Merge generic-gcm method into generic-gmac

4 files changed, 33 insertions, 293 deletions

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 <mschiffer@universe-factory.net>
-  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) {