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);
35 struct sha256_state state;
38 sha256_update(&state, (__force u8 *)&input, sizeof(input));
39 sha256_final(&state, (u8 *)mptcp_hashed_key);
42 *token = be32_to_cpu(mptcp_hashed_key[0]);
44 *idsn = be64_to_cpu(*((__be64 *)&mptcp_hashed_key[6]));
47 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
50 u8 input[SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE];
51 __be32 mptcp_hashed_key[SHA256_DIGEST_WORDS];
52 __be32 *hash_out = (__force __be32 *)hmac;
53 struct sha256_state state;
58 put_unaligned_be64(key1, key1be);
59 put_unaligned_be64(key2, key2be);
61 /* Generate key xored with ipad */
62 memset(input, 0x36, SHA_MESSAGE_BYTES);
63 for (i = 0; i < 8; i++)
64 input[i] ^= key1be[i];
65 for (i = 0; i < 8; i++)
66 input[i + 8] ^= key2be[i];
68 put_unaligned_be32(nonce1, &input[SHA256_BLOCK_SIZE]);
69 put_unaligned_be32(nonce2, &input[SHA256_BLOCK_SIZE + 4]);
72 sha256_update(&state, input, SHA256_BLOCK_SIZE + 8);
74 /* emit sha256(K1 || msg) on the second input block, so we can
75 * reuse 'input' for the last hashing
77 sha256_final(&state, &input[SHA256_BLOCK_SIZE]);
79 /* Prepare second part of hmac */
80 memset(input, 0x5C, SHA_MESSAGE_BYTES);
81 for (i = 0; i < 8; i++)
82 input[i] ^= key1be[i];
83 for (i = 0; i < 8; i++)
84 input[i + 8] ^= key2be[i];
87 sha256_update(&state, input, SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE);
88 sha256_final(&state, (u8 *)mptcp_hashed_key);
90 /* takes only first 160 bits */
91 for (i = 0; i < 5; i++)
92 hash_out[i] = mptcp_hashed_key[i];
95 #ifdef CONFIG_MPTCP_HMAC_TEST
102 /* we can't reuse RFC 4231 test vectors, as we have constraint on the
103 * input and key size, and we truncate the output.
105 static struct test_cast tests[] = {
107 .key = "0b0b0b0b0b0b0b0b",
109 .result = "8385e24fb4235ac37556b6b886db106284a1da67",
112 .key = "aaaaaaaaaaaaaaaa",
114 .result = "2c5e219164ff1dca1c4a92318d847bb6b9d44492",
117 .key = "0102030405060708",
119 .result = "e73b9ba9969969cefb04aa0d6df18ec2fcc075b6",
123 static int __init test_mptcp_crypto(void)
125 char hmac[20], hmac_hex[41];
130 for (i = 0; i < ARRAY_SIZE(tests); ++i) {
131 /* mptcp hmap will convert to be before computing the hmac */
132 key1 = be64_to_cpu(*((__be64 *)&tests[i].key[0]));
133 key2 = be64_to_cpu(*((__be64 *)&tests[i].key[8]));
134 nonce1 = be32_to_cpu(*((__be32 *)&tests[i].msg[0]));
135 nonce2 = be32_to_cpu(*((__be32 *)&tests[i].msg[4]));
137 mptcp_crypto_hmac_sha(key1, key2, nonce1, nonce2, hmac);
138 for (j = 0; j < 20; ++j)
139 sprintf(&hmac_hex[j << 1], "%02x", hmac[j] & 0xff);
142 if (memcmp(hmac_hex, tests[i].result, 40))
143 pr_err("test %d failed, got %s expected %s", i,
144 hmac_hex, tests[i].result);
146 pr_info("test %d [ ok ]", i);
151 late_initcall(test_mptcp_crypto);