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authorMatthias Schiffer <mschiffer@universe-factory.net>2013-11-29 06:18:26 +0100
committerMatthias Schiffer <mschiffer@universe-factory.net>2013-11-29 06:18:26 +0100
commit3cd025bb177388556ddaf20e45c0e0ae6b7f7e22 (patch)
tree5b8db87b757db7de5cf34e5433bdebe72fd004d3 /src/methods/generic_gmac/generic_gmac.c
parentf04696e7451f787112e35ac184ff5057f45269eb (diff)
downloadfastd-3cd025bb177388556ddaf20e45c0e0ae6b7f7e22.tar
fastd-3cd025bb177388556ddaf20e45c0e0ae6b7f7e22.zip
generic-gmac: use HKDF expansion instead of the stream cipher to generate H
Diffstat (limited to 'src/methods/generic_gmac/generic_gmac.c')
-rw-r--r--src/methods/generic_gmac/generic_gmac.c12
1 files changed, 2 insertions, 10 deletions
diff --git a/src/methods/generic_gmac/generic_gmac.c b/src/methods/generic_gmac/generic_gmac.c
index d42b2c4..5501076 100644
--- a/src/methods/generic_gmac/generic_gmac.c
+++ b/src/methods/generic_gmac/generic_gmac.c
@@ -94,7 +94,7 @@ static size_t method_key_length(fastd_context_t *ctx, const char *name) {
if (!cipher_get(NULL, name, &cipher_info, NULL, NULL))
exit_bug(ctx, "generic-gmac: can't get cipher key length");
- return cipher_info->key_length;
+ return cipher_info->key_length + sizeof(fastd_block128_t);
}
static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const char *name, const uint8_t *secret, bool initiator) {
@@ -107,22 +107,14 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, c
session->cipher_state = session->cipher->init_state(ctx, session->cipher_ctx, secret);
- static const fastd_block128_t zeroblock = {};
- fastd_block128_t H;
-
if (session->cipher_info->iv_length <= COMMON_NONCEBYTES)
exit_bug(ctx, "generic-gmac: iv_length to small");
- 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_info, &session->ghash_ctx);
if (!session->ghash)
exit_bug(ctx, "generic-gmac: can't instanciate ghash mac");
- session->ghash_state = session->ghash->init_state(ctx, session->ghash_ctx, H.b);
+ session->ghash_state = session->ghash->init_state(ctx, session->ghash_ctx, secret + session->cipher_info->key_length);
return session;
}