From c62a0f592c49b41d393fae580ce9f1293ee7a16d Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Mon, 25 Nov 2013 23:18:11 +0100 Subject: Move crypto algorithm information out of implementation --- src/methods/generic_gcm/generic_gcm.c | 56 ++++++++++++++++++++++------------- 1 file changed, 35 insertions(+), 21 deletions(-) (limited to 'src/methods/generic_gcm') diff --git a/src/methods/generic_gcm/generic_gcm.c b/src/methods/generic_gcm/generic_gcm.c index 5d3f6c4..a92ad1e 100644 --- a/src/methods/generic_gcm/generic_gcm.c +++ b/src/methods/generic_gcm/generic_gcm.c @@ -31,18 +31,20 @@ struct fastd_method_session_state { fastd_method_common_t common; + const fastd_cipher_info_t *cipher_info; const fastd_cipher_t *cipher; const fastd_cipher_context_t *cipher_ctx; fastd_cipher_state_t *cipher_state; + const fastd_mac_info_t *ghash_info; const fastd_mac_t *ghash; const fastd_mac_context_t *ghash_ctx; fastd_mac_state_t *ghash_state; }; -static bool cipher_get(fastd_context_t *ctx, const char *name, const fastd_cipher_t **cipher, const fastd_cipher_context_t **cctx) { - if (!fastd_mac_available("ghash")) +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_context_t **cctx) { + if (!fastd_mac_info_get_by_name("ghash")) return false; size_t len = strlen(name); @@ -57,27 +59,39 @@ static bool cipher_get(fastd_context_t *ctx, const char *name, const fastd_ciphe memcpy(name_ctr, name, len-3); strncpy(name_ctr+len-3, "ctr", 4); + const fastd_cipher_info_t *info = NULL; + if (ctx) { - *cipher = fastd_cipher_get_by_name(ctx, name_ctr, cctx); - return *cipher; + *cipher = fastd_cipher_get_by_name(ctx, name_ctr, &info, cctx); + if (!*cipher) + return false; } else { - return fastd_cipher_available(name_ctr); + info = fastd_cipher_info_get_by_name(name_ctr); + if (!info) + return false; } + + if (info->iv_length <= COMMON_NONCEBYTES) + return false; + + if (cipher_info) + *cipher_info = info; + + return true; } static bool method_provides(const char *name) { - return cipher_get(NULL, name, NULL, NULL); + return cipher_get(NULL, name, NULL, NULL, NULL); } 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; - if (!cipher_get(ctx, name, &cipher, &cctx)) + const fastd_cipher_info_t *cipher_info; + if (!cipher_get(NULL, name, &cipher_info, NULL, NULL)) exit_bug(ctx, "generic-gcm: can't get cipher key length"); - return cipher->key_length; + return 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) { @@ -85,7 +99,7 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, c fastd_method_common_init(ctx, &session->common, initiator); - if (!cipher_get(ctx, name, &session->cipher, &session->cipher_ctx)) + if (!cipher_get(ctx, name, &session->cipher_info, &session->cipher, &session->cipher_ctx)) exit_bug(ctx, "generic-gcm: can't instanciate cipher"); session->cipher_state = session->cipher->init_state(ctx, session->cipher_ctx, secret); @@ -93,15 +107,15 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, c static const fastd_block128_t zeroblock = {}; fastd_block128_t H; - if (session->cipher->iv_length <= COMMON_NONCEBYTES) + if (session->cipher_info->iv_length <= COMMON_NONCEBYTES) exit_bug(ctx, "generic-gcm: iv_length to small"); - uint8_t zeroiv[session->cipher->iv_length]; - memset(zeroiv, 0, session->cipher->iv_length); + uint8_t zeroiv[session->cipher_info->iv_length]; + memset(zeroiv, 0, session->cipher_info->iv_length); session->cipher->crypt(ctx, session->cipher_state, &H, &zeroblock, sizeof(fastd_block128_t), zeroiv); - session->ghash = fastd_mac_get_by_name(ctx, "ghash", &session->ghash_ctx); + session->ghash = fastd_mac_get_by_name(ctx, "ghash", &session->ghash_info, &session->ghash_ctx); if (!session->ghash) exit_bug(ctx, "generic-gcm: can't instanciate ghash mac"); @@ -161,10 +175,10 @@ 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->iv_length]; - memset(nonce, 0, session->cipher->iv_length); + uint8_t nonce[session->cipher_info->iv_length]; + memset(nonce, 0, session->cipher_info->iv_length); memcpy(nonce, session->common.send_nonce, COMMON_NONCEBYTES); - nonce[session->cipher->iv_length-1] = 1; + nonce[session->cipher_info->iv_length-1] = 1; int n_blocks = block_count(in.len, sizeof(fastd_block128_t)); @@ -214,10 +228,10 @@ 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->iv_length]; - memset(nonce, 0, session->cipher->iv_length); + uint8_t nonce[session->cipher_info->iv_length]; + memset(nonce, 0, session->cipher_info->iv_length); memcpy(nonce, in.data, COMMON_NONCEBYTES); - nonce[session->cipher->iv_length-1] = 1; + nonce[session->cipher_info->iv_length-1] = 1; int64_t age; if (!fastd_method_is_nonce_valid(ctx, &session->common, nonce, &age)) -- cgit v1.2.3