diff options
| author | David Clark <david.a.clark@nokia.com> | 2010-11-18 16:20:48 +1000 |
|---|---|---|
| committer | David Clark <david.a.clark@nokia.com> | 2010-11-18 16:20:48 +1000 |
| commit | c223232bc15106750da632598047a35ad3762723 (patch) | |
| tree | 403f7aa2c3a5a912edce6feae869046c89d29178 /botan/src/modes/eax/eax.cpp | |
| parent | b984b0b62076067f1f75db5a7eda5aaa2cdaad2a (diff) | |
Diffstat (limited to 'botan/src/modes/eax/eax.cpp')
| -rw-r--r-- | botan/src/modes/eax/eax.cpp | 172 |
1 files changed, 0 insertions, 172 deletions
diff --git a/botan/src/modes/eax/eax.cpp b/botan/src/modes/eax/eax.cpp deleted file mode 100644 index 67465a7..0000000 --- a/botan/src/modes/eax/eax.cpp +++ /dev/null @@ -1,172 +0,0 @@ -/* -* EAX Mode Encryption -* (C) 1999-2007 Jack Lloyd -* -* Distributed under the terms of the Botan license -*/ - -#include <botan/eax.h> -#include <botan/cmac.h> -#include <botan/xor_buf.h> -#include <botan/parsing.h> -#include <algorithm> - -namespace Botan { - -namespace { - -/* -* EAX MAC-based PRF -*/ -SecureVector<byte> eax_prf(byte tag, u32bit BLOCK_SIZE, - MessageAuthenticationCode* mac, - const byte in[], u32bit length) - { - for(u32bit j = 0; j != BLOCK_SIZE - 1; ++j) - mac->update(0); - mac->update(tag); - mac->update(in, length); - return mac->final(); - } - -} - -/* -* EAX_Base Constructor -*/ -EAX_Base::EAX_Base(BlockCipher* ciph, - u32bit tag_size) : - TAG_SIZE(tag_size ? tag_size / 8 : ciph->BLOCK_SIZE), - BLOCK_SIZE(ciph->BLOCK_SIZE) - { - cipher = ciph; - mac = new CMAC(cipher->clone()); - - if(tag_size % 8 != 0 || TAG_SIZE == 0 || TAG_SIZE > mac->OUTPUT_LENGTH) - throw Invalid_Argument(name() + ": Bad tag size " + to_string(tag_size)); - - state.create(BLOCK_SIZE); - buffer.create(BLOCK_SIZE); - position = 0; - } - -/* -* Check if a keylength is valid for EAX -*/ -bool EAX_Base::valid_keylength(u32bit n) const - { - if(!cipher->valid_keylength(n)) - return false; - if(!mac->valid_keylength(n)) - return false; - return true; - } - -/* -* Set the EAX key -*/ -void EAX_Base::set_key(const SymmetricKey& key) - { - cipher->set_key(key); - mac->set_key(key); - header_mac = eax_prf(1, BLOCK_SIZE, mac, 0, 0); - } - -/* -* Do setup at the start of each message -*/ -void EAX_Base::start_msg() - { - for(u32bit j = 0; j != BLOCK_SIZE - 1; ++j) - mac->update(0); - mac->update(2); - } - -/* -* Set the EAX nonce -*/ -void EAX_Base::set_iv(const InitializationVector& iv) - { - nonce_mac = eax_prf(0, BLOCK_SIZE, mac, iv.begin(), iv.length()); - state = nonce_mac; - cipher->encrypt(state, buffer); - } - -/* -* Set the EAX header -*/ -void EAX_Base::set_header(const byte header[], u32bit length) - { - header_mac = eax_prf(1, BLOCK_SIZE, mac, header, length); - } - -/* -* Return the name of this cipher mode -*/ -std::string EAX_Base::name() const - { - return (cipher->name() + "/EAX"); - } - -/* -* Increment the counter and update the buffer -*/ -void EAX_Base::increment_counter() - { - for(s32bit j = BLOCK_SIZE - 1; j >= 0; --j) - if(++state[j]) - break; - cipher->encrypt(state, buffer); - position = 0; - } - -/* -* Encrypt in EAX mode -*/ -void EAX_Encryption::write(const byte input[], u32bit length) - { - u32bit copied = std::min(BLOCK_SIZE - position, length); - xor_buf(buffer + position, input, copied); - send(buffer + position, copied); - mac->update(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); - mac->update(buffer, BLOCK_SIZE); - - input += BLOCK_SIZE; - length -= BLOCK_SIZE; - increment_counter(); - } - - xor_buf(buffer + position, input, length); - send(buffer + position, length); - mac->update(buffer + position, length); - position += length; - } - -/* -* Finish encrypting in EAX mode -*/ -void EAX_Encryption::end_msg() - { - SecureVector<byte> data_mac = mac->final(); - xor_buf(data_mac, nonce_mac, data_mac.size()); - xor_buf(data_mac, header_mac, data_mac.size()); - - send(data_mac, TAG_SIZE); - - state.clear(); - buffer.clear(); - position = 0; - } - -} |
