public static PQPair parsePQ(byte[] pqStr)
{
if (pqStr.Length > 8)
{
return(null);
}
PQPair pPair = new PQPair(0, 0);
byte[] pStr = new byte[4];
byte[] qStr = new byte[4];
UInt64 pq = 0, p, q;
for (UInt32 i = 0, l = (UInt32)pqStr.Length; i < l; ++i)
{
pq <<= 8;
pq |= (UInt64)pqStr[i];
}
UInt64 pqSqrt = (UInt64)System.Math.Sqrt((double)pq), ySqr, y;
while (pqSqrt * pqSqrt > pq)
{
--pqSqrt;
}
while (pqSqrt * pqSqrt < pq)
{
++pqSqrt;
}
for (ySqr = pqSqrt * pqSqrt - pq; ; ++pqSqrt, ySqr = pqSqrt * pqSqrt - pq)
{
y = (UInt64)System.Math.Sqrt((double)ySqr);
while (y * y > ySqr)
{
--y;
}
while (y * y < ySqr)
{
++y;
}
if (ySqr == 0 || y + pqSqrt >= pq)
{
return(null);
}
if (y * y == ySqr)
{
p = pqSqrt + y;
q = (pqSqrt > y) ? (pqSqrt - y) : (y - pqSqrt);
break;
}
}
if (p > q)
{
Swap(ref p, ref q);
}
for (UInt32 i = 0; i < 4; ++i)
{
pStr[3 - i] = (byte)(p & 0xFF);
p >>= 8;
}
pPair.P = new Math.BigInteger(pStr);
for (UInt32 i = 0; i < 4; ++i)
{
qStr[3 - i] = (byte)(q & 0xFF);
q >>= 8;
}
pPair.Q = new Math.BigInteger(qStr);
return(pPair);
}
public static PQPair parsePQ(byte[] pqStr)
{
if (pqStr.Length > 8)
{
return null;
}
PQPair pPair = new PQPair(0, 0);
byte[] pStr = new byte[4];
byte[] qStr = new byte[4];
UInt64 pq = 0, p, q;
for (UInt32 i = 0, l = (UInt32)pqStr.Length; i < l; ++i)
{
pq <<= 8;
pq |= (UInt64)pqStr[i];
}
UInt64 pqSqrt = (UInt64)System.Math.Sqrt((double)pq), ySqr, y;
while (pqSqrt * pqSqrt > pq)
{
--pqSqrt;
}
while (pqSqrt * pqSqrt < pq)
{
++pqSqrt;
}
for (ySqr = pqSqrt * pqSqrt - pq; ; ++pqSqrt, ySqr = pqSqrt * pqSqrt - pq)
{
y = (UInt64)System.Math.Sqrt((double)ySqr);
while (y * y > ySqr)
{
--y;
}
while (y * y < ySqr)
{
++y;
}
if (ySqr == 0 || y + pqSqrt >= pq)
{
return null;
}
if (y * y == ySqr)
{
p = pqSqrt + y;
q = (pqSqrt > y) ? (pqSqrt - y) : (y - pqSqrt);
break;
}
}
if (p > q)
{
Swap(ref p, ref q);
}
for (UInt32 i = 0; i < 4; ++i)
{
pStr[3 - i] = (byte)(p & 0xFF);
p >>= 8;
}
pPair.P = new Math.BigInteger(pStr);
for (UInt32 i = 0; i < 4; ++i)
{
qStr[3 - i] = (byte)(q & 0xFF);
q >>= 8;
}
pPair.Q = new Math.BigInteger(qStr);
return pPair;
}
