X-Git-Url: https://www.bearssl.org/gitweb//home/git/?p=BearSSL;a=blobdiff_plain;f=src%2Fsymcipher%2Faes_big_ctrcbc.c;fp=src%2Fsymcipher%2Faes_big_ctrcbc.c;h=d45ca76963668dd32a6e1eee8b5e7954b8532986;hp=0000000000000000000000000000000000000000;hb=dddc412922f42f9c7dd6177133828be724f44424;hpb=8e94ad2fcb11794c559025277e56f3fbeb676f5d

diff --git a/src/symcipher/aes_big_ctrcbc.c b/src/symcipher/aes_big_ctrcbc.c
new file mode 100644
index 0000000..d45ca76
--- /dev/null
+++ b/src/symcipher/aes_big_ctrcbc.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2017 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_big_ctrcbc_init(br_aes_big_ctrcbc_keys *ctx,
+	const void *key, size_t len)
+{
+	ctx->vtable = &br_aes_big_ctrcbc_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 */
+void
+br_aes_big_ctrcbc_ctr(const br_aes_big_ctrcbc_keys *ctx,
+	void *ctr, void *data, size_t len)
+{
+	unsigned char *buf, *bctr;
+	uint32_t cc0, cc1, cc2, cc3;
+
+	buf = data;
+	bctr = ctr;
+	cc3 = br_dec32be(bctr +  0);
+	cc2 = br_dec32be(bctr +  4);
+	cc1 = br_dec32be(bctr +  8);
+	cc0 = br_dec32be(bctr + 12);
+	while (len > 0) {
+		unsigned char tmp[16];
+		uint32_t carry;
+
+		br_enc32be(tmp +  0, cc3);
+		br_enc32be(tmp +  4, cc2);
+		br_enc32be(tmp +  8, cc1);
+		br_enc32be(tmp + 12, cc0);
+		br_aes_big_encrypt(ctx->num_rounds, ctx->skey, tmp);
+		xorbuf(buf, tmp, 16);
+		buf += 16;
+		len -= 16;
+		cc0 ++;
+		carry = (~(cc0 | -cc0)) >> 31;
+		cc1 += carry;
+		carry &= (~(cc1 | -cc1)) >> 31;
+		cc2 += carry;
+		carry &= (~(cc2 | -cc2)) >> 31;
+		cc3 += carry;
+	}
+	br_enc32be(bctr +  0, cc3);
+	br_enc32be(bctr +  4, cc2);
+	br_enc32be(bctr +  8, cc1);
+	br_enc32be(bctr + 12, cc0);
+}
+
+/* see bearssl_block.h */
+void
+br_aes_big_ctrcbc_mac(const br_aes_big_ctrcbc_keys *ctx,
+	void *cbcmac, const void *data, size_t len)
+{
+	const unsigned char *buf;
+
+	buf = data;
+	while (len > 0) {
+		xorbuf(cbcmac, buf, 16);
+		br_aes_big_encrypt(ctx->num_rounds, ctx->skey, cbcmac);
+		buf += 16;
+		len -= 16;
+	}
+}
+
+/* see bearssl_block.h */
+void
+br_aes_big_ctrcbc_encrypt(const br_aes_big_ctrcbc_keys *ctx,
+	void *ctr, void *cbcmac, void *data, size_t len)
+{
+	br_aes_big_ctrcbc_ctr(ctx, ctr, data, len);
+	br_aes_big_ctrcbc_mac(ctx, cbcmac, data, len);
+}
+
+/* see bearssl_block.h */
+void
+br_aes_big_ctrcbc_decrypt(const br_aes_big_ctrcbc_keys *ctx,
+	void *ctr, void *cbcmac, void *data, size_t len)
+{
+	br_aes_big_ctrcbc_mac(ctx, cbcmac, data, len);
+	br_aes_big_ctrcbc_ctr(ctx, ctr, data, len);
+}
+
+/* see bearssl_block.h */
+const br_block_ctrcbc_class br_aes_big_ctrcbc_vtable = {
+	sizeof(br_aes_big_ctrcbc_keys),
+	16,
+	4,
+	(void (*)(const br_block_ctrcbc_class **, const void *, size_t))
+		&br_aes_big_ctrcbc_init,
+	(void (*)(const br_block_ctrcbc_class *const *,
+		void *, void *, void *, size_t))
+		&br_aes_big_ctrcbc_encrypt,
+	(void (*)(const br_block_ctrcbc_class *const *,
+		void *, void *, void *, size_t))
+		&br_aes_big_ctrcbc_decrypt,
+	(void (*)(const br_block_ctrcbc_class *const *,
+		void *, void *, size_t))
+		&br_aes_big_ctrcbc_ctr,
+	(void (*)(const br_block_ctrcbc_class *const *,
+		void *, const void *, size_t))
+		&br_aes_big_ctrcbc_mac
+};