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/*
* Interface for AEAD modes
* (C) 2013 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/aead.h>
#include <botan/block_cipher.h>
#include <botan/libstate.h>
#if defined(BOTAN_HAS_AEAD_CCM)
#include <botan/ccm.h>
#endif
#if defined(BOTAN_HAS_AEAD_EAX)
#include <botan/eax.h>
#endif
#if defined(BOTAN_HAS_AEAD_GCM)
#include <botan/gcm.h>
#endif
#if defined(BOTAN_HAS_AEAD_SIV)
#include <botan/siv.h>
#endif
#if defined(BOTAN_HAS_AEAD_OCB)
#include <botan/ocb.h>
#endif
#if defined(BOTAN_HAS_AEAD_CHACHA20_POLY1305)
#include <botan/chacha20poly1305.h>
#endif
namespace Botan {
AEAD_Mode* get_aead(const std::string& algo_spec, Cipher_Dir direction)
{
#if defined(BOTAN_HAS_AEAD_CHACHA20_POLY1305)
if(algo_spec == "ChaCha20Poly1305")
{
if(direction == ENCRYPTION)
return new ChaCha20Poly1305_Encryption;
else
return new ChaCha20Poly1305_Decryption;
}
#endif
Algorithm_Factory& af = global_state().algorithm_factory();
const std::vector<std::string> algo_parts = split_on(algo_spec, '/');
if(algo_parts.empty())
throw Invalid_Algorithm_Name(algo_spec);
if(algo_parts.size() < 2)
return nullptr;
const std::string cipher_name = algo_parts[0];
const BlockCipher* cipher = af.prototype_block_cipher(cipher_name);
if(!cipher)
return nullptr;
const std::vector<std::string> mode_info = parse_algorithm_name(algo_parts[1]);
if(mode_info.empty())
return nullptr;
const std::string mode_name = mode_info[0];
const size_t tag_size = (mode_info.size() > 1) ? to_u32bit(mode_info[1]) : cipher->block_size();
#if defined(BOTAN_HAS_AEAD_CCM)
if(mode_name == "CCM-8")
{
if(direction == ENCRYPTION)
return new CCM_Encryption(cipher->clone(), 8, 3);
else
return new CCM_Decryption(cipher->clone(), 8, 3);
}
if(mode_name == "CCM" || mode_name == "CCM-8")
{
const size_t L = (mode_info.size() > 2) ? to_u32bit(mode_info[2]) : 3;
if(direction == ENCRYPTION)
return new CCM_Encryption(cipher->clone(), tag_size, L);
else
return new CCM_Decryption(cipher->clone(), tag_size, L);
}
#endif
#if defined(BOTAN_HAS_AEAD_EAX)
if(mode_name == "EAX")
{
if(direction == ENCRYPTION)
return new EAX_Encryption(cipher->clone(), tag_size);
else
return new EAX_Decryption(cipher->clone(), tag_size);
}
#endif
#if defined(BOTAN_HAS_AEAD_SIV)
if(mode_name == "SIV")
{
BOTAN_ASSERT(tag_size == 16, "Valid tag size for SIV");
if(direction == ENCRYPTION)
return new SIV_Encryption(cipher->clone());
else
return new SIV_Decryption(cipher->clone());
}
#endif
#if defined(BOTAN_HAS_AEAD_GCM)
if(mode_name == "GCM")
{
if(direction == ENCRYPTION)
return new GCM_Encryption(cipher->clone(), tag_size);
else
return new GCM_Decryption(cipher->clone(), tag_size);
}
#endif
#if defined(BOTAN_HAS_AEAD_OCB)
if(mode_name == "OCB")
{
if(direction == ENCRYPTION)
return new OCB_Encryption(cipher->clone(), tag_size);
else
return new OCB_Decryption(cipher->clone(), tag_size);
}
#endif
return nullptr;
}
}
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