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, u32 nonce1, u32 nonce2, 48 void *hmac) 49 { 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; 54 u8 key1be[8]; 55 u8 key2be[8]; 56 int i; 57 58 put_unaligned_be64(key1, key1be); 59 put_unaligned_be64(key2, key2be); 60 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]; 67 68 put_unaligned_be32(nonce1, &input[SHA256_BLOCK_SIZE]); 69 put_unaligned_be32(nonce2, &input[SHA256_BLOCK_SIZE + 4]); 70 71 sha256_init(&state); 72 sha256_update(&state, input, SHA256_BLOCK_SIZE + 8); 73 74 /* emit sha256(K1 || msg) on the second input block, so we can 75 * reuse 'input' for the last hashing 76 */ 77 sha256_final(&state, &input[SHA256_BLOCK_SIZE]); 78 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]; 85 86 sha256_init(&state); 87 sha256_update(&state, input, SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE); 88 sha256_final(&state, (u8 *)mptcp_hashed_key); 89 90 /* takes only first 160 bits */ 91 for (i = 0; i < 5; i++) 92 hash_out[i] = mptcp_hashed_key[i]; 93 } 94 95 #ifdef CONFIG_MPTCP_HMAC_TEST 96 struct test_cast { 97 char *key; 98 char *msg; 99 char *result; 100 }; 101 102 /* we can't reuse RFC 4231 test vectors, as we have constraint on the 103 * input and key size, and we truncate the output. 104 */ 105 static struct test_cast tests[] = { 106 { 107 .key = "0b0b0b0b0b0b0b0b", 108 .msg = "48692054", 109 .result = "8385e24fb4235ac37556b6b886db106284a1da67", 110 }, 111 { 112 .key = "aaaaaaaaaaaaaaaa", 113 .msg = "dddddddd", 114 .result = "2c5e219164ff1dca1c4a92318d847bb6b9d44492", 115 }, 116 { 117 .key = "0102030405060708", 118 .msg = "cdcdcdcd", 119 .result = "e73b9ba9969969cefb04aa0d6df18ec2fcc075b6", 120 }, 121 }; 122 123 static int __init test_mptcp_crypto(void) 124 { 125 char hmac[20], hmac_hex[41]; 126 u32 nonce1, nonce2; 127 u64 key1, key2; 128 int i, j; 129 130 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])); 136 137 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); 140 hmac_hex[40] = 0; 141 142 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); 145 else 146 pr_info("test %d [ ok ]", i); 147 } 148 return 0; 149 } 150 151 late_initcall(test_mptcp_crypto); 152 #endif 153