/*************************************************
* Derive a key *
*************************************************/
SecureVector<byte> DH_PrivateKey::derive_key(const BigInt& w) const
{
const BigInt& p = group_p();
if(w <= 1 || w >= p-1)
throw Invalid_Argument(algo_name() + "::derive_key: Invalid key input");
return BigInt::encode_1363(core.agree(w), p.bytes());
}
/*
* Load a DH private key
*/
DH_PrivateKey::DH_PrivateKey(const AlgorithmIdentifier& alg_id,
const secure_vector<uint8_t>& key_bits) :
DL_Scheme_PrivateKey(alg_id, key_bits, DL_Group::ANSI_X9_42)
{
if(m_y == 0)
m_y = power_mod(group_g(), m_x, group_p());
}
NR_PrivateKey::NR_PrivateKey(const AlgorithmIdentifier& alg_id,
const secure_vector<byte>& key_bits,
RandomNumberGenerator& rng) :
DL_Scheme_PrivateKey(alg_id, key_bits, DL_Group::ANSI_X9_57)
{
m_y = power_mod(group_g(), m_x, group_p());
load_check(rng);
}
DSA_PrivateKey::DSA_PrivateKey(const AlgorithmIdentifier& alg_id,
const MemoryRegion<byte>& key_bits,
RandomNumberGenerator& rng) :
DL_Scheme_PrivateKey(alg_id, key_bits, DL_Group::ANSI_X9_57)
{
y = power_mod(group_g(), x, group_p());
load_check(rng);
}
/*************************************************
* Algorithm Specific PKCS #8 Initialization Code *
*************************************************/
void DH_PrivateKey::PKCS8_load_hook(RandomNumberGenerator& rng,
bool generated)
{
if(y == 0)
y = power_mod(group_g(), x, group_p());
core = DH_Core(rng, group, x);
if(generated)
gen_check(rng);
else
load_check(rng);
}
/*
* Create a DH private key
*/
DH_PrivateKey::DH_PrivateKey(RandomNumberGenerator& rng,
const DL_Group& grp,
const BigInt& x_arg)
{
m_group = grp;
if(x_arg == 0)
{
const BigInt& p = group_p();
m_x.randomize(rng, dl_exponent_size(p.bits()));
}
else
{
m_x = x_arg;
}
if(m_y == 0)
{
m_y = power_mod(group_g(), m_x, group_p());
}
}
/*
* Create a DH private key
*/
DH_PrivateKey::DH_PrivateKey(RandomNumberGenerator& rng,
const DL_Group& grp,
const BigInt& x_arg)
{
group = grp;
x = x_arg;
if(x == 0)
{
const BigInt& p = group_p();
x.randomize(rng, 2 * dl_work_factor(p.bits()));
}
if(y == 0)
y = power_mod(group_g(), x, group_p());
if(x == 0)
gen_check(rng);
else
load_check(rng);
}
/*************************************************
* Create a DH private key *
*************************************************/
DH_PrivateKey::DH_PrivateKey(RandomNumberGenerator& rng,
const DL_Group& grp,
const BigInt& x_arg)
{
group = grp;
x = x_arg;
if(x == 0)
{
const BigInt& p = group_p();
x.randomize(rng, 2 * dl_work_factor(p.bits()));
PKCS8_load_hook(rng, true);
}
else
PKCS8_load_hook(rng, false);
}
/*
* Create a NR private key
*/
NR_PrivateKey::NR_PrivateKey(RandomNumberGenerator& rng,
const DL_Group& grp,
const BigInt& x_arg)
{
m_group = grp;
m_x = x_arg;
if(m_x == 0)
m_x = BigInt::random_integer(rng, 2, group_q() - 1);
m_y = power_mod(group_g(), m_x, group_p());
if(x_arg == 0)
gen_check(rng);
else
load_check(rng);
}
/*************************************************
* Return the public value for key agreement *
*************************************************/
MemoryVector<byte> DH_PublicKey::public_value() const
{
return BigInt::encode_1363(y, group_p().bytes());
}
/*************************************************
* Return the maximum input size in bits *
*************************************************/
u32bit DH_PublicKey::max_input_bits() const
{
return group_p().bits();
}
/*
* Return the public value for key agreement
*/
std::vector<uint8_t> DH_PublicKey::public_value() const
{
return unlock(BigInt::encode_1363(m_y, group_p().bytes()));
}