1 /* taint.c 2 * 3 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 4 * 2000, 2001, 2002, 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 # if Uid_t_size == 1 29 { 30 const UV uid = PL_uid; 31 const UV euid = PL_euid; 32 33 DEBUG_u(PerlIO_printf(Perl_debug_log, 34 "%s %d %"UVuf" %"UVuf"\n", 35 s, PL_tainted, uid, euid)); 36 } 37 # else 38 { 39 const IV uid = PL_uid; 40 const IV euid = PL_euid; 41 42 DEBUG_u(PerlIO_printf(Perl_debug_log, 43 "%s %d %"IVdf" %"IVdf"\n", 44 s, PL_tainted, uid, euid)); 45 } 46 # endif 47 #endif 48 49 if (PL_tainted) { 50 const char *ug; 51 52 if (!f) 53 f = PL_no_security; 54 if (PL_euid != PL_uid) 55 ug = " while running setuid"; 56 else if (PL_egid != PL_gid) 57 ug = " while running setgid"; 58 else if (PL_taint_warn) 59 ug = " while running with -t switch"; 60 else 61 ug = " while running with -T switch"; 62 if (PL_unsafe || PL_taint_warn) { 63 if(ckWARN(WARN_TAINT)) 64 Perl_warner(aTHX_ packWARN(WARN_TAINT), f, s, ug); 65 } 66 else { 67 Perl_croak(aTHX_ f, s, ug); 68 } 69 } 70 } 71 72 void 73 Perl_taint_env(pTHX) 74 { 75 SV** svp; 76 MAGIC* mg; 77 const char* const *e; 78 static const char* const misc_env[] = { 79 "IFS", /* most shells' inter-field separators */ 80 "CDPATH", /* ksh dain bramage #1 */ 81 "ENV", /* ksh dain bramage #2 */ 82 "BASH_ENV", /* bash dain bramage -- I guess it's contagious */ 83 NULL 84 }; 85 86 /* Don't bother if there's no *ENV glob */ 87 if (!PL_envgv) 88 return; 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))) { 93 const bool was_tainted = PL_tainted; 94 const char * const name = GvENAME(PL_envgv); 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 } 105 106 #ifdef VMS 107 { 108 int i = 0; 109 char name[10 + TYPE_DIGITS(int)] = "DCL$PATH"; 110 111 while (1) { 112 if (i) 113 (void)sprintf(name,"DCL$PATH;%d", i); 114 svp = hv_fetch(GvHVn(PL_envgv), name, strlen(name), FALSE); 115 if (!svp || *svp == &PL_sv_undef) 116 break; 117 if (SvTAINTED(*svp)) { 118 TAINT; 119 taint_proper("Insecure %s%s", "$ENV{DCL$PATH}"); 120 } 121 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { 122 TAINT; 123 taint_proper("Insecure directory in %s%s", "$ENV{DCL$PATH}"); 124 } 125 i++; 126 } 127 } 128 #endif /* VMS */ 129 130 svp = hv_fetch(GvHVn(PL_envgv),"PATH",4,FALSE); 131 if (svp && *svp) { 132 if (SvTAINTED(*svp)) { 133 TAINT; 134 taint_proper("Insecure %s%s", "$ENV{PATH}"); 135 } 136 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { 137 TAINT; 138 taint_proper("Insecure directory in %s%s", "$ENV{PATH}"); 139 } 140 } 141 142 #ifndef VMS 143 /* tainted $TERM is okay if it contains no metachars */ 144 svp = hv_fetch(GvHVn(PL_envgv),"TERM",4,FALSE); 145 if (svp && *svp && SvTAINTED(*svp)) { 146 STRLEN len; 147 const bool was_tainted = PL_tainted; 148 const char *t = SvPV_const(*svp, len); 149 const char * const e = t + len; 150 PL_tainted = was_tainted; 151 if (t < e && isALNUM(*t)) 152 t++; 153 while (t < e && (isALNUM(*t) || strchr("-_.+", *t))) 154 t++; 155 if (t < e) { 156 TAINT; 157 taint_proper("Insecure $ENV{%s}%s", "TERM"); 158 } 159 } 160 #endif /* !VMS */ 161 162 for (e = misc_env; *e; e++) { 163 SV ** const svp = hv_fetch(GvHVn(PL_envgv), *e, strlen(*e), FALSE); 164 if (svp && *svp != &PL_sv_undef && SvTAINTED(*svp)) { 165 TAINT; 166 taint_proper("Insecure $ENV{%s}%s", *e); 167 } 168 } 169 } 170 171 /* 172 * Local variables: 173 * c-indentation-style: bsd 174 * c-basic-offset: 4 175 * indent-tabs-mode: t 176 * End: 177 * 178 * ex: set ts=8 sts=4 sw=4 noet: 179 */ 180