| /* ==================================================================== |
| * Copyright (c) 2013 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 <stdint.h> |
| #include <string.h> |
| #include <openssl/opensslconf.h> |
| |
| #if !defined(OPENSSL_NO_CHACHA) && !defined(OPENSSL_NO_POLY1305) |
| |
| #include <openssl/chacha.h> |
| #include <openssl/poly1305.h> |
| #include <openssl/evp.h> |
| #include <openssl/err.h> |
| #include "evp_locl.h" |
| |
| #define POLY1305_TAG_LEN 16 |
| #define CHACHA20_NONCE_LEN 8 |
| |
| struct aead_chacha20_poly1305_ctx |
| { |
| unsigned char key[32]; |
| unsigned char tag_len; |
| }; |
| |
| static int aead_chacha20_poly1305_init(EVP_AEAD_CTX *ctx, const unsigned char *key, size_t key_len, size_t tag_len) |
| { |
| struct aead_chacha20_poly1305_ctx *c20_ctx; |
| |
| if (tag_len == 0) |
| tag_len = POLY1305_TAG_LEN; |
| |
| if (tag_len > POLY1305_TAG_LEN) |
| { |
| EVPerr(EVP_F_AEAD_CHACHA20_POLY1305_INIT, EVP_R_TOO_LARGE); |
| return 0; |
| } |
| |
| if (key_len != sizeof(c20_ctx->key)) |
| return 0; /* internal error - EVP_AEAD_CTX_init should catch this. */ |
| |
| c20_ctx = OPENSSL_malloc(sizeof(struct aead_chacha20_poly1305_ctx)); |
| if (c20_ctx == NULL) |
| return 0; |
| |
| memcpy(&c20_ctx->key[0], key, key_len); |
| c20_ctx->tag_len = tag_len; |
| ctx->aead_state = c20_ctx; |
| |
| return 1; |
| } |
| |
| static void aead_chacha20_poly1305_cleanup(EVP_AEAD_CTX *ctx) |
| { |
| struct aead_chacha20_poly1305_ctx *c20_ctx = ctx->aead_state; |
| OPENSSL_cleanse(c20_ctx->key, sizeof(c20_ctx->key)); |
| OPENSSL_free(c20_ctx); |
| } |
| |
| static void poly1305_update_with_length(poly1305_state *poly1305, |
| const unsigned char *data, size_t data_len) |
| { |
| size_t j = data_len; |
| unsigned char length_bytes[8]; |
| unsigned i; |
| |
| for (i = 0; i < sizeof(length_bytes); i++) |
| { |
| length_bytes[i] = j; |
| j >>= 8; |
| } |
| |
| CRYPTO_poly1305_update(poly1305, data, data_len); |
| CRYPTO_poly1305_update(poly1305, length_bytes, sizeof(length_bytes)); |
| } |
| |
| #if __arm__ |
| #define ALIGNED __attribute__((aligned(16))) |
| #else |
| #define ALIGNED |
| #endif |
| |
| static ssize_t aead_chacha20_poly1305_seal(const EVP_AEAD_CTX *ctx, |
| unsigned char *out, size_t max_out_len, |
| const unsigned char *nonce, size_t nonce_len, |
| const unsigned char *in, size_t in_len, |
| const unsigned char *ad, size_t ad_len) |
| { |
| const struct aead_chacha20_poly1305_ctx *c20_ctx = ctx->aead_state; |
| unsigned char poly1305_key[32] ALIGNED; |
| poly1305_state poly1305; |
| const uint64_t in_len_64 = in_len; |
| |
| /* The underlying ChaCha implementation may not overflow the block |
| * counter into the second counter word. Therefore we disallow |
| * individual operations that work on more than 2TB at a time. |
| * |in_len_64| is needed because, on 32-bit platforms, size_t is only |
| * 32-bits and this produces a warning because it's always false. |
| * Casting to uint64_t inside the conditional is not sufficient to stop |
| * the warning. */ |
| if (in_len_64 >= (1ull << 32)*64-64) |
| { |
| EVPerr(EVP_F_AEAD_CHACHA20_POLY1305_SEAL, EVP_R_TOO_LARGE); |
| return -1; |
| } |
| |
| if (max_out_len < in_len + c20_ctx->tag_len) |
| { |
| EVPerr(EVP_F_AEAD_CHACHA20_POLY1305_SEAL, EVP_R_BUFFER_TOO_SMALL); |
| return -1; |
| } |
| |
| if (nonce_len != CHACHA20_NONCE_LEN) |
| { |
| EVPerr(EVP_F_AEAD_CHACHA20_POLY1305_SEAL, EVP_R_IV_TOO_LARGE); |
| return -1; |
| } |
| |
| memset(poly1305_key, 0, sizeof(poly1305_key)); |
| CRYPTO_chacha_20(poly1305_key, poly1305_key, sizeof(poly1305_key), c20_ctx->key, nonce, 0); |
| |
| CRYPTO_poly1305_init(&poly1305, poly1305_key); |
| poly1305_update_with_length(&poly1305, ad, ad_len); |
| CRYPTO_chacha_20(out, in, in_len, c20_ctx->key, nonce, 1); |
| poly1305_update_with_length(&poly1305, out, in_len); |
| |
| if (c20_ctx->tag_len != POLY1305_TAG_LEN) |
| { |
| unsigned char tag[POLY1305_TAG_LEN]; |
| CRYPTO_poly1305_finish(&poly1305, tag); |
| memcpy(out + in_len, tag, c20_ctx->tag_len); |
| return in_len + c20_ctx->tag_len; |
| } |
| |
| CRYPTO_poly1305_finish(&poly1305, out + in_len); |
| return in_len + POLY1305_TAG_LEN; |
| } |
| |
| static ssize_t aead_chacha20_poly1305_open(const EVP_AEAD_CTX *ctx, |
| unsigned char *out, size_t max_out_len, |
| const unsigned char *nonce, size_t nonce_len, |
| const unsigned char *in, size_t in_len, |
| const unsigned char *ad, size_t ad_len) |
| { |
| const struct aead_chacha20_poly1305_ctx *c20_ctx = ctx->aead_state; |
| unsigned char mac[POLY1305_TAG_LEN]; |
| unsigned char poly1305_key[32] ALIGNED; |
| size_t out_len; |
| poly1305_state poly1305; |
| const uint64_t in_len_64 = in_len; |
| |
| if (in_len < c20_ctx->tag_len) |
| { |
| EVPerr(EVP_F_AEAD_CHACHA20_POLY1305_OPEN, EVP_R_BAD_DECRYPT); |
| return -1; |
| } |
| |
| /* The underlying ChaCha implementation may not overflow the block |
| * counter into the second counter word. Therefore we disallow |
| * individual operations that work on more than 2TB at a time. |
| * |in_len_64| is needed because, on 32-bit platforms, size_t is only |
| * 32-bits and this produces a warning because it's always false. |
| * Casting to uint64_t inside the conditional is not sufficient to stop |
| * the warning. */ |
| if (in_len_64 >= (1ull << 32)*64-64) |
| { |
| EVPerr(EVP_F_AEAD_CHACHA20_POLY1305_SEAL, EVP_R_TOO_LARGE); |
| return -1; |
| } |
| |
| if (nonce_len != CHACHA20_NONCE_LEN) |
| { |
| EVPerr(EVP_F_AEAD_CHACHA20_POLY1305_OPEN, EVP_R_IV_TOO_LARGE); |
| return -1; |
| } |
| |
| out_len = in_len - c20_ctx->tag_len; |
| |
| if (max_out_len < out_len) |
| { |
| EVPerr(EVP_F_AEAD_CHACHA20_POLY1305_OPEN, EVP_R_BUFFER_TOO_SMALL); |
| return -1; |
| } |
| |
| memset(poly1305_key, 0, sizeof(poly1305_key)); |
| CRYPTO_chacha_20(poly1305_key, poly1305_key, sizeof(poly1305_key), c20_ctx->key, nonce, 0); |
| |
| CRYPTO_poly1305_init(&poly1305, poly1305_key); |
| poly1305_update_with_length(&poly1305, ad, ad_len); |
| poly1305_update_with_length(&poly1305, in, out_len); |
| CRYPTO_poly1305_finish(&poly1305, mac); |
| |
| if (CRYPTO_memcmp(mac, in + out_len, c20_ctx->tag_len) != 0) |
| { |
| EVPerr(EVP_F_AEAD_CHACHA20_POLY1305_OPEN, EVP_R_BAD_DECRYPT); |
| return -1; |
| } |
| |
| CRYPTO_chacha_20(out, in, out_len, c20_ctx->key, nonce, 1); |
| return out_len; |
| } |
| |
| static const EVP_AEAD aead_chacha20_poly1305 = |
| { |
| 32, /* key len */ |
| CHACHA20_NONCE_LEN, /* nonce len */ |
| POLY1305_TAG_LEN, /* overhead */ |
| POLY1305_TAG_LEN, /* max tag length */ |
| |
| aead_chacha20_poly1305_init, |
| aead_chacha20_poly1305_cleanup, |
| aead_chacha20_poly1305_seal, |
| aead_chacha20_poly1305_open, |
| }; |
| |
| const EVP_AEAD *EVP_aead_chacha20_poly1305() |
| { |
| return &aead_chacha20_poly1305; |
| } |
| |
| #endif /* !OPENSSL_NO_CHACHA && !OPENSSL_NO_POLY1305 */ |