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/*
* Base class for message authentiction codes
* (C) 1999-2007 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_MESSAGE_AUTH_CODE_BASE_H_
#define BOTAN_MESSAGE_AUTH_CODE_BASE_H_
#include <botan/buf_comp.h>
#include <botan/sym_algo.h>
#include <string>
#include <memory>
namespace Botan {
/**
* This class represents Message Authentication Code (MAC) objects.
*/
class BOTAN_PUBLIC_API(2,0) MessageAuthenticationCode : public Buffered_Computation,
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 use
* @return a null pointer if the algo/provider combination cannot be found
*/
static std::unique_ptr<MessageAuthenticationCode>
create(const std::string& algo_spec,
const std::string& provider = "");
/*
* 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 use
* Throws a Lookup_Error if algo/provider combination cannot be found
*/
static std::unique_ptr<MessageAuthenticationCode>
create_or_throw(const std::string& algo_spec,
const std::string& provider = "");
/**
* @return list of available providers for this algorithm, empty if not available
*/
static std::vector<std::string> providers(const std::string& algo_spec);
virtual ~MessageAuthenticationCode() = default;
/**
* Prepare for processing a message under the specified nonce
*
* Most MACs neither require nor support a nonce; for these algorithms
* calling `start_msg` is optional and calling it with anything other than
* an empty string is an error. One MAC which *requires* a per-message
* nonce be specified is GMAC.
*
* @param nonce the message nonce bytes
* @param nonce_len the size of len in bytes
* Default implementation simply rejects all non-empty nonces
* since most hash/MAC algorithms do not support randomization
*/
virtual void start_msg(const uint8_t nonce[], size_t nonce_len);
/**
* Begin processing a message with a nonce
*
* @param nonce the per message nonce
*/
template<typename Alloc>
void start(const std::vector<uint8_t, Alloc>& nonce)
{
start_msg(nonce.data(), nonce.size());
}
/**
* Begin processing a message.
* @param nonce the per message nonce
* @param nonce_len length of nonce
*/
void start(const uint8_t nonce[], size_t nonce_len)
{
start_msg(nonce, nonce_len);
}
/**
* Begin processing a message.
*/
void start()
{
return start_msg(nullptr, 0);
}
/**
* Verify a MAC.
* @param in the MAC to verify as a byte array
* @param length the length of param in
* @return true if the MAC is valid, false otherwise
*/
virtual bool verify_mac(const uint8_t in[], size_t length);
/**
* Verify a MAC.
* @param in the MAC to verify as a byte array
* @return true if the MAC is valid, false otherwise
*/
virtual bool verify_mac(const std::vector<uint8_t>& in)
{
return verify_mac(in.data(), in.size());
}
/**
* Verify a MAC.
* @param in the MAC to verify as a byte array
* @return true if the MAC is valid, false otherwise
*/
virtual bool verify_mac(const secure_vector<uint8_t>& in)
{
return verify_mac(in.data(), in.size());
}
/**
* Get a new object representing the same algorithm as *this
*/
virtual MessageAuthenticationCode* clone() const = 0;
/**
* @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"; }
};
typedef MessageAuthenticationCode MAC;
}
#endif