/* * CTR-BE Mode * (C) 1999-2007 Jack Lloyd * * Botan is released under the Simplified BSD License (see license.txt) */ #ifndef BOTAN_CTR_BE_H__ #define BOTAN_CTR_BE_H__ #include <botan/block_cipher.h> #include <botan/stream_cipher.h> namespace Botan { /** * CTR-BE (Counter mode, big-endian) */ class BOTAN_DLL CTR_BE final : public StreamCipher { public: void cipher(const byte in[], byte out[], size_t length) override; void set_iv(const byte iv[], size_t iv_len) override; bool valid_iv_length(size_t iv_len) const override { return (iv_len <= m_cipher->block_size()); } Key_Length_Specification key_spec() const override { return m_cipher->key_spec(); } std::string name() const override; CTR_BE* clone() const override { return new CTR_BE(m_cipher->clone()); } void clear() override; static CTR_BE* make(const Spec& spec); /** * @param cipher the underlying block cipher to use */ explicit CTR_BE(BlockCipher* cipher); private: void key_schedule(const byte key[], size_t key_len) override; void increment_counter(); std::unique_ptr<BlockCipher> m_cipher; secure_vector<byte> m_counter, m_pad; size_t m_pad_pos; }; } #endif