Pkcs7Padding
A padder that adds PKCS7/PKCS5 padding to a block.
using Org.BouncyCastle.Security;
using System;
namespace Org.BouncyCastle.Crypto.Paddings
{
public class Pkcs7Padding : IBlockCipherPadding
{
public string PaddingName => "PKCS7";
public void Init(SecureRandom random)
{
}
public int AddPadding(byte[] input, int inOff)
{
int num = input.Length - inOff;
byte b = (byte)num;
while (inOff < input.Length) {
input[inOff++] = b;
}
return num;
}
public int AddPadding(Span<byte> block, int position)
{
int num = block.Length - position;
byte value = (byte)num;
block.Slice(position, block.Length - position).Fill(value);
return num;
}
public int PadCount(byte[] input)
{
byte b = input[input.Length - 1];
int num = b;
int num2 = input.Length - num;
int num3 = (num2 | (num - 1)) >> 31;
for (int i = 0; i < input.Length; i++) {
num3 |= ((input[i] ^ b) & ~(i - num2 >> 31));
}
if (num3 != 0)
throw new InvalidCipherTextException("pad block corrupted");
return num;
}
public int PadCount(ReadOnlySpan<byte> block)
{
byte b = block[block.Length - 1];
int num = b;
int num2 = block.Length - num;
int num3 = (num2 | (num - 1)) >> 31;
for (int i = 0; i < block.Length; i++) {
num3 |= ((block[i] ^ b) & ~(i - num2 >> 31));
}
if (num3 != 0)
throw new InvalidCipherTextException("pad block corrupted");
return num;
}
}
}