Move tinycrypt function

components/bt/porting/ext/tinycrypt/src/hmac.c

@@ -0,0 +1,148 @@
+/* hmac.c - TinyCrypt implementation of the HMAC algorithm */
+
+/*
+ *  Copyright (C) 2017 by Intel Corporation, All Rights Reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *
+ *    - Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *
+ *    - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ *    - Neither the name of Intel Corporation nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *  POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <tinycrypt/hmac.h>
+#include <tinycrypt/constants.h>
+#include <tinycrypt/utils.h>
+
+static void rekey(uint8_t *key, const uint8_t *new_key, unsigned int key_size)
+{
+	const uint8_t inner_pad = (uint8_t) 0x36;
+	const uint8_t outer_pad = (uint8_t) 0x5c;
+	unsigned int i;
+
+	for (i = 0; i < key_size; ++i) {
+		key[i] = inner_pad ^ new_key[i];
+		key[i + TC_SHA256_BLOCK_SIZE] = outer_pad ^ new_key[i];
+	}
+	for (; i < TC_SHA256_BLOCK_SIZE; ++i) {
+		key[i] = inner_pad; key[i + TC_SHA256_BLOCK_SIZE] = outer_pad;
+	}
+}
+
+int tc_hmac_set_key(TCHmacState_t ctx, const uint8_t *key,
+		    unsigned int key_size)
+{
+
+	/* input sanity check: */
+	if (ctx == (TCHmacState_t) 0 ||
+	    key == (const uint8_t *) 0 ||
+	    key_size == 0) {
+		return TC_CRYPTO_FAIL;
+	}
+
+	const uint8_t dummy_key[key_size];
+	struct tc_hmac_state_struct dummy_state;
+
+	if (key_size <= TC_SHA256_BLOCK_SIZE) {
+		/*
+		 * The next three lines consist of dummy calls just to avoid
+		 * certain timing attacks. Without these dummy calls,
+		 * adversaries would be able to learn whether the key_size is
+		 * greater than TC_SHA256_BLOCK_SIZE by measuring the time
+		 * consumed in this process.
+		 */
+		(void)tc_sha256_init(&dummy_state.hash_state);
+		(void)tc_sha256_update(&dummy_state.hash_state,
+				       dummy_key,
+				       key_size);
+		(void)tc_sha256_final(&dummy_state.key[TC_SHA256_DIGEST_SIZE],
+				      &dummy_state.hash_state);
+
+		/* Actual code for when key_size <= TC_SHA256_BLOCK_SIZE: */
+		rekey(ctx->key, key, key_size);
+	} else {
+		(void)tc_sha256_init(&ctx->hash_state);
+		(void)tc_sha256_update(&ctx->hash_state, key, key_size);
+		(void)tc_sha256_final(&ctx->key[TC_SHA256_DIGEST_SIZE],
+				      &ctx->hash_state);
+		rekey(ctx->key,
+		      &ctx->key[TC_SHA256_DIGEST_SIZE],
+		      TC_SHA256_DIGEST_SIZE);
+	}
+
+	return TC_CRYPTO_SUCCESS;
+}
+
+int tc_hmac_init(TCHmacState_t ctx)
+{
+
+	/* input sanity check: */
+	if (ctx == (TCHmacState_t) 0) {
+		return TC_CRYPTO_FAIL;
+	}
+
+  (void) tc_sha256_init(&ctx->hash_state);
+  (void) tc_sha256_update(&ctx->hash_state, ctx->key, TC_SHA256_BLOCK_SIZE);
+
+	return TC_CRYPTO_SUCCESS;
+}
+
+int tc_hmac_update(TCHmacState_t ctx,
+		   const void *data,
+		   unsigned int data_length)
+{
+
+	/* input sanity check: */
+	if (ctx == (TCHmacState_t) 0) {
+		return TC_CRYPTO_FAIL;
+	}
+
+	(void)tc_sha256_update(&ctx->hash_state, data, data_length);
+
+	return TC_CRYPTO_SUCCESS;
+}
+
+int tc_hmac_final(uint8_t *tag, unsigned int taglen, TCHmacState_t ctx)
+{
+
+	/* input sanity check: */
+	if (tag == (uint8_t *) 0 ||
+	    taglen != TC_SHA256_DIGEST_SIZE ||
+	    ctx == (TCHmacState_t) 0) {
+		return TC_CRYPTO_FAIL;
+	}
+
+	(void) tc_sha256_final(tag, &ctx->hash_state);
+
+	(void)tc_sha256_init(&ctx->hash_state);
+	(void)tc_sha256_update(&ctx->hash_state,
+			       &ctx->key[TC_SHA256_BLOCK_SIZE],
+				TC_SHA256_BLOCK_SIZE);
+	(void)tc_sha256_update(&ctx->hash_state, tag, TC_SHA256_DIGEST_SIZE);
+	(void)tc_sha256_final(tag, &ctx->hash_state);
+
+	/* destroy the current state */
+	_set(ctx, 0, sizeof(*ctx));
+
+	return TC_CRYPTO_SUCCESS;
+}