From 9bf498263765328011ee105e5e7b3e1cc1b2bc3f Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Mon, 25 Aug 2014 02:19:32 +0200 Subject: Experimental HMAC-SHA1 implementation This adds experimental support for +hmac-sha1 methods. It currently depends on OpenSSL and is not yet ready for production use. --- src/methods/CMakeLists.txt | 1 + src/methods/generic_hmac_sha1/CMakeLists.txt | 4 + src/methods/generic_hmac_sha1/generic_hmac_sha1.c | 259 ++++++++++++++++++++++ 3 files changed, 264 insertions(+) create mode 100644 src/methods/generic_hmac_sha1/CMakeLists.txt create mode 100644 src/methods/generic_hmac_sha1/generic_hmac_sha1.c (limited to 'src/methods') diff --git a/src/methods/CMakeLists.txt b/src/methods/CMakeLists.txt index f83f7b4..5bdd24c 100644 --- a/src/methods/CMakeLists.txt +++ b/src/methods/CMakeLists.txt @@ -26,6 +26,7 @@ add_subdirectory(null) add_subdirectory(cipher_test) add_subdirectory(composed_gmac) add_subdirectory(generic_gmac) +add_subdirectory(generic_hmac_sha1) add_subdirectory(generic_poly1305) add_subdirectory(xsalsa20_poly1305) diff --git a/src/methods/generic_hmac_sha1/CMakeLists.txt b/src/methods/generic_hmac_sha1/CMakeLists.txt new file mode 100644 index 0000000..b70bc1d --- /dev/null +++ b/src/methods/generic_hmac_sha1/CMakeLists.txt @@ -0,0 +1,4 @@ +fastd_method(generic-hmac-sha1 + generic_hmac_sha1.c +) +fastd_method_link_libraries(generic-hmac-sha1 method_common) diff --git a/src/methods/generic_hmac_sha1/generic_hmac_sha1.c b/src/methods/generic_hmac_sha1/generic_hmac_sha1.c new file mode 100644 index 0000000..530abe3 --- /dev/null +++ b/src/methods/generic_hmac_sha1/generic_hmac_sha1.c @@ -0,0 +1,259 @@ +/* + Copyright (c) 2012-2014, Matthias Schiffer + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + 1. Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + 2. Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +*/ + +/** + \file + + generic-gmac method provider + + generic-gmac can combine any stream cipher with the GMAC authentication. +*/ + + +#include "../../crypto.h" +#include "../../method.h" +#include "../common.h" + + +/** A specific method provided by this provider */ +struct fastd_method { + const fastd_cipher_info_t *cipher_info; /**< The cipher used */ + const fastd_mac_info_t *hmac_sha1_info; /**< HMAC-SHA1 */ +}; + +/** The method-specific session state */ +struct fastd_method_session_state { + fastd_method_common_t common; /**< The common method state */ + + const fastd_method_t *method; /**< The specific method used */ + + const fastd_cipher_t *cipher; /**< The cipher implementation used */ + fastd_cipher_state_t *cipher_state; /**< The cipher state */ + + const fastd_mac_t *hmac_sha1; /**< The HMAC-SHA1 implementation */ + fastd_mac_state_t *hmac_sha1_state; /**< The HMAC-SHA1 state */ +}; + + +/** Instanciates a method using a name of the pattern "+hmac-sha1" */ +static bool method_create_by_name(const char *name, fastd_method_t **method) { + fastd_method_t m; + + m.hmac_sha1_info = fastd_mac_info_get_by_name("hmac-sha1"); + if (!m.hmac_sha1_info) + return false; + + size_t len = strlen(name); + if (len < 10) + return false; + + if (strcmp(name+len-10, "+hmac-sha1")) + return false; + + char cipher_name[len-9]; + memcpy(cipher_name, name, len-10); + cipher_name[len-10] = 0; + + m.cipher_info = fastd_cipher_info_get_by_name(cipher_name); + if (!m.cipher_info) + return false; + + *method = fastd_new(fastd_method_t); + **method = m; + + return true; +} + +/** Frees a method */ +static void method_destroy(fastd_method_t *method) { + free(method); +} + +/** Returns the key length used by a method */ +static size_t method_key_length(const fastd_method_t *method) { + return method->cipher_info->key_length + method->hmac_sha1_info->key_length; +} + +/** Initializes a session */ +static fastd_method_session_state_t * method_session_init(const fastd_method_t *method, const uint8_t *secret, bool initiator) { + fastd_method_session_state_t *session = fastd_new(fastd_method_session_state_t); + + fastd_method_common_init(&session->common, initiator); + session->method = method; + + session->cipher = fastd_cipher_get(method->cipher_info); + session->cipher_state = session->cipher->init(secret); + + session->hmac_sha1 = fastd_mac_get(method->hmac_sha1_info); + session->hmac_sha1_state = session->hmac_sha1->init(secret + method->cipher_info->key_length); + + return session; +} + +/** Checks if the session is currently valid */ +static bool method_session_is_valid(fastd_method_session_state_t *session) { + return (session && fastd_method_session_common_is_valid(&session->common)); +} + +/** Checks if this side is the initator of the session */ +static bool method_session_is_initiator(fastd_method_session_state_t *session) { + return fastd_method_session_common_is_initiator(&session->common); +} + +/** Checks if the session should be refreshed */ +static bool method_session_want_refresh(fastd_method_session_state_t *session) { + return fastd_method_session_common_want_refresh(&session->common); +} + +/** Marks the session as superseded */ +static void method_session_superseded(fastd_method_session_state_t *session) { + fastd_method_session_common_superseded(&session->common); +} + +/** Frees the session state */ +static void method_session_free(fastd_method_session_state_t *session) { + if (session) { + session->cipher->free(session->cipher_state); + session->hmac_sha1->free(session->hmac_sha1_state); + + free(session); + } +} + + +/** Encrypts and authenticates a packet */ +static bool method_encrypt(fastd_peer_t *peer UNUSED, fastd_method_session_state_t *session, fastd_buffer_t *out, fastd_buffer_t in) { + size_t tail_len = alignto(in.len, sizeof(fastd_block128_t))-in.len; + *out = fastd_buffer_alloc(in.len + sizeof(fastd_block128_t), alignto(COMMON_HEADBYTES, 16), sizeof(fastd_block128_t)+tail_len); + + if (tail_len) + memset(in.data+in.len, 0, tail_len); + + uint8_t nonce[session->method->cipher_info->iv_length] __attribute__((aligned(8))); + fastd_method_expand_nonce(nonce, session->common.send_nonce, sizeof(nonce)); + + fastd_block128_t *outblocks = out->data; + fastd_block128_t tag; + + bool ok = session->cipher->crypt(session->cipher_state, outblocks+1, in.data, in.len, nonce); + + if (ok) { + fastd_method_expand_nonce(out->data, session->common.send_nonce, sizeof(fastd_block128_t)); + ok = session->hmac_sha1->digest(session->hmac_sha1_state, &tag, out->data, out->len); + } + + if (!ok) { + fastd_buffer_free(*out); + return false; + } + + outblocks[0] = tag; + + fastd_buffer_free(in); + + fastd_method_put_common_header(out, session->common.send_nonce, 0); + fastd_method_increment_nonce(&session->common); + + return true; +} + +/** Verifies and decrypts a packet */ +static bool method_decrypt(fastd_peer_t *peer, fastd_method_session_state_t *session, fastd_buffer_t *out, fastd_buffer_t in) { + if (in.len < COMMON_HEADBYTES+sizeof(fastd_block128_t)) + return false; + + if (!method_session_is_valid(session)) + return false; + + uint8_t in_nonce[COMMON_NONCEBYTES]; + uint8_t flags; + int64_t age; + if (!fastd_method_handle_common_header(&session->common, &in, in_nonce, &flags, &age)) + return false; + + if (flags) + return false; + + uint8_t nonce[session->method->cipher_info->iv_length] __attribute__((aligned(8))); + fastd_method_expand_nonce(nonce, in_nonce, sizeof(nonce)); + + fastd_block128_t *inblocks = in.data; + fastd_block128_t tag = inblocks[0], tag2; + + fastd_method_expand_nonce(in.data, in_nonce, sizeof(fastd_block128_t)); + bool ok = session->hmac_sha1->digest(session->hmac_sha1_state, &tag2, in.data, in.len); + + if (ok && memcmp(&tag, &tag2, sizeof(fastd_block128_t)) != 0) + ok = false; + + if (ok) { + size_t tail_len = alignto(in.len, sizeof(fastd_block128_t))-in.len; + *out = fastd_buffer_alloc(in.len - sizeof(fastd_block128_t), 0, tail_len); + + ok = session->cipher->crypt(session->cipher_state, out->data, inblocks+1, in.len - sizeof(fastd_block128_t), nonce); + + if (!ok) + fastd_buffer_free(*out); + } + + if (!ok) { + inblocks[0] = tag; + return false; + } + + fastd_buffer_free(in); + + if (!fastd_method_reorder_check(peer, &session->common, in_nonce, age)) { + fastd_buffer_free(*out); + *out = fastd_buffer_alloc(0, 0, 0); + } + + return true; +} + + +/** The generic-hmac-sha1 method provider */ +const fastd_method_provider_t fastd_method_generic_hmac_sha1 = { + .max_overhead = COMMON_HEADBYTES + sizeof(fastd_block128_t), + .min_encrypt_head_space = 0, + .min_decrypt_head_space = 0, + .min_encrypt_tail_space = sizeof(fastd_block128_t)-1, + .min_decrypt_tail_space = sizeof(fastd_block128_t)-1, + + .create_by_name = method_create_by_name, + .destroy = method_destroy, + + .key_length = method_key_length, + + .session_init = method_session_init, + .session_is_valid = method_session_is_valid, + .session_is_initiator = method_session_is_initiator, + .session_want_refresh = method_session_want_refresh, + .session_superseded = method_session_superseded, + .session_free = method_session_free, + + .encrypt = method_encrypt, + .decrypt = method_decrypt, +}; 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