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