5.8.4/distrib/taint.c

/*    taint.c
 *
 *    Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999,
 *    2000, 2001, 2002, by Larry Wall and others
 *
 *    You may distribute under the terms of either the GNU General Public
 *    License or the Artistic License, as specified in the README file.
 *
 */

/*
 * "...we will have peace, when you and all your works have perished--and
 * the works of your dark master to whom you would deliver us.  You are a
 * liar, Saruman, and a corrupter of men's hearts."  --Theoden
 */

#include "EXTERN.h"
#define PERL_IN_TAINT_C
#include "perl.h"

void
Perl_taint_proper(pTHX_ const char *f, const char *s)
{
    char *ug;

#if defined(HAS_SETEUID) && defined(DEBUGGING)
#   if Uid_t_size == 1
    {
     UV  uid = PL_uid;
     UV euid = PL_euid;

     DEBUG_u(PerlIO_printf(Perl_debug_log,
                   "%s %d %"UVuf" %"UVuf"\n",
                   s, PL_tainted, uid, euid));
    }
#   else
    {
     IV  uid = PL_uid;
     IV euid = PL_euid;

     DEBUG_u(PerlIO_printf(Perl_debug_log,
                   "%s %d %"IVdf" %"IVdf"\n",
                   s, PL_tainted, uid, euid));
    }
#   endif
#endif

    if (PL_tainted) {
    if (!f)
        f = PL_no_security;
    if (PL_euid != PL_uid)
        ug = " while running setuid";
    else if (PL_egid != PL_gid)
        ug = " while running setgid";
    else if (PL_taint_warn)
            ug = " while running with -t switch";
        else
        ug = " while running with -T switch";
    if (PL_unsafe || PL_taint_warn) {
            if(ckWARN(WARN_TAINT))
                Perl_warner(aTHX_ packWARN(WARN_TAINT), f, s, ug);
        }
        else {
            Perl_croak(aTHX_ f, s, ug);
        }
    }
}

void
Perl_taint_env(pTHX)
{
    SV** svp;
    MAGIC* mg;
    char** e;
    static char* misc_env[] = {
    "IFS",      /* most shells' inter-field separators */
    "CDPATH",   /* ksh dain bramage #1 */
    "ENV",      /* ksh dain bramage #2 */
    "BASH_ENV", /* bash dain bramage -- I guess it's contagious */
    NULL
    };

    if (!PL_envgv)
    return;

#ifdef VMS
    {
    int i = 0;
    char name[10 + TYPE_DIGITS(int)] = "DCL$PATH";

    while (1) {
    if (i)
        (void)sprintf(name,"DCL$PATH;%d", i);
    svp = hv_fetch(GvHVn(PL_envgv), name, strlen(name), FALSE);
    if (!svp || *svp == &PL_sv_undef)
        break;
    if (SvTAINTED(*svp)) {
        TAINT;
        taint_proper("Insecure %s%s", "$ENV{DCL$PATH}");
    }
    if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) {
        TAINT;
        taint_proper("Insecure directory in %s%s", "$ENV{DCL$PATH}");
    }
    i++;
    }
  }
#endif /* VMS */

    svp = hv_fetch(GvHVn(PL_envgv),"PATH",4,FALSE);
    if (svp && *svp) {
    if (SvTAINTED(*svp)) {
        TAINT;
        taint_proper("Insecure %s%s", "$ENV{PATH}");
    }
    if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) {
        TAINT;
        taint_proper("Insecure directory in %s%s", "$ENV{PATH}");
    }
    }

#ifndef VMS
    /* tainted $TERM is okay if it contains no metachars */
    svp = hv_fetch(GvHVn(PL_envgv),"TERM",4,FALSE);
    if (svp && *svp && SvTAINTED(*svp)) {
    STRLEN n_a;
    bool was_tainted = PL_tainted;
    char *t = SvPV(*svp, n_a);
    char *e = t + n_a;
    PL_tainted = was_tainted;
    if (t < e && isALNUM(*t))
        t++;
    while (t < e && (isALNUM(*t) || strchr("-_.+", *t)))
        t++;
    if (t < e) {
        TAINT;
        taint_proper("Insecure $ENV{%s}%s", "TERM");
    }
    }
#endif /* !VMS */

    for (e = misc_env; *e; e++) {
    svp = hv_fetch(GvHVn(PL_envgv), *e, strlen(*e), FALSE);
    if (svp && *svp != &PL_sv_undef && SvTAINTED(*svp)) {
        TAINT;
        taint_proper("Insecure $ENV{%s}%s", *e);
    }
    }
}