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 *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 if(ckWARN_d(WARN_TAINT)) 70 Perl_warner(aTHX_ packWARN(WARN_TAINT), f, s, ug); 71 } 72 else { 73 Perl_croak(aTHX_ f, s, ug); 74 } 75 } 76 } 77 78 void 79 Perl_taint_env(pTHX) 80 { 81 dVAR; 82 SV** svp; 83 MAGIC* mg; 84 const char* const *e; 85 static const char* const misc_env[] = { 86 "IFS", /* most shells' inter-field separators */ 87 "CDPATH", /* ksh dain bramage #1 */ 88 "ENV", /* ksh dain bramage #2 */ 89 "BASH_ENV", /* bash dain bramage -- I guess it's contagious */ 90 #ifdef WIN32 91 "PERL5SHELL", /* used for system() on Windows */ 92 #endif 93 NULL 94 }; 95 96 /* Don't bother if there's no *ENV glob */ 97 if (!PL_envgv) 98 return; 99 /* If there's no %ENV hash of if it's not magical, croak, because 100 * it probably doesn't reflect the actual environment */ 101 if (!GvHV(PL_envgv) || !(SvRMAGICAL(GvHV(PL_envgv)) 102 && mg_find((const SV *)GvHV(PL_envgv), PERL_MAGIC_env))) { 103 const bool was_tainted = PL_tainted; 104 const char * const name = GvENAME(PL_envgv); 105 PL_tainted = TRUE; 106 if (strEQ(name,"ENV")) 107 /* hash alias */ 108 taint_proper("%%ENV is aliased to %s%s", "another variable"); 109 else 110 /* glob alias: report it in the error message */ 111 taint_proper("%%ENV is aliased to %%%s%s", name); 112 /* this statement is reached under -t or -U */ 113 PL_tainted = was_tainted; 114 } 115 116 #ifdef VMS 117 { 118 int i = 0; 119 char name[10 + TYPE_DIGITS(int)] = "DCL$PATH"; 120 STRLEN len = 8; /* strlen(name) */ 121 122 while (1) { 123 if (i) 124 len = my_sprintf(name,"DCL$PATH;%d", i); 125 svp = hv_fetch(GvHVn(PL_envgv), name, len, FALSE); 126 if (!svp || *svp == &PL_sv_undef) 127 break; 128 if (SvTAINTED(*svp)) { 129 TAINT; 130 taint_proper("Insecure %s%s", "$ENV{DCL$PATH}"); 131 } 132 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { 133 TAINT; 134 taint_proper("Insecure directory in %s%s", "$ENV{DCL$PATH}"); 135 } 136 i++; 137 } 138 } 139 #endif /* VMS */ 140 141 svp = hv_fetchs(GvHVn(PL_envgv),"PATH",FALSE); 142 if (svp && *svp) { 143 if (SvTAINTED(*svp)) { 144 TAINT; 145 taint_proper("Insecure %s%s", "$ENV{PATH}"); 146 } 147 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { 148 TAINT; 149 taint_proper("Insecure directory in %s%s", "$ENV{PATH}"); 150 } 151 } 152 153 #ifndef VMS 154 /* tainted $TERM is okay if it contains no metachars */ 155 svp = hv_fetchs(GvHVn(PL_envgv),"TERM",FALSE); 156 if (svp && *svp && SvTAINTED(*svp)) { 157 STRLEN len; 158 const bool was_tainted = PL_tainted; 159 const char *t = SvPV_const(*svp, len); 160 const char * const e = t + len; 161 PL_tainted = was_tainted; 162 if (t < e && isALNUM(*t)) 163 t++; 164 while (t < e && (isALNUM(*t) || strchr("-_.+", *t))) 165 t++; 166 if (t < e) { 167 TAINT; 168 taint_proper("Insecure $ENV{%s}%s", "TERM"); 169 } 170 } 171 #endif /* !VMS */ 172 173 for (e = misc_env; *e; e++) { 174 SV * const * const svp = hv_fetch(GvHVn(PL_envgv), *e, strlen(*e), FALSE); 175 if (svp && *svp != &PL_sv_undef && SvTAINTED(*svp)) { 176 TAINT; 177 taint_proper("Insecure $ENV{%s}%s", *e); 178 } 179 } 180 } 181 182 /* 183 * Local variables: 184 * c-indentation-style: bsd 185 * c-basic-offset: 4 186 * indent-tabs-mode: t 187 * End: 188 * 189 * ex: set ts=8 sts=4 sw=4 noet: 190 */ 191