| 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 = PL_uid; |
| 37 | const UV euid = PL_euid; |
| 38 | |
| 39 | DEBUG_u(PerlIO_printf(Perl_debug_log, |
| 40 | "%s %d %"UVuf" %"UVuf"\n", |
| 41 | s, PL_tainted, uid, euid)); |
| 42 | } |
| 43 | # else |
| 44 | { |
| 45 | const IV uid = PL_uid; |
| 46 | const IV euid = PL_euid; |
| 47 | |
| 48 | DEBUG_u(PerlIO_printf(Perl_debug_log, |
| 49 | "%s %d %"IVdf" %"IVdf"\n", |
| 50 | s, PL_tainted, uid, euid)); |
| 51 | } |
| 52 | # endif |
| 53 | #endif |
| 54 | |
| 55 | if (PL_tainted) { |
| 56 | const char *ug; |
| 57 | |
| 58 | if (!f) |
| 59 | f = PL_no_security; |
| 60 | if (PL_euid != PL_uid) |
| 61 | ug = " while running setuid"; |
| 62 | else if (PL_egid != PL_gid) |
| 63 | ug = " while running setgid"; |
| 64 | else if (PL_taint_warn) |
| 65 | ug = " while running with -t switch"; |
| 66 | else |
| 67 | ug = " while running with -T switch"; |
| 68 | if (PL_unsafe || PL_taint_warn) { |
| 69 | if(ckWARN_d(WARN_TAINT)) |
| 70 | Perl_warner(aTHX_ packWARN(WARN_TAINT), f, s, ug); |
| 71 | } |
| 72 | else { |
| 73 | Perl_croak(aTHX_ f, s, ug); |
| 74 | } |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | void |
| 79 | Perl_taint_env(pTHX) |
| 80 | { |
| 81 | dVAR; |
| 82 | SV** svp; |
| 83 | MAGIC* mg; |
| 84 | const char* const *e; |
| 85 | static const char* const misc_env[] = { |
| 86 | "IFS", /* most shells' inter-field separators */ |
| 87 | "CDPATH", /* ksh dain bramage #1 */ |
| 88 | "ENV", /* ksh dain bramage #2 */ |
| 89 | "BASH_ENV", /* bash dain bramage -- I guess it's contagious */ |
| 90 | #ifdef WIN32 |
| 91 | "PERL5SHELL", /* used for system() on Windows */ |
| 92 | #endif |
| 93 | NULL |
| 94 | }; |
| 95 | |
| 96 | /* Don't bother if there's no *ENV glob */ |
| 97 | if (!PL_envgv) |
| 98 | return; |
| 99 | /* If there's no %ENV hash of if it's not magical, croak, because |
| 100 | * it probably doesn't reflect the actual environment */ |
| 101 | if (!GvHV(PL_envgv) || !(SvRMAGICAL(GvHV(PL_envgv)) |
| 102 | && mg_find((const SV *)GvHV(PL_envgv), PERL_MAGIC_env))) { |
| 103 | const bool was_tainted = PL_tainted; |
| 104 | const char * const name = GvENAME(PL_envgv); |
| 105 | PL_tainted = TRUE; |
| 106 | if (strEQ(name,"ENV")) |
| 107 | /* hash alias */ |
| 108 | taint_proper("%%ENV is aliased to %s%s", "another variable"); |
| 109 | else |
| 110 | /* glob alias: report it in the error message */ |
| 111 | taint_proper("%%ENV is aliased to %%%s%s", name); |
| 112 | /* this statement is reached under -t or -U */ |
| 113 | PL_tainted = was_tainted; |
| 114 | } |
| 115 | |
| 116 | #ifdef VMS |
| 117 | { |
| 118 | int i = 0; |
| 119 | char name[10 + TYPE_DIGITS(int)] = "DCL$PATH"; |
| 120 | STRLEN len = 8; /* strlen(name) */ |
| 121 | |
| 122 | while (1) { |
| 123 | if (i) |
| 124 | len = my_sprintf(name,"DCL$PATH;%d", i); |
| 125 | svp = hv_fetch(GvHVn(PL_envgv), name, len, FALSE); |
| 126 | if (!svp || *svp == &PL_sv_undef) |
| 127 | break; |
| 128 | if (SvTAINTED(*svp)) { |
| 129 | TAINT; |
| 130 | taint_proper("Insecure %s%s", "$ENV{DCL$PATH}"); |
| 131 | } |
| 132 | if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { |
| 133 | TAINT; |
| 134 | taint_proper("Insecure directory in %s%s", "$ENV{DCL$PATH}"); |
| 135 | } |
| 136 | i++; |
| 137 | } |
| 138 | } |
| 139 | #endif /* VMS */ |
| 140 | |
| 141 | svp = hv_fetchs(GvHVn(PL_envgv),"PATH",FALSE); |
| 142 | if (svp && *svp) { |
| 143 | if (SvTAINTED(*svp)) { |
| 144 | TAINT; |
| 145 | taint_proper("Insecure %s%s", "$ENV{PATH}"); |
| 146 | } |
| 147 | if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) { |
| 148 | TAINT; |
| 149 | taint_proper("Insecure directory in %s%s", "$ENV{PATH}"); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | #ifndef VMS |
| 154 | /* tainted $TERM is okay if it contains no metachars */ |
| 155 | svp = hv_fetchs(GvHVn(PL_envgv),"TERM",FALSE); |
| 156 | if (svp && *svp && SvTAINTED(*svp)) { |
| 157 | STRLEN len; |
| 158 | const bool was_tainted = PL_tainted; |
| 159 | const char *t = SvPV_const(*svp, len); |
| 160 | const char * const e = t + len; |
| 161 | PL_tainted = was_tainted; |
| 162 | if (t < e && isALNUM(*t)) |
| 163 | t++; |
| 164 | while (t < e && (isALNUM(*t) || strchr("-_.+", *t))) |
| 165 | t++; |
| 166 | if (t < e) { |
| 167 | TAINT; |
| 168 | taint_proper("Insecure $ENV{%s}%s", "TERM"); |
| 169 | } |
| 170 | } |
| 171 | #endif /* !VMS */ |
| 172 | |
| 173 | for (e = misc_env; *e; e++) { |
| 174 | SV * const * const svp = hv_fetch(GvHVn(PL_envgv), *e, strlen(*e), FALSE); |
| 175 | if (svp && *svp != &PL_sv_undef && SvTAINTED(*svp)) { |
| 176 | TAINT; |
| 177 | taint_proper("Insecure $ENV{%s}%s", *e); |
| 178 | } |
| 179 | } |
| 180 | } |
| 181 | |
| 182 | /* |
| 183 | * Local variables: |
| 184 | * c-indentation-style: bsd |
| 185 | * c-basic-offset: 4 |
| 186 | * indent-tabs-mode: t |
| 187 | * End: |
| 188 | * |
| 189 | * ex: set ts=8 sts=4 sw=4 noet: |
| 190 | */ |