void Montgomery_Params::square_this(BigInt& x,
secure_vector<word>& ws) const
{
const size_t output_size = 2*m_p_words + 2;
if(ws.size() < 2*output_size)
ws.resize(2*output_size);
word* z_data = &ws[0];
word* ws_data = &ws[output_size];
BOTAN_DEBUG_ASSERT(x.sig_words() <= m_p_words);
bigint_sqr(z_data, output_size,
x.data(), x.size(), std::min(m_p_words, x.size()),
ws_data, output_size);
bigint_monty_redc(z_data,
m_p.data(), m_p_words, m_p_dash,
ws_data, output_size);
if(x.size() < output_size)
x.grow_to(output_size);
copy_mem(x.mutable_data(), z_data, output_size);
}
/*
* Square a BigInt
*/
BigInt square(const BigInt& x)
{
const size_t x_sw = x.sig_words();
BigInt z(BigInt::Positive, round_up<size_t>(2*x_sw, 16));
SecureVector<word> workspace(z.size());
bigint_sqr(z.get_reg(), z.size(), workspace,
x.data(), x.size(), x_sw);
return z;
}
void bigint_monty_sqr(word z[], size_t z_size,
const word x[], size_t x_size, size_t x_sw,
const word p[], size_t p_size, word p_dash,
word ws[])
{
bigint_sqr(&z[0], z_size, &ws[0],
&x[0], x_size, x_sw);
bigint_monty_redc(&z[0],
&p[0], p_size, p_dash,
&ws[0]);
}
/*
* Square a BigInt
*/
BigInt square(const BigInt& x)
{
const size_t x_sw = x.sig_words();
BigInt z(BigInt::Positive, round_up(2*x_sw, 16));
secure_vector<word> workspace(z.size());
bigint_sqr(z.mutable_data(), z.size(),
workspace.data(),
x.data(), x.size(), x_sw);
return z;
}
BigInt Montgomery_Params::sqr(const BigInt& x, secure_vector<word>& ws) const
{
const size_t output_size = 2*m_p_words + 2;
if(ws.size() < output_size)
ws.resize(output_size);
BigInt z(BigInt::Positive, output_size);
BOTAN_DEBUG_ASSERT(x.sig_words() <= m_p_words);
bigint_sqr(z.mutable_data(), z.size(),
x.data(), x.size(), std::min(m_p_words, x.size()),
ws.data(), ws.size());
bigint_monty_redc(z.mutable_data(),
m_p.data(), m_p_words, m_p_dash,
ws.data(), ws.size());
return z;
}
