diff options
Diffstat (limited to 'src/methods/generic_gcm')
| -rw-r--r-- | src/methods/generic_gcm/generic_gcm.c | 53 |
1 files changed, 33 insertions, 20 deletions
diff --git a/src/methods/generic_gcm/generic_gcm.c b/src/methods/generic_gcm/generic_gcm.c index ba8729a..8ae9dbe 100644 --- a/src/methods/generic_gcm/generic_gcm.c +++ b/src/methods/generic_gcm/generic_gcm.c @@ -32,16 +32,17 @@ struct fastd_method_session_state { fastd_method_common_t common; const fastd_cipher_t *cipher; - fastd_cipher_context_t *cipher_ctx; + const fastd_cipher_context_t *cipher_ctx; fastd_cipher_state_t *cipher_state; + size_t ivlen; const fastd_mac_t *ghash; - fastd_mac_context_t *ghash_ctx; + 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, fastd_cipher_context_t **cctx) { +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")) return false; @@ -93,8 +94,13 @@ static size_t method_min_decrypt_tail_space(fastd_context_t *ctx UNUSED) { } -static size_t method_key_length(fastd_context_t *ctx UNUSED) { - return sizeof(fastd_block128_t); +static size_t method_key_length(fastd_context_t *ctx, const char *name) { + const fastd_cipher_t *cipher; + const fastd_cipher_context_t *cctx; + if (!cipher_get(ctx, name, &cipher, &cctx)) + exit_bug(ctx, "generic-gcm: can't get cipher key length"); + + return cipher->key_length(ctx, cctx); } static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const char *name, const uint8_t *secret, bool initiator) { @@ -110,7 +116,14 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, c static const fastd_block128_t zeroblock = {}; fastd_block128_t H; - session->cipher->crypt(ctx, session->cipher_state, &H, &zeroblock, sizeof(fastd_block128_t), &zeroblock); + session->ivlen = session->cipher->iv_length(ctx, session->cipher_state); + if (session->ivlen <= COMMON_NONCEBYTES) + exit_bug(ctx, "generic-gcm: iv_length to small"); + + uint8_t zeroiv[session->ivlen]; + memset(zeroiv, 0, session->ivlen); + + 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); if (!session->ghash) @@ -173,18 +186,18 @@ 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); - fastd_block128_t nonce; - memcpy(nonce.b, session->common.send_nonce, COMMON_NONCEBYTES); - memset(nonce.b+COMMON_NONCEBYTES, 0, sizeof(fastd_block128_t)-COMMON_NONCEBYTES-1); - nonce.b[sizeof(fastd_block128_t)-1] = 1; + uint8_t nonce[session->ivlen]; + memset(nonce, 0, session->ivlen); + memcpy(nonce, session->common.send_nonce, COMMON_NONCEBYTES); + nonce[session->ivlen-1] = 1; - int n_blocks = (in.len+sizeof(fastd_block128_t)-1)/sizeof(fastd_block128_t); + int n_blocks = block_count(in.len, sizeof(fastd_block128_t)); fastd_block128_t *inblocks = in.data; fastd_block128_t *outblocks = out->data; fastd_block128_t sig; - bool ok = session->cipher->crypt(ctx, session->cipher_state, outblocks, inblocks, n_blocks*sizeof(fastd_block128_t), &nonce); + bool ok = session->cipher->crypt(ctx, session->cipher_state, outblocks, inblocks, n_blocks*sizeof(fastd_block128_t), nonce); if (ok) { if (tail_len) @@ -220,13 +233,13 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho if (!method_session_is_valid(ctx, session)) return false; - fastd_block128_t nonce; - memcpy(nonce.b, in.data, COMMON_NONCEBYTES); - memset(nonce.b+COMMON_NONCEBYTES, 0, sizeof(fastd_block128_t)-COMMON_NONCEBYTES-1); - nonce.b[sizeof(fastd_block128_t)-1] = 1; + uint8_t nonce[session->ivlen]; + memset(nonce, 0, session->ivlen); + memcpy(nonce, in.data, COMMON_NONCEBYTES); + nonce[session->ivlen-1] = 1; int64_t age; - if (!fastd_method_is_nonce_valid(ctx, &session->common, nonce.b, &age)) + if (!fastd_method_is_nonce_valid(ctx, &session->common, nonce, &age)) return false; fastd_buffer_push_head(ctx, &in, COMMON_NONCEBYTES); @@ -234,13 +247,13 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho size_t tail_len = alignto(in.len, sizeof(fastd_block128_t))-in.len; *out = fastd_buffer_alloc(ctx, in.len, 0, tail_len); - int n_blocks = (in.len+sizeof(fastd_block128_t)-1)/sizeof(fastd_block128_t); + int n_blocks = block_count(in.len, sizeof(fastd_block128_t)); fastd_block128_t *inblocks = in.data; fastd_block128_t *outblocks = out->data; fastd_block128_t sig; - bool ok = session->cipher->crypt(ctx, session->cipher_state, outblocks, inblocks, n_blocks*sizeof(fastd_block128_t), &nonce); + bool ok = session->cipher->crypt(ctx, session->cipher_state, outblocks, inblocks, n_blocks*sizeof(fastd_block128_t), nonce); if (ok) { if (tail_len) @@ -260,7 +273,7 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho fastd_buffer_push_head(ctx, out, sizeof(fastd_block128_t)); - if (!fastd_method_reorder_check(ctx, peer, &session->common, nonce.b, age)) { + if (!fastd_method_reorder_check(ctx, peer, &session->common, nonce, age)) { fastd_buffer_free(*out); *out = fastd_buffer_alloc(ctx, 0, 0, 0); } |