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Diffstat (limited to 'net/mptcp/crypto.c')
| -rw-r--r-- | net/mptcp/crypto.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/net/mptcp/crypto.c b/net/mptcp/crypto.c new file mode 100644 index 000000000000..40d1bb18fd60 --- /dev/null +++ b/net/mptcp/crypto.c @@ -0,0 +1,152 @@ +// 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 |