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/*
* Block Cipher Base Class
* (C) 1999-2009 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_BLOCK_CIPHER_H_
#define BOTAN_BLOCK_CIPHER_H_
#include <botan/sym_algo.h>
#include <string>
#include <memory>
namespace Botan {
/**
* This class represents a block cipher object.
*/
class BOTAN_PUBLIC_API(2,0) BlockCipher : public SymmetricAlgorithm
{
public:
/**
* Create an instance based on a name
* If provider is empty then best available is chosen.
* @param algo_spec algorithm name
* @param provider provider implementation to choose
* @return a null pointer if the algo/provider combination cannot be found
*/
static std::unique_ptr<BlockCipher>
create(const std::string& algo_spec,
const std::string& provider = "");
/**
* Create an instance based on a name, or throw if the
* algo/provider combination cannot be found. If provider is
* empty then best available is chosen.
*/
static std::unique_ptr<BlockCipher>
create_or_throw(const std::string& algo_spec,
const std::string& provider = "");
/**
* @return list of available providers for this algorithm, empty if not available
* @param algo_spec algorithm name
*/
static std::vector<std::string> providers(const std::string& algo_spec);
/**
* @return block size of this algorithm
*/
virtual size_t block_size() const = 0;
/**
* @return native parallelism of this cipher in blocks
*/
virtual size_t parallelism() const { return 1; }
/**
* @return prefererred parallelism of this cipher in bytes
*/
size_t parallel_bytes() const
{
return parallelism() * block_size() * BOTAN_BLOCK_CIPHER_PAR_MULT;
}
/**
* @return provider information about this implementation. Default is "base",
* might also return "sse2", "avx2", "openssl", or some other arbitrary string.
*/
virtual std::string provider() const { return "base"; }
/**
* Encrypt a block.
* @param in The plaintext block to be encrypted as a byte array.
* Must be of length block_size().
* @param out The byte array designated to hold the encrypted block.
* Must be of length block_size().
*/
void encrypt(const uint8_t in[], uint8_t out[]) const
{ encrypt_n(in, out, 1); }
/**
* Decrypt a block.
* @param in The ciphertext block to be decypted as a byte array.
* Must be of length block_size().
* @param out The byte array designated to hold the decrypted block.
* Must be of length block_size().
*/
void decrypt(const uint8_t in[], uint8_t out[]) const
{ decrypt_n(in, out, 1); }
/**
* Encrypt a block.
* @param block the plaintext block to be encrypted
* Must be of length block_size(). Will hold the result when the function
* has finished.
*/
void encrypt(uint8_t block[]) const { encrypt_n(block, block, 1); }
/**
* Decrypt a block.
* @param block the ciphertext block to be decrypted
* Must be of length block_size(). Will hold the result when the function
* has finished.
*/
void decrypt(uint8_t block[]) const { decrypt_n(block, block, 1); }
/**
* Encrypt one or more blocks
* @param block the input/output buffer (multiple of block_size())
*/
template<typename Alloc>
void encrypt(std::vector<uint8_t, Alloc>& block) const
{
return encrypt_n(block.data(), block.data(), block.size() / block_size());
}
/**
* Decrypt one or more blocks
* @param block the input/output buffer (multiple of block_size())
*/
template<typename Alloc>
void decrypt(std::vector<uint8_t, Alloc>& block) const
{
return decrypt_n(block.data(), block.data(), block.size() / block_size());
}
/**
* Encrypt one or more blocks
* @param in the input buffer (multiple of block_size())
* @param out the output buffer (same size as in)
*/
template<typename Alloc, typename Alloc2>
void encrypt(const std::vector<uint8_t, Alloc>& in,
std::vector<uint8_t, Alloc2>& out) const
{
return encrypt_n(in.data(), out.data(), in.size() / block_size());
}
/**
* Decrypt one or more blocks
* @param in the input buffer (multiple of block_size())
* @param out the output buffer (same size as in)
*/
template<typename Alloc, typename Alloc2>
void decrypt(const std::vector<uint8_t, Alloc>& in,
std::vector<uint8_t, Alloc2>& out) const
{
return decrypt_n(in.data(), out.data(), in.size() / block_size());
}
/**
* Encrypt one or more blocks
* @param in the input buffer (multiple of block_size())
* @param out the output buffer (same size as in)
* @param blocks the number of blocks to process
*/
virtual void encrypt_n(const uint8_t in[], uint8_t out[],
size_t blocks) const = 0;
/**
* Decrypt one or more blocks
* @param in the input buffer (multiple of block_size())
* @param out the output buffer (same size as in)
* @param blocks the number of blocks to process
*/
virtual void decrypt_n(const uint8_t in[], uint8_t out[],
size_t blocks) const = 0;
virtual void encrypt_n_xex(uint8_t data[],
const uint8_t mask[],
size_t blocks) const
{
const size_t BS = block_size();
xor_buf(data, mask, blocks * BS);
encrypt_n(data, data, blocks);
xor_buf(data, mask, blocks * BS);
}
virtual void decrypt_n_xex(uint8_t data[],
const uint8_t mask[],
size_t blocks) const
{
const size_t BS = block_size();
xor_buf(data, mask, blocks * BS);
decrypt_n(data, data, blocks);
xor_buf(data, mask, blocks * BS);
}
/**
* @return new object representing the same algorithm as *this
*/
virtual BlockCipher* clone() const = 0;
virtual ~BlockCipher() = default;
};
/**
* Tweakable block ciphers allow setting a tweak which is a non-keyed
* value which affects the encryption/decryption operation.
*/
class BOTAN_PUBLIC_API(2,8) Tweakable_Block_Cipher : public BlockCipher
{
public:
/**
* Set the tweak value. This must be called after setting a key. The value
* persists until either set_tweak, set_key, or clear is called.
* Different algorithms support different tweak length(s). If called with
* an unsupported length, Invalid_Argument will be thrown.
*/
virtual void set_tweak(const uint8_t tweak[], size_t len) = 0;
};
/**
* Represents a block cipher with a single fixed block size
*/
template<size_t BS, size_t KMIN, size_t KMAX = 0, size_t KMOD = 1, typename BaseClass = BlockCipher>
class Block_Cipher_Fixed_Params : public BaseClass
{
public:
enum { BLOCK_SIZE = BS };
size_t block_size() const final override { return BS; }
// override to take advantage of compile time constant block size
void encrypt_n_xex(uint8_t data[],
const uint8_t mask[],
size_t blocks) const final override
{
xor_buf(data, mask, blocks * BS);
this->encrypt_n(data, data, blocks);
xor_buf(data, mask, blocks * BS);
}
void decrypt_n_xex(uint8_t data[],
const uint8_t mask[],
size_t blocks) const final override
{
xor_buf(data, mask, blocks * BS);
this->decrypt_n(data, data, blocks);
xor_buf(data, mask, blocks * BS);
}
Key_Length_Specification key_spec() const final override
{
return Key_Length_Specification(KMIN, KMAX, KMOD);
}
};
}
#endif
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