if (env.env_len + 2 > env.env_size) {
env.env_size += 128;
env.envp = erealloc3(env.envp, env.env_size, sizeof(char *));
#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)
errorx(1, _("sudo_putenv: corrupted envp, length mismatch"));
#endif
if (dupcheck) {
len = (strchr(str, '=') - str) + 1;
for (ep = env.envp; !found && *ep != NULL; ep++) {
if (strncmp(str, *ep, len) == 0) {
if (overwrite)
*ep = str;
found = TRUE;
}
}
/* Prune out duplicate variables. */
if (found && overwrite) {
while (*ep != NULL) {
if (strncmp(str, *ep, len) == 0) {
char **cur = ep;
while ((*cur = *(cur + 1)) != NULL)
cur++;
} else {
ep++;
}
}
env.env_len = ep - env.envp;
}
}
if (!found) {
ep = env.envp + env.env_len;
env.env_len++;
*ep++ = str;
*ep = NULL;
}
}
/*
* Check the env_delete blacklist.
* Returns TRUE if the variable was found, else false.
*/
static int
matches_env_delete(const char *var)
{
struct list_member *cur;
size_t len;
int iswild, match = FALSE;
/* Skip anything listed in env_delete. */
for (cur = def_env_delete; cur; cur = cur->next) {
len = strlen(cur->value);
/* Deal with '*' wildcard */
if (cur->value[len - 1] == '*') {
len--;
iswild = TRUE;
} else
iswild = FALSE;
if (strncmp(cur->value, var, len) == 0 &&
(iswild || var[len] == '=')) {
match = TRUE;
break;
}
}
return match;
}
/*
* 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)
{
struct list_member *cur;
size_t len;
int iswild, keepit = -1;
for (cur = def_env_check; cur; cur = cur->next) {
len = strlen(cur->value);
/* Deal with '*' wildcard */
if (cur->value[len - 1] == '*') {
len--;
iswild = TRUE;
} else
iswild = FALSE;
if (strncmp(cur->value, var, len) == 0 &&
(iswild || var[len] == '=')) {
keepit = !strpbrk(var, "/%");
break;
}
}
return keepit;
}
/*
* Check the env_keep list.
* Returns TRUE if the variable is allowed else FALSE.
*/
static int
matches_env_keep(const char *var)
{
struct list_member *cur;
size_t len;
int iswild, keepit = FALSE;
/* Preserve SHELL variable for "sudo -s". */
if (ISSET(sudo_mode, MODE_SHELL) && strncmp(var, "SHELL=", 6) == 0)
return TRUE;
for (cur = def_env_keep; cur; cur = cur->next) {
len = strlen(cur->value);
/* Deal with '*' wildcard */
if (cur->value[len - 1] == '*') {
len--;
iswild = TRUE;
} else
iswild = FALSE;
if (strncmp(cur->value, var, len) == 0 &&
(iswild || var[len] == '=')) {
keepit = TRUE;
break;
}
}
return keepit;
}
/*
* Build a new environment and ether clear potentially dangerous
* variables from the old one or start with a clean slate.
* Also adds sudo-specific variables (SUDO_*).
*/
void
rebuild_env(void)
{
char **old_envp, **ep, *cp, *ps1;
char idbuf[MAX_UID_T_LEN];
unsigned int didvar;
int reset_home = FALSE;
/*
* Either clean out the environment or reset to a safe default.
*/
ps1 = NULL;
didvar = 0;
env.env_len = 0;
env.env_size = 128;
old_envp = env.envp;
env.envp = emalloc2(env.env_size, sizeof(char *));
#ifdef ENV_DEBUG
memset(env.envp, 0, env.env_size * sizeof(char *));
#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)) {
/* Pull in vars we want to keep from the old environment. */
for (ep = old_envp; *ep; ep++) {
int keepit;
/* Skip variables with values beginning with () (bash functions) */
if ((cp = strchr(*ep, '=')) != NULL) {
if (strncmp(cp, "=() ", 3) == 0)
continue;
}
/*
* First check certain variables for '%' and '/' characters.
* If no match there, check the keep list.
* If nothing matched, we remove it from the environment.
*/
keepit = matches_env_check(*ep);
if (keepit == -1)
keepit = matches_env_keep(*ep);
/* For SUDO_PS1 -> PS1 conversion. */
if (strncmp(*ep, "SUDO_PS1=", 8) == 0)
ps1 = *ep + 5;
if (keepit) {
/* Preserve variable. */
switch (**ep) {
case 'H':
if (strncmp(*ep, "HOME=", 5) == 0)
SET(didvar, DID_HOME);
break;
case 'L':
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);
if (strncmp(*ep, "USERNAME=", 5) == 0)
SET(didvar, DID_USERNAME);
break;
}
sudo_putenv(*ep, FALSE, FALSE);
}
}
didvar |= didvar << 8; /* 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)) {
sudo_setenv("SHELL", runas_pw->pw_shell, ISSET(didvar, DID_SHELL));
sudo_setenv("LOGNAME", runas_pw->pw_name,
ISSET(didvar, DID_LOGNAME));
sudo_setenv("USER", runas_pw->pw_name, ISSET(didvar, DID_USER));
sudo_setenv("USERNAME", runas_pw->pw_name,
ISSET(didvar, DID_USERNAME));
} else {
if (!ISSET(didvar, DID_SHELL))
sudo_setenv("SHELL", sudo_user.pw->pw_shell, FALSE);
if (!ISSET(didvar, DID_LOGNAME))
sudo_setenv("LOGNAME", user_name, FALSE);
if (!ISSET(didvar, DID_USER))
sudo_setenv("USER", user_name, FALSE);
if (!ISSET(didvar, DID_USERNAME))
sudo_setenv("USERNAME", user_name, FALSE);
}
/* 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)) {
cp = _PATH_MAILDIR;
if (cp[sizeof(_PATH_MAILDIR) - 2] == '/')
easprintf(&cp, "MAIL=%s%s", _PATH_MAILDIR, runas_pw->pw_name);
else
easprintf(&cp, "MAIL=%s/%s", _PATH_MAILDIR, runas_pw->pw_name);
sudo_putenv(cp, ISSET(didvar, DID_MAIL), TRUE);
}
} else {
/*
* Copy environ entries as long as they don't match env_delete or
* env_check.
*/
for (ep = old_envp; *ep; ep++) {
int okvar;
/* Skip variables with values beginning with () (bash functions) */
if ((cp = strchr(*ep, '=')) != NULL) {
if (strncmp(cp, "=() ", 3) == 0)
continue;
}
/*
* First check variables against the blacklist in env_delete.
* If no match there check for '%' and '/' characters.
*/
okvar = matches_env_delete(*ep) != TRUE;
if (okvar)
okvar = matches_env_check(*ep) != FALSE;
if (okvar) {
if (strncmp(*ep, "SUDO_PS1=", 9) == 0)
ps1 = *ep + 5;
else if (strncmp(*ep, "PATH=", 5) == 0)
SET(didvar, DID_PATH);
else if (strncmp(*ep, "TERM=", 5) == 0)
SET(didvar, DID_TERM);
sudo_putenv(*ep, FALSE, FALSE);
}
}
}
/* Replace the PATH envariable with a secure one? */
if (def_secure_path && !user_is_exempt()) {
sudo_setenv("PATH", def_secure_path, TRUE);
SET(didvar, DID_PATH);
}
/*
* Set $USER, $LOGNAME and $USERNAME to target if "set_logname" is not
* disabled. We skip this if we are running a login shell (because
* they have already been set them) or sudoedit (because we want the
* editor to find the user's startup files).
*/
if (def_set_logname && !ISSET(sudo_mode, MODE_LOGIN_SHELL|MODE_EDIT)) {
if (!ISSET(didvar, KEPT_LOGNAME))
sudo_setenv("LOGNAME", runas_pw->pw_name, TRUE);
if (!ISSET(didvar, KEPT_USER))
sudo_setenv("USER", runas_pw->pw_name, TRUE);
if (!ISSET(didvar, KEPT_USERNAME))
sudo_setenv("USERNAME", runas_pw->pw_name, TRUE);
}
/* Set $HOME to target user if not preserving user's value. */
if (reset_home)
sudo_setenv("HOME", runas_pw->pw_dir, TRUE);
/* Provide default values for $TERM and $PATH if they are not set. */
if (!ISSET(didvar, DID_TERM))
sudo_putenv("TERM=unknown", FALSE, FALSE);
if (!ISSET(didvar, DID_PATH))
sudo_setenv("PATH", _PATH_STDPATH, FALSE);
/* Set PS1 if SUDO_PS1 is set. */
if (ps1 != NULL)
sudo_putenv(ps1, TRUE, TRUE);
/* Add the SUDO_COMMAND envariable (cmnd + args). */
if (user_args) {
easprintf(&cp, "%s %s", user_cmnd, user_args);
sudo_setenv("SUDO_COMMAND", cp, TRUE);
efree(cp);
} else {
sudo_setenv("SUDO_COMMAND", user_cmnd, TRUE);
}
/* Add the SUDO_USER, SUDO_UID, SUDO_GID environment variables. */
sudo_setenv("SUDO_USER", user_name, TRUE);
snprintf(idbuf, sizeof(idbuf), "%u", (unsigned int) user_uid);
sudo_setenv("SUDO_UID", idbuf, TRUE);
snprintf(idbuf, sizeof(idbuf), "%u", (unsigned int) user_gid);
sudo_setenv("SUDO_GID", idbuf, TRUE);
/* Free old environment. */
efree(old_envp);
}
void
insert_env_vars(char * const envp[])
{
char * const *ep;
if (envp == NULL)
return;
/* Add user-specified environment variables. */
for (ep = envp; *ep != NULL; ep++)
sudo_putenv(*ep, TRUE, TRUE);
}
/*
* Validate the list of environment variables passed in on the command
* line against env_delete, env_check, and env_keep.
* Calls log_error() if any specified variables are not allowed.
*/
void
validate_env_vars(char * const env_vars[])
{
char * const *ep;
char *eq, *bad = NULL;
size_t len, blen = 0, bsize = 0;
int okvar;
if (env_vars == NULL)
return;
/* Add user-specified environment variables. */
for (ep = env_vars; *ep != NULL; ep++) {
if (def_secure_path && !user_is_exempt() &&
strncmp(*ep, "PATH=", 5) == 0) {
okvar = FALSE;
} else if (def_env_reset) {
okvar = matches_env_check(*ep);
if (okvar == -1)
okvar = matches_env_keep(*ep);
} else {
okvar = matches_env_delete(*ep) == FALSE;
if (okvar == FALSE)
okvar = matches_env_check(*ep) != FALSE;
}
if (okvar == FALSE) {
/* Not allowed, add to error string, allocating as needed. */
if ((eq = strchr(*ep, '=')) != NULL)
*eq = '\0';
len = strlen(*ep) + 2;
if (blen + len >= bsize) {
do {
bsize += 1024;
} while (blen + len >= bsize);
bad = erealloc(bad, bsize);
bad[blen] = '\0';
}
strlcat(bad, *ep, bsize);
strlcat(bad, ", ", bsize);
blen += len;
if (eq != NULL)
*eq = '=';
}
}
if (bad != NULL) {
bad[blen - 2] = '\0'; /* remove trailing ", " */
log_error(NO_MAIL,
_("sorry, you are not allowed to set the following environment variables: %s"), bad);
/* NOTREACHED */
efree(bad);
}
}
/*
* Read in /etc/environment 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.
*/
void
read_env_file(const char *path, int overwrite)
{
FILE *fp;
char *cp, *var, *val;
size_t var_len, val_len;
if ((fp = fopen(path, "r")) == NULL)
return;
while ((var = sudo_parseln(fp)) != NULL) {
/* Skip blank or comment lines */
if (*var == '\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++)
;
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[0] == val[val_len - 1]) {
val[val_len - 1] = '\0';
val++;
val_len -= 2;
}
cp = emalloc(var_len + 1 + val_len + 1);
memcpy(cp, var, var_len + 1); /* includes '=' */
memcpy(cp + var_len + 1, val, val_len + 1); /* includes NUL */
sudo_putenv(cp, TRUE, overwrite);
}
fclose(fp);
}
void
init_envtables(void)
{
struct list_member *cur;
const char **p;
/* Fill in the "env_delete" list. */
for (p = initial_badenv_table; *p; p++) {
cur = emalloc(sizeof(struct list_member));
cur->value = estrdup(*p);
cur->next = def_env_delete;
def_env_delete = cur;
}
/* Fill in the "env_check" list. */
for (p = initial_checkenv_table; *p; p++) {
cur = emalloc(sizeof(struct list_member));
cur->value = estrdup(*p);
cur->next = def_env_check;
def_env_check = cur;
}
/* Fill in the "env_keep" list. */
for (p = initial_keepenv_table; *p; p++) {
cur = emalloc(sizeof(struct list_member));
cur->value = estrdup(*p);
cur->next = def_env_keep;
def_env_keep = cur;
}
}
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