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/*
* 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.
*
* 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 "config.h"
#if defined(ENABLE_CRYPTO_REFRESH)
#include "v2_seipd.h"
#include "logging.h"
#include "crypto/hkdf.hpp"
seipd_v2_aead_fields_t
seipd_v2_key_and_nonce_derivation(pgp_seipdv2_hdr_t &hdr, uint8_t *sesskey)
{
auto hkdf = rnp::Hkdf::create(PGP_HASH_SHA256);
size_t sesskey_len = pgp_key_size(hdr.cipher_alg);
uint32_t nonce_size = 0;
uint32_t key_size = pgp_key_size(hdr.cipher_alg);
switch (hdr.aead_alg) {
case PGP_AEAD_EAX:
nonce_size = 16;
break;
case PGP_AEAD_OCB:
nonce_size = 15;
break;
case PGP_AEAD_NONE:
case PGP_AEAD_UNKNOWN:
RNP_LOG("only EAX and OCB is supported for v2 SEIPD packets");
throw rnp::rnp_exception(RNP_ERROR_NOT_SUPPORTED);
}
const uint8_t info[5] = {
static_cast<uint8_t>(PGP_PKT_SE_IP_DATA | PGP_PTAG_ALWAYS_SET | PGP_PTAG_NEW_FORMAT),
static_cast<uint8_t>(hdr.version),
static_cast<uint8_t>(hdr.cipher_alg),
static_cast<uint8_t>(hdr.aead_alg),
hdr.chunk_size_octet};
uint32_t out_size = key_size + nonce_size - 8;
std::vector<uint8_t> hkdf_out(out_size);
hkdf->extract_expand(hdr.salt,
sizeof(hdr.salt),
sesskey,
sesskey_len,
info,
sizeof(info),
hkdf_out.data(),
hkdf_out.size());
seipd_v2_aead_fields_t result;
result.key = std::vector<uint8_t>(hkdf_out.data(), hkdf_out.data() + key_size);
result.nonce =
std::vector<uint8_t>(hkdf_out.data() + key_size, hkdf_out.data() + hkdf_out.size());
for (uint32_t i = 0; i < 8; i++) {
// fill up the nonce with zero octets
result.nonce.push_back(0);
}
return result;
}
#endif