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1/* taint.c
2 *
663f364b 3 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
1129b882 4 * 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
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5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
8 *
9 */
10
a0d0e21e 11/*
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12 * '...we will have peace, when you and all your works have perished--and
13 * the works of your dark master to whom you would deliver us. You are a
cdad3b53 14 * liar, Saruman, and a corrupter of men's hearts.' --Théoden
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15 *
16 * [p.580 of _The Lord of the Rings_, III/x: "The Voice of Saruman"]
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17 */
18
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19/* This file contains a few functions for handling data tainting in Perl
20 */
21
463ee0b2 22#include "EXTERN.h"
864dbfa3 23#define PERL_IN_TAINT_C
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24#include "perl.h"
25
26void
e1c41806 27Perl_taint_proper(pTHX_ const char *f, const char *const s)
79072805 28{
26e623cf 29#if defined(HAS_SETEUID) && defined(DEBUGGING)
97aff369 30 dVAR;
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31
32 PERL_ARGS_ASSERT_TAINT_PROPER;
33
26e623cf 34 {
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35 const Uid_t uid = PerlProc_getuid();
36 const Uid_t euid = PerlProc_geteuid();
26e623cf 37
8772537c 38 DEBUG_u(PerlIO_printf(Perl_debug_log,
dfff4baf 39 "%s %d %"Uid_t_f" %"Uid_t_f"\n",
284167a5 40 s, TAINT_get, uid, euid));
26e623cf 41 }
a52cb5f7 42#endif
1e422769 43
284167a5 44 if (TAINT_get) {
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45 const char *ug;
46
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47 if (!f)
48 f = PL_no_security;
985213f2 49 if (PerlProc_getuid() != PerlProc_geteuid())
bbce6d69 50 ug = " while running setuid";
985213f2 51 else if (PerlProc_getgid() != PerlProc_getegid())
bbce6d69 52 ug = " while running setgid";
284167a5 53 else if (TAINT_WARN_get)
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54 ug = " while running with -t switch";
55 else
bbce6d69 56 ug = " while running with -T switch";
5d37acd6 57
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58 /* XXX because taint_proper adds extra format args, we can't
59 * get the caller to check properly; o we just silence the warning
60 * and hope the callers aren't naughty */
61 GCC_DIAG_IGNORE(-Wformat-nonliteral);
284167a5 62 if (PL_unsafe || TAINT_WARN_get) {
9b387841 63 Perl_ck_warner_d(aTHX_ packWARN(WARN_TAINT), f, s, ug);
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64 }
65 else {
66 Perl_croak(aTHX_ f, s, ug);
67 }
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68 GCC_DIAG_RESTORE;
69
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70 }
71}
72
73void
864dbfa3 74Perl_taint_env(pTHX)
79072805 75{
97aff369 76 dVAR;
79072805 77 SV** svp;
7bac28a0 78 MAGIC* mg;
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79 const char* const *e;
80 static const char* const misc_env[] = {
7bac28a0 81 "IFS", /* most shells' inter-field separators */
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82 "CDPATH", /* ksh dain bramage #1 */
83 "ENV", /* ksh dain bramage #2 */
84 "BASH_ENV", /* bash dain bramage -- I guess it's contagious */
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85#ifdef WIN32
86 "PERL5SHELL", /* used for system() on Windows */
87#endif
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88 NULL
89 };
1e422769 90
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91 /* Don't bother if there's no *ENV glob */
92 if (!PL_envgv)
142393a6 93 return;
284167a5 94 /* If there's no %ENV hash or if it's not magical, croak, because
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95 * it probably doesn't reflect the actual environment */
96 if (!GvHV(PL_envgv) || !(SvRMAGICAL(GvHV(PL_envgv))
daba3364 97 && mg_find((const SV *)GvHV(PL_envgv), PERL_MAGIC_env))) {
284167a5 98 const bool was_tainted = TAINT_get;
8772537c 99 const char * const name = GvENAME(PL_envgv);
284167a5 100 TAINT;
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101 if (strEQ(name,"ENV"))
102 /* hash alias */
103 taint_proper("%%ENV is aliased to %s%s", "another variable");
104 else
105 /* glob alias: report it in the error message */
106 taint_proper("%%ENV is aliased to %%%s%s", name);
107 /* this statement is reached under -t or -U */
284167a5 108 TAINT_set(was_tainted);
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109#ifdef NO_TAINT_SUPPORT
110 PERL_UNUSED_VAR(was_tainted);
111#endif
c038024b 112 }
142393a6 113
1e422769 114#ifdef VMS
82f1aded 115 {
1e422769 116 int i = 0;
0dc443ab 117 char name[10 + TYPE_DIGITS(int)] = "DCL$PATH";
86c11942 118 STRLEN len = 8; /* strlen(name) */
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119
120 while (1) {
121 if (i)
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122 len = my_sprintf(name,"DCL$PATH;%d", i);
123 svp = hv_fetch(GvHVn(PL_envgv), name, len, FALSE);
6b88bc9c 124 if (!svp || *svp == &PL_sv_undef)
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125 break;
126 if (SvTAINTED(*svp)) {
127 TAINT;
128 taint_proper("Insecure %s%s", "$ENV{DCL$PATH}");
129 }
c038024b 130 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) {
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131 TAINT;
132 taint_proper("Insecure directory in %s%s", "$ENV{DCL$PATH}");
133 }
134 i++;
135 }
82f1aded 136 }
1e422769 137#endif /* VMS */
79072805 138
a4fc7abc 139 svp = hv_fetchs(GvHVn(PL_envgv),"PATH",FALSE);
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140 if (svp && *svp) {
141 if (SvTAINTED(*svp)) {
142 TAINT;
bbce6d69 143 taint_proper("Insecure %s%s", "$ENV{PATH}");
1e422769 144 }
c038024b 145 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) {
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146 TAINT;
147 taint_proper("Insecure directory in %s%s", "$ENV{PATH}");
148 }
79072805 149 }
79072805 150
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151#ifndef VMS
152 /* tainted $TERM is okay if it contains no metachars */
a4fc7abc 153 svp = hv_fetchs(GvHVn(PL_envgv),"TERM",FALSE);
c90c0ff4 154 if (svp && *svp && SvTAINTED(*svp)) {
8b6b16e7 155 STRLEN len;
284167a5 156 const bool was_tainted = TAINT_get;
cfd0369c 157 const char *t = SvPV_const(*svp, len);
8772537c 158 const char * const e = t + len;
9a9b5ec9 159
284167a5 160 TAINT_set(was_tainted);
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161#ifdef NO_TAINT_SUPPORT
162 PERL_UNUSED_VAR(was_tainted);
163#endif
0eb30aeb 164 if (t < e && isWORDCHAR(*t))
c90c0ff4 165 t++;
0eb30aeb 166 while (t < e && (isWORDCHAR(*t) || strchr("-_.+", *t)))
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167 t++;
168 if (t < e) {
169 TAINT;
170 taint_proper("Insecure $ENV{%s}%s", "TERM");
171 }
172 }
173#endif /* !VMS */
174
7bac28a0 175 for (e = misc_env; *e; e++) {
0bd48802 176 SV * const * const svp = hv_fetch(GvHVn(PL_envgv), *e, strlen(*e), FALSE);
3280af22 177 if (svp && *svp != &PL_sv_undef && SvTAINTED(*svp)) {
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178 TAINT;
179 taint_proper("Insecure $ENV{%s}%s", *e);
180 }
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181 }
182}
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183
184/*
185 * Local variables:
186 * c-indentation-style: bsd
187 * c-basic-offset: 4
14d04a33 188 * indent-tabs-mode: nil
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189 * End:
190 *
14d04a33 191 * ex: set ts=8 sts=4 sw=4 et:
37442d52 192 */