From 3d6e771dd203cb6fc693632c4de98e46703f6810 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Thu, 5 Dec 2013 13:52:52 +0100 Subject: Merge generic-gcm method into generic-gmac --- src/methods/CMakeLists.txt | 1 - src/methods/generic_gcm/CMakeLists.txt | 4 - src/methods/generic_gcm/generic_gcm.c | 272 -------------------------------- src/methods/generic_gmac/generic_gmac.c | 49 ++++-- 4 files changed, 33 insertions(+), 293 deletions(-) delete mode 100644 src/methods/generic_gcm/CMakeLists.txt delete mode 100644 src/methods/generic_gcm/generic_gcm.c diff --git a/src/methods/CMakeLists.txt b/src/methods/CMakeLists.txt index 8bd04c8..f83f7b4 100644 --- a/src/methods/CMakeLists.txt +++ b/src/methods/CMakeLists.txt @@ -25,7 +25,6 @@ endmacro(fastd_method_require) add_subdirectory(null) add_subdirectory(cipher_test) add_subdirectory(composed_gmac) -add_subdirectory(generic_gcm) add_subdirectory(generic_gmac) add_subdirectory(generic_poly1305) add_subdirectory(xsalsa20_poly1305) diff --git a/src/methods/generic_gcm/CMakeLists.txt b/src/methods/generic_gcm/CMakeLists.txt deleted file mode 100644 index c50c1ab..0000000 --- a/src/methods/generic_gcm/CMakeLists.txt +++ /dev/null @@ -1,4 +0,0 @@ -fastd_method(generic-gcm - generic_gcm.c -) -fastd_method_link_libraries(generic-gcm method_common) diff --git a/src/methods/generic_gcm/generic_gcm.c b/src/methods/generic_gcm/generic_gcm.c deleted file mode 100644 index f1aebd5..0000000 --- a/src/methods/generic_gcm/generic_gcm.c +++ /dev/null @@ -1,272 +0,0 @@ -/* - Copyright (c) 2012-2013, 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. -*/ - - -#include "../../crypto.h" -#include "../../method.h" -#include "../common.h" - - -struct fastd_method { - const fastd_cipher_info_t *cipher_info; - const fastd_mac_info_t *ghash_info; -}; - -struct fastd_method_session_state { - fastd_method_common_t common; - - const fastd_method_t *method; - - const fastd_cipher_t *cipher; - fastd_cipher_state_t *cipher_state; - - const fastd_mac_t *ghash; - fastd_mac_state_t *ghash_state; -}; - - -static bool method_create_by_name(const char *name, fastd_method_t **method) { - fastd_method_t m; - - m.ghash_info = fastd_mac_info_get_by_name("ghash"); - if (!m.ghash_info) - return false; - - size_t len = strlen(name); - if (len < 4) - return false; - - if (strcmp(name+len-4, "-gcm")) - return false; - - char cipher_name[len+1]; - memcpy(cipher_name, name, len-3); - strncpy(cipher_name+len-3, "ctr", 4); - - m.cipher_info = fastd_cipher_info_get_by_name(cipher_name); - if (!m.cipher_info) - return false; - - if (m.cipher_info->iv_length <= COMMON_NONCEBYTES) - return false; - - *method = malloc(sizeof(fastd_method_t)); - **method = m; - - return true; -} - -static void method_destroy(fastd_method_t *method) { - free(method); -} - -static size_t method_key_length(fastd_context_t *ctx UNUSED, const fastd_method_t *method) { - return method->cipher_info->key_length; -} - -static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const fastd_method_t *method, const uint8_t *secret, bool initiator) { - fastd_method_session_state_t *session = malloc(sizeof(fastd_method_session_state_t)); - - fastd_method_common_init(ctx, &session->common, initiator); - session->method = method; - - session->cipher = fastd_cipher_get(ctx, method->cipher_info); - session->cipher_state = session->cipher->init(secret); - - static const fastd_block128_t zeroblock = {}; - fastd_block128_t H; - - size_t iv_length = method->cipher_info->iv_length; - uint8_t zeroiv[iv_length]; - memset(zeroiv, 0, iv_length); - - if (!session->cipher->crypt(session->cipher_state, &H, &zeroblock, sizeof(fastd_block128_t), zeroiv)) { - session->cipher->free(session->cipher_state); - free(session); - return NULL; - } - - session->ghash = fastd_mac_get(ctx, method->ghash_info); - session->ghash_state = session->ghash->init(H.b); - - return session; -} - -static bool method_session_is_valid(fastd_context_t *ctx, fastd_method_session_state_t *session) { - return (session && fastd_method_session_common_is_valid(ctx, &session->common)); -} - -static bool method_session_is_initiator(fastd_context_t *ctx UNUSED, fastd_method_session_state_t *session) { - return fastd_method_session_common_is_initiator(&session->common); -} - -static bool method_session_want_refresh(fastd_context_t *ctx, fastd_method_session_state_t *session) { - return fastd_method_session_common_want_refresh(ctx, &session->common); -} - -static void method_session_superseded(fastd_context_t *ctx, fastd_method_session_state_t *session) { - fastd_method_session_common_superseded(ctx, &session->common); -} - -static void method_session_free(fastd_context_t *ctx UNUSED, fastd_method_session_state_t *session) { - if (session) { - session->cipher->free(session->cipher_state); - session->ghash->free(session->ghash_state); - - free(session); - } -} - -static inline void put_size(fastd_block128_t *out, size_t len) { - memset(out, 0, sizeof(fastd_block128_t)-5); - out->b[sizeof(fastd_block128_t)-5] = len >> 29; - out->b[sizeof(fastd_block128_t)-4] = len >> 21; - out->b[sizeof(fastd_block128_t)-3] = len >> 13; - out->b[sizeof(fastd_block128_t)-2] = len >> 5; - out->b[sizeof(fastd_block128_t)-1] = len << 3; -} - -static bool method_encrypt(fastd_context_t *ctx, fastd_peer_t *peer UNUSED, fastd_method_session_state_t *session, fastd_buffer_t *out, fastd_buffer_t in) { - fastd_buffer_pull_head_zero(ctx, &in, sizeof(fastd_block128_t)); - - size_t tail_len = alignto(in.len, sizeof(fastd_block128_t))-in.len; - *out = fastd_buffer_alloc(ctx, in.len, 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]; - fastd_method_expand_nonce(nonce, session->common.send_nonce, sizeof(nonce)); - - int n_blocks = block_count(in.len, sizeof(fastd_block128_t)); - - fastd_block128_t *inblocks = in.data; - fastd_block128_t *outblocks = out->data; - fastd_block128_t tag; - - bool ok = session->cipher->crypt(session->cipher_state, outblocks, inblocks, n_blocks*sizeof(fastd_block128_t), nonce); - - if (ok) { - if (tail_len) - memset(out->data+out->len, 0, tail_len); - - put_size(&outblocks[n_blocks], in.len-sizeof(fastd_block128_t)); - - ok = session->ghash->hash(session->ghash_state, &tag, outblocks+1, n_blocks); - } - - if (!ok) { - fastd_buffer_free(*out); - return false; - } - - xor_a(&outblocks[0], &tag); - - fastd_buffer_free(in); - - fastd_method_put_common_header(ctx, out, session->common.send_nonce, 0); - fastd_method_increment_nonce(&session->common); - - return true; -} - -static bool method_decrypt(fastd_context_t *ctx, 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(ctx, session)) - return false; - - uint8_t in_nonce[COMMON_NONCEBYTES]; - uint8_t flags; - int64_t age; - if (!fastd_method_handle_common_header(ctx, &session->common, &in, in_nonce, &flags, &age)) - return false; - - if (flags) - return false; - - uint8_t nonce[session->method->cipher_info->iv_length]; - fastd_method_expand_nonce(nonce, in_nonce, sizeof(nonce)); - - size_t tail_len = alignto(in.len, sizeof(fastd_block128_t))-in.len; - *out = fastd_buffer_alloc(ctx, in.len, 0, tail_len); - - int n_blocks = block_count(in.len, sizeof(fastd_block128_t)); - - fastd_block128_t *inblocks = in.data; - fastd_block128_t *outblocks = out->data; - fastd_block128_t tag; - - bool ok = session->cipher->crypt(session->cipher_state, outblocks, inblocks, n_blocks*sizeof(fastd_block128_t), nonce); - - if (ok) { - if (tail_len) - memset(in.data+in.len, 0, tail_len); - - put_size(&inblocks[n_blocks], in.len-sizeof(fastd_block128_t)); - - ok = session->ghash->hash(session->ghash_state, &tag, inblocks+1, n_blocks); - } - - if (!ok || memcmp(&tag, &outblocks[0], sizeof(fastd_block128_t)) != 0) { - fastd_buffer_free(*out); - return false; - } - - fastd_buffer_free(in); - - fastd_buffer_push_head(ctx, out, sizeof(fastd_block128_t)); - - if (!fastd_method_reorder_check(ctx, peer, &session->common, in_nonce, age)) { - fastd_buffer_free(*out); - *out = fastd_buffer_alloc(ctx, 0, 0, 0); - } - - return true; -} - -const fastd_method_provider_t fastd_method_generic_gcm = { - .max_overhead = COMMON_HEADBYTES + sizeof(fastd_block128_t), - .min_encrypt_head_space = sizeof(fastd_block128_t), - .min_decrypt_head_space = 0, - .min_encrypt_tail_space = sizeof(fastd_block128_t)-1, - .min_decrypt_tail_space = 2*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, -}; diff --git a/src/methods/generic_gmac/generic_gmac.c b/src/methods/generic_gmac/generic_gmac.c index f1d98ca..0580e1a 100644 --- a/src/methods/generic_gmac/generic_gmac.c +++ b/src/methods/generic_gmac/generic_gmac.c @@ -55,18 +55,22 @@ static bool method_create_by_name(const char *name, fastd_method_t **method) { return false; size_t len = strlen(name); - if (len < 5) - return false; + char cipher_name[len+1]; - if (strcmp(name+len-5, "+gmac")) - return false; + if (len >= 4 && !strcmp(name+len-4, "-gcm")) { + memcpy(cipher_name, name, len-3); + strncpy(cipher_name+len-3, "ctr", 4); + } + else if (len >= 5 && !strcmp(name+len-5, "+gmac")) { + if (len >= 9 && !strcmp(name+len-9, "-ctr+gmac")) + return false; - if (len >= 9 && !strcmp(name+len-9, "-ctr+gmac")) + memcpy(cipher_name, name, len-5); + cipher_name[len-5] = 0; + } + else { return false; - - char cipher_name[len-4]; - memcpy(cipher_name, name, len-5); - cipher_name[len-5] = 0; + } m.cipher_info = fastd_cipher_info_get_by_name(cipher_name); if (!m.cipher_info) @@ -86,7 +90,7 @@ static void method_destroy(fastd_method_t *method) { } static size_t method_key_length(fastd_context_t *ctx UNUSED, const fastd_method_t *method) { - return method->cipher_info->key_length + method->ghash_info->key_length; + return method->cipher_info->key_length; } static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const fastd_method_t *method, const uint8_t *secret, bool initiator) { @@ -98,8 +102,21 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, c session->cipher = fastd_cipher_get(ctx, method->cipher_info); session->cipher_state = session->cipher->init(secret); + static const fastd_block128_t zeroblock = {}; + fastd_block128_t H; + + size_t iv_length = method->cipher_info->iv_length; + uint8_t zeroiv[iv_length]; + memset(zeroiv, 0, iv_length); + + if (!session->cipher->crypt(session->cipher_state, &H, &zeroblock, sizeof(fastd_block128_t), zeroiv)) { + session->cipher->free(session->cipher_state); + free(session); + return NULL; + } + session->ghash = fastd_mac_get(ctx, method->ghash_info); - session->ghash_state = session->ghash->init(secret + method->cipher_info->key_length); + session->ghash_state = session->ghash->init(H.b); return session; } @@ -131,11 +148,11 @@ static void method_session_free(fastd_context_t *ctx UNUSED, fastd_method_sessio static inline void put_size(fastd_block128_t *out, size_t len) { memset(out, 0, sizeof(fastd_block128_t)); - out->b[3] = len >> 29; - out->b[4] = len >> 21; - out->b[5] = len >> 13; - out->b[6] = len >> 5; - out->b[7] = len << 3; + out->b[11] = len >> 29; + out->b[12] = len >> 21; + out->b[13] = len >> 13; + out->b[14] = len >> 5; + out->b[15] = len << 3; } static bool method_encrypt(fastd_context_t *ctx, fastd_peer_t *peer UNUSED, fastd_method_session_state_t *session, fastd_buffer_t *out, fastd_buffer_t in) { -- cgit v1.2.3