diff options
Diffstat (limited to 'net/mptcp/crypto.c')
| -rw-r--r-- | net/mptcp/crypto.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/net/mptcp/crypto.c b/net/mptcp/crypto.c new file mode 100644 index 000000000000..bbd6d01af211 --- /dev/null +++ b/net/mptcp/crypto.c @@ -0,0 +1,122 @@ +// 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 <linux/cryptohash.h> +#include <asm/unaligned.h> + +#include "protocol.h" + +struct sha1_state { + u32 workspace[SHA_WORKSPACE_WORDS]; + u32 digest[SHA_DIGEST_WORDS]; + unsigned int count; +}; + +static void sha1_init(struct sha1_state *state) +{ + sha_init(state->digest); + state->count = 0; +} + +static void sha1_update(struct sha1_state *state, u8 *input) +{ + sha_transform(state->digest, input, state->workspace); + state->count += SHA_MESSAGE_BYTES; +} + +static void sha1_pad_final(struct sha1_state *state, u8 *input, + unsigned int length, __be32 *mptcp_hashed_key) +{ + int i; + + input[length] = 0x80; + memset(&input[length + 1], 0, SHA_MESSAGE_BYTES - length - 9); + put_unaligned_be64((length + state->count) << 3, + &input[SHA_MESSAGE_BYTES - 8]); + + sha_transform(state->digest, input, state->workspace); + for (i = 0; i < SHA_DIGEST_WORDS; ++i) + put_unaligned_be32(state->digest[i], &mptcp_hashed_key[i]); + + memzero_explicit(state->workspace, SHA_WORKSPACE_WORDS << 2); +} + +void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn) +{ + __be32 mptcp_hashed_key[SHA_DIGEST_WORDS]; + u8 input[SHA_MESSAGE_BYTES]; + struct sha1_state state; + + sha1_init(&state); + put_unaligned_be64(key, input); + sha1_pad_final(&state, input, 8, mptcp_hashed_key); + + if (token) + *token = be32_to_cpu(mptcp_hashed_key[0]); + if (idsn) + *idsn = be64_to_cpu(*((__be64 *)&mptcp_hashed_key[3])); +} + +void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u32 nonce1, u32 nonce2, + u32 *hash_out) +{ + u8 input[SHA_MESSAGE_BYTES * 2]; + struct sha1_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[SHA_MESSAGE_BYTES]); + put_unaligned_be32(nonce2, &input[SHA_MESSAGE_BYTES + 4]); + + sha1_init(&state); + sha1_update(&state, input); + + /* emit sha256(K1 || msg) on the second input block, so we can + * reuse 'input' for the last hashing + */ + sha1_pad_final(&state, &input[SHA_MESSAGE_BYTES], 8, + (__force __be32 *)&input[SHA_MESSAGE_BYTES]); + + /* 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]; + + sha1_init(&state); + sha1_update(&state, input); + sha1_pad_final(&state, &input[SHA_MESSAGE_BYTES], SHA_DIGEST_WORDS << 2, + (__be32 *)hash_out); +} |