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.' --Théoden 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 = PerlProc_getuid(); 37 const UV euid = PerlProc_geteuid(); 38 39 DEBUG_u(PerlIO_printf(Perl_debug_log, 40 "%s %d %"UVuf" %"UVuf"\n", 41 s, TAINT_get, uid, euid)); 42 } 43 # else 44 { 45 const IV uid = PerlProc_getuid(); 46 const IV euid = PerlProc_geteuid(); 47 48 DEBUG_u(PerlIO_printf(Perl_debug_log, 49 "%s %d %"IVdf" %"IVdf"\n", 50 s, TAINT_get, uid, euid)); 51 } 52 # endif 53 #endif 54 55 if (TAINT_get) { 56 const char *ug; 57 58 if (!f) 59 f = PL_no_security; 60 if (PerlProc_getuid() != PerlProc_geteuid()) 61 ug = " while running setuid"; 62 else if (PerlProc_getgid() != PerlProc_getegid()) 63 ug = " while running setgid"; 64 else if (TAINT_WARN_get) 65 ug = " while running with -t switch"; 66 else 67 ug = " while running with -T switch"; 68 if (PL_unsafe || TAINT_WARN_get) { 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 or 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 = TAINT_get; 103 const char * const name = GvENAME(PL_envgv); 104 TAINT; 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 TAINT_set(was_tainted); 113 #ifdef NO_TAINT_SUPPORT 114 PERL_UNUSED_VAR(was_tainted); 115 #endif 116 } 117 118 #ifdef VMS 119 { 120 int i = 0; 121 char name[10 + TYPE_DIGITS(int)] = "DCL$PATH"; 122 STRLEN len = 8; /* strlen(name) */ 123 124 while (1) { 125 if (i) 126 len = my_sprintf(name,"DCL$PATH;%d", i); 127 svp = hv_fetch(GvHVn(PL_envgv), name, len, FALSE); 128 if (!svp || *svp == &PL_sv_undef) 129 break; 130 if (SvTAINTED(*svp)) { 131 TAINT; 132 taint_proper("Insecure %s%s", "$ENV{DCL$PATH}"); 133 } 134 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { 135 TAINT; 136 taint_proper("Insecure directory in %s%s", "$ENV{DCL$PATH}"); 137 } 138 i++; 139 } 140 } 141 #endif /* VMS */ 142 143 svp = hv_fetchs(GvHVn(PL_envgv),"PATH",FALSE); 144 if (svp && *svp) { 145 if (SvTAINTED(*svp)) { 146 TAINT; 147 taint_proper("Insecure %s%s", "$ENV{PATH}"); 148 } 149 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { 150 TAINT; 151 taint_proper("Insecure directory in %s%s", "$ENV{PATH}"); 152 } 153 } 154 155 #ifndef VMS 156 /* tainted $TERM is okay if it contains no metachars */ 157 svp = hv_fetchs(GvHVn(PL_envgv),"TERM",FALSE); 158 if (svp && *svp && SvTAINTED(*svp)) { 159 STRLEN len; 160 const bool was_tainted = TAINT_get; 161 const char *t = SvPV_const(*svp, len); 162 const char * const e = t + len; 163 164 TAINT_set(was_tainted); 165 #ifdef NO_TAINT_SUPPORT 166 PERL_UNUSED_VAR(was_tainted); 167 #endif 168 if (t < e && isWORDCHAR(*t)) 169 t++; 170 while (t < e && (isWORDCHAR(*t) || strchr("-_.+", *t))) 171 t++; 172 if (t < e) { 173 TAINT; 174 taint_proper("Insecure $ENV{%s}%s", "TERM"); 175 } 176 } 177 #endif /* !VMS */ 178 179 for (e = misc_env; *e; e++) { 180 SV * const * const svp = hv_fetch(GvHVn(PL_envgv), *e, strlen(*e), FALSE); 181 if (svp && *svp != &PL_sv_undef && SvTAINTED(*svp)) { 182 TAINT; 183 taint_proper("Insecure $ENV{%s}%s", *e); 184 } 185 } 186 } 187 188 /* 189 * Local variables: 190 * c-indentation-style: bsd 191 * c-basic-offset: 4 192 * indent-tabs-mode: nil 193 * End: 194 * 195 * ex: set ts=8 sts=4 sw=4 et: 196 */ 197