From b5112ff67f3dd5bb263f5ca6283f170906acaab6 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Wed, 20 Nov 2013 01:51:12 +0100 Subject: Slightly simplify method/cipher/MAC definitions --- src/methods/generic_gmac/generic_gmac.c | 67 ++++++++++++--------------------- 1 file changed, 25 insertions(+), 42 deletions(-) (limited to 'src/methods/generic_gmac') diff --git a/src/methods/generic_gmac/generic_gmac.c b/src/methods/generic_gmac/generic_gmac.c index c3ad0e6..71ee898 100644 --- a/src/methods/generic_gmac/generic_gmac.c +++ b/src/methods/generic_gmac/generic_gmac.c @@ -36,12 +36,10 @@ struct fastd_method_session_state { const fastd_cipher_t *cipher; const fastd_cipher_context_t *cipher_ctx; fastd_cipher_state_t *cipher_state; - size_t ivlen; const fastd_cipher_t *gmac_cipher; const fastd_cipher_context_t *gmac_cipher_ctx; fastd_cipher_state_t *gmac_cipher_state; - size_t gmac_ivlen; const fastd_mac_t *ghash; const fastd_mac_context_t *ghash_ctx; @@ -93,19 +91,6 @@ static size_t method_max_packet_size(fastd_context_t *ctx) { } -static size_t method_min_head_space(fastd_context_t *ctx UNUSED) { - return 0; -} - -static size_t method_min_encrypt_tail_space(fastd_context_t *ctx UNUSED) { - return (sizeof(fastd_block128_t)-1); -} - -static size_t method_min_decrypt_tail_space(fastd_context_t *ctx UNUSED) { - return (2*sizeof(fastd_block128_t)-1); -} - - static size_t method_key_length(fastd_context_t *ctx, const char *name) { const fastd_cipher_t *cipher = NULL; const fastd_cipher_context_t *cctx; @@ -116,7 +101,7 @@ static size_t method_key_length(fastd_context_t *ctx, const char *name) { if (!cipher_get(ctx, name, &cipher, &cctx, &gmac_cipher, &gmac_cctx)) exit_bug(ctx, "generic-gmac: can't get cipher key length"); - return cipher->key_length(ctx, cctx) + gmac_cipher->key_length(ctx, gmac_cctx); + return cipher->key_length + gmac_cipher->key_length; } static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const char *name, const uint8_t *secret, bool initiator) { @@ -128,19 +113,17 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, c exit_bug(ctx, "generic-gmac: can't instanciate cipher"); session->cipher_state = session->cipher->init_state(ctx, session->cipher_ctx, secret); - session->ivlen = session->cipher->iv_length(ctx, session->cipher_state); - if (session->ivlen && session->ivlen <= COMMON_NONCEBYTES) + if (session->cipher->iv_length && session->cipher->iv_length <= COMMON_NONCEBYTES) exit_bug(ctx, "generic-gmac: iv_length to small"); - session->gmac_cipher_state = session->gmac_cipher->init_state(ctx, session->gmac_cipher_ctx, secret + session->cipher->key_length(ctx, session->cipher_ctx)); - session->gmac_ivlen = session->gmac_cipher->iv_length(ctx, session->gmac_cipher_state); - if (session->gmac_ivlen <= COMMON_NONCEBYTES) - exit_bug(ctx, "generic-gmac: gmac cipher iv_length to small"); + session->gmac_cipher_state = session->gmac_cipher->init_state(ctx, session->gmac_cipher_ctx, secret + session->cipher->key_length); + if (session->gmac_cipher->iv_length <= COMMON_NONCEBYTES) + exit_bug(ctx, "generic-gmac: GMAC cipher iv_length to small"); fastd_block128_t H; - uint8_t zeroiv[session->gmac_ivlen]; - memset(zeroiv, 0, session->gmac_ivlen); + uint8_t zeroiv[session->gmac_cipher->iv_length]; + memset(zeroiv, 0, session->gmac_cipher->iv_length); session->gmac_cipher->crypt(ctx, session->gmac_cipher_state, &H, &ZERO_BLOCK, sizeof(fastd_block128_t), zeroiv); @@ -201,19 +184,19 @@ 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_ivlen]; - memset(gmac_nonce, 0, session->gmac_ivlen); + uint8_t gmac_nonce[session->gmac_cipher->iv_length]; + memset(gmac_nonce, 0, session->gmac_cipher->iv_length); memcpy(gmac_nonce, session->common.send_nonce, COMMON_NONCEBYTES); - gmac_nonce[session->gmac_ivlen-1] = 1; + gmac_nonce[session->gmac_cipher->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->ivlen]; - if (session->ivlen) { - memset(nonce, 0, session->ivlen); + uint8_t nonce[session->cipher->iv_length]; + if (session->cipher->iv_length) { + memset(nonce, 0, session->cipher->iv_length); memcpy(nonce, session->common.send_nonce, COMMON_NONCEBYTES); - nonce[session->ivlen-1] = 1; + nonce[session->cipher->iv_length-1] = 1; } ok = session->cipher->crypt(ctx, session->cipher_state, outblocks+1, inblocks, n_blocks*sizeof(fastd_block128_t), nonce); @@ -263,16 +246,16 @@ 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_ivlen]; - memset(gmac_nonce, 0, session->gmac_ivlen); + uint8_t gmac_nonce[session->gmac_cipher->iv_length]; + memset(gmac_nonce, 0, session->gmac_cipher->iv_length); memcpy(gmac_nonce, common_nonce, COMMON_NONCEBYTES); - gmac_nonce[session->gmac_ivlen-1] = 1; + gmac_nonce[session->gmac_cipher->iv_length-1] = 1; - uint8_t nonce[session->ivlen]; - if (session->ivlen) { - memset(nonce, 0, session->ivlen); + uint8_t nonce[session->cipher->iv_length]; + if (session->cipher->iv_length) { + memset(nonce, 0, session->cipher->iv_length); memcpy(nonce, common_nonce, COMMON_NONCEBYTES); - nonce[session->ivlen-1] = 1; + nonce[session->cipher->iv_length-1] = 1; } fastd_buffer_push_head(ctx, &in, COMMON_HEADBYTES); @@ -321,10 +304,10 @@ const fastd_method_t fastd_method_generic_gmac = { .provides = method_provides, .max_packet_size = method_max_packet_size, - .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, + .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, .key_length = method_key_length, .session_init = method_session_init, -- cgit v1.2.3