diff options
Diffstat (limited to 'src/crypto/cipher_extra/e_aesccm.c')
-rw-r--r-- | src/crypto/cipher_extra/e_aesccm.c | 266 |
1 files changed, 254 insertions, 12 deletions
diff --git a/src/crypto/cipher_extra/e_aesccm.c b/src/crypto/cipher_extra/e_aesccm.c index 3e186593..e9e9e16e 100644 --- a/src/crypto/cipher_extra/e_aesccm.c +++ b/src/crypto/cipher_extra/e_aesccm.c @@ -1,21 +1,56 @@ -/* Copyright (c) 2018, Google Inc. +/* ==================================================================== + * Copyright (c) 2008 The OpenSSL Project. All rights reserved. * - * Permission to use, copy, modify, and/or distribute this software for any - * purpose with or without fee is hereby granted, provided that the above - * copyright notice and this permission notice appear in all copies. + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: * - * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES - * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF - * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY - * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES - * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION - * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN - * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ + * 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 <openssl/aead.h> #include <assert.h> +#include <openssl/cpu.h> #include <openssl/cipher.h> #include <openssl/err.h> #include <openssl/mem.h> @@ -23,6 +58,213 @@ #include "../fipsmodule/cipher/internal.h" +struct ccm128_context { + block128_f block; + ctr128_f ctr; + unsigned M, L; +}; + +struct ccm128_state { + union { + uint64_t u[2]; + uint8_t c[16]; + } nonce, cmac; +}; + +static int CRYPTO_ccm128_init(struct ccm128_context *ctx, const AES_KEY *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; +} + +static size_t CRYPTO_ccm128_max_input(const struct 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 struct ccm128_context *ctx, + struct ccm128_state *state, const AES_KEY *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 struct ccm128_context *ctx, + struct ccm128_state *state, const AES_KEY *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 struct ccm128_context *ctx, + struct ccm128_state *state, const AES_KEY *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; +} + +static int CRYPTO_ccm128_encrypt(const struct ccm128_context *ctx, + const AES_KEY *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); +} + +static int CRYPTO_ccm128_decrypt(const struct ccm128_context *ctx, + const AES_KEY *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); +} + #define EVP_AEAD_AES_CCM_MAX_TAG_LEN 16 struct aead_aes_ccm_ctx { @@ -30,7 +272,7 @@ struct aead_aes_ccm_ctx { double align; AES_KEY ks; } ks; - CCM128_CONTEXT ccm; + struct ccm128_context ccm; }; OPENSSL_STATIC_ASSERT(sizeof(((EVP_AEAD_CTX *)NULL)->state) >= |