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// 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/sha.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);
struct sha256_state state;
sha256_init(&state);
sha256_update(&state, (__force u8 *)&input, sizeof(input));
sha256_final(&state, (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, u32 nonce1, u32 nonce2,
void *hmac)
{
u8 input[SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE];
__be32 mptcp_hashed_key[SHA256_DIGEST_WORDS];
__be32 *hash_out = (__force __be32 *)hmac;
struct sha256_state state;
u8 key1be[8];
u8 key2be[8];
int i;
put_unaligned_be64(key1, key1be);
put_unaligned_be64(key2, key2be);
/* Generate key xored with ipad */
memset(input, 0x36, SHA_MESSAGE_BYTES);
for (i = 0; i < 8; i++)
input[i] ^= key1be[i];
for (i = 0; i < 8; i++)
input[i + 8] ^= key2be[i];
put_unaligned_be32(nonce1, &input[SHA256_BLOCK_SIZE]);
put_unaligned_be32(nonce2, &input[SHA256_BLOCK_SIZE + 4]);
sha256_init(&state);
sha256_update(&state, input, SHA256_BLOCK_SIZE + 8);
/* emit sha256(K1 || msg) on the second input block, so we can
* reuse 'input' for the last hashing
*/
sha256_final(&state, &input[SHA256_BLOCK_SIZE]);
/* Prepare second part of hmac */
memset(input, 0x5C, SHA_MESSAGE_BYTES);
for (i = 0; i < 8; i++)
input[i] ^= key1be[i];
for (i = 0; i < 8; i++)
input[i + 8] ^= key2be[i];
sha256_init(&state);
sha256_update(&state, input, SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE);
sha256_final(&state, (u8 *)mptcp_hashed_key);
/* takes only first 160 bits */
for (i = 0; i < 5; i++)
hash_out[i] = mptcp_hashed_key[i];
}
#ifdef CONFIG_MPTCP_HMAC_TEST
struct test_cast {
char *key;
char *msg;
char *result;
};
/* we can't reuse RFC 4231 test vectors, as we have constraint on the
* input and key size, and we truncate the output.
*/
static struct test_cast tests[] = {
{
.key = "0b0b0b0b0b0b0b0b",
.msg = "48692054",
.result = "8385e24fb4235ac37556b6b886db106284a1da67",
},
{
.key = "aaaaaaaaaaaaaaaa",
.msg = "dddddddd",
.result = "2c5e219164ff1dca1c4a92318d847bb6b9d44492",
},
{
.key = "0102030405060708",
.msg = "cdcdcdcd",
.result = "e73b9ba9969969cefb04aa0d6df18ec2fcc075b6",
},
};
static int __init test_mptcp_crypto(void)
{
char hmac[20], hmac_hex[41];
u32 nonce1, nonce2;
u64 key1, key2;
int i, j;
for (i = 0; i < ARRAY_SIZE(tests); ++i) {
/* mptcp hmap will convert to be before computing the hmac */
key1 = be64_to_cpu(*((__be64 *)&tests[i].key[0]));
key2 = be64_to_cpu(*((__be64 *)&tests[i].key[8]));
nonce1 = be32_to_cpu(*((__be32 *)&tests[i].msg[0]));
nonce2 = be32_to_cpu(*((__be32 *)&tests[i].msg[4]));
mptcp_crypto_hmac_sha(key1, key2, nonce1, nonce2, hmac);
for (j = 0; j < 20; ++j)
sprintf(&hmac_hex[j << 1], "%02x", hmac[j] & 0xff);
hmac_hex[40] = 0;
if (memcmp(hmac_hex, tests[i].result, 40))
pr_err("test %d failed, got %s expected %s", i,
hmac_hex, tests[i].result);
else
pr_info("test %d [ ok ]", i);
}
return 0;
}
late_initcall(test_mptcp_crypto);
#endif
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