Initial import.

src/symcipher/aes_ct64_ctr.c

@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * 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_ct64_ctr_init(br_aes_ct64_ctr_keys *ctx,
+	const void *key, size_t len)
+{
+	ctx->vtable = &br_aes_ct64_ctr_vtable;
+	ctx->num_rounds = br_aes_ct64_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_ct64_ctr_run(const br_aes_ct64_ctr_keys *ctx,
+	const void *iv, uint32_t cc, void *data, size_t len)
+{
+	unsigned char *buf;
+	uint32_t ivw[16];
+	uint64_t sk_exp[240];
+
+	br_aes_ct64_skey_expand(sk_exp, ctx->num_rounds, ctx->skey);
+	br_range_dec32le(ivw, 3, iv);
+	memcpy(ivw + 4, ivw, 3 * sizeof(uint32_t));
+	memcpy(ivw + 8, ivw, 3 * sizeof(uint32_t));
+	memcpy(ivw + 12, ivw, 3 * sizeof(uint32_t));
+	buf = data;
+	while (len > 0) {
+		uint64_t q[8];
+		uint32_t w[16];
+		unsigned char tmp[64];
+		int i;
+
+		/*
+		 * TODO: see if we can save on the first br_aes_ct64_ortho()
+		 * call, since iv0/iv1/iv2 are constant for the whole run.
+		 */
+		memcpy(w, ivw, sizeof ivw);
+		w[3] = br_swap32(cc);
+		w[7] = br_swap32(cc + 1);
+		w[11] = br_swap32(cc + 2);
+		w[15] = br_swap32(cc + 3);
+		for (i = 0; i < 4; i ++) {
+			br_aes_ct64_interleave_in(
+				&q[i], &q[i + 4], w + (i << 2));
+		}
+		br_aes_ct64_ortho(q);
+		br_aes_ct64_bitslice_encrypt(ctx->num_rounds, sk_exp, q);
+		br_aes_ct64_ortho(q);
+		for (i = 0; i < 4; i ++) {
+			br_aes_ct64_interleave_out(
+				w + (i << 2), q[i], q[i + 4]);
+		}
+		br_range_enc32le(tmp, w, 16);
+		if (len <= 64) {
+			xorbuf(buf, tmp, len);
+			cc += (uint32_t)len >> 4;
+			break;
+		}
+		xorbuf(buf, tmp, 64);
+		buf += 64;
+		len -= 64;
+		cc += 4;
+	}
+	return cc;
+}
+
+/* see bearssl_block.h */
+const br_block_ctr_class br_aes_ct64_ctr_vtable = {
+	sizeof(br_aes_ct64_ctr_keys),
+	16,
+	4,
+	(void (*)(const br_block_ctr_class **, const void *, size_t))
+		&br_aes_ct64_ctr_init,
+	(uint32_t (*)(const br_block_ctr_class *const *,
+		const void *, uint32_t, void *, size_t))
+		&br_aes_ct64_ctr_run
+};