1 /* taint.c 2 * 3 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 4 * 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others 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 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.' --Th�oden 15 * 16 * [p.580 of _The Lord of the Rings_, III/x: "The Voice of Saruman"] 17 */ 18 19 /* This file contains a few functions for handling data tainting in Perl 20 */ 21 22 #include "EXTERN.h" 23 #define PERL_IN_TAINT_C 24 #include "perl.h" 25 26 void 27 Perl_taint_proper(pTHX_ const char *f, const char *const s) 28 { 29 #if defined(HAS_SETEUID) && defined(DEBUGGING) 30 dVAR; 31 32 PERL_ARGS_ASSERT_TAINT_PROPER; 33 34 # if Uid_t_size == 1 35 { 36 const UV uid = PL_uid; 37 const UV euid = PL_euid; 38 39 DEBUG_u(PerlIO_printf(Perl_debug_log, 40 "%s %d %"UVuf" %"UVuf"\n", 41 s, PL_tainted, uid, euid)); 42 } 43 # else 44 { 45 const IV uid = PL_uid; 46 const IV euid = PL_euid; 47 48 DEBUG_u(PerlIO_printf(Perl_debug_log, 49 "%s %d %"IVdf" %"IVdf"\n", 50 s, PL_tainted, uid, euid)); 51 } 52 # endif 53 #endif 54 55 if (PL_tainted) { 56 const char *ug; 57 58 if (!f) 59 f = PL_no_security; 60 if (PL_euid != PL_uid) 61 ug = " while running setuid"; 62 else if (PL_egid != PL_gid) 63 ug = " while running setgid"; 64 else if (PL_taint_warn) 65 ug = " while running with -t switch"; 66 else 67 ug = " while running with -T switch"; 68 if (PL_unsafe || PL_taint_warn) { 69 Perl_ck_warner_d(aTHX_ packWARN(WARN_TAINT), f, s, ug); 70 } 71 else { 72 Perl_croak(aTHX_ f, s, ug); 73 } 74 } 75 } 76 77 void 78 Perl_taint_env(pTHX) 79 { 80 dVAR; 81 SV** svp; 82 MAGIC* mg; 83 const char* const *e; 84 static const char* const misc_env[] = { 85 "IFS", /* most shells' inter-field separators */ 86 "CDPATH", /* ksh dain bramage #1 */ 87 "ENV", /* ksh dain bramage #2 */ 88 "BASH_ENV", /* bash dain bramage -- I guess it's contagious */ 89 #ifdef WIN32 90 "PERL5SHELL", /* used for system() on Windows */ 91 #endif 92 NULL 93 }; 94 95 /* Don't bother if there's no *ENV glob */ 96 if (!PL_envgv) 97 return; 98 /* If there's no %ENV hash of if it's not magical, croak, because 99 * it probably doesn't reflect the actual environment */ 100 if (!GvHV(PL_envgv) || !(SvRMAGICAL(GvHV(PL_envgv)) 101 && mg_find((const SV *)GvHV(PL_envgv), PERL_MAGIC_env))) { 102 const bool was_tainted = PL_tainted; 103 const char * const name = GvENAME(PL_envgv); 104 PL_tainted = TRUE; 105 if (strEQ(name,"ENV")) 106 /* hash alias */ 107 taint_proper("%%ENV is aliased to %s%s", "another variable"); 108 else 109 /* glob alias: report it in the error message */ 110 taint_proper("%%ENV is aliased to %%%s%s", name); 111 /* this statement is reached under -t or -U */ 112 PL_tainted = was_tainted; 113 } 114 115 #ifdef VMS 116 { 117 int i = 0; 118 char name[10 + TYPE_DIGITS(int)] = "DCL$PATH"; 119 STRLEN len = 8; /* strlen(name) */ 120 121 while (1) { 122 if (i) 123 len = my_sprintf(name,"DCL$PATH;%d", i); 124 svp = hv_fetch(GvHVn(PL_envgv), name, len, FALSE); 125 if (!svp || *svp == &PL_sv_undef) 126 break; 127 if (SvTAINTED(*svp)) { 128 TAINT; 129 taint_proper("Insecure %s%s", "$ENV{DCL$PATH}"); 130 } 131 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { 132 TAINT; 133 taint_proper("Insecure directory in %s%s", "$ENV{DCL$PATH}"); 134 } 135 i++; 136 } 137 } 138 #endif /* VMS */ 139 140 svp = hv_fetchs(GvHVn(PL_envgv),"PATH",FALSE); 141 if (svp && *svp) { 142 if (SvTAINTED(*svp)) { 143 TAINT; 144 taint_proper("Insecure %s%s", "$ENV{PATH}"); 145 } 146 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { 147 TAINT; 148 taint_proper("Insecure directory in %s%s", "$ENV{PATH}"); 149 } 150 } 151 152 #ifndef VMS 153 /* tainted $TERM is okay if it contains no metachars */ 154 svp = hv_fetchs(GvHVn(PL_envgv),"TERM",FALSE); 155 if (svp && *svp && SvTAINTED(*svp)) { 156 STRLEN len; 157 const bool was_tainted = PL_tainted; 158 const char *t = SvPV_const(*svp, len); 159 const char * const e = t + len; 160 PL_tainted = was_tainted; 161 if (t < e && isALNUM(*t)) 162 t++; 163 while (t < e && (isALNUM(*t) || strchr("-_.+", *t))) 164 t++; 165 if (t < e) { 166 TAINT; 167 taint_proper("Insecure $ENV{%s}%s", "TERM"); 168 } 169 } 170 #endif /* !VMS */ 171 172 for (e = misc_env; *e; e++) { 173 SV * const * const svp = hv_fetch(GvHVn(PL_envgv), *e, strlen(*e), FALSE); 174 if (svp && *svp != &PL_sv_undef && SvTAINTED(*svp)) { 175 TAINT; 176 taint_proper("Insecure $ENV{%s}%s", *e); 177 } 178 } 179 } 180 181 /* 182 * Local variables: 183 * c-indentation-style: bsd 184 * c-basic-offset: 4 185 * indent-tabs-mode: t 186 * End: 187 * 188 * ex: set ts=8 sts=4 sw=4 noet: 189 */ 190