source: trunk/third/perl/taint.c @ 17035

/*
 * "...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;

#ifdef HAS_SETEUID
    DEBUG_u(PerlIO_printf(Perl_debug_log,
            "%s %d %"Uid_t_f" %"Uid_t_f"\n", s, PL_tainted, PL_uid, PL_euid));
#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
            ug = " while running with -T switch";
        if (!PL_unsafe)
            Perl_croak(aTHX_ f, s, ug);
        else if (ckWARN(WARN_TAINT))
            Perl_warner(aTHX_ WARN_TAINT, 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$PATH}");
        }
        if ((mg = mg_find(*svp, 'e')) && MgTAINTEDDIR(mg)) {
            TAINT;
            taint_proper("Insecure directory in %s%s", "$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", "$ENV{PATH}");
        }
        if ((mg = mg_find(*svp, 'e')) && MgTAINTEDDIR(mg)) {
            TAINT;
            taint_proper("Insecure directory in %s%s", "$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) || *t == '-' || *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);
        }
    }
}