diff options
author | Uros Majstorovic <majstor@majstor.org> | 2022-02-02 06:40:10 +0100 |
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committer | Uros Majstorovic <majstor@majstor.org> | 2022-02-02 06:40:10 +0100 |
commit | 64b55e7e1236121ea4197d9a37cfec43b196cfe8 (patch) | |
tree | eb16f4a2d3eae3d9485eccbd923812a56b627979 /ecp/src/ecp/crypto/e_chacha20poly1305.c | |
parent | a4401c99c2a54ba9a964317cbff915d40d16e470 (diff) |
moved ecp, platform -> src
Diffstat (limited to 'ecp/src/ecp/crypto/e_chacha20poly1305.c')
-rw-r--r-- | ecp/src/ecp/crypto/e_chacha20poly1305.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/ecp/src/ecp/crypto/e_chacha20poly1305.c b/ecp/src/ecp/crypto/e_chacha20poly1305.c new file mode 100644 index 0000000..17fcab8 --- /dev/null +++ b/ecp/src/ecp/crypto/e_chacha20poly1305.c @@ -0,0 +1,229 @@ +/* $OpenBSD: e_chacha20poly1305.c,v 1.15 2017/01/29 17:49:23 beck Exp $ */ + +/* + * Copyright (c) 2015 Reyk Floter <reyk@openbsd.org> + * Copyright (c) 2014, Google Inc. + * + * 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. + * + * 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. + */ + +#include <stdint.h> +#include <string.h> + +#if !defined(OPENSSL_NO_CHACHA) && !defined(OPENSSL_NO_POLY1305) + +#include <compat.h> +#include <chacha.h> +#include <poly1305.h> + +#define POLY1305_TAG_LEN 16 +#define CHACHA20_NONCE_LEN_OLD 8 + +/* + * The informational RFC 7539, "ChaCha20 and Poly1305 for IETF Protocols", + * introduced a modified AEAD construction that is incompatible with the + * common style that has been already used in TLS. The IETF version also + * adds a constant (salt) that is prepended to the nonce. + */ +#define CHACHA20_CONSTANT_LEN 4 +#define CHACHA20_IV_LEN 8 +#define CHACHA20_NONCE_LEN (CHACHA20_CONSTANT_LEN + CHACHA20_IV_LEN) + + +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; + } + + if (data != NULL) + CRYPTO_poly1305_update(poly1305, data, data_len); + CRYPTO_poly1305_update(poly1305, length_bytes, sizeof(length_bytes)); +} + +static void +poly1305_update_with_pad16(poly1305_state *poly1305, + const unsigned char *data, size_t data_len) +{ + static const unsigned char zero_pad16[16]; + size_t pad_len; + + CRYPTO_poly1305_update(poly1305, data, data_len); + + /* pad16() is defined in RFC 7539 2.8.1. */ + if ((pad_len = data_len % 16) == 0) + return; + + CRYPTO_poly1305_update(poly1305, zero_pad16, 16 - pad_len); +} + +int +aead_chacha20_poly1305_seal(unsigned char *out, size_t *out_len, + size_t max_out_len, unsigned char key[32], unsigned char tag_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) +{ + unsigned char poly1305_key[32]; + poly1305_state poly1305; + const unsigned char *iv; + const uint64_t in_len_64 = in_len; + uint64_t ctr; + + /* 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) { + // EVPerror(EVP_R_TOO_LARGE); + return 0; + } + + if (max_out_len < in_len + tag_len) { + // EVPerror(EVP_R_BUFFER_TOO_SMALL); + return 0; + } + + if (nonce_len == CHACHA20_NONCE_LEN_OLD) { + /* Google's draft-agl-tls-chacha20poly1305-04, Nov 2013 */ + + memset(poly1305_key, 0, sizeof(poly1305_key)); + CRYPTO_chacha_20(poly1305_key, poly1305_key, + sizeof(poly1305_key), key, nonce, 0); + + CRYPTO_poly1305_init(&poly1305, poly1305_key); + poly1305_update_with_length(&poly1305, ad, ad_len); + CRYPTO_chacha_20(out, in, in_len, key, nonce, 1); + poly1305_update_with_length(&poly1305, out, in_len); + } else if (nonce_len == CHACHA20_NONCE_LEN) { + /* RFC 7539, May 2015 */ + + ctr = (uint64_t)(nonce[0] | nonce[1] << 8 | + nonce[2] << 16 | nonce[3] << 24) << 32; + iv = nonce + CHACHA20_CONSTANT_LEN; + + memset(poly1305_key, 0, sizeof(poly1305_key)); + CRYPTO_chacha_20(poly1305_key, poly1305_key, + sizeof(poly1305_key), key, iv, ctr); + + CRYPTO_poly1305_init(&poly1305, poly1305_key); + poly1305_update_with_pad16(&poly1305, ad, ad_len); + CRYPTO_chacha_20(out, in, in_len, key, iv, ctr + 1); + poly1305_update_with_pad16(&poly1305, out, in_len); + poly1305_update_with_length(&poly1305, NULL, ad_len); + poly1305_update_with_length(&poly1305, NULL, in_len); + } + + if (tag_len != POLY1305_TAG_LEN) { + unsigned char tag[POLY1305_TAG_LEN]; + CRYPTO_poly1305_finish(&poly1305, tag); + memcpy(out + in_len, tag, tag_len); + *out_len = in_len + tag_len; + return 1; + } + + CRYPTO_poly1305_finish(&poly1305, out + in_len); + *out_len = in_len + POLY1305_TAG_LEN; + return 1; +} + +int +aead_chacha20_poly1305_open(unsigned char *out, size_t *out_len, + size_t max_out_len, unsigned char key[32], unsigned char tag_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) +{ + unsigned char mac[POLY1305_TAG_LEN]; + unsigned char poly1305_key[32]; + const unsigned char *iv = nonce; + poly1305_state poly1305; + const uint64_t in_len_64 = in_len; + size_t plaintext_len; + uint64_t ctr = 0; + + if (in_len < tag_len) { + // EVPerror(EVP_R_BAD_DECRYPT); + return 0; + } + + /* 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) { + // EVPerror(EVP_R_TOO_LARGE); + return 0; + } + + plaintext_len = in_len - tag_len; + + if (max_out_len < plaintext_len) { + // EVPerror(EVP_R_BUFFER_TOO_SMALL); + return 0; + } + + if (nonce_len == CHACHA20_NONCE_LEN_OLD) { + /* Google's draft-agl-tls-chacha20poly1305-04, Nov 2013 */ + + memset(poly1305_key, 0, sizeof(poly1305_key)); + CRYPTO_chacha_20(poly1305_key, poly1305_key, + sizeof(poly1305_key), key, nonce, 0); + + CRYPTO_poly1305_init(&poly1305, poly1305_key); + poly1305_update_with_length(&poly1305, ad, ad_len); + poly1305_update_with_length(&poly1305, in, plaintext_len); + } else if (nonce_len == CHACHA20_NONCE_LEN) { + /* RFC 7539, May 2015 */ + + ctr = (uint64_t)(nonce[0] | nonce[1] << 8 | + nonce[2] << 16 | nonce[3] << 24) << 32; + iv = nonce + CHACHA20_CONSTANT_LEN; + + memset(poly1305_key, 0, sizeof(poly1305_key)); + CRYPTO_chacha_20(poly1305_key, poly1305_key, + sizeof(poly1305_key), key, iv, ctr); + + CRYPTO_poly1305_init(&poly1305, poly1305_key); + poly1305_update_with_pad16(&poly1305, ad, ad_len); + poly1305_update_with_pad16(&poly1305, in, plaintext_len); + poly1305_update_with_length(&poly1305, NULL, ad_len); + poly1305_update_with_length(&poly1305, NULL, plaintext_len); + } + + CRYPTO_poly1305_finish(&poly1305, mac); + + if (timingsafe_memcmp(mac, in + plaintext_len, tag_len) != 0) { + // EVPerror(EVP_R_BAD_DECRYPT); + return 0; + } + + CRYPTO_chacha_20(out, in, plaintext_len, key, iv, ctr + 1); + *out_len = plaintext_len; + return 1; +} + +#endif /* !OPENSSL_NO_CHACHA && !OPENSSL_NO_POLY1305 */ |