File: [local] / src / usr.bin / sudo / Attic / env.c (download)
Revision 1.16, Wed Aug 1 22:36:04 2007 UTC (16 years, 10 months ago) by millert
Branch: MAIN
CVS Tags: OPENBSD_4_3_BASE, OPENBSD_4_3, OPENBSD_4_2_BASE, OPENBSD_4_2 Changes since 1.15: +2 -2 lines
PYTHONINSPECT not PYTHONINSPEC; David Krause
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/*
* Copyright (c) 2000-2007 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>
#else
# ifdef HAVE_STRINGS_H
# include <strings.h>
# endif
#endif /* HAVE_STRING_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#ifdef HAVE_ERR_H
# include <err.h>
#else
# include "emul/err.h"
#endif /* HAVE_ERR_H */
#include <pwd.h>
#include "sudo.h"
#ifndef lint
__unused static const char rcsid[] = "$Sudo: env.c,v 1.39.2.17 2007/07/31 18:04:31 millert Exp $";
#endif /* lint */
/*
* 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_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_MAX
#define KEPT_MAX 0xff00
#undef VNULL
#define VNULL (VOID *)NULL
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
*/
char **rebuild_env __P((char **, int, int));
static void insert_env __P((char *, struct environment *, int));
static char *format_env __P((char *, ...));
/*
* 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",
#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 */
"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",
"MAIL",
"PATH",
"PS1",
"PS2",
"TZ",
"XAUTHORITY",
"XAUTHORIZATION",
NULL
};
/*
* Given a variable and value, allocate and format an environment string.
*/
static char *
#ifdef __STDC__
format_env(char *var, ...)
#else
format_env(var, va_alist)
char *var;
va_dcl
#endif
{
char *estring;
char *val;
size_t esize;
va_list ap;
#ifdef __STDC__
va_start(ap, var);
#else
va_start(ap);
#endif
esize = strlen(var) + 2;
while ((val = va_arg(ap, char *)) != NULL)
esize += strlen(val);
va_end(ap);
estring = (char *) emalloc(esize);
/* Store variable name and the '=' separator. */
if (strlcpy(estring, var, esize) >= esize ||
strlcat(estring, "=", esize) >= esize) {
errx(1, "internal error, format_env() overflow");
}
/* Now store the variable's value (if any) */
#ifdef __STDC__
va_start(ap, var);
#else
va_start(ap);
#endif
while ((val = va_arg(ap, char *)) != NULL) {
if (strlcat(estring, val, esize) >= esize)
errx(1, "internal error, format_env() overflow");
}
va_end(ap);
return(estring);
}
/*
* Insert str into e->envp, assumes str has an '=' in it.
*/
static void
insert_env(str, e, dupcheck)
char *str;
struct environment *e;
int dupcheck;
{
char **nep;
size_t varlen;
/* Make sure there is room for the new entry plus a NULL. */
if (e->env_len + 2 > e->env_size) {
e->env_size += 128;
e->envp = erealloc3(e->envp, e->env_size, sizeof(char *));
}
if (dupcheck) {
varlen = (strchr(str, '=') - str) + 1;
for (nep = e->envp; *nep; nep++) {
if (strncmp(str, *nep, varlen) == 0) {
*nep = str;
return;
}
}
} else
nep = e->envp + e->env_len;
e->env_len++;
*nep++ = str;
*nep = NULL;
}
/*
* Check the env_delete blacklist.
* Returns TRUE if the variable was found, else false.
*/
static int
matches_env_delete(var)
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(var)
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(var)
const char *var;
{
struct list_member *cur;
size_t len;
int iswild, keepit = FALSE;
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_*).
*/
char **
rebuild_env(envp, sudo_mode, noexec)
char **envp;
int sudo_mode;
int noexec;
{
char **ep, *cp, *ps1;
unsigned int didvar;
/*
* Either clean out the environment or reset to a safe default.
*/
ps1 = NULL;
didvar = 0;
memset(&env, 0, sizeof(env));
if (def_env_reset) {
/* Pull in vars we want to keep from the old environment. */
for (ep = 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 '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;
}
insert_env(*ep, &env, 0);
}
}
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)) {
insert_env(format_env("HOME", runas_pw->pw_dir, VNULL), &env,
ISSET(didvar, DID_HOME));
insert_env(format_env("SHELL", runas_pw->pw_shell, VNULL), &env,
ISSET(didvar, DID_SHELL));
insert_env(format_env("LOGNAME", runas_pw->pw_name, VNULL), &env,
ISSET(didvar, DID_LOGNAME));
insert_env(format_env("USER", runas_pw->pw_name, VNULL), &env,
ISSET(didvar, DID_USER));
insert_env(format_env("USERNAME", runas_pw->pw_name, VNULL), &env,
ISSET(didvar, DID_USERNAME));
} else {
if (!ISSET(didvar, DID_HOME))
insert_env(format_env("HOME", user_dir, VNULL), &env, 0);
if (!ISSET(didvar, DID_SHELL))
insert_env(format_env("SHELL", sudo_user.pw->pw_shell, VNULL),
&env, 0);
if (!ISSET(didvar, DID_LOGNAME))
insert_env(format_env("LOGNAME", user_name, VNULL), &env, 0);
if (!ISSET(didvar, DID_USER))
insert_env(format_env("USER", user_name, VNULL), &env, 0);
if (!ISSET(didvar, DID_USERNAME))
insert_env(format_env("USERNAME", user_name, VNULL), &env, 0);
}
} else {
/*
* Copy envp entries as long as they don't match env_delete or
* env_check.
*/
for (ep = 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);
insert_env(*ep, &env, 0);
}
}
}
#ifdef SECURE_PATH
/* Replace the PATH envariable with a secure one. */
if (!user_is_exempt()) {
insert_env(format_env("PATH", SECURE_PATH, VNULL), &env, 1);
SET(didvar, DID_PATH);
}
#endif
/* Set $USER, $LOGNAME and $USERNAME to target if "set_logname" is true. */
if (def_set_logname && runas_pw->pw_name) {
if (!ISSET(didvar, KEPT_LOGNAME))
insert_env(format_env("LOGNAME", runas_pw->pw_name, VNULL), &env, 1);
if (!ISSET(didvar, KEPT_USER))
insert_env(format_env("USER", runas_pw->pw_name, VNULL), &env, 1);
if (!ISSET(didvar, KEPT_USERNAME))
insert_env(format_env("USERNAME", runas_pw->pw_name, VNULL), &env, 1);
}
/* Set $HOME for `sudo -H'. Only valid at PERM_FULL_RUNAS. */
if (runas_pw->pw_dir) {
if (ISSET(sudo_mode, MODE_RESET_HOME) ||
(ISSET(sudo_mode, MODE_RUN) && (def_always_set_home ||
(ISSET(sudo_mode, MODE_SHELL) && def_set_home))))
insert_env(format_env("HOME", runas_pw->pw_dir, VNULL), &env, 1);
}
/* Provide default values for $TERM and $PATH if they are not set. */
if (!ISSET(didvar, DID_TERM))
insert_env("TERM=unknown", &env, 0);
if (!ISSET(didvar, DID_PATH))
insert_env(format_env("PATH", _PATH_DEFPATH, VNULL), &env, 0);
/*
* Preload a noexec file? For a list of LD_PRELOAD-alikes, see
* http://www.fortran-2000.com/ArnaudRecipes/sharedlib.html
* XXX - should prepend to original value, if any
*/
if (noexec && def_noexec_file != NULL) {
#if defined(__darwin__) || defined(__APPLE__)
insert_env(format_env("DYLD_INSERT_LIBRARIES", def_noexec_file, VNULL),
&env, 1);
insert_env(format_env("DYLD_FORCE_FLAT_NAMESPACE", VNULL), &env, 1);
#else
# if defined(__osf__) || defined(__sgi)
insert_env(format_env("_RLD_LIST", def_noexec_file, ":DEFAULT", VNULL),
&env, 1);
# else
# ifdef _AIX
insert_env(format_env("LDR_PRELOAD", def_noexec_file, VNULL), &env, 1);
# else
insert_env(format_env("LD_PRELOAD", def_noexec_file, VNULL), &env, 1);
# endif /* _AIX */
# endif /* __osf__ || __sgi */
#endif /* __darwin__ || __APPLE__ */
}
/* Set PS1 if SUDO_PS1 is set. */
if (ps1)
insert_env(ps1, &env, 1);
/* Add the SUDO_COMMAND envariable (cmnd + args). */
if (user_args)
insert_env(format_env("SUDO_COMMAND", user_cmnd, " ", user_args, VNULL),
&env, 1);
else
insert_env(format_env("SUDO_COMMAND", user_cmnd, VNULL), &env, 1);
/* Add the SUDO_USER, SUDO_UID, SUDO_GID environment variables. */
insert_env(format_env("SUDO_USER", user_name, VNULL), &env, 1);
easprintf(&cp, "SUDO_UID=%lu", (unsigned long) user_uid);
insert_env(cp, &env, 1);
easprintf(&cp, "SUDO_GID=%lu", (unsigned long) user_gid);
insert_env(cp, &env, 1);
return(env.envp);
}
char **
insert_env_vars(envp, env_vars)
char **envp;
struct list_member *env_vars;
{
struct list_member *cur;
if (env_vars == NULL)
return (envp);
/*
* Make sure we still own the environment and steal it back if not.
*/
if (env.envp != envp) {
size_t evlen;
char **ep;
for (ep = envp; *ep != NULL; ep++)
continue;
evlen = ep - envp;
if (evlen + 1 > env.env_size) {
efree(env.envp);
env.env_size = evlen + 1 + 128;
env.envp = emalloc2(env.env_size, sizeof(char *));
}
memcpy(env.envp, envp, (evlen + 1) * sizeof(char *));
env.env_len = evlen;
}
/* Add user-specified environment variables. */
for (cur = env_vars; cur != NULL; cur = cur->next)
insert_env(cur->value, &env, 1);
return(env.envp);
}
/*
* 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(env_vars)
struct list_member *env_vars;
{
struct list_member *var;
char *eq, *bad = NULL;
size_t len, blen = 0, bsize = 0;
int okvar;
for (var = env_vars; var != NULL; var = var->next) {
#ifdef SECURE_PATH
if (!user_is_exempt() && strncmp(var->value, "PATH=", 5) == 0) {
okvar = FALSE;
} else
#endif
if (def_env_reset) {
okvar = matches_env_check(var->value);
if (okvar == -1)
okvar = matches_env_keep(var->value);
} else {
okvar = matches_env_delete(var->value) == FALSE;
if (okvar == FALSE)
okvar = matches_env_check(var->value) != FALSE;
}
if (okvar == FALSE) {
/* Not allowed, add to error string, allocating as needed. */
if ((eq = strchr(var->value, '=')) != NULL)
*eq = '\0';
len = strlen(var->value) + 2;
if (blen + len >= bsize) {
do {
bsize += 1024;
} while (blen + len >= bsize);
bad = erealloc(bad, bsize);
bad[blen] = '\0';
}
strlcat(bad, var->value, 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);
}
}
void
init_envtables()
{
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;
}
}