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 PERL_ARGS_ASSERT_TAINT_PROPER; 31 32 { 33 const Uid_t uid = PerlProc_getuid(); 34 const Uid_t euid = PerlProc_geteuid(); 35 36 #if Uid_t_sign == 1 /* uid_t is unsigned. */ 37 DEBUG_u(PerlIO_printf(Perl_debug_log, 38 "%s %d %" UVuf " %" UVuf "\n", 39 s, TAINT_get, (UV)uid, (UV)euid)); 40 #else /* uid_t is signed (Uid_t_sign == -1), or don't know. */ 41 DEBUG_u(PerlIO_printf(Perl_debug_log, 42 "%s %d %" IVdf " %" IVdf "\n", 43 s, TAINT_get, (IV)uid, (IV)euid)); 44 #endif 45 } 46 #endif 47 48 if (TAINT_get) { 49 const char *ug; 50 51 if (!f) 52 f = PL_no_security; 53 if (PerlProc_getuid() != PerlProc_geteuid()) 54 ug = " while running setuid"; 55 else if (PerlProc_getgid() != PerlProc_getegid()) 56 ug = " while running setgid"; 57 else if (TAINT_WARN_get) 58 ug = " while running with -t switch"; 59 else 60 ug = " while running with -T switch"; 61 62 /* XXX because taint_proper adds extra format args, we can't 63 * get the caller to check properly; o we just silence the warning 64 * and hope the callers aren't naughty */ 65 GCC_DIAG_IGNORE_STMT(-Wformat-nonliteral); 66 if (PL_unsafe || TAINT_WARN_get) { 67 Perl_ck_warner_d(aTHX_ packWARN(WARN_TAINT), f, s, ug); 68 } 69 else { 70 Perl_croak(aTHX_ f, s, ug); 71 } 72 GCC_DIAG_RESTORE_STMT; 73 74 } 75 } 76 77 void 78 Perl_taint_env(pTHX) 79 { 80 SV** svp; 81 const char* const *e; 82 static const char* const misc_env[] = { 83 "IFS", /* most shells' inter-field separators */ 84 "CDPATH", /* ksh dain bramage #1 */ 85 "ENV", /* ksh dain bramage #2 */ 86 "BASH_ENV", /* bash dain bramage -- I guess it's contagious */ 87 #ifdef WIN32 88 "PERL5SHELL", /* used for system() on Windows */ 89 #endif 90 NULL 91 }; 92 93 /* Don't bother if there's no *ENV glob */ 94 if (!PL_envgv) 95 return; 96 /* If there's no %ENV hash or if it's not magical, croak, because 97 * it probably doesn't reflect the actual environment */ 98 if (!GvHV(PL_envgv) || !(SvRMAGICAL(GvHV(PL_envgv)) 99 && mg_find((const SV *)GvHV(PL_envgv), PERL_MAGIC_env))) { 100 const bool was_tainted = TAINT_get; 101 const char * const name = GvENAME(PL_envgv); 102 TAINT; 103 if (strEQ(name,"ENV")) 104 /* hash alias */ 105 taint_proper("%%ENV is aliased to %s%s", "another variable"); 106 else 107 /* glob alias: report it in the error message */ 108 taint_proper("%%ENV is aliased to %%%s%s", name); 109 /* this statement is reached under -t or -U */ 110 TAINT_set(was_tainted); 111 #ifdef NO_TAINT_SUPPORT 112 PERL_UNUSED_VAR(was_tainted); 113 #endif 114 } 115 116 #ifdef VMS 117 { 118 int i = 0; 119 char name[10 + TYPE_DIGITS(int)] = "DCL$PATH"; 120 STRLEN len = 8; /* strlen(name) */ 121 122 while (1) { 123 MAGIC* mg; 124 if (i) 125 len = my_snprintf(name, sizeof name, "DCL$PATH;%d", i); 126 svp = hv_fetch(GvHVn(PL_envgv), name, len, FALSE); 127 if (!svp || *svp == &PL_sv_undef) 128 break; 129 if (SvTAINTED(*svp)) { 130 TAINT; 131 taint_proper("Insecure %s%s", "$ENV{DCL$PATH}"); 132 } 133 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { 134 TAINT; 135 taint_proper("Insecure directory in %s%s", "$ENV{DCL$PATH}"); 136 } 137 i++; 138 } 139 } 140 #endif /* VMS */ 141 142 svp = hv_fetchs(GvHVn(PL_envgv),"PATH",FALSE); 143 if (svp && *svp) { 144 MAGIC* mg; 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 * ex: set ts=8 sts=4 sw=4 et: 190 */ 191