1 // SPDX-License-Identifier: GPL-2.0
2 /* Multipath TCP cryptographic functions
3 * Copyright (c) 2017 - 2019, Intel Corporation.
5 * Note: This code is based on mptcp_ctrl.c, mptcp_ipv4.c, and
6 * mptcp_ipv6 from multipath-tcp.org, authored by:
8 * Sébastien Barré <sebastien.barre@uclouvain.be>
9 * Christoph Paasch <christoph.paasch@uclouvain.be>
10 * Jaakko Korkeaniemi <jaakko.korkeaniemi@aalto.fi>
11 * Gregory Detal <gregory.detal@uclouvain.be>
12 * Fabien Duchêne <fabien.duchene@uclouvain.be>
13 * Andreas Seelinger <Andreas.Seelinger@rwth-aachen.de>
14 * Lavkesh Lahngir <lavkesh51@gmail.com>
15 * Andreas Ripke <ripke@neclab.eu>
16 * Vlad Dogaru <vlad.dogaru@intel.com>
17 * Octavian Purdila <octavian.purdila@intel.com>
18 * John Ronan <jronan@tssg.org>
19 * Catalin Nicutar <catalin.nicutar@gmail.com>
20 * Brandon Heller <brandonh@stanford.edu>
23 #include <linux/kernel.h>
24 #include <crypto/sha.h>
25 #include <asm/unaligned.h>
29 #define SHA256_DIGEST_WORDS (SHA256_DIGEST_SIZE / 4)
31 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn)
33 __be32 mptcp_hashed_key[SHA256_DIGEST_WORDS];
34 __be64 input = cpu_to_be64(key);
36 sha256((__force u8 *)&input, sizeof(input), (u8 *)mptcp_hashed_key);
39 *token = be32_to_cpu(mptcp_hashed_key[0]);
41 *idsn = be64_to_cpu(*((__be64 *)&mptcp_hashed_key[6]));
44 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac)
46 u8 input[SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE];
51 if (WARN_ON_ONCE(len > SHA256_DIGEST_SIZE))
52 len = SHA256_DIGEST_SIZE;
54 put_unaligned_be64(key1, key1be);
55 put_unaligned_be64(key2, key2be);
57 /* Generate key xored with ipad */
58 memset(input, 0x36, SHA256_BLOCK_SIZE);
59 for (i = 0; i < 8; i++)
60 input[i] ^= key1be[i];
61 for (i = 0; i < 8; i++)
62 input[i + 8] ^= key2be[i];
64 memcpy(&input[SHA256_BLOCK_SIZE], msg, len);
66 /* emit sha256(K1 || msg) on the second input block, so we can
67 * reuse 'input' for the last hashing
69 sha256(input, SHA256_BLOCK_SIZE + len, &input[SHA256_BLOCK_SIZE]);
71 /* Prepare second part of hmac */
72 memset(input, 0x5C, SHA256_BLOCK_SIZE);
73 for (i = 0; i < 8; i++)
74 input[i] ^= key1be[i];
75 for (i = 0; i < 8; i++)
76 input[i + 8] ^= key2be[i];
78 sha256(input, SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE, hmac);
81 #ifdef CONFIG_MPTCP_HMAC_TEST
88 /* we can't reuse RFC 4231 test vectors, as we have constraint on the
91 static struct test_cast tests[] = {
93 .key = "0b0b0b0b0b0b0b0b",
95 .result = "8385e24fb4235ac37556b6b886db106284a1da671699f46db1f235ec622dcafa",
98 .key = "aaaaaaaaaaaaaaaa",
100 .result = "2c5e219164ff1dca1c4a92318d847bb6b9d44492984e1eb71aff9022f71046e9",
103 .key = "0102030405060708",
105 .result = "e73b9ba9969969cefb04aa0d6df18ec2fcc075b6f23b4d8c4da736a5dbbc6e7d",
109 static int __init test_mptcp_crypto(void)
111 char hmac[32], hmac_hex[65];
117 for (i = 0; i < ARRAY_SIZE(tests); ++i) {
118 /* mptcp hmap will convert to be before computing the hmac */
119 key1 = be64_to_cpu(*((__be64 *)&tests[i].key[0]));
120 key2 = be64_to_cpu(*((__be64 *)&tests[i].key[8]));
121 nonce1 = be32_to_cpu(*((__be32 *)&tests[i].msg[0]));
122 nonce2 = be32_to_cpu(*((__be32 *)&tests[i].msg[4]));
124 put_unaligned_be32(nonce1, &msg[0]);
125 put_unaligned_be32(nonce2, &msg[4]);
127 mptcp_crypto_hmac_sha(key1, key2, msg, 8, hmac);
128 for (j = 0; j < 32; ++j)
129 sprintf(&hmac_hex[j << 1], "%02x", hmac[j] & 0xff);
132 if (memcmp(hmac_hex, tests[i].result, 64))
133 pr_err("test %d failed, got %s expected %s", i,
134 hmac_hex, tests[i].result);
136 pr_info("test %d [ ok ]", i);
141 late_initcall(test_mptcp_crypto);