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 36 sha256((__force u8 *)&input, sizeof(input), (u8 *)mptcp_hashed_key); 37 38 if (token) 39 *token = be32_to_cpu(mptcp_hashed_key[0]); 40 if (idsn) 41 *idsn = be64_to_cpu(*((__be64 *)&mptcp_hashed_key[6])); 42 } 43 44 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac) 45 { 46 u8 input[SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE]; 47 u8 key1be[8]; 48 u8 key2be[8]; 49 int i; 50 51 if (WARN_ON_ONCE(len > SHA256_DIGEST_SIZE)) 52 len = SHA256_DIGEST_SIZE; 53 54 put_unaligned_be64(key1, key1be); 55 put_unaligned_be64(key2, key2be); 56 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]; 63 64 memcpy(&input[SHA256_BLOCK_SIZE], msg, len); 65 66 /* emit sha256(K1 || msg) on the second input block, so we can 67 * reuse 'input' for the last hashing 68 */ 69 sha256(input, SHA256_BLOCK_SIZE + len, &input[SHA256_BLOCK_SIZE]); 70 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]; 77 78 sha256(input, SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE, hmac); 79 } 80 81 #if IS_MODULE(CONFIG_MPTCP_KUNIT_TESTS) 82 EXPORT_SYMBOL_GPL(mptcp_crypto_hmac_sha); 83 #endif 84