Source code
Revision control
Copy as Markdown
Other Tools
/*
* XMSS WOTS Private Key
* A Winternitz One Time Signature private key for use with Extended Hash-Based
* Signatures.
*
* (C) 2016,2017 Matthias Gierlings
*
* Botan is released under the Simplified BSD License (see license.txt)
**/
#include <botan/xmss_wots.h>
#include <botan/internal/xmss_tools.h>
#include <botan/internal/xmss_address.h>
namespace Botan {
wots_keysig_t
XMSS_WOTS_PrivateKey::generate(const secure_vector<uint8_t>& priv_seed,
XMSS_Hash& hash)
{
wots_keysig_t priv_key(m_wots_params.len(),
secure_vector<uint8_t>(0));
for(size_t i = 0; i < m_wots_params.len(); i++)
{
XMSS_Tools::concat<size_t>(priv_key[i], i, 32);
hash.prf(priv_key[i], priv_seed, priv_key[i]);
}
return priv_key;
}
XMSS_WOTS_PublicKey
XMSS_WOTS_PrivateKey::generate_public_key(XMSS_Address& adrs)
{
XMSS_WOTS_PublicKey pub_key(m_wots_params.oid(),
public_seed());
generate_public_key(pub_key, wots_keysig_t((*this)[adrs]), adrs);
return pub_key;
}
void
XMSS_WOTS_PrivateKey::generate_public_key(XMSS_WOTS_PublicKey& pub_key,
wots_keysig_t&& in_key_data,
XMSS_Address& adrs,
XMSS_Hash& hash)
{
BOTAN_ASSERT(wots_parameters() == pub_key.wots_parameters() &&
public_seed() == pub_key.public_seed(),
"Conflicting public key data.");
pub_key.set_key_data(std::move(in_key_data));
for(size_t i = 0; i < m_wots_params.len(); i++)
{
adrs.set_chain_address(static_cast<uint32_t>(i));
chain(pub_key[i], 0, m_wots_params.wots_parameter() - 1, adrs,
public_seed(), hash);
}
}
wots_keysig_t
XMSS_WOTS_PrivateKey::sign(const secure_vector<uint8_t>& msg,
XMSS_Address& adrs,
XMSS_Hash& hash)
{
secure_vector<uint8_t> msg_digest
{
m_wots_params.base_w(msg, m_wots_params.len_1())
};
m_wots_params.append_checksum(msg_digest);
wots_keysig_t sig(this->at(adrs, hash));
for(size_t i = 0; i < m_wots_params.len(); i++)
{
adrs.set_chain_address(static_cast<uint32_t>(i));
chain(sig[i], 0 , msg_digest[i], adrs, m_public_seed, hash);
}
return sig;
}
wots_keysig_t XMSS_WOTS_PrivateKey::at(const XMSS_Address& adrs, XMSS_Hash& hash)
{
secure_vector<uint8_t> result;
hash.prf(result, m_private_seed, adrs.bytes());
return generate(result, hash);
}
wots_keysig_t XMSS_WOTS_PrivateKey::at(size_t i, XMSS_Hash& hash)
{
secure_vector<uint8_t> idx_bytes;
XMSS_Tools::concat(idx_bytes, i, m_wots_params.element_size());
hash.h(idx_bytes, m_private_seed, idx_bytes);
return generate(idx_bytes, hash);
}
}