From 8088a82a2a91d29967cef920ba780eecdf72518e Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Sat, 30 Nov 2013 03:19:38 +0100 Subject: Perform string-based lookup of method-related information only once --- src/methods/generic_poly1305/generic_poly1305.c | 77 +++++++++++-------------- 1 file changed, 34 insertions(+), 43 deletions(-) (limited to 'src/methods/generic_poly1305') diff --git a/src/methods/generic_poly1305/generic_poly1305.c b/src/methods/generic_poly1305/generic_poly1305.c index c40e70f..f84046e 100644 --- a/src/methods/generic_poly1305/generic_poly1305.c +++ b/src/methods/generic_poly1305/generic_poly1305.c @@ -25,6 +25,7 @@ #include "../../crypto.h" +#include "../../method.h" #include "../common.h" #include @@ -33,18 +34,23 @@ #define AUTHBLOCKS 2 +struct fastd_method_context { + const fastd_cipher_info_t *cipher_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; }; -static bool cipher_get(fastd_context_t *ctx, const char *name, const fastd_cipher_info_t **cipher_info, const fastd_cipher_t **cipher) { - size_t len = strlen(name); +static bool method_create_by_name(const char *name, fastd_method_context_t **method_ctx) { + fastd_method_context_t ctx; + size_t len = strlen(name); if (len < 9) return false; @@ -55,54 +61,35 @@ static bool cipher_get(fastd_context_t *ctx, const char *name, const fastd_ciphe memcpy(cipher_name, name, len-9); cipher_name[len-9] = 0; - const fastd_cipher_info_t *info = NULL; - - if (ctx) { - *cipher = fastd_cipher_get_by_name(ctx, cipher_name, &info); - if (!*cipher) - return false; - } - else { - info = fastd_cipher_info_get_by_name(cipher_name); - if (!info) - return false; - } + ctx.cipher_info = fastd_cipher_info_get_by_name(cipher_name); + if (!ctx.cipher_info) + return false; - if (info->iv_length <= COMMON_NONCEBYTES) + if (ctx.cipher_info->iv_length <= COMMON_NONCEBYTES) return false; - if (cipher_info) - *cipher_info = info; + *method_ctx = malloc(sizeof(fastd_method_context_t)); + **method_ctx = ctx; return true; } - -static bool method_provides(const char *name) { - return cipher_get(NULL, name, NULL, NULL); +static void method_destroy(fastd_method_context_t *method_ctx) { + free(method_ctx); } -static size_t method_key_length(fastd_context_t *ctx, const char *name) { - const fastd_cipher_info_t *cipher_info; - if (!cipher_get(NULL, name, &cipher_info, NULL)) - exit_bug(ctx, "generic-poly1305: can't get cipher key length"); - - return 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; } -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); - - if (!cipher_get(ctx, name, &session->cipher_info, &session->cipher)) - exit_bug(ctx, "generic-poly1305: can't instanciate cipher"); - + session->ctx = method_ctx; + session->cipher = fastd_cipher_get(ctx, session->ctx->cipher_info); session->cipher_state = session->cipher->init(ctx, secret); - if (session->cipher_info->iv_length <= COMMON_NONCEBYTES) - exit_bug(ctx, "generic-poly1305: iv_length to small"); - return session; } @@ -139,10 +126,11 @@ static bool method_encrypt(fastd_context_t *ctx, fastd_peer_t *peer UNUSED, fast if (tail_len) memset(in.data+in.len, 0, tail_len); - uint8_t nonce[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]; + 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; int n_blocks = block_count(in.len, sizeof(fastd_block128_t)); @@ -186,10 +174,11 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho if (((const uint8_t*)in.data)[COMMON_NONCEBYTES]) /* flags */ return false; - uint8_t nonce[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]; + memset(nonce, 0, iv_length); memcpy(nonce, in.data, COMMON_NONCEBYTES); - nonce[session->cipher_info->iv_length-1] = 1; + nonce[iv_length-1] = 1; int64_t age; if (!fastd_method_is_nonce_valid(ctx, &session->common, nonce, &age)) @@ -245,15 +234,17 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho } const fastd_method_t fastd_method_generic_poly1305 = { - .provides = method_provides, - .max_overhead = COMMON_HEADBYTES + crypto_onetimeauth_poly1305_BYTES, .min_encrypt_head_space = AUTHBLOCKS*sizeof(fastd_block128_t), .min_decrypt_head_space = AUTHBLOCKS*sizeof(fastd_block128_t) - crypto_onetimeauth_poly1305_BYTES, .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, -- cgit v1.2.3