Perform string-based lookup of method-related information only once

1 files changed, 62 insertions, 76 deletions

diff --git a/src/methods/composed_gmac/composed_gmac.c b/src/methods/composed_gmac/composed_gmac.c
index 0705b7d..d1627ee 100644
--- a/src/methods/composed_gmac/composed_gmac.c
+++ b/src/methods/composed_gmac/composed_gmac.c
@@ -25,36 +25,43 @@
 
 
 #include "../../crypto.h"
+#include "../../method.h"
 #include "../common.h"
 
 
 static const fastd_block128_t ZERO_BLOCK = {};
 
+
+struct fastd_method_context {
+	const fastd_cipher_info_t *cipher_info;
+	const fastd_cipher_info_t *gmac_cipher_info;
+	const fastd_mac_info_t *ghash_info;
+};
+
 struct fastd_method_session_state {
 	fastd_method_common_t common;
 
-	const fastd_cipher_info_t *cipher_info;
+	const fastd_method_context_t *ctx;
+
 	const fastd_cipher_t *cipher;
 	fastd_cipher_state_t *cipher_state;
 
-	const fastd_cipher_info_t *gmac_cipher_info;
 	const fastd_cipher_t *gmac_cipher;
 	fastd_cipher_state_t *gmac_cipher_state;
 
-	const fastd_mac_info_t *ghash_info;
 	const fastd_mac_t *ghash;
 	fastd_mac_state_t *ghash_state;
 };
 
 
-static bool cipher_get(fastd_context_t *ctx, const char *name,
-		       const fastd_cipher_info_t **cipher_info, const fastd_cipher_t **cipher,
-		       const fastd_cipher_info_t **gmac_cipher_info, const fastd_cipher_t **gmac_cipher) {
-	if (!fastd_mac_info_get_by_name("ghash"))
+static bool method_create_by_name(const char *name, fastd_method_context_t **method_ctx) {
+	fastd_method_context_t ctx;
+
+	ctx.ghash_info = fastd_mac_info_get_by_name("ghash");
+	if (!ctx.ghash_info)
 		return false;
 
 	size_t len = strlen(name);
-
 	if (len < 5)
 		return false;
 
@@ -73,76 +80,52 @@ static bool cipher_get(fastd_context_t *ctx, const char *name,
 	*gmac_cipher_name = 0;
 	gmac_cipher_name++;
 
-	const fastd_cipher_info_t *info = NULL;
-	const fastd_cipher_info_t *gmac_info = NULL;
-
-	if (ctx) {
-		*cipher = fastd_cipher_get_by_name(ctx, cipher_name, &info);
-		*gmac_cipher = fastd_cipher_get_by_name(ctx, gmac_cipher_name, &gmac_info);
-		if (!(*cipher && *gmac_cipher))
-			return false;
-	}
-	else {
-		info = fastd_cipher_info_get_by_name(cipher_name);
-		gmac_info = fastd_cipher_info_get_by_name(gmac_cipher_name);
-		if (!(info && gmac_info))
-			return false;
-	}
-
-	if (cipher_info)
-		*cipher_info = info;
-
-	if (gmac_cipher_info)
-		*gmac_cipher_info = gmac_info;
-
-	return true;
-}
-
+	ctx.cipher_info = fastd_cipher_info_get_by_name(cipher_name);
+	if (!ctx.cipher_info)
+		return false;
 
-static bool method_provides(const char *name) {
-	const fastd_cipher_info_t *gmac_cipher_info;
+	if (ctx.cipher_info->iv_length && ctx.cipher_info->iv_length <= COMMON_NONCEBYTES)
+		return false;
 
-	if (!cipher_get(NULL, name, NULL, NULL, &gmac_cipher_info, NULL))
+	ctx.gmac_cipher_info = fastd_cipher_info_get_by_name(gmac_cipher_name);
+	if (!ctx.gmac_cipher_info)
 		return false;
 
-	if (gmac_cipher_info->iv_length <= COMMON_NONCEBYTES)
+	if (ctx.gmac_cipher_info->iv_length <= COMMON_NONCEBYTES)
 		return false;
 
+	*method_ctx = malloc(sizeof(fastd_method_context_t));
+	**method_ctx = ctx;
+
 	return true;
 }
 
-static size_t method_key_length(fastd_context_t *ctx, const char *name) {
-	const fastd_cipher_info_t *cipher_info;
-	const fastd_cipher_info_t *gmac_cipher_info;
+static void method_destroy(fastd_method_context_t *method_ctx) {
+	free(method_ctx);
+}
 
-	if (!cipher_get(NULL, name, &cipher_info, NULL, &gmac_cipher_info, NULL))
-		exit_bug(ctx, "composed-gmac: can't get cipher key length");
 
-	return cipher_info->key_length + gmac_cipher_info->key_length;
+static size_t method_key_length(fastd_context_t *ctx UNUSED, const fastd_method_context_t *method_ctx) {
+	return method_ctx->cipher_info->key_length + method_ctx->gmac_cipher_info->key_length;
 }
 
-static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const char *name, const uint8_t *secret, bool initiator) {
+static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const fastd_method_context_t *method_ctx, 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->ctx = method_ctx;
 
-	if (!cipher_get(ctx, name,
-			&session->cipher_info, &session->cipher,
-			&session->gmac_cipher_info, &session->gmac_cipher))
-		exit_bug(ctx, "composed-gmac: can't instanciate cipher");
-
+	session->cipher = fastd_cipher_get(ctx, session->ctx->cipher_info);
 	session->cipher_state = session->cipher->init(ctx, secret);
-	if (session->cipher_info->iv_length && session->cipher_info->iv_length <= COMMON_NONCEBYTES)
-		exit_bug(ctx, "composed-gmac: iv_length to small");
 
-	session->gmac_cipher_state = session->gmac_cipher->init(ctx, secret + session->cipher_info->key_length);
-	if (session->gmac_cipher_info->iv_length <= COMMON_NONCEBYTES)
-		exit_bug(ctx, "composed-gmac: GMAC cipher iv_length to small");
+	session->gmac_cipher = fastd_cipher_get(ctx, session->ctx->gmac_cipher_info);
+	session->gmac_cipher_state = session->gmac_cipher->init(ctx, secret + session->ctx->cipher_info->key_length);
 
 	fastd_block128_t H;
 
-	uint8_t zeroiv[session->gmac_cipher_info->iv_length];
-	memset(zeroiv, 0, session->gmac_cipher_info->iv_length);
+	size_t gmac_iv_length = session->ctx->gmac_cipher_info->iv_length;
+	uint8_t zeroiv[gmac_iv_length];
+	memset(zeroiv, 0, gmac_iv_length);
 
 	if (!session->gmac_cipher->crypt(ctx, session->gmac_cipher_state, &H, &ZERO_BLOCK, sizeof(fastd_block128_t), zeroiv)) {
 		session->cipher->free(ctx, session->cipher_state);
@@ -152,10 +135,7 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, c
 		return NULL;
 	}
 
-	session->ghash = fastd_mac_get_by_name(ctx, "ghash", &session->ghash_info);
-	if (!session->ghash)
-		exit_bug(ctx, "composed-gmac: can't instanciate ghash mac");
-
+	session->ghash = fastd_mac_get(ctx, session->ctx->ghash_info);
 	session->ghash_state = session->ghash->init(ctx, H.b);
 
 	return session;
@@ -209,19 +189,21 @@ static bool method_encrypt(fastd_context_t *ctx, fastd_peer_t *peer UNUSED, fast
 	fastd_block128_t *outblocks = out->data;
 	fastd_block128_t sig;
 
-	uint8_t gmac_nonce[session->gmac_cipher_info->iv_length];
-	memset(gmac_nonce, 0, session->gmac_cipher_info->iv_length);
+	size_t gmac_iv_length = session->ctx->gmac_cipher_info->iv_length;
+	uint8_t gmac_nonce[gmac_iv_length];
+	memset(gmac_nonce, 0, gmac_iv_length);
 	memcpy(gmac_nonce, session->common.send_nonce, COMMON_NONCEBYTES);
-	gmac_nonce[session->gmac_cipher_info->iv_length-1] = 1;
+	gmac_nonce[gmac_iv_length-1] = 1;
 
 	bool ok = session->gmac_cipher->crypt(ctx, session->gmac_cipher_state, outblocks, &ZERO_BLOCK, sizeof(fastd_block128_t), gmac_nonce);
 
 	if (ok) {
-		uint8_t nonce[session->cipher_info->iv_length];
-		if (session->cipher_info->iv_length) {
-			memset(nonce, 0, session->cipher_info->iv_length);
+		size_t iv_length = session->ctx->cipher_info->iv_length;
+		uint8_t nonce[iv_length];
+		if (iv_length) {
+			memset(nonce, 0, iv_length);
 			memcpy(nonce, session->common.send_nonce, COMMON_NONCEBYTES);
-			nonce[session->cipher_info->iv_length-1] = 1;
+			nonce[iv_length-1] = 1;
 		}
 
 		ok = session->cipher->crypt(ctx, session->cipher_state, outblocks+1, inblocks, n_blocks*sizeof(fastd_block128_t), nonce);
@@ -271,16 +253,18 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho
 	if (!fastd_method_is_nonce_valid(ctx, &session->common, common_nonce, &age))
 		return false;
 
-	uint8_t gmac_nonce[session->gmac_cipher_info->iv_length];
-	memset(gmac_nonce, 0, session->gmac_cipher_info->iv_length);
+	size_t gmac_iv_length = session->ctx->gmac_cipher_info->iv_length;
+	uint8_t gmac_nonce[gmac_iv_length];
+	memset(gmac_nonce, 0, gmac_iv_length);
 	memcpy(gmac_nonce, common_nonce, COMMON_NONCEBYTES);
-	gmac_nonce[session->gmac_cipher_info->iv_length-1] = 1;
+	gmac_nonce[gmac_iv_length-1] = 1;
 
-	uint8_t nonce[session->cipher_info->iv_length];
-	if (session->cipher_info->iv_length) {
-		memset(nonce, 0, session->cipher_info->iv_length);
+	size_t iv_length = session->ctx->cipher_info->iv_length;
+	uint8_t nonce[iv_length];
+	if (iv_length) {
+		memset(nonce, 0, iv_length);
 		memcpy(nonce, common_nonce, COMMON_NONCEBYTES);
-		nonce[session->cipher_info->iv_length-1] = 1;
+		nonce[iv_length-1] = 1;
 	}
 
 	fastd_buffer_push_head(ctx, &in, COMMON_HEADBYTES);
@@ -326,15 +310,17 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho
 }
 
 const fastd_method_t fastd_method_composed_gmac = {
-	.provides = method_provides,
-
 	.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 = 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,