X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/4e35701fd273ba8d0093a29660dee38a92408e9b..9287cc840c2c31d0850ec27d031eeb1df6fd8e4d:/taint.c

diff --git a/taint.c b/taint.c
index c8c6800..1b78928 100644
--- a/taint.c
+++ b/taint.c
@@ -1,77 +1,152 @@
+/*    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_proper(const char *f, char *s)
+Perl_taint_proper(pTHX_ const char *f, const char *const s)
 {
-    char *ug;
+#if defined(HAS_SETEUID) && defined(DEBUGGING)
+    PERL_ARGS_ASSERT_TAINT_PROPER;
 
-    DEBUG_u(PerlIO_printf(Perl_debug_log,
-            "%s %d %d %d\n", s, tainted, uid, euid));
+    {
+	const Uid_t  uid = PerlProc_getuid();
+	const Uid_t euid = PerlProc_geteuid();
 
-    if (tainted) {
-	if (euid != uid)
+#if Uid_t_sign == 1 /* uid_t is unsigned. */
+	DEBUG_u(PerlIO_printf(Perl_debug_log,
+                              "%s %d %" UVuf " %" UVuf "\n",
+                              s, TAINT_get, (UV)uid, (UV)euid));
+#else /* uid_t is signed (Uid_t_sign == -1), or don't know. */
+	DEBUG_u(PerlIO_printf(Perl_debug_log,
+                              "%s %d %" IVdf " %" IVdf "\n",
+                              s, TAINT_get, (IV)uid, (IV)euid));
+#endif
+    }
+#endif
+
+    if (TAINT_get) {
+	const char *ug;
+
+	if (!f)
+	    f = PL_no_security;
+	if (PerlProc_getuid() != PerlProc_geteuid())
 	    ug = " while running setuid";
-	else if (egid != gid)
+	else if (PerlProc_getgid() != PerlProc_getegid())
 	    ug = " while running setgid";
-	else
+	else if (TAINT_WARN_get)
+            ug = " while running with -t switch";
+        else
 	    ug = " while running with -T switch";
-	if (!unsafe)
-	    croak(f, s, ug);
-	else if (dowarn)
-	    warn(f, s, ug);
+
+        /* XXX because taint_proper adds extra format args, we can't
+         * get the caller to check properly; o we just silence the warning
+         * and hope the callers aren't naughty */
+        GCC_DIAG_IGNORE(-Wformat-nonliteral);
+	if (PL_unsafe || TAINT_WARN_get) {
+	    Perl_ck_warner_d(aTHX_ packWARN(WARN_TAINT), f, s, ug);
+        }
+        else {
+            Perl_croak(aTHX_ f, s, ug);
+        }
+        GCC_DIAG_RESTORE;
+
     }
 }
 
 void
-taint_env(void)
+Perl_taint_env(pTHX)
 {
     SV** svp;
-    MAGIC* mg;
-    char** e;
-    static char* misc_env[] = {
+    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
     };
 
+    /* Don't bother if there's no *ENV glob */
+    if (!PL_envgv)
+	return;
+    /* If there's no %ENV hash or 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 = TAINT_get;
+	const char * const name = GvENAME(PL_envgv);
+	TAINT;
+	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 */
+	TAINT_set(was_tainted);
+#ifdef NO_TAINT_SUPPORT
+        PERL_UNUSED_VAR(was_tainted);
+#endif
+    }
+
 #ifdef VMS
+    {
     int i = 0;
     char name[10 + TYPE_DIGITS(int)] = "DCL$PATH";
+    STRLEN len = 8; /* strlen(name)  */
 
     while (1) {
+        MAGIC* mg;
 	if (i)
-	    (void)sprintf(name,"DCL$PATH;%d", i);
-	svp = hv_fetch(GvHVn(envgv), name, strlen(name), FALSE);
-	if (!svp || *svp == &sv_undef)
+	    len = my_sprintf(name,"DCL$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, 'e')) && MgTAINTEDDIR(mg)) {
+	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(envgv),"PATH",4,FALSE);
+    svp = hv_fetchs(GvHVn(PL_envgv),"PATH",FALSE);
     if (svp && *svp) {
+        MAGIC* mg;
 	if (SvTAINTED(*svp)) {
 	    TAINT;
 	    taint_proper("Insecure %s%s", "$ENV{PATH}");
 	}
-	if ((mg = mg_find(*svp, 'e')) && MgTAINTEDDIR(mg)) {
+	if ((mg = mg_find(*svp, PERL_MAGIC_envelem)) && MgTAINTEDDIR(mg)) {
 	    TAINT;
 	    taint_proper("Insecure directory in %s%s", "$ENV{PATH}");
 	}
@@ -79,15 +154,20 @@ taint_env(void)
 
 #ifndef VMS
     /* tainted $TERM is okay if it contains no metachars */
-    svp = hv_fetch(GvHVn(envgv),"TERM",4,FALSE);
+    svp = hv_fetchs(GvHVn(PL_envgv),"TERM",FALSE);
     if (svp && *svp && SvTAINTED(*svp)) {
-	bool was_tainted = tainted;
-	char *t = SvPV(*svp, na);
-	char *e = t + na;
-	tainted = was_tainted;
-	if (t < e && isALNUM(*t))
+	STRLEN len;
+	const bool was_tainted = TAINT_get;
+	const char *t = SvPV_const(*svp, len);
+	const char * const e = t + len;
+
+	TAINT_set(was_tainted);
+#ifdef NO_TAINT_SUPPORT
+        PERL_UNUSED_VAR(was_tainted);
+#endif
+	if (t < e && isWORDCHAR(*t))
 	    t++;
-	while (t < e && (isALNUM(*t) || *t == '-' || *t == ':'))
+	while (t < e && (isWORDCHAR(*t) || strchr("-_.+", *t)))
 	    t++;
 	if (t < e) {
 	    TAINT;
@@ -97,10 +177,14 @@ taint_env(void)
 #endif /* !VMS */
 
     for (e = misc_env; *e; e++) {
-	svp = hv_fetch(GvHVn(envgv), *e, strlen(*e), FALSE);
-	if (svp && *svp != &sv_undef && SvTAINTED(*svp)) {
+	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);
 	}
     }
 }
+
+/*
+ * ex: set ts=8 sts=4 sw=4 et:
+ */