// SPDX-License-Identifier: GPL-2.0 /* Multipath TCP cryptographic functions * Copyright (c) 2017 - 2019, Intel Corporation. * * Note: This code is based on mptcp_ctrl.c, mptcp_ipv4.c, and * mptcp_ipv6 from multipath-tcp.org, authored by: * * Sébastien Barré <sebastien.barre@uclouvain.be> * Christoph Paasch <christoph.paasch@uclouvain.be> * Jaakko Korkeaniemi <jaakko.korkeaniemi@aalto.fi> * Gregory Detal <gregory.detal@uclouvain.be> * Fabien Duchêne <fabien.duchene@uclouvain.be> * Andreas Seelinger <Andreas.Seelinger@rwth-aachen.de> * Lavkesh Lahngir <lavkesh51@gmail.com> * Andreas Ripke <ripke@neclab.eu> * Vlad Dogaru <vlad.dogaru@intel.com> * Octavian Purdila <octavian.purdila@intel.com> * John Ronan <jronan@tssg.org> * Catalin Nicutar <catalin.nicutar@gmail.com> * Brandon Heller <brandonh@stanford.edu> */ #include <linux/kernel.h> #include <crypto/sha.h> #include <asm/unaligned.h> #include "protocol.h" #define SHA256_DIGEST_WORDS (SHA256_DIGEST_SIZE / 4) void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn) { __be32 mptcp_hashed_key[SHA256_DIGEST_WORDS]; __be64 input = cpu_to_be64(key); struct sha256_state state; sha256_init(&state); sha256_update(&state, (__force u8 *)&input, sizeof(input)); sha256_final(&state, (u8 *)mptcp_hashed_key); if (token) *token = be32_to_cpu(mptcp_hashed_key[0]); if (idsn) *idsn = be64_to_cpu(*((__be64 *)&mptcp_hashed_key[6])); } void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u32 nonce1, u32 nonce2, void *hmac) { u8 input[SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE]; __be32 mptcp_hashed_key[SHA256_DIGEST_WORDS]; __be32 *hash_out = (__force __be32 *)hmac; struct sha256_state state; u8 key1be[8]; u8 key2be[8]; int i; put_unaligned_be64(key1, key1be); put_unaligned_be64(key2, key2be); /* Generate key xored with ipad */ memset(input, 0x36, SHA_MESSAGE_BYTES); for (i = 0; i < 8; i++) input[i] ^= key1be[i]; for (i = 0; i < 8; i++) input[i + 8] ^= key2be[i]; put_unaligned_be32(nonce1, &input[SHA256_BLOCK_SIZE]); put_unaligned_be32(nonce2, &input[SHA256_BLOCK_SIZE + 4]); sha256_init(&state); sha256_update(&state, input, SHA256_BLOCK_SIZE + 8); /* emit sha256(K1 || msg) on the second input block, so we can * reuse 'input' for the last hashing */ sha256_final(&state, &input[SHA256_BLOCK_SIZE]); /* Prepare second part of hmac */ memset(input, 0x5C, SHA_MESSAGE_BYTES); for (i = 0; i < 8; i++) input[i] ^= key1be[i]; for (i = 0; i < 8; i++) input[i + 8] ^= key2be[i]; sha256_init(&state); sha256_update(&state, input, SHA256_BLOCK_SIZE + SHA256_DIGEST_SIZE); sha256_final(&state, (u8 *)mptcp_hashed_key); /* takes only first 160 bits */ for (i = 0; i < 5; i++) hash_out[i] = mptcp_hashed_key[i]; } #ifdef CONFIG_MPTCP_HMAC_TEST struct test_cast { char *key; char *msg; char *result; }; /* we can't reuse RFC 4231 test vectors, as we have constraint on the * input and key size, and we truncate the output. */ static struct test_cast tests[] = { { .key = "0b0b0b0b0b0b0b0b", .msg = "48692054", .result = "8385e24fb4235ac37556b6b886db106284a1da67", }, { .key = "aaaaaaaaaaaaaaaa", .msg = "dddddddd", .result = "2c5e219164ff1dca1c4a92318d847bb6b9d44492", }, { .key = "0102030405060708", .msg = "cdcdcdcd", .result = "e73b9ba9969969cefb04aa0d6df18ec2fcc075b6", }, }; static int __init test_mptcp_crypto(void) { char hmac[20], hmac_hex[41]; u32 nonce1, nonce2; u64 key1, key2; int i, j; for (i = 0; i < ARRAY_SIZE(tests); ++i) { /* mptcp hmap will convert to be before computing the hmac */ key1 = be64_to_cpu(*((__be64 *)&tests[i].key[0])); key2 = be64_to_cpu(*((__be64 *)&tests[i].key[8])); nonce1 = be32_to_cpu(*((__be32 *)&tests[i].msg[0])); nonce2 = be32_to_cpu(*((__be32 *)&tests[i].msg[4])); mptcp_crypto_hmac_sha(key1, key2, nonce1, nonce2, hmac); for (j = 0; j < 20; ++j) sprintf(&hmac_hex[j << 1], "%02x", hmac[j] & 0xff); hmac_hex[40] = 0; if (memcmp(hmac_hex, tests[i].result, 40)) pr_err("test %d failed, got %s expected %s", i, hmac_hex, tests[i].result); else pr_info("test %d [ ok ]", i); } return 0; } late_initcall(test_mptcp_crypto); #endif