public static byte[] Pkcs1Unpad(byte[] data, int length, PKCS1PadType type)
{
int offset = 0;
while (offset < data.Length && data[offset] == 0)
{
++offset;
}
if (data.Length - offset != length - 1 || data[offset] != ((byte)type + 1))
{
throw new Exception(string.Format("PKCS#1 UNPAD: Offset={0}, expected Data[Offset]==[{1}]; Got Data[Offset]={2}", offset, type + 1, data[offset]));
}
++offset;
while (data[offset] != 0)
{
if (++offset >= data.Length)
{
throw new Exception(string.Format("PKCS#1 UNPAD: Offset={0}, Data[Offset - 1] != 0 (={1:X})", offset, data[offset - 1]));
}
}
var outCome = new byte[(data.Length - offset) - 1];
for (int j = 0; ++offset < data.Length; j++)
{
outCome[j] = data[offset];
}
return(outCome);
}
public static byte[] Pkcs1Pad(byte[] data, int length, PKCS1PadType type)
{
var outCome = new byte[length];
for (int i = data.Length - 1; (i >= 0 && length > 11);)
{
outCome[--length] = data[i--];
}
outCome[--length] = 0;
while (length > 2)
{
byte x = (type == PKCS1PadType.RandomByte) ? (byte)ByteGen.Next(1, 256) : byte.MaxValue;
outCome[--length] = x;
}
outCome[--length] = (byte)(type + 1);
outCome[--length] = 0;
return(outCome);
}
private void _Encrypt(Func <BigInteger, BigInteger> doFunc, ref byte[] data, PKCS1PadType type)
{
int blockSize = GetBlockSize();
data = doFunc(new BigInteger(Pkcs1Pad(data, blockSize, type))).ToBytes();
}
