From 3d6e771dd203cb6fc693632c4de98e46703f6810 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Thu, 5 Dec 2013 13:52:52 +0100 Subject: Merge generic-gcm method into generic-gmac --- src/methods/generic_gmac/generic_gmac.c | 49 ++++++++++++++++++++++----------- 1 file changed, 33 insertions(+), 16 deletions(-) (limited to 'src/methods/generic_gmac/generic_gmac.c') diff --git a/src/methods/generic_gmac/generic_gmac.c b/src/methods/generic_gmac/generic_gmac.c index f1d98ca..0580e1a 100644 --- a/src/methods/generic_gmac/generic_gmac.c +++ b/src/methods/generic_gmac/generic_gmac.c @@ -55,18 +55,22 @@ static bool method_create_by_name(const char *name, fastd_method_t **method) { return false; size_t len = strlen(name); - if (len < 5) - return false; + char cipher_name[len+1]; - if (strcmp(name+len-5, "+gmac")) - return false; + if (len >= 4 && !strcmp(name+len-4, "-gcm")) { + memcpy(cipher_name, name, len-3); + strncpy(cipher_name+len-3, "ctr", 4); + } + else if (len >= 5 && !strcmp(name+len-5, "+gmac")) { + if (len >= 9 && !strcmp(name+len-9, "-ctr+gmac")) + return false; - if (len >= 9 && !strcmp(name+len-9, "-ctr+gmac")) + memcpy(cipher_name, name, len-5); + cipher_name[len-5] = 0; + } + else { return false; - - char cipher_name[len-4]; - memcpy(cipher_name, name, len-5); - cipher_name[len-5] = 0; + } m.cipher_info = fastd_cipher_info_get_by_name(cipher_name); if (!m.cipher_info) @@ -86,7 +90,7 @@ static void method_destroy(fastd_method_t *method) { } static size_t method_key_length(fastd_context_t *ctx UNUSED, const fastd_method_t *method) { - return method->cipher_info->key_length + method->ghash_info->key_length; + return method->cipher_info->key_length; } static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const fastd_method_t *method, const uint8_t *secret, bool initiator) { @@ -98,8 +102,21 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, c session->cipher = fastd_cipher_get(ctx, method->cipher_info); session->cipher_state = session->cipher->init(secret); + static const fastd_block128_t zeroblock = {}; + fastd_block128_t H; + + size_t iv_length = method->cipher_info->iv_length; + uint8_t zeroiv[iv_length]; + memset(zeroiv, 0, iv_length); + + if (!session->cipher->crypt(session->cipher_state, &H, &zeroblock, sizeof(fastd_block128_t), zeroiv)) { + session->cipher->free(session->cipher_state); + free(session); + return NULL; + } + session->ghash = fastd_mac_get(ctx, method->ghash_info); - session->ghash_state = session->ghash->init(secret + method->cipher_info->key_length); + session->ghash_state = session->ghash->init(H.b); return session; } @@ -131,11 +148,11 @@ static void method_session_free(fastd_context_t *ctx UNUSED, fastd_method_sessio static inline void put_size(fastd_block128_t *out, size_t len) { memset(out, 0, sizeof(fastd_block128_t)); - out->b[3] = len >> 29; - out->b[4] = len >> 21; - out->b[5] = len >> 13; - out->b[6] = len >> 5; - out->b[7] = len << 3; + out->b[11] = len >> 29; + out->b[12] = len >> 21; + out->b[13] = len >> 13; + out->b[14] = len >> 5; + out->b[15] = len << 3; } 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) { -- cgit v1.2.3