File: [local] / src / usr.bin / sudo / Attic / env.c (download)
Revision 1.3, Wed Jan 16 18:09:13 2002 UTC (22 years, 4 months ago) by millert
Branch: MAIN
CVS Tags: OPENBSD_3_1_BASE, OPENBSD_3_1 Branch point for: OPENBSD_3_0, OPENBSD_2_9
Changes since 1.2: +2 -2 lines
update to sudo 1.6.4p2
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/*
* Copyright (c) 2000, 2001 Todd C. Miller <Todd.Miller@courtesan.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 4. Products derived from this software may not be called "Sudo" nor
* may "Sudo" appear in their names without specific prior written
* permission from the author.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#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 */
#include <pwd.h>
#include <errno.h>
#include "sudo.h"
#ifndef lint
static const char rcsid[] = "$Sudo: env.c,v 1.15 2002/01/15 23:43:58 millert Exp $";
#endif /* lint */
/*
* Flags used in env_reset()
*/
#undef DID_TERM
#define DID_TERM 0x01
#undef DID_PATH
#define DID_PATH 0x02
#undef DID_HOME
#define DID_HOME 0x04
#undef DID_SHELL
#define DID_SHELL 0x08
#undef DID_LOGNAME
#define DID_LOGNAME 0x10
#undef DID_USER
#define DID_USER 0x12
/*
* Prototypes
*/
char **rebuild_env __P((int, char **));
char **zero_env __P((char **));
static void insert_env __P((char **, char *));
static char *format_env __P((char *, char *));
/*
* Default table of "bad" variables to remove from the environment.
* XXX - how to omit TERMCAP if it starts with '/'?
*/
char *initial_badenv_table[] = {
"IFS",
"LOCALDOMAIN",
"RES_OPTIONS",
"HOSTALIASES",
"NLSPATH",
"PATH_LOCALE",
"LD_*",
"_RLD*",
#ifdef __hpux
"SHLIB_PATH",
#endif /* __hpux */
#ifdef _AIX
"LIBPATH",
#endif /* _AIX */
#ifdef HAVE_KERB4
"KRB_CONF*",
"KRBCONFDIR"
"KRBTKFILE",
#endif /* HAVE_KERB4 */
#ifdef HAVE_KERB5
"KRB5_CONFIG*",
#endif /* HAVE_KERB5 */
#ifdef HAVE_SECURID
"VAR_ACE",
"USR_ACE",
"DLC_ACE",
#endif /* HAVE_SECURID */
"TERMINFO",
"TERMINFO_DIRS",
"TERMPATH",
"TERMCAP", /* XXX - only if it starts with '/' */
"ENV",
"BASH_ENV",
NULL
};
/*
* Default table of variables to check for '%' and '/' characters.
*/
char *initial_checkenv_table[] = {
"LC_*",
"LANG",
"LANGUAGE",
NULL
};
/*
* Zero out environment and replace with a minimal set of
* USER, LOGNAME, HOME, TZ, PATH (XXX - should just set path to default)
* May set user_path, user_shell, and/or user_prompt as side effects.
*/
char **
zero_env(envp)
char **envp;
{
char **ep, **nep;
static char *newenv[7];
for (ep = envp; *ep; ep++) {
switch (**ep) {
case 'H':
if (strncmp("HOME=", *ep, 5) == 0)
break;
continue;
case 'L':
if (strncmp("LOGNAME=", *ep, 8) == 0)
break;
continue;
case 'P':
if (strncmp("PATH=", *ep, 5) == 0) {
user_path = *ep + 5;
/* XXX - set to sane default instead of user's? */
break;
}
continue;
case 'S':
if (strncmp("SHELL=", *ep, 6) == 0)
user_shell = *ep + 6;
else if (!user_prompt && !strncmp("SUDO_PROMPT=", *ep, 12))
user_prompt = *ep + 12;
continue;
case 'T':
if (strncmp("TZ=", *ep, 3) == 0)
break;
continue;
case 'U':
if (strncmp("USER=", *ep, 5) == 0)
break;
continue;
default:
continue;
}
/* Deal with multiply defined variables (take first instance) */
for (nep = newenv; *nep; nep++) {
if (**nep == **ep)
break;
}
if (*nep == NULL)
*nep++ = *ep;
}
return(&newenv[0]);
}
/*
* Given a variable and value, allocate and format an environment string.
*/
static char *
format_env(var, val)
char *var;
char *val;
{
char *estring, *p;
size_t varlen, vallen;
varlen = strlen(var);
vallen = strlen(val);
p = estring = (char *) emalloc(varlen + vallen + 2);
strcpy(p, var);
p += varlen;
*p++ = '=';
strcpy(p, val);
return(estring);
}
/*
* Insert str into envp.
* Assumes str has an '=' in it and does not check for available space!
*/
static void
insert_env(envp, str)
char **envp;
char *str;
{
char **ep;
size_t varlen;
varlen = (strchr(str, '=') - str) + 1;
for (ep = envp; *ep; ep++) {
if (strncmp(str, *ep, varlen) == 0) {
*ep = str;
break;
}
}
if (*ep == NULL) {
*ep++ = str;
*ep = NULL;
}
}
/*
* 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(sudo_mode, envp)
int sudo_mode;
char **envp;
{
char **newenvp, **ep, **nep, *cp, *ps1;
int okvar, iswild, didvar;
size_t env_size, len;
struct list_member *cur;
/* Count number of items in "env_keep" list (if any) */
for (len = 0, cur = def_list(I_ENV_KEEP); cur; cur = cur->next)
len++;
/*
* Either clean out the environment or reset to a safe default.
*/
ps1 = NULL;
didvar = 0;
if (def_flag(I_ENV_RESET)) {
int keepit;
/* Alloc space for new environment. */
env_size = 32 + len;
nep = newenvp = (char **) emalloc(env_size * sizeof(char *));
/* Pull in vars we want to keep from the old environment. */
for (ep = envp; *ep; ep++) {
keepit = 0;
for (cur = def_list(I_ENV_KEEP); cur; cur = cur->next) {
len = strlen(cur->value);
/* Deal with '*' wildcard */
if (cur->value[len - 1] == '*') {
len--;
iswild = 1;
} else
iswild = 0;
if (strncmp(cur->value, *ep, len) == 0 &&
(iswild || (*ep)[len] == '=')) {
/* We always preserve TERM, no special treatment needed. */
if (strncmp(*ep, "TERM=", 5) != 0)
keepit = 1;
break;
}
}
/* 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)
didvar |= DID_HOME;
break;
case 'S':
if (strncmp(*ep, "SHELL=", 6) == 0)
didvar |= DID_SHELL;
break;
case 'L':
if (strncmp(*ep, "LOGNAME=", 8) == 0)
didvar |= DID_LOGNAME;
break;
case 'U':
if (strncmp(*ep, "USER=", 5) == 0)
didvar |= DID_USER;
break;
}
*nep++ = *ep;
} else {
/* Preserve TERM and PATH, ignore anything else. */
if (!(didvar & DID_TERM) && !strncmp(*ep, "TERM=", 5)) {
*nep++ = *ep;
didvar |= DID_TERM;
} else if (!(didvar & DID_PATH) && !strncmp(*ep, "PATH=", 5)) {
*nep++ = *ep;
didvar |= DID_PATH;
}
}
}
/*
* Add in defaults unless they were preserved from the
* user's environment.
*/
if (!(didvar & DID_HOME))
*nep++ = format_env("HOME", user_dir);
if (!(didvar & DID_SHELL))
*nep++ = format_env("SHELL", sudo_user.pw->pw_shell);
if (!(didvar & DID_LOGNAME))
*nep++ = format_env("LOGNAME", user_name);
if (!(didvar & DID_USER))
*nep++ = format_env("USER", user_name);
} else {
/* Alloc space for new environment. */
for (env_size = 16 + len, ep = envp; *ep; ep++, env_size++)
;
nep = newenvp = (char **) emalloc(env_size * sizeof(char *));
/*
* Copy envp entries as long as they don't match env_delete or
* env_check.
*/
for (ep = envp; *ep; ep++) {
okvar = 1;
/* Skip anything listed in env_delete. */
for (cur = def_list(I_ENV_DELETE); cur && okvar; cur = cur->next) {
len = strlen(cur->value);
/* Deal with '*' wildcard */
if (cur->value[len - 1] == '*') {
len--;
iswild = 1;
} else
iswild = 0;
if (strncmp(cur->value, *ep, len) == 0 &&
(iswild || (*ep)[len] == '=')) {
okvar = 0;
}
}
/* Check certain variables for '%' and '/' characters. */
for (cur = def_list(I_ENV_CHECK); cur && okvar; cur = cur->next) {
len = strlen(cur->value);
/* Deal with '*' wildcard */
if (cur->value[len - 1] == '*') {
len--;
iswild = 1;
} else
iswild = 0;
if (strncmp(cur->value, *ep, len) == 0 &&
(iswild || (*ep)[len] == '=') &&
strpbrk(*ep, "/%")) {
okvar = 0;
}
}
if (okvar) {
if (strncmp(*ep, "SUDO_PS1=", 9) == 0)
ps1 = *ep + 5;
else if (strncmp(*ep, "PATH=", 5) == 0)
didvar |= DID_PATH;
else if (strncmp(*ep, "TERM=", 5) == 0)
didvar |= DID_TERM;
*nep++ = *ep;
}
}
}
/* Provide default values for $TERM and $PATH if they are not set. */
if (!(didvar & DID_TERM))
*nep++ = "TERM=unknown";
if (!(didvar & DID_PATH))
*nep++ = format_env("PATH", _PATH_DEFPATH);
*nep = NULL;
/*
* At this point we must use insert_env() to modify newenvp.
* Access via 'nep' is not allowed (since we must check for dupes).
*/
#ifdef SECURE_PATH
/* Replace the PATH envariable with a secure one. */
insert_env(newenvp, format_env("PATH", SECURE_PATH));
#endif
/* Set $USER and $LOGNAME to target if "set_logname" is true. */
if (def_flag(I_SET_LOGNAME) && runas_pw->pw_name) {
insert_env(newenvp, format_env("LOGNAME", runas_pw->pw_name));
insert_env(newenvp, format_env("USER", runas_pw->pw_name));
}
/* Set $HOME for `sudo -H'. Only valid at PERM_RUNAS. */
if ((sudo_mode & MODE_RESET_HOME) && runas_pw->pw_dir)
insert_env(newenvp, format_env("HOME", runas_pw->pw_dir));
/* Set PS1 if SUDO_PS1 is set. */
if (ps1)
insert_env(newenvp, ps1);
/* Add the SUDO_COMMAND envariable (cmnd + args). */
if (user_args) {
cp = emalloc(strlen(user_cmnd) + strlen(user_args) + 15);
sprintf(cp, "SUDO_COMMAND=%s %s", user_cmnd, user_args);
insert_env(newenvp, cp);
} else
insert_env(newenvp, format_env("SUDO_COMMAND", user_cmnd));
/* Add the SUDO_USER, SUDO_UID, SUDO_GID environment variables. */
insert_env(newenvp, format_env("SUDO_USER", user_name));
cp = emalloc(MAX_UID_T_LEN + 10);
sprintf(cp, "SUDO_UID=%ld", (long) user_uid);
insert_env(newenvp, cp);
cp = emalloc(MAX_UID_T_LEN + 10);
sprintf(cp, "SUDO_GID=%ld", (long) user_gid);
insert_env(newenvp, cp);
return(newenvp);
}
void
dump_badenv()
{
struct list_member *cur;
puts("Default table of environment variables to clear");
for (cur = def_list(I_ENV_DELETE); cur; cur = cur->next)
printf("\t%s\n", cur->value);
puts("Default table of environment variables to sanity check");
for (cur = def_list(I_ENV_CHECK); cur; cur = cur->next)
printf("\t%s\n", cur->value);
}
void
init_envtables()
{
struct list_member *cur;
char **p;
/* Fill in "env_delete" variable. */
for (p = initial_badenv_table; *p; p++) {
cur = emalloc(sizeof(struct list_member));
cur->value = estrdup(*p);
cur->next = def_list(I_ENV_DELETE);
def_list(I_ENV_DELETE) = cur;
}
/* Fill in "env_check" variable. */
for (p = initial_checkenv_table; *p; p++) {
cur = emalloc(sizeof(struct list_member));
cur->value = estrdup(*p);
cur->next = def_list(I_ENV_CHECK);
def_list(I_ENV_CHECK) = cur;
}
}