From: Arran Cudbard-Bell <a.cudbardb@freeradius.org>
Date: Sat, 20 Jan 2024 02:18:02 +0000 (-0600)
Subject: Don't crash when decoding empty base64 strings
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d21c967734a67b38b146a1266980993c95d14383;p=thirdparty%2Ffreeradius-server.git

Don't crash when decoding empty base64 strings
---

diff --git a/src/lib/unlang/xlat_builtin.c b/src/lib/unlang/xlat_builtin.c
index 38b276a8014..b5824a811a2 100644
--- a/src/lib/unlang/xlat_builtin.c
+++ b/src/lib/unlang/xlat_builtin.c
@@ -44,6 +44,7 @@ RCSID("$Id$")
 #include <freeradius-devel/util/misc.h>
 #include <freeradius-devel/util/rand.h>
 #include <freeradius-devel/util/sha1.h>
+#include <freeradius-devel/util/value.h>
 
 #ifdef HAVE_OPENSSL_EVP_H
 #  include <freeradius-devel/tls/openssl_user_macros.h>
@@ -1783,6 +1784,17 @@ static xlat_action_t xlat_func_base64_decode(TALLOC_CTX *ctx, fr_dcursor_t *out,
 
 	XLAT_ARGS(args, &in);
 
+	/*
+	 *	Pass empty arguments through
+	 *
+	 *	FR_BASE64_DEC_LENGTH produces 2 for empty strings...
+	 */
+	if (in->vb_length == 0) {
+		fr_value_box_list_remove(args, in);
+		fr_dcursor_append(out, in);
+		return XLAT_ACTION_DONE;
+	}
+
 	alen = FR_BASE64_DEC_LENGTH(in->vb_length);
 	MEM(vb = fr_value_box_alloc_null(ctx));
 	if (alen > 0) {
diff --git a/src/tests/keywords/base64 b/src/tests/keywords/base64
index f23ea7ff256..e6f6c5cfffd 100644
--- a/src/tests/keywords/base64
+++ b/src/tests/keywords/base64
@@ -100,6 +100,13 @@ if (!(&test_output == 'IDk4Nz4=')) {
 	test_fail
 }
 
+# Something weird causes this test not to parse
+# &test_octets := %base64.decode("")
+#if (!(&test_octets == "")) {
+#	test_fail
+#}
+
+# Regression test, this used to crash...
 &test_octets := %base64.decode(Zm9v)
 if (!(&test_octets == "foo")) {
 	debug_request