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Re: stringification of v-string references
[perl5.git] / taint.c
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1/* taint.c
2 *
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3 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 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
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11/*
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
14 * liar, Saruman, and a corrupter of men's hearts." --Theoden
15 */
16
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17/* This file contains a few functions for handling data tainting in Perl
18 */
19
463ee0b2 20#include "EXTERN.h"
864dbfa3 21#define PERL_IN_TAINT_C
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22#include "perl.h"
23
24void
dff6d3cd 25Perl_taint_proper(pTHX_ const char *f, const char *s)
79072805 26{
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27#if defined(HAS_SETEUID) && defined(DEBUGGING)
28# if Uid_t_size == 1
29 {
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30 const UV uid = PL_uid;
31 const UV euid = PL_euid;
26e623cf 32
8772537c 33 DEBUG_u(PerlIO_printf(Perl_debug_log,
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34 "%s %d %"UVuf" %"UVuf"\n",
35 s, PL_tainted, uid, euid));
36 }
37# else
38 {
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39 const IV uid = PL_uid;
40 const IV euid = PL_euid;
26e623cf 41
8772537c 42 DEBUG_u(PerlIO_printf(Perl_debug_log,
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43 "%s %d %"IVdf" %"IVdf"\n",
44 s, PL_tainted, uid, euid));
45 }
46# endif
a52cb5f7 47#endif
1e422769 48
3280af22 49 if (PL_tainted) {
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50 const char *ug;
51
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52 if (!f)
53 f = PL_no_security;
3280af22 54 if (PL_euid != PL_uid)
bbce6d69 55 ug = " while running setuid";
3280af22 56 else if (PL_egid != PL_gid)
bbce6d69 57 ug = " while running setgid";
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58 else if (PL_taint_warn)
59 ug = " while running with -t switch";
60 else
bbce6d69 61 ug = " while running with -T switch";
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62 if (PL_unsafe || PL_taint_warn) {
63 if(ckWARN(WARN_TAINT))
9014280d 64 Perl_warner(aTHX_ packWARN(WARN_TAINT), f, s, ug);
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65 }
66 else {
67 Perl_croak(aTHX_ f, s, ug);
68 }
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69 }
70}
71
72void
864dbfa3 73Perl_taint_env(pTHX)
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74{
75 SV** svp;
7bac28a0 76 MAGIC* mg;
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77 const char* const *e;
78 static const char* const misc_env[] = {
7bac28a0 79 "IFS", /* most shells' inter-field separators */
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80 "CDPATH", /* ksh dain bramage #1 */
81 "ENV", /* ksh dain bramage #2 */
82 "BASH_ENV", /* bash dain bramage -- I guess it's contagious */
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83 NULL
84 };
1e422769 85
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86 /* Don't bother if there's no *ENV glob */
87 if (!PL_envgv)
142393a6 88 return;
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89 /* If there's no %ENV hash of if it's not magical, croak, because
90 * it probably doesn't reflect the actual environment */
91 if (!GvHV(PL_envgv) || !(SvRMAGICAL(GvHV(PL_envgv))
92 && mg_find((SV*)GvHV(PL_envgv), PERL_MAGIC_env))) {
e1ec3a88 93 const bool was_tainted = PL_tainted;
8772537c 94 const char * const name = GvENAME(PL_envgv);
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95 PL_tainted = TRUE;
96 if (strEQ(name,"ENV"))
97 /* hash alias */
98 taint_proper("%%ENV is aliased to %s%s", "another variable");
99 else
100 /* glob alias: report it in the error message */
101 taint_proper("%%ENV is aliased to %%%s%s", name);
102 /* this statement is reached under -t or -U */
103 PL_tainted = was_tainted;
104 }
142393a6 105
1e422769 106#ifdef VMS
82f1aded 107 {
1e422769 108 int i = 0;
0dc443ab 109 char name[10 + TYPE_DIGITS(int)] = "DCL$PATH";
86c11942 110 STRLEN len = 8; /* strlen(name) */
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111
112 while (1) {
113 if (i)
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114 len = my_sprintf(name,"DCL$PATH;%d", i);
115 svp = hv_fetch(GvHVn(PL_envgv), name, len, FALSE);
6b88bc9c 116 if (!svp || *svp == &PL_sv_undef)
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117 break;
118 if (SvTAINTED(*svp)) {
119 TAINT;
120 taint_proper("Insecure %s%s", "$ENV{DCL$PATH}");
121 }
c038024b 122 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) {
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123 TAINT;
124 taint_proper("Insecure directory in %s%s", "$ENV{DCL$PATH}");
125 }
126 i++;
127 }
82f1aded 128 }
1e422769 129#endif /* VMS */
79072805 130
3280af22 131 svp = hv_fetch(GvHVn(PL_envgv),"PATH",4,FALSE);
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132 if (svp && *svp) {
133 if (SvTAINTED(*svp)) {
134 TAINT;
bbce6d69 135 taint_proper("Insecure %s%s", "$ENV{PATH}");
1e422769 136 }
c038024b 137 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) {
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138 TAINT;
139 taint_proper("Insecure directory in %s%s", "$ENV{PATH}");
140 }
79072805 141 }
79072805 142
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143#ifndef VMS
144 /* tainted $TERM is okay if it contains no metachars */
3280af22 145 svp = hv_fetch(GvHVn(PL_envgv),"TERM",4,FALSE);
c90c0ff4 146 if (svp && *svp && SvTAINTED(*svp)) {
8b6b16e7 147 STRLEN len;
73d840c0 148 const bool was_tainted = PL_tainted;
cfd0369c 149 const char *t = SvPV_const(*svp, len);
8772537c 150 const char * const e = t + len;
3280af22 151 PL_tainted = was_tainted;
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152 if (t < e && isALNUM(*t))
153 t++;
d085cc71 154 while (t < e && (isALNUM(*t) || strchr("-_.+", *t)))
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155 t++;
156 if (t < e) {
157 TAINT;
158 taint_proper("Insecure $ENV{%s}%s", "TERM");
159 }
160 }
161#endif /* !VMS */
162
7bac28a0 163 for (e = misc_env; *e; e++) {
8772537c 164 SV ** const svp = hv_fetch(GvHVn(PL_envgv), *e, strlen(*e), FALSE);
3280af22 165 if (svp && *svp != &PL_sv_undef && SvTAINTED(*svp)) {
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166 TAINT;
167 taint_proper("Insecure $ENV{%s}%s", *e);
168 }
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169 }
170}
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171
172/*
173 * Local variables:
174 * c-indentation-style: bsd
175 * c-basic-offset: 4
176 * indent-tabs-mode: t
177 * End:
178 *
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179 * ex: set ts=8 sts=4 sw=4 noet:
180 */