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