Use sourcecode for libjuice

thirdparty/libjuice/src/const_time.c

@@ -0,0 +1,34 @@
+/**
+ * Copyright (c) 2021 Paul-Louis Ageneau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#include "const_time.h"
+
+int const_time_memcmp(const void *a, const void *b, size_t len) {
+	const unsigned char *ca = a;
+	const unsigned char *cb = b;
+	unsigned char x = 0;
+	for (size_t i = 0; i < len; i++)
+		x |= ca[i] ^ cb[i];
+
+	return x;
+}
+
+int const_time_strcmp(const void *a, const void *b) {
+	const unsigned char *ca = a;
+	const unsigned char *cb = b;
+	unsigned char x = 0;
+	size_t i = 0;
+	for(;;) {
+		x |= ca[i] ^ cb[i];
+		if (!ca[i] || !cb[i])
+			break;
+		++i;
+	}
+
+	return x;
+}