Added generic EAX and CCM implementations.

[BearSSL] / src / symcipher / aes_big_ctrcbc.c

diff --git a/src/symcipher/aes_big_ctrcbc.c b/src/symcipher/aes_big_ctrcbc.c
new file mode 100644 (file)
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
+};