--- /dev/null
+/* ====================================================================
+ * Copyright (c) 2011 The OpenSSL Project. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ * software must display the following acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For written permission, please contact
+ * openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ * nor may "OpenSSL" appear in their names without prior written
+ * permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED 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 OpenSSL PROJECT OR
+ * ITS 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 <assert.h>
+#include <string.h>
+
+#include <openssl/cpu.h>
+#include <openssl/mem.h>
+
+#include "../../internal.h"
+#include "internal.h"
+
+
+struct ccm128_state {
+ union {
+ uint64_t u[2];
+ uint8_t c[16];
+ } nonce, cmac;
+};
+
+int CRYPTO_ccm128_init(CCM128_CONTEXT *ctx, const void *key, block128_f block,
+ ctr128_f ctr, unsigned M, unsigned L) {
+ if (M < 4 || M > 16 || (M & 1) != 0 || L < 2 || L > 8) {
+ return 0;
+ }
+ ctx->block = block;
+ ctx->ctr = ctr;
+ ctx->M = M;
+ ctx->L = L;
+ return 1;
+}
+
+size_t CRYPTO_ccm128_max_input(const CCM128_CONTEXT *ctx) {
+ return ctx->L >= sizeof(size_t) ? (size_t)-1
+ : (((size_t)1) << (ctx->L * 8)) - 1;
+}
+
+static int ccm128_init_state(const CCM128_CONTEXT *ctx,
+ struct ccm128_state *state, const void *key,
+ const uint8_t *nonce, size_t nonce_len,
+ const uint8_t *aad, size_t aad_len,
+ size_t plaintext_len) {
+ const block128_f block = ctx->block;
+ const unsigned M = ctx->M;
+ const unsigned L = ctx->L;
+
+ // |L| determines the expected |nonce_len| and the limit for |plaintext_len|.
+ if (plaintext_len > CRYPTO_ccm128_max_input(ctx) ||
+ nonce_len != 15 - L) {
+ return 0;
+ }
+
+ // Assemble the first block for computing the MAC.
+ OPENSSL_memset(state, 0, sizeof(*state));
+ state->nonce.c[0] = (uint8_t)((L - 1) | ((M - 2) / 2) << 3);
+ if (aad_len != 0) {
+ state->nonce.c[0] |= 0x40; // Set AAD Flag
+ }
+ OPENSSL_memcpy(&state->nonce.c[1], nonce, nonce_len);
+ for (unsigned i = 0; i < L; i++) {
+ state->nonce.c[15 - i] = (uint8_t)(plaintext_len >> (8 * i));
+ }
+
+ (*block)(state->nonce.c, state->cmac.c, key);
+ size_t blocks = 1;
+
+ if (aad_len != 0) {
+ unsigned i;
+ // Cast to u64 to avoid the compiler complaining about invalid shifts.
+ uint64_t aad_len_u64 = aad_len;
+ if (aad_len_u64 < 0x10000 - 0x100) {
+ state->cmac.c[0] ^= (uint8_t)(aad_len_u64 >> 8);
+ state->cmac.c[1] ^= (uint8_t)aad_len_u64;
+ i = 2;
+ } else if (aad_len_u64 <= 0xffffffff) {
+ state->cmac.c[0] ^= 0xff;
+ state->cmac.c[1] ^= 0xfe;
+ state->cmac.c[2] ^= (uint8_t)(aad_len_u64 >> 24);
+ state->cmac.c[3] ^= (uint8_t)(aad_len_u64 >> 16);
+ state->cmac.c[4] ^= (uint8_t)(aad_len_u64 >> 8);
+ state->cmac.c[5] ^= (uint8_t)aad_len_u64;
+ i = 6;
+ } else {
+ state->cmac.c[0] ^= 0xff;
+ state->cmac.c[1] ^= 0xff;
+ state->cmac.c[2] ^= (uint8_t)(aad_len_u64 >> 56);
+ state->cmac.c[3] ^= (uint8_t)(aad_len_u64 >> 48);
+ state->cmac.c[4] ^= (uint8_t)(aad_len_u64 >> 40);
+ state->cmac.c[5] ^= (uint8_t)(aad_len_u64 >> 32);
+ state->cmac.c[6] ^= (uint8_t)(aad_len_u64 >> 24);
+ state->cmac.c[7] ^= (uint8_t)(aad_len_u64 >> 16);
+ state->cmac.c[8] ^= (uint8_t)(aad_len_u64 >> 8);
+ state->cmac.c[9] ^= (uint8_t)aad_len_u64;
+ i = 10;
+ }
+
+ do {
+ for (; i < 16 && aad_len != 0; i++) {
+ state->cmac.c[i] ^= *aad;
+ aad++;
+ aad_len--;
+ }
+ (*block)(state->cmac.c, state->cmac.c, key);
+ blocks++;
+ i = 0;
+ } while (aad_len != 0);
+ }
+
+ // Per RFC 3610, section 2.6, the total number of block cipher operations done
+ // must not exceed 2^61. There are two block cipher operations remaining per
+ // message block, plus one block at the end to encrypt the MAC.
+ size_t remaining_blocks = 2 * ((plaintext_len + 15) / 16) + 1;
+ if (plaintext_len + 15 < plaintext_len ||
+ remaining_blocks + blocks < blocks ||
+ (uint64_t) remaining_blocks + blocks > UINT64_C(1) << 61) {
+ return 0;
+ }
+
+ // Assemble the first block for encrypting and decrypting. The bottom |L|
+ // bytes are replaced with a counter and all bit the encoding of |L| is
+ // cleared in the first byte.
+ state->nonce.c[0] &= 7;
+ return 1;
+}
+
+static int ccm128_encrypt(const CCM128_CONTEXT *ctx, struct ccm128_state *state,
+ const void *key, uint8_t *out, const uint8_t *in,
+ size_t len) {
+ // The counter for encryption begins at one.
+ for (unsigned i = 0; i < ctx->L; i++) {
+ state->nonce.c[15 - i] = 0;
+ }
+ state->nonce.c[15] = 1;
+
+ uint8_t partial_buf[16];
+ unsigned num = 0;
+ if (ctx->ctr != NULL) {
+ CRYPTO_ctr128_encrypt_ctr32(in, out, len, key, state->nonce.c, partial_buf,
+ &num, ctx->ctr);
+ } else {
+ CRYPTO_ctr128_encrypt(in, out, len, key, state->nonce.c, partial_buf, &num,
+ ctx->block);
+ }
+ return 1;
+}
+
+static int ccm128_compute_mac(const CCM128_CONTEXT *ctx,
+ struct ccm128_state *state, const void *key,
+ uint8_t *out_tag, size_t tag_len,
+ const uint8_t *in, size_t len) {
+ block128_f block = ctx->block;
+ if (tag_len != ctx->M) {
+ return 0;
+ }
+
+ // Incorporate |in| into the MAC.
+ union {
+ uint64_t u[2];
+ uint8_t c[16];
+ } tmp;
+ while (len >= 16) {
+ OPENSSL_memcpy(tmp.c, in, 16);
+ state->cmac.u[0] ^= tmp.u[0];
+ state->cmac.u[1] ^= tmp.u[1];
+ (*block)(state->cmac.c, state->cmac.c, key);
+ in += 16;
+ len -= 16;
+ }
+ if (len > 0) {
+ for (size_t i = 0; i < len; i++) {
+ state->cmac.c[i] ^= in[i];
+ }
+ (*block)(state->cmac.c, state->cmac.c, key);
+ }
+
+ // Encrypt the MAC with counter zero.
+ for (unsigned i = 0; i < ctx->L; i++) {
+ state->nonce.c[15 - i] = 0;
+ }
+ (*block)(state->nonce.c, tmp.c, key);
+ state->cmac.u[0] ^= tmp.u[0];
+ state->cmac.u[1] ^= tmp.u[1];
+
+ OPENSSL_memcpy(out_tag, state->cmac.c, tag_len);
+ return 1;
+}
+
+int CRYPTO_ccm128_encrypt(const CCM128_CONTEXT *ctx, const void *key,
+ uint8_t *out, uint8_t *out_tag, size_t tag_len,
+ const uint8_t *nonce, size_t nonce_len,
+ const uint8_t *in, size_t len, const uint8_t *aad,
+ size_t aad_len) {
+ struct ccm128_state state;
+ return ccm128_init_state(ctx, &state, key, nonce, nonce_len, aad, aad_len,
+ len) &&
+ ccm128_compute_mac(ctx, &state, key, out_tag, tag_len, in, len) &&
+ ccm128_encrypt(ctx, &state, key, out, in, len);
+}
+
+int CRYPTO_ccm128_decrypt(const CCM128_CONTEXT *ctx, const void *key,
+ uint8_t *out, uint8_t *out_tag, size_t tag_len,
+ const uint8_t *nonce, size_t nonce_len,
+ const uint8_t *in, size_t len, const uint8_t *aad,
+ size_t aad_len) {
+ struct ccm128_state state;
+ return ccm128_init_state(ctx, &state, key, nonce, nonce_len, aad, aad_len,
+ len) &&
+ ccm128_encrypt(ctx, &state, key, out, in, len) &&
+ ccm128_compute_mac(ctx, &state, key, out_tag, tag_len, out, len);
+}
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