X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/760ac839baf413929cd31cc32ffd6dba6b781a81..e3c71926d33e006cc01a7516d80dda2a9888bb0e:/taint.c

diff --git a/taint.c b/taint.c
index be69c0e..fa1366f 100644
--- a/taint.c
+++ b/taint.c
@@ -1,71 +1,189 @@
+/*    taint.c
+ *
+ *    Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
+ *    2002, 2003, 2004, 2005, 2006, 2007, 2008 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
+ * '...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.'       --Théoden
+ *
+ *     [p.580 of _The Lord of the Rings_, III/x: "The Voice of Saruman"]
+ */
+
+/* This file contains a few functions for handling data tainting in Perl
  */
 
 #include "EXTERN.h"
+#define PERL_IN_TAINT_C
 #include "perl.h"
 
 void
-taint_not(s)
-char *s;
+Perl_taint_proper(pTHX_ const char *f, const char *const s)
 {
-    if (euid != uid)
-        croak("No %s allowed while running setuid", s);
-    if (egid != gid)
-        croak("No %s allowed while running setgid", s);
-}
+#if defined(HAS_SETEUID) && defined(DEBUGGING)
+    dVAR;
 
-void
-taint_proper(f, s)
-char *f;
-char *s;
-{
-    if (tainting) {
-	DEBUG_u(PerlIO_printf(PerlIO_stderr(), "%s %d %d %d\n",s,tainted,uid, euid));
-	if (tainted) {
-	    char *ug = 0;
-	    if (euid != uid)
-		ug = " while running setuid";
-	    else if (egid != gid)
-		ug = " while running setgid";
-	    else if (tainting)
-		ug = " while running with -T switch";
-	    if (ug) {
-		if (!unsafe)
-		    croak(f, s, ug);
-		else if (dowarn)
-		    warn(f, s, ug);
-	    }
-	}
+    PERL_ARGS_ASSERT_TAINT_PROPER;
+
+#   if Uid_t_size == 1
+    {
+	const UV  uid = PL_uid;
+	const UV euid = PL_euid;
+
+	DEBUG_u(PerlIO_printf(Perl_debug_log,
+			       "%s %d %"UVuf" %"UVuf"\n",
+			       s, PL_tainted, uid, euid));
+    }
+#   else
+    {
+	const IV  uid = PL_uid;
+	const 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) {
+	const char *ug;
+
+	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) {
+	    Perl_ck_warner_d(aTHX_ packWARN(WARN_TAINT), f, s, ug);
+        }
+        else {
+            Perl_croak(aTHX_ f, s, ug);
+        }
     }
 }
 
 void
-taint_env()
+Perl_taint_env(pTHX)
 {
+    dVAR;
     SV** svp;
+    MAGIC* mg;
+    const char* const *e;
+    static const char* const 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 */
+#ifdef WIN32
+	"PERL5SHELL",	/* used for system() on Windows */
+#endif
+	NULL
+    };
 
-    if (tainting) {
-	MAGIC *mg = 0;
-	svp = hv_fetch(GvHVn(envgv),"PATH",4,FALSE);
-	if (!svp || *svp == &sv_undef ||
-	  ((mg = mg_find(*svp, 't')) && mg->mg_len & 1))
-	{
-	    tainted = TRUE;
-	    if (mg && MgTAINTEDDIR(mg))
-		taint_proper("Insecure directory in %s%s", "$ENV{PATH}");
-	    else
-		taint_proper("Insecure %s%s", "$ENV{PATH}");
+    /* Don't bother if there's no *ENV glob */
+    if (!PL_envgv)
+	return;
+    /* If there's no %ENV hash of if it's not magical, croak, because
+     * it probably doesn't reflect the actual environment */
+    if (!GvHV(PL_envgv) || !(SvRMAGICAL(GvHV(PL_envgv))
+	    && mg_find((const SV *)GvHV(PL_envgv), PERL_MAGIC_env))) {
+	const bool was_tainted = PL_tainted;
+	const char * const name = GvENAME(PL_envgv);
+	PL_tainted = TRUE;
+	if (strEQ(name,"ENV"))
+	    /* hash alias */
+	    taint_proper("%%ENV is aliased to %s%s", "another variable");
+	else
+	    /* glob alias: report it in the error message */
+	    taint_proper("%%ENV is aliased to %%%s%s", name);
+	/* this statement is reached under -t or -U */
+	PL_tainted = was_tainted;
+    }
+
+#ifdef VMS
+    {
+    int i = 0;
+    char name[10 + TYPE_DIGITS(int)] = "DCL$PATH";
+    STRLEN len = 8; /* strlen(name)  */
+
+    while (1) {
+	if (i)
+	    len = my_sprintf(name,"DCL$PATH;%d", i);
+	svp = hv_fetch(GvHVn(PL_envgv), name, len, 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}");
 	}
-	svp = hv_fetch(GvHVn(envgv),"IFS",3,FALSE);
-	if (svp && *svp != &sv_undef &&
-	  (mg = mg_find(*svp, 't')) && mg->mg_len & 1)
-	{
-	    tainted = TRUE;
-	    taint_proper("Insecure %s%s", "$ENV{IFS}");
+	i++;
+    }
+  }
+#endif /* VMS */
+
+    svp = hv_fetchs(GvHVn(PL_envgv),"PATH",FALSE);
+    if (svp && *svp) {
+	if (SvTAINTED(*svp)) {
+	    TAINT;
+	    taint_proper("Insecure %s%s", "$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_fetchs(GvHVn(PL_envgv),"TERM",FALSE);
+    if (svp && *svp && SvTAINTED(*svp)) {
+	STRLEN len;
+	const bool was_tainted = PL_tainted;
+	const char *t = SvPV_const(*svp, len);
+	const char * const e = t + len;
+	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++) {
+	SV * const * const 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);
 	}
     }
 }
 
+/*
+ * Local variables:
+ * c-indentation-style: bsd
+ * c-basic-offset: 4
+ * indent-tabs-mode: t
+ * End:
+ *
+ * ex: set ts=8 sts=4 sw=4 noet:
+ */