diff options
Diffstat (limited to 'old/botan/src/modes/ofb/ofb.cpp')
-rw-r--r-- | old/botan/src/modes/ofb/ofb.cpp | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/old/botan/src/modes/ofb/ofb.cpp b/old/botan/src/modes/ofb/ofb.cpp new file mode 100644 index 0000000..cb40fde --- /dev/null +++ b/old/botan/src/modes/ofb/ofb.cpp @@ -0,0 +1,66 @@ +/* +* OFB Mode +* (C) 1999-2007 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ + +#include <botan/ofb.h> +#include <botan/xor_buf.h> +#include <algorithm> + +namespace Botan { + +/* +* OFB Constructor +*/ +OFB::OFB(BlockCipher* ciph) : + BlockCipherMode(ciph, "OFB", ciph->BLOCK_SIZE, 2) + { + } + +/* +* OFB Constructor +*/ +OFB::OFB(BlockCipher* ciph, const SymmetricKey& key, + const InitializationVector& iv) : + BlockCipherMode(ciph, "OFB", ciph->BLOCK_SIZE, 2) + { + set_key(key); + set_iv(iv); + } + +/* +* OFB Encryption/Decryption +*/ +void OFB::write(const byte input[], u32bit length) + { + u32bit copied = std::min(BLOCK_SIZE - position, length); + xor_buf(buffer, input, state + position, copied); + send(buffer, copied); + input += copied; + length -= copied; + position += copied; + + if(position == BLOCK_SIZE) + { + cipher->encrypt(state); + position = 0; + } + + while(length >= BLOCK_SIZE) + { + xor_buf(buffer, input, state, BLOCK_SIZE); + send(buffer, BLOCK_SIZE); + + input += BLOCK_SIZE; + length -= BLOCK_SIZE; + cipher->encrypt(state); + } + + xor_buf(buffer, input, state + position, length); + send(buffer, length); + position += length; + } + +} |