// SPDX-License-Identifier: GPL-2.0
/* Multipath TCP cryptographic functions
* Copyright (c) 2017 - 2019, Intel Corporation.
*
* Note: This code is based on mptcp_ctrl.c, mptcp_ipv4.c, and
* mptcp_ipv6 from multipath-tcp.org, authored by:
*
* Sébastien Barré <sebastien.barre@uclouvain.be>
* Christoph Paasch <christoph.paasch@uclouvain.be>
* Jaakko Korkeaniemi <jaakko.korkeaniemi@aalto.fi>
* Gregory Detal <gregory.detal@uclouvain.be>
* Fabien Duchêne <fabien.duchene@uclouvain.be>
* Andreas Seelinger <Andreas.Seelinger@rwth-aachen.de>
* Lavkesh Lahngir <lavkesh51@gmail.com>
* Andreas Ripke <ripke@neclab.eu>
* Vlad Dogaru <vlad.dogaru@intel.com>
* Octavian Purdila <octavian.purdila@intel.com>
* John Ronan <jronan@tssg.org>
* Catalin Nicutar <catalin.nicutar@gmail.com>
* Brandon Heller <brandonh@stanford.edu>
*/
#include <linux/kernel.h>
#include <crypto/sha2.h>
#include <asm/unaligned.h>
#include "protocol.h"
#define SHA256_DIGEST_WORDS (SHA256_DIGEST_SIZE / 4)
void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn)
{
__be32 mptcp_hashed_key[SHA256_DIGEST_WORDS];
__be64 input = cpu_to_be64(key);
sha256((__force u8 *)&input, sizeof(input), (u8 *)mptcp_hashed_key);
if (token)
*token = be32_to_cpu(mptcp_hashed_key[0]);
if (idsn)
*idsn = be64_to_cpu(*((__be64 *)&mptcp_hashed_key[6]));
}
void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac)
{
u8 input[SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE];
u8 key1be[8];
u8 key2be[8];
int i;
if (WARN_ON_ONCE(len > SHA256_DIGEST_SIZE))
len = SHA256_DIGEST_SIZE;
put_unaligned_be64(key1, key1be);
put_unaligned_be64(key2, key2be);
/* Generate key xored with ipad */
memset(input, 0x36, SHA256_BLOCK_SIZE);
for (i = 0; i < 8; i++)
input[i] ^= key1be[i];
for (i = 0; i < 8; i++)
input[i + 8] ^= key2be[i];
memcpy(&input[SHA256_BLOCK_SIZE], msg, len);
/* emit sha256(K1 || msg) on the second input block, so we can
* reuse 'input' for the last hashing
*/
sha256(input, SHA256_BLOCK_SIZE + len, &input[SHA256_BLOCK_SIZE]);
/* Prepare second part of hmac */
memset(input, 0x5C, SHA256_BLOCK_SIZE);
for (i = 0; i < 8; i++)
input[i] ^= key1be[i];
for (i = 0; i < 8; i++)
input[i + 8] ^= key2be[i];
sha256(input, SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE, hmac);
}
#if IS_MODULE(CONFIG_MPTCP_KUNIT_TESTS)
EXPORT_SYMBOL_GPL(mptcp_crypto_hmac_sha);
#endif
