1 files changed, 84 insertions, 0 deletions
diff --git a/third_party/bearssl/src/aes_big_ctr.c b/third_party/bearssl/src/aes_big_ctr.c
new file mode 100644
index 0000000..18fbb84
--- /dev/null
+++ b/third_party/bearssl/src/aes_big_ctr.c
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <[email protected]>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "inner.h"
+
+/* see bearssl_block.h */
+void
+br_aes_big_ctr_init(br_aes_big_ctr_keys *ctx,
+	const void *key, size_t len)
+{
+	ctx->vtable = &br_aes_big_ctr_vtable;
+	ctx->num_rounds = br_aes_keysched(ctx->skey, key, len);
+}
+
+static void
+xorbuf(void *dst, const void *src, size_t len)
+{
+	unsigned char *d;
+	const unsigned char *s;
+
+	d = dst;
+	s = src;
+	while (len -- > 0) {
+		*d ++ ^= *s ++;
+	}
+}
+
+/* see bearssl_block.h */
+uint32_t
+br_aes_big_ctr_run(const br_aes_big_ctr_keys *ctx,
+	const void *iv, uint32_t cc, void *data, size_t len)
+{
+	unsigned char *buf;
+
+	buf = data;
+	while (len > 0) {
+		unsigned char tmp[16];
+
+		memcpy(tmp, iv, 12);
+		br_enc32be(tmp + 12, cc ++);
+		br_aes_big_encrypt(ctx->num_rounds, ctx->skey, tmp);
+		if (len <= 16) {
+			xorbuf(buf, tmp, len);
+			break;
+		}
+		xorbuf(buf, tmp, 16);
+		buf += 16;
+		len -= 16;
+	}
+	return cc;
+}
+
+/* see bearssl_block.h */
+const br_block_ctr_class br_aes_big_ctr_vtable = {
+	sizeof(br_aes_big_ctr_keys),
+	16,
+	4,
+	(void (*)(const br_block_ctr_class **, const void *, size_t))
+		&br_aes_big_ctr_init,
+	(uint32_t (*)(const br_block_ctr_class *const *,
+		const void *, uint32_t, void *, size_t))
+		&br_aes_big_ctr_run
+};