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/* taint.c
*
* Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
* 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
*
* You may distribute under the terms of either the GNU General Public
* License or the Artistic License, as specified in the README file.
*
*/
/*
* '...we will have peace, when you and all your works have perished--and
* the works of your dark master to whom you would deliver us. You are a
* liar, Saruman, and a corrupter of men's hearts.' --Théoden
*
* [p.580 of _The Lord of the Rings_, III/x: "The Voice of Saruman"]
*/
/* This file contains a few functions for handling data tainting in Perl
*/
#include "EXTERN.h"
#define PERL_IN_TAINT_C
#include "perl.h"
void
Perl_taint_proper(pTHX_ const char *f, const char *const s)
{
#if defined(HAS_SETEUID) && defined(DEBUGGING)
dVAR;
PERL_ARGS_ASSERT_TAINT_PROPER;
{
const Uid_t uid = PerlProc_getuid();
const Uid_t euid = PerlProc_geteuid();
DEBUG_u(PerlIO_printf(Perl_debug_log,
"%s %d %"Uid_t_f" %"Uid_t_f"\n",
s, TAINT_get, uid, euid));
}
#endif
if (TAINT_get) {
const char *ug;
if (!f)
f = PL_no_security;
if (PerlProc_getuid() != PerlProc_geteuid())
ug = " while running setuid";
else if (PerlProc_getgid() != PerlProc_getegid())
ug = " while running setgid";
else if (TAINT_WARN_get)
ug = " while running with -t switch";
else
ug = " while running with -T switch";
/* XXX because taint_proper adds extra format args, we can't
* get the caller to check properly; o we just silence the warning
* and hope the callers aren't naughty */
GCC_DIAG_IGNORE(-Wformat-nonliteral);
if (PL_unsafe || TAINT_WARN_get) {
Perl_ck_warner_d(aTHX_ packWARN(WARN_TAINT), f, s, ug);
}
else {
Perl_croak(aTHX_ f, s, ug);
}
GCC_DIAG_RESTORE;
}
}
void
Perl_taint_env(pTHX)
{
dVAR;
SV** svp;
MAGIC* mg;
const char* const *e;
static const char* const misc_env[] = {
"IFS", /* most shells' inter-field separators */
"CDPATH", /* ksh dain bramage #1 */
"ENV", /* ksh dain bramage #2 */
"BASH_ENV", /* bash dain bramage -- I guess it's contagious */
#ifdef WIN32
"PERL5SHELL", /* used for system() on Windows */
#endif
NULL
};
/* Don't bother if there's no *ENV glob */
if (!PL_envgv)
return;
/* If there's no %ENV hash or if it's not magical, croak, because
* it probably doesn't reflect the actual environment */
if (!GvHV(PL_envgv) || !(SvRMAGICAL(GvHV(PL_envgv))
&& mg_find((const SV *)GvHV(PL_envgv), PERL_MAGIC_env))) {
const bool was_tainted = TAINT_get;
const char * const name = GvENAME(PL_envgv);
TAINT;
if (strEQ(name,"ENV"))
/* hash alias */
taint_proper("%%ENV is aliased to %s%s", "another variable");
else
/* glob alias: report it in the error message */
taint_proper("%%ENV is aliased to %%%s%s", name);
/* this statement is reached under -t or -U */
TAINT_set(was_tainted);
#ifdef NO_TAINT_SUPPORT
PERL_UNUSED_VAR(was_tainted);
#endif
}
#ifdef VMS
{
int i = 0;
char name[10 + TYPE_DIGITS(int)] = "DCL$PATH";
STRLEN len = 8; /* strlen(name) */
while (1) {
if (i)
len = my_sprintf(name,"DCL$PATH;%d", i);
svp = hv_fetch(GvHVn(PL_envgv), name, len, FALSE);
if (!svp || *svp == &PL_sv_undef)
break;
if (SvTAINTED(*svp)) {
TAINT;
taint_proper("Insecure %s%s", "$ENV{DCL$PATH}");
}
if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) {
TAINT;
taint_proper("Insecure directory in %s%s", "$ENV{DCL$PATH}");
}
i++;
}
}
#endif /* VMS */
svp = hv_fetchs(GvHVn(PL_envgv),"PATH",FALSE);
if (svp && *svp) {
if (SvTAINTED(*svp)) {
TAINT;
taint_proper("Insecure %s%s", "$ENV{PATH}");
}
if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) {
TAINT;
taint_proper("Insecure directory in %s%s", "$ENV{PATH}");
}
}
#ifndef VMS
/* tainted $TERM is okay if it contains no metachars */
svp = hv_fetchs(GvHVn(PL_envgv),"TERM",FALSE);
if (svp && *svp && SvTAINTED(*svp)) {
STRLEN len;
const bool was_tainted = TAINT_get;
const char *t = SvPV_const(*svp, len);
const char * const e = t + len;
TAINT_set(was_tainted);
#ifdef NO_TAINT_SUPPORT
PERL_UNUSED_VAR(was_tainted);
#endif
if (t < e && isWORDCHAR(*t))
t++;
while (t < e && (isWORDCHAR(*t) || strchr("-_.+", *t)))
t++;
if (t < e) {
TAINT;
taint_proper("Insecure $ENV{%s}%s", "TERM");
}
}
#endif /* !VMS */
for (e = misc_env; *e; e++) {
SV * const * const svp = hv_fetch(GvHVn(PL_envgv), *e, strlen(*e), FALSE);
if (svp && *svp != &PL_sv_undef && SvTAINTED(*svp)) {
TAINT;
taint_proper("Insecure $ENV{%s}%s", *e);
}
}
}
/*
* Local variables:
* c-indentation-style: bsd
* c-basic-offset: 4
* indent-tabs-mode: nil
* End:
*
* ex: set ts=8 sts=4 sw=4 et:
*/
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