1 // SPDX-License-Identifier: GPL-2.0 2 /* Multipath TCP cryptographic functions 3 * Copyright (c) 2017 - 2019, Intel Corporation. 4 * 5 * Note: This code is based on mptcp_ctrl.c, mptcp_ipv4.c, and 6 * mptcp_ipv6 from multipath-tcp.org, authored by: 7 * 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> 21 */ 22 23 #include <linux/kernel.h> 24 #include <crypto/sha.h> 25 #include <asm/unaligned.h> 26 27 #include "protocol.h" 28 29 #define SHA256_DIGEST_WORDS (SHA256_DIGEST_SIZE / 4) 30 31 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn) 32 { 33 __be32 mptcp_hashed_key[SHA256_DIGEST_WORDS]; 34 __be64 input = cpu_to_be64(key); 35 struct sha256_state state; 36 37 sha256_init(&state); 38 sha256_update(&state, (__force u8 *)&input, sizeof(input)); 39 sha256_final(&state, (u8 *)mptcp_hashed_key); 40 41 if (token) 42 *token = be32_to_cpu(mptcp_hashed_key[0]); 43 if (idsn) 44 *idsn = be64_to_cpu(*((__be64 *)&mptcp_hashed_key[6])); 45 } 46 47 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac) 48 { 49 u8 input[SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE]; 50 __be32 mptcp_hashed_key[SHA256_DIGEST_WORDS]; 51 __be32 *hash_out = (__force __be32 *)hmac; 52 struct sha256_state state; 53 u8 key1be[8]; 54 u8 key2be[8]; 55 int i; 56 57 if (WARN_ON_ONCE(len > SHA256_DIGEST_SIZE)) 58 len = SHA256_DIGEST_SIZE; 59 60 put_unaligned_be64(key1, key1be); 61 put_unaligned_be64(key2, key2be); 62 63 /* Generate key xored with ipad */ 64 memset(input, 0x36, SHA_MESSAGE_BYTES); 65 for (i = 0; i < 8; i++) 66 input[i] ^= key1be[i]; 67 for (i = 0; i < 8; i++) 68 input[i + 8] ^= key2be[i]; 69 70 memcpy(&input[SHA256_BLOCK_SIZE], msg, len); 71 72 sha256_init(&state); 73 sha256_update(&state, input, SHA256_BLOCK_SIZE + len); 74 75 /* emit sha256(K1 || msg) on the second input block, so we can 76 * reuse 'input' for the last hashing 77 */ 78 sha256_final(&state, &input[SHA256_BLOCK_SIZE]); 79 80 /* Prepare second part of hmac */ 81 memset(input, 0x5C, SHA_MESSAGE_BYTES); 82 for (i = 0; i < 8; i++) 83 input[i] ^= key1be[i]; 84 for (i = 0; i < 8; i++) 85 input[i + 8] ^= key2be[i]; 86 87 sha256_init(&state); 88 sha256_update(&state, input, SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE); 89 sha256_final(&state, (u8 *)mptcp_hashed_key); 90 91 /* takes only first 160 bits */ 92 for (i = 0; i < 5; i++) 93 hash_out[i] = mptcp_hashed_key[i]; 94 } 95 96 #ifdef CONFIG_MPTCP_HMAC_TEST 97 struct test_cast { 98 char *key; 99 char *msg; 100 char *result; 101 }; 102 103 /* we can't reuse RFC 4231 test vectors, as we have constraint on the 104 * input and key size, and we truncate the output. 105 */ 106 static struct test_cast tests[] = { 107 { 108 .key = "0b0b0b0b0b0b0b0b", 109 .msg = "48692054", 110 .result = "8385e24fb4235ac37556b6b886db106284a1da67", 111 }, 112 { 113 .key = "aaaaaaaaaaaaaaaa", 114 .msg = "dddddddd", 115 .result = "2c5e219164ff1dca1c4a92318d847bb6b9d44492", 116 }, 117 { 118 .key = "0102030405060708", 119 .msg = "cdcdcdcd", 120 .result = "e73b9ba9969969cefb04aa0d6df18ec2fcc075b6", 121 }, 122 }; 123 124 static int __init test_mptcp_crypto(void) 125 { 126 char hmac[20], hmac_hex[41]; 127 u32 nonce1, nonce2; 128 u64 key1, key2; 129 u8 msg[8]; 130 int i, j; 131 132 for (i = 0; i < ARRAY_SIZE(tests); ++i) { 133 /* mptcp hmap will convert to be before computing the hmac */ 134 key1 = be64_to_cpu(*((__be64 *)&tests[i].key[0])); 135 key2 = be64_to_cpu(*((__be64 *)&tests[i].key[8])); 136 nonce1 = be32_to_cpu(*((__be32 *)&tests[i].msg[0])); 137 nonce2 = be32_to_cpu(*((__be32 *)&tests[i].msg[4])); 138 139 put_unaligned_be32(nonce1, &msg[0]); 140 put_unaligned_be32(nonce2, &msg[4]); 141 142 mptcp_crypto_hmac_sha(key1, key2, msg, 8, hmac); 143 for (j = 0; j < 20; ++j) 144 sprintf(&hmac_hex[j << 1], "%02x", hmac[j] & 0xff); 145 hmac_hex[40] = 0; 146 147 if (memcmp(hmac_hex, tests[i].result, 40)) 148 pr_err("test %d failed, got %s expected %s", i, 149 hmac_hex, tests[i].result); 150 else 151 pr_info("test %d [ ok ]", i); 152 } 153 return 0; 154 } 155 156 late_initcall(test_mptcp_crypto); 157 #endif 158