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 { 35 const Uid_t uid = PerlProc_getuid(); 36 const Uid_t euid = PerlProc_geteuid(); 37 38 DEBUG_u(PerlIO_printf(Perl_debug_log, 39 "%s %d %"Uid_t_f" %"Uid_t_f"\n", 40 s, TAINT_get, uid, euid)); 41 } 42 #endif 43 44 if (TAINT_get) { 45 const char *ug; 46 47 if (!f) 48 f = PL_no_security; 49 if (PerlProc_getuid() != PerlProc_geteuid()) 50 ug = " while running setuid"; 51 else if (PerlProc_getgid() != PerlProc_getegid()) 52 ug = " while running setgid"; 53 else if (TAINT_WARN_get) 54 ug = " while running with -t switch"; 55 else 56 ug = " while running with -T switch"; 57 58 /* XXX because taint_proper adds extra format args, we can't 59 * get the caller to check properly; o we just silence the warning 60 * and hope the callers aren't naughty */ 61 GCC_DIAG_IGNORE(-Wformat-nonliteral); 62 if (PL_unsafe || TAINT_WARN_get) { 63 Perl_ck_warner_d(aTHX_ packWARN(WARN_TAINT), f, s, ug); 64 } 65 else { 66 Perl_croak(aTHX_ f, s, ug); 67 } 68 GCC_DIAG_RESTORE; 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 or 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((const SV *)GvHV(PL_envgv), PERL_MAGIC_env))) { 98 const bool was_tainted = TAINT_get; 99 const char * const name = GvENAME(PL_envgv); 100 TAINT; 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 TAINT_set(was_tainted); 109 #ifdef NO_TAINT_SUPPORT 110 PERL_UNUSED_VAR(was_tainted); 111 #endif 112 } 113 114 #ifdef VMS 115 { 116 int i = 0; 117 char name[10 + TYPE_DIGITS(int)] = "DCL$PATH"; 118 STRLEN len = 8; /* strlen(name) */ 119 120 while (1) { 121 if (i) 122 len = my_sprintf(name,"DCL$PATH;%d", i); 123 svp = hv_fetch(GvHVn(PL_envgv), name, len, FALSE); 124 if (!svp || *svp == &PL_sv_undef) 125 break; 126 if (SvTAINTED(*svp)) { 127 TAINT; 128 taint_proper("Insecure %s%s", "$ENV{DCL$PATH}"); 129 } 130 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { 131 TAINT; 132 taint_proper("Insecure directory in %s%s", "$ENV{DCL$PATH}"); 133 } 134 i++; 135 } 136 } 137 #endif /* VMS */ 138 139 svp = hv_fetchs(GvHVn(PL_envgv),"PATH",FALSE); 140 if (svp && *svp) { 141 if (SvTAINTED(*svp)) { 142 TAINT; 143 taint_proper("Insecure %s%s", "$ENV{PATH}"); 144 } 145 if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { 146 TAINT; 147 taint_proper("Insecure directory in %s%s", "$ENV{PATH}"); 148 } 149 } 150 151 #ifndef VMS 152 /* tainted $TERM is okay if it contains no metachars */ 153 svp = hv_fetchs(GvHVn(PL_envgv),"TERM",FALSE); 154 if (svp && *svp && SvTAINTED(*svp)) { 155 STRLEN len; 156 const bool was_tainted = TAINT_get; 157 const char *t = SvPV_const(*svp, len); 158 const char * const e = t + len; 159 160 TAINT_set(was_tainted); 161 #ifdef NO_TAINT_SUPPORT 162 PERL_UNUSED_VAR(was_tainted); 163 #endif 164 if (t < e && isWORDCHAR(*t)) 165 t++; 166 while (t < e && (isWORDCHAR(*t) || strchr("-_.+", *t))) 167 t++; 168 if (t < e) { 169 TAINT; 170 taint_proper("Insecure $ENV{%s}%s", "TERM"); 171 } 172 } 173 #endif /* !VMS */ 174 175 for (e = misc_env; *e; e++) { 176 SV * const * const svp = hv_fetch(GvHVn(PL_envgv), *e, strlen(*e), FALSE); 177 if (svp && *svp != &PL_sv_undef && SvTAINTED(*svp)) { 178 TAINT; 179 taint_proper("Insecure $ENV{%s}%s", *e); 180 } 181 } 182 } 183 184 /* 185 * Local variables: 186 * c-indentation-style: bsd 187 * c-basic-offset: 4 188 * indent-tabs-mode: nil 189 * End: 190 * 191 * ex: set ts=8 sts=4 sw=4 et: 192 */ 193