From a97526d3d39dd1fb284308080a3968443d381b95 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Mon, 18 Nov 2013 21:16:40 +0100 Subject: generic-gmac: some code simplifications --- src/methods/generic_gmac/generic_gmac.c | 30 +++++++++++------------------- 1 file changed, 11 insertions(+), 19 deletions(-) diff --git a/src/methods/generic_gmac/generic_gmac.c b/src/methods/generic_gmac/generic_gmac.c index 4b4109e..c3ad0e6 100644 --- a/src/methods/generic_gmac/generic_gmac.c +++ b/src/methods/generic_gmac/generic_gmac.c @@ -28,6 +28,8 @@ #include "../common.h" +static const fastd_block128_t ZERO_BLOCK = {}; + struct fastd_method_session_state { fastd_method_common_t common; @@ -91,11 +93,7 @@ static size_t method_max_packet_size(fastd_context_t *ctx) { } -static size_t method_min_encrypt_head_space(fastd_context_t *ctx UNUSED) { - return sizeof(fastd_block128_t); -} - -static size_t method_min_decrypt_head_space(fastd_context_t *ctx UNUSED) { +static size_t method_min_head_space(fastd_context_t *ctx UNUSED) { return 0; } @@ -139,13 +137,12 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, c if (session->gmac_ivlen <= COMMON_NONCEBYTES) exit_bug(ctx, "generic-gmac: gmac cipher iv_length to small"); - static const fastd_block128_t zeroblock = {}; fastd_block128_t H; uint8_t zeroiv[session->gmac_ivlen]; memset(zeroiv, 0, session->gmac_ivlen); - session->gmac_cipher->crypt(ctx, session->gmac_cipher_state, &H, &zeroblock, sizeof(fastd_block128_t), zeroiv); + session->gmac_cipher->crypt(ctx, session->gmac_cipher_state, &H, &ZERO_BLOCK, sizeof(fastd_block128_t), zeroiv); session->ghash = fastd_mac_get_by_name(ctx, "ghash", &session->ghash_ctx); if (!session->ghash) @@ -192,11 +189,8 @@ static inline void put_size(fastd_block128_t *out, size_t len) { } 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(ctx, &in, sizeof(fastd_block128_t)); - memset(in.data, 0, 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); + *out = fastd_buffer_alloc(ctx, sizeof(fastd_block128_t)+in.len, alignto(COMMON_HEADBYTES, 16), sizeof(fastd_block128_t)+tail_len); if (tail_len) memset(in.data+in.len, 0, tail_len); @@ -212,7 +206,7 @@ static bool method_encrypt(fastd_context_t *ctx, fastd_peer_t *peer UNUSED, fast memcpy(gmac_nonce, session->common.send_nonce, COMMON_NONCEBYTES); gmac_nonce[session->gmac_ivlen-1] = 1; - bool ok = session->gmac_cipher->crypt(ctx, session->gmac_cipher_state, outblocks, inblocks, sizeof(fastd_block128_t), gmac_nonce); + 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->ivlen]; @@ -222,21 +216,19 @@ static bool method_encrypt(fastd_context_t *ctx, fastd_peer_t *peer UNUSED, fast nonce[session->ivlen-1] = 1; } - ok = session->cipher->crypt(ctx, session->cipher_state, outblocks+1, inblocks+1, (n_blocks-1)*sizeof(fastd_block128_t), nonce); + ok = session->cipher->crypt(ctx, session->cipher_state, outblocks+1, 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)); + put_size(&outblocks[n_blocks+1], in.len); - ok = session->ghash->hash(ctx, session->ghash_state, &sig, outblocks+1, n_blocks); + ok = session->ghash->hash(ctx, session->ghash_state, &sig, outblocks+1, n_blocks+1); } if (!ok) { - /* restore original buffer */ - fastd_buffer_push_head(ctx, &in, sizeof(fastd_block128_t)); fastd_buffer_free(*out); return false; } @@ -329,8 +321,8 @@ const fastd_method_t fastd_method_generic_gmac = { .provides = method_provides, .max_packet_size = method_max_packet_size, - .min_encrypt_head_space = method_min_encrypt_head_space, - .min_decrypt_head_space = method_min_decrypt_head_space, + .min_encrypt_head_space = method_min_head_space, + .min_decrypt_head_space = method_min_head_space, .min_encrypt_tail_space = method_min_encrypt_tail_space, .min_decrypt_tail_space = method_min_decrypt_tail_space, -- cgit v1.2.3