diff options
Diffstat (limited to 'src/eax.cpp')
-rw-r--r-- | src/eax.cpp | 114 |
1 files changed, 1 insertions, 113 deletions
diff --git a/src/eax.cpp b/src/eax.cpp index c5ae5e9fa..f246a9dea 100644 --- a/src/eax.cpp +++ b/src/eax.cpp @@ -1,5 +1,5 @@ /************************************************* -* EAX Mode Source File * +* EAX Mode Encryption Source File * * (C) 1999-2007 Jack Lloyd * *************************************************/ @@ -191,116 +191,4 @@ void EAX_Encryption::end_msg() position = 0; } -/************************************************* -* EAX_Decryption Constructor * -*************************************************/ -EAX_Decryption::EAX_Decryption(const std::string& cipher_name, - u32bit tag_size) : - EAX_Base(cipher_name, tag_size) - { - queue.create(2*TAG_SIZE + DEFAULT_BUFFERSIZE); - queue_start = queue_end = 0; - } - -/************************************************* -* EAX_Decryption Constructor * -*************************************************/ -EAX_Decryption::EAX_Decryption(const std::string& cipher_name, - const SymmetricKey& key, - const InitializationVector& iv, - u32bit tag_size) : - EAX_Base(cipher_name, tag_size) - { - set_key(key); - set_iv(iv); - queue.create(2*TAG_SIZE + DEFAULT_BUFFERSIZE); - queue_start = queue_end = 0; - } - -/************************************************* -* Decrypt in EAX mode * -*************************************************/ -void EAX_Decryption::write(const byte input[], u32bit length) - { - while(length) - { - const u32bit copied = std::min(length, queue.size() - queue_end); - - queue.copy(queue_end, input, copied); - input += copied; - length -= copied; - queue_end += copied; - - SecureVector<byte> block_buf(cipher->BLOCK_SIZE); - while((queue_end - queue_start) > TAG_SIZE) - { - u32bit removed = (queue_end - queue_start) - TAG_SIZE; - do_write(queue + queue_start, removed); - queue_start += removed; - } - - if(queue_start + TAG_SIZE == queue_end && - queue_start >= queue.size() / 2) - { - SecureVector<byte> queue_data(TAG_SIZE); - queue_data.copy(queue + queue_start, TAG_SIZE); - queue.copy(queue_data, TAG_SIZE); - queue_start = 0; - queue_end = TAG_SIZE; - } - } - } - -/************************************************* -* Decrypt in EAX mode * -*************************************************/ -void EAX_Decryption::do_write(const byte input[], u32bit length) - { - mac->update(input, length); - - u32bit copied = std::min(BLOCK_SIZE - position, length); - xor_buf(buffer + position, input, copied); - send(buffer + position, copied); - input += copied; - length -= copied; - position += copied; - - if(position == BLOCK_SIZE) - increment_counter(); - - while(length >= BLOCK_SIZE) - { - xor_buf(buffer, input, BLOCK_SIZE); - send(buffer, BLOCK_SIZE); - - input += BLOCK_SIZE; - length -= BLOCK_SIZE; - increment_counter(); - } - - xor_buf(buffer + position, input, length); - send(buffer + position, length); - position += length; - } - -/************************************************* -* Finish decrypting in EAX mode * -*************************************************/ -void EAX_Decryption::end_msg() - { - if((queue_end - queue_start) != TAG_SIZE) - throw Integrity_Failure(name() + ": Message authentication failure"); - - SecureVector<byte> data_mac = mac->final(); - - for(u32bit j = 0; j != TAG_SIZE; ++j) - if(queue[queue_start+j] != (data_mac[j] ^ nonce_mac[j] ^ header_mac[j])) - throw Integrity_Failure(name() + ": Message authentication failure"); - - state.clear(); - buffer.clear(); - position = 0; - queue_start = queue_end = 0; - } - } |