| protected static Xor ( byte block, byte val ) : void | ||
| block | byte | |
| val | byte | |
| Результат | void | |
protected virtual void UpdateHASH(byte[] LSub)
{
OcbBlockCipher.Xor(this.OffsetHASH, LSub);
OcbBlockCipher.Xor(this.hashBlock, this.OffsetHASH);
this.hashCipher.ProcessBlock(this.hashBlock, 0, this.hashBlock, 0);
OcbBlockCipher.Xor(this.Sum, this.hashBlock);
}
public virtual int DoFinal(byte[] output, int outOff)
{
byte[] array = null;
if (!this.forEncryption)
{
if (this.mainBlockPos < this.macSize)
{
throw new InvalidCipherTextException("data too short");
}
this.mainBlockPos -= this.macSize;
array = new byte[this.macSize];
Array.Copy(this.mainBlock, this.mainBlockPos, array, 0, this.macSize);
}
if (this.hashBlockPos > 0)
{
OcbBlockCipher.OCB_extend(this.hashBlock, this.hashBlockPos);
this.UpdateHASH(this.L_Asterisk);
}
if (this.mainBlockPos > 0)
{
if (this.forEncryption)
{
OcbBlockCipher.OCB_extend(this.mainBlock, this.mainBlockPos);
OcbBlockCipher.Xor(this.Checksum, this.mainBlock);
}
OcbBlockCipher.Xor(this.OffsetMAIN, this.L_Asterisk);
byte[] array2 = new byte[16];
this.hashCipher.ProcessBlock(this.OffsetMAIN, 0, array2, 0);
OcbBlockCipher.Xor(this.mainBlock, array2);
Check.OutputLength(output, outOff, this.mainBlockPos, "Output buffer too short");
Array.Copy(this.mainBlock, 0, output, outOff, this.mainBlockPos);
if (!this.forEncryption)
{
OcbBlockCipher.OCB_extend(this.mainBlock, this.mainBlockPos);
OcbBlockCipher.Xor(this.Checksum, this.mainBlock);
}
}
OcbBlockCipher.Xor(this.Checksum, this.OffsetMAIN);
OcbBlockCipher.Xor(this.Checksum, this.L_Dollar);
this.hashCipher.ProcessBlock(this.Checksum, 0, this.Checksum, 0);
OcbBlockCipher.Xor(this.Checksum, this.Sum);
this.macBlock = new byte[this.macSize];
Array.Copy(this.Checksum, 0, this.macBlock, 0, this.macSize);
int num = this.mainBlockPos;
if (this.forEncryption)
{
Check.OutputLength(output, outOff, num + this.macSize, "Output buffer too short");
Array.Copy(this.macBlock, 0, output, outOff + num, this.macSize);
num += this.macSize;
}
else if (!Arrays.ConstantTimeAreEqual(this.macBlock, array))
{
throw new InvalidCipherTextException("mac check in OCB failed");
}
this.Reset(false);
return(num);
}
protected virtual void ProcessMainBlock(byte[] output, int outOff)
{
Check.DataLength(output, outOff, 16, "Output buffer too short");
if (this.forEncryption)
{
OcbBlockCipher.Xor(this.Checksum, this.mainBlock);
this.mainBlockPos = 0;
}
OcbBlockCipher.Xor(this.OffsetMAIN, this.GetLSub(OcbBlockCipher.OCB_ntz(this.mainBlockCount += 1L)));
OcbBlockCipher.Xor(this.mainBlock, this.OffsetMAIN);
this.mainCipher.ProcessBlock(this.mainBlock, 0, this.mainBlock, 0);
OcbBlockCipher.Xor(this.mainBlock, this.OffsetMAIN);
Array.Copy(this.mainBlock, 0, output, outOff, 16);
if (!this.forEncryption)
{
OcbBlockCipher.Xor(this.Checksum, this.mainBlock);
Array.Copy(this.mainBlock, 16, this.mainBlock, 0, this.macSize);
this.mainBlockPos = this.macSize;
}
}
