ext: Pull in tinycrypt v0.2.6
Zephyr 1.9 moves to tinycrypt v0.2.7. This introduces a breaking API
change. This makes things challenging for mcuboot, which would like to
be able to work across multiple platforms.
To help with this, bring in the last working version of Tinycrypt v0.2.6
from https://github.com/01org/tinycrypt. Tinycrypt is released under a
3-clause BSD-style license, with parts under the micro-ecc license,
which is a 2-clause license. Please see ext/tinycrypt/LICENSE for
details.
Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/ext/tinycrypt/lib/source/ccm_mode.c b/ext/tinycrypt/lib/source/ccm_mode.c
new file mode 100644
index 0000000..7b6d485
--- /dev/null
+++ b/ext/tinycrypt/lib/source/ccm_mode.c
@@ -0,0 +1,260 @@
+/* ccm_mode.c - TinyCrypt implementation of CCM mode */
+
+/*
+ * Copyright (C) 2015 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/ccm_mode.h>
+#include <tinycrypt/constants.h>
+#include <tinycrypt/utils.h>
+
+#include <stdio.h>
+
+int32_t tc_ccm_config(TCCcmMode_t c, TCAesKeySched_t sched, uint8_t *nonce,
+ uint32_t nlen, uint32_t mlen)
+{
+
+ /* input sanity check: */
+ if (c == (TCCcmMode_t) 0 ||
+ sched == (TCAesKeySched_t) 0 ||
+ nonce == (uint8_t *) 0) {
+ return TC_CRYPTO_FAIL;
+ } else if (nlen != 13) {
+ return TC_CRYPTO_FAIL; /* The allowed nonce size is: 13. See documentation.*/
+ } else if ((mlen < 4) || (mlen > 16) || (mlen & 1)) {
+ return TC_CRYPTO_FAIL; /* The allowed mac sizes are: 4, 6, 8, 10, 12, 14, 16.*/
+ }
+
+ c->mlen = mlen;
+ c->sched = sched;
+ c->nonce = nonce;
+
+ return TC_CRYPTO_SUCCESS;
+}
+
+/**
+ * Variation of CBC-MAC mode used in CCM.
+ */
+static void ccm_cbc_mac(uint8_t *T, const uint8_t *data, uint32_t dlen,
+ uint32_t flag, TCAesKeySched_t sched)
+{
+
+ uint32_t i;
+
+ if (flag > 0) {
+ T[0] ^= (uint8_t)(dlen >> 8);
+ T[1] ^= (uint8_t)(dlen);
+ dlen += 2; i = 2;
+ } else {
+ i = 0;
+ }
+
+ while (i < dlen) {
+ T[i++ % (Nb * Nk)] ^= *data++;
+ if (((i % (Nb * Nk)) == 0) || dlen == i) {
+ (void) tc_aes_encrypt(T, T, sched);
+ }
+ }
+}
+
+/**
+ * Variation of CTR mode used in CCM.
+ * The CTR mode used by CCM is slightly different than the conventional CTR
+ * mode (the counter is increased before encryption, instead of after
+ * encryption). Besides, it is assumed that the counter is stored in the last
+ * 2 bytes of the nonce.
+ */
+static int32_t ccm_ctr_mode(uint8_t *out, uint32_t outlen, const uint8_t *in,
+ uint32_t inlen, uint8_t *ctr, const TCAesKeySched_t sched)
+{
+
+ uint8_t buffer[TC_AES_BLOCK_SIZE];
+ uint8_t nonce[TC_AES_BLOCK_SIZE];
+ uint16_t block_num;
+ uint32_t i;
+
+ /* input sanity check: */
+ if (out == (uint8_t *) 0 ||
+ in == (uint8_t *) 0 ||
+ ctr == (uint8_t *) 0 ||
+ sched == (TCAesKeySched_t) 0 ||
+ inlen == 0 ||
+ outlen == 0 ||
+ outlen != inlen) {
+ return TC_CRYPTO_FAIL;
+ }
+
+ /* copy the counter to the nonce */
+ (void) _copy(nonce, sizeof(nonce), ctr, sizeof(nonce));
+
+ /* select the last 2 bytes of the nonce to be incremented */
+ block_num = (uint16_t) ((nonce[14] << 8)|(nonce[15]));
+ for (i = 0; i < inlen; ++i) {
+ if ((i % (TC_AES_BLOCK_SIZE)) == 0) {
+ block_num++;
+ nonce[14] = (uint8_t)(block_num >> 8);
+ nonce[15] = (uint8_t)(block_num);
+ if (!tc_aes_encrypt(buffer, nonce, sched)) {
+ return TC_CRYPTO_FAIL;
+ }
+ }
+ /* update the output */
+ *out++ = buffer[i % (TC_AES_BLOCK_SIZE)] ^ *in++;
+ }
+
+ /* update the counter */
+ ctr[14] = nonce[14]; ctr[15] = nonce[15];
+
+ return TC_CRYPTO_SUCCESS;
+}
+
+int32_t tc_ccm_generation_encryption(uint8_t *out, const uint8_t *associated_data,
+ uint32_t alen, const uint8_t *payload,
+ uint32_t plen, TCCcmMode_t c)
+{
+ /* input sanity check: */
+ if ((out == (uint8_t *) 0) ||
+ (c == (TCCcmMode_t) 0) ||
+ ((plen > 0) && (payload == (uint8_t *) 0)) ||
+ ((alen > 0) && (associated_data == (uint8_t *) 0)) ||
+ (alen >= TC_CCM_AAD_MAX_BYTES) || /* associated data size unsupported */
+ (plen >= TC_CCM_PAYLOAD_MAX_BYTES)) { /* payload size unsupported */
+ return TC_CRYPTO_FAIL;
+ }
+
+ uint8_t b[Nb * Nk];
+ uint8_t tag[Nb * Nk];
+ uint32_t i;
+
+ /* GENERATING THE AUTHENTICATION TAG: */
+
+ /* formatting the sequence b for authentication: */
+ b[0] = ((alen > 0) ? 0x40:0) | (((c->mlen - 2) / 2 << 3)) | (1);
+ for (i = 1; i <= 13; ++i) {
+ b[i] = c->nonce[i - 1];
+ }
+ b[14] = (uint8_t)(plen >> 8);
+ b[15] = (uint8_t)(plen);
+
+ /* computing the authentication tag using cbc-mac: */
+ (void) tc_aes_encrypt(tag, b, c->sched);
+ if (alen > 0) {
+ ccm_cbc_mac(tag, associated_data, alen, 1, c->sched);
+ }
+ if (plen > 0) {
+ ccm_cbc_mac(tag, payload, plen, 0, c->sched);
+ }
+
+ /* ENCRYPTION: */
+
+ /* formatting the sequence b for encryption: */
+ b[0] = 1; /* q - 1 = 2 - 1 = 1 */
+ b[14] = b[15] = TC_ZERO_BYTE;
+
+ /* encrypting payload using ctr mode: */
+ ccm_ctr_mode(out, plen, payload, plen, b, c->sched);
+
+ b[14] = b[15] = TC_ZERO_BYTE; /* restoring initial counter for ctr_mode (0):*/
+
+ /* encrypting b and adding the tag to the output: */
+ (void) tc_aes_encrypt(b, b, c->sched);
+ out += plen;
+ for (i = 0; i < c->mlen; ++i) {
+ *out++ = tag[i] ^ b[i];
+ }
+
+ return TC_CRYPTO_SUCCESS;
+}
+
+int32_t tc_ccm_decryption_verification(uint8_t *out, const uint8_t *associated_data,
+ uint32_t alen, const uint8_t *payload,
+ uint32_t plen, TCCcmMode_t c)
+{
+ /* input sanity check: */
+ if ((out == (uint8_t *) 0) ||
+ (c == (TCCcmMode_t) 0) ||
+ ((plen > 0) && (payload == (uint8_t *) 0)) ||
+ ((alen > 0) && (associated_data == (uint8_t *) 0)) ||
+ (alen >= TC_CCM_AAD_MAX_BYTES) || /* associated data size unsupported */
+ (plen >= TC_CCM_PAYLOAD_MAX_BYTES)) { /* payload size unsupported */
+ return TC_CRYPTO_FAIL;
+ }
+
+ uint8_t b[Nb * Nk];
+ uint8_t tag[Nb * Nk];
+ uint32_t i;
+
+ /* DECRYPTION: */
+
+ /* formatting the sequence b for decryption: */
+ b[0] = 1; /* q - 1 = 2 - 1 = 1 */
+ for (i = 1; i < 14; ++i) {
+ b[i] = c->nonce[i - 1];
+ }
+ b[14] = b[15] = TC_ZERO_BYTE; /* initial counter value is 0 */
+
+ /* decrypting payload using ctr mode: */
+ ccm_ctr_mode(out, plen - c->mlen, payload, plen - c->mlen, b, c->sched);
+
+ b[14] = b[15] = TC_ZERO_BYTE; /* restoring initial counter value (0) */
+
+ /* encrypting b and restoring the tag from input: */
+ (void) tc_aes_encrypt(b, b, c->sched);
+ for (i = 0; i < c->mlen; ++i) {
+ tag[i] = *(payload + plen - c->mlen + i) ^ b[i];
+ }
+
+ /* VERIFYING THE AUTHENTICATION TAG: */
+
+ /* formatting the sequence b for authentication: */
+ b[0] = ((alen > 0) ? 0x40:0)|(((c->mlen - 2) / 2 << 3)) | (1);
+ for (i = 1; i < 14; ++i) {
+ b[i] = c->nonce[i - 1];
+ }
+ b[14] = (uint8_t)((plen - c->mlen) >> 8);
+ b[15] = (uint8_t)(plen - c->mlen);
+
+ /* computing the authentication tag using cbc-mac: */
+ (void) tc_aes_encrypt(b, b, c->sched);
+ if (alen > 0) {
+ ccm_cbc_mac(b, associated_data, alen, 1, c->sched);
+ }
+ if (plen > 0) {
+ ccm_cbc_mac(b, out, plen - c->mlen, 0, c->sched);
+ }
+
+ /* comparing the received tag and the computed one: */
+ if (_compare(b, tag, c->mlen) != 0) {
+ /* erase the decrypted buffer in case of mac validation failure: */
+ _set(out, 0, sizeof(*out));
+ return TC_CRYPTO_FAIL;
+ }
+
+ return TC_CRYPTO_SUCCESS;
+}