#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
#pragma warning disable
using System;
using System.Runtime.CompilerServices;
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
using System.Buffers.Binary;
using System.Runtime.InteropServices;
#endif
#if NETCOREAPP3_0_OR_GREATER
using System.Runtime.InteropServices;
using System.Runtime.Intrinsics;
using System.Runtime.Intrinsics.X86;
#endif
using Best.HTTP.Shared.PlatformSupport.Memory;
using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto;
using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Macs;
using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Modes;
using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Modes.Gcm;
using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Parameters;
using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Utilities;
using Best.HTTP.SecureProtocol.Org.BouncyCastle.Utilities;
namespace Best.HTTP.Shared.TLS.Crypto.Impl
{
///
/// Implements the Galois/Counter mode (GCM) detailed in NIST Special Publication 800-38D.
///
[Best.HTTP.Shared.PlatformSupport.IL2CPP.Il2CppEagerStaticClassConstructionAttribute]
#if BESTHTTP_WITH_BURST
[Unity.Burst.BurstCompile]
#endif
public sealed class FastGcmBlockCipher
: IAeadBlockCipher
{
private static IGcmMultiplier CreateGcmMultiplier()
{
#if NETCOREAPP3_0_OR_GREATER
// TODO Prefer more tightly coupled test
if (Pclmulqdq.IsSupported)
{
return new BasicGcmMultiplier();
}
#endif
return new Tables8kGcmMultiplier();
}
public const int BlockSize = 16;
byte[] ctrBlock = new byte[BlockSize];
private readonly IBlockCipher cipher;
private readonly BurstTables8kGcmMultiplier multiplier;
private IGcmExponentiator exp;
// These fields are set by Init and not modified by processing
private bool forEncryption;
private bool initialised;
private int macSize;
private byte[] lastKey;
private byte[] nonce;
private byte[] initialAssociatedText;
private byte[] H;
private byte[] J0;
// These fields are modified during processing
private byte[] bufBlock;
private byte[] macBlock;
private byte[] S, S_at, S_atPre;
private byte[] counter;
private uint counter32;
private uint blocksRemaining;
private int bufOff;
private ulong totalLength;
private byte[] atBlock;
private int atBlockPos;
private ulong atLength;
private ulong atLengthPre;
public FastGcmBlockCipher(
IBlockCipher c)
: this(c, null)
{
}
public FastGcmBlockCipher(
IBlockCipher c,
IGcmMultiplier m)
{
if (c.GetBlockSize() != BlockSize)
throw new ArgumentException("cipher required with a block size of " + BlockSize + ".");
//if (m == null)
//{
// m = CreateGcmMultiplier();
//}
this.cipher = c;
this.multiplier = new BurstTables8kGcmMultiplier();
}
public string AlgorithmName => cipher.AlgorithmName + "/GCM";
public IBlockCipher UnderlyingCipher => cipher;
public int GetBlockSize()
{
return BlockSize;
}
///
/// MAC sizes from 32 bits to 128 bits (must be a multiple of 8) are supported. The default is 128 bits.
/// Sizes less than 96 are not recommended, but are supported for specialized applications.
///
public void Init(bool forEncryption, ICipherParameters parameters)
{
this.forEncryption = forEncryption;
//this.macBlock = null;
if (this.macBlock != null)
Array.Clear(this.macBlock, 0, this.macBlock.Length);
this.initialised = true;
KeyParameter keyParam;
byte[] newNonce = null;
if (parameters is AeadParameters)
{
AeadParameters param = (AeadParameters)parameters;
newNonce = param.GetNonce();
initialAssociatedText = param.GetAssociatedText();
int macSizeBits = param.MacSize;
if (macSizeBits < 32 || macSizeBits > 128 || macSizeBits % 8 != 0)
{
throw new ArgumentException("Invalid value for MAC size: " + macSizeBits);
}
macSize = macSizeBits / 8;
keyParam = param.Key;
}
else if (parameters is ParametersWithIV)
{
ParametersWithIV param = (ParametersWithIV)parameters;
newNonce = param.GetIV();
initialAssociatedText = null;
macSize = 16;
keyParam = (KeyParameter)param.Parameters;
}
else
{
throw new ArgumentException("invalid parameters passed to GCM");
}
int bufLength = forEncryption ? BlockSize : (BlockSize + macSize);
this.bufBlock = new byte[bufLength];
if (newNonce == null || newNonce.Length < 1)
{
throw new ArgumentException("IV must be at least 1 byte");
}
if (forEncryption)
{
if (nonce != null && Arrays.AreEqual(nonce, newNonce))
{
if (keyParam == null)
{
throw new ArgumentException("cannot reuse nonce for GCM encryption");
}
if (lastKey != null && Arrays.AreEqual(lastKey, keyParam.GetKey()))
{
throw new ArgumentException("cannot reuse nonce for GCM encryption");
}
}
}
nonce = newNonce;
if (keyParam != null)
{
lastKey = keyParam.GetKey();
}
// TODO Restrict macSize to 16 if nonce length not 12?
// Cipher always used in forward mode
// if keyParam is null we're reusing the last key.
if (keyParam != null)
{
cipher.Init(true, keyParam);
this.H = new byte[BlockSize];
cipher.ProcessBlock(H, 0, H, 0);
// if keyParam is null we're reusing the last key and the multiplier doesn't need re-init
multiplier.Init(H);
exp = null;
}
else if (this.H == null)
{
throw new ArgumentException("Key must be specified in initial init");
}
this.J0 = new byte[BlockSize];
if (nonce.Length == 12)
{
Array.Copy(nonce, 0, J0, 0, nonce.Length);
this.J0[BlockSize - 1] = 0x01;
}
else
{
gHASH(J0, nonce, nonce.Length);
byte[] X = new byte[BlockSize];
Pack.UInt64_To_BE((ulong)nonce.Length * 8UL, X, 8);
gHASHBlock(J0, X);
}
this.S = new byte[BlockSize];
this.S_at = new byte[BlockSize];
this.S_atPre = new byte[BlockSize];
this.atBlock = new byte[BlockSize];
this.atBlockPos = 0;
this.atLength = 0;
this.atLengthPre = 0;
this.counter = Arrays.Clone(J0);
this.counter32 = Pack.BE_To_UInt32(counter, 12);
this.blocksRemaining = uint.MaxValue - 1; // page 8, len(P) <= 2^39 - 256, 1 block used by tag
this.bufOff = 0;
this.totalLength = 0;
if (initialAssociatedText != null)
{
ProcessAadBytes(initialAssociatedText, 0, initialAssociatedText.Length);
}
}
public byte[] GetMac()
{
return macBlock == null
? new byte[macSize]
: Arrays.Clone(macBlock);
}
public int GetOutputSize(int len)
{
int totalData = len + bufOff;
if (forEncryption)
{
return totalData + macSize;
}
return totalData < macSize ? 0 : totalData - macSize;
}
public int GetUpdateOutputSize(int len)
{
int totalData = len + bufOff;
if (!forEncryption)
{
if (totalData < macSize)
{
return 0;
}
totalData -= macSize;
}
return totalData - totalData % BlockSize;
}
public void ProcessAadByte(byte input)
{
CheckStatus();
atBlock[atBlockPos] = input;
if (++atBlockPos == BlockSize)
{
// Hash each block as it fills
gHASHBlock(S_at, atBlock);
atBlockPos = 0;
atLength += BlockSize;
}
}
public void ProcessAadBytes(byte[] inBytes, int inOff, int len)
{
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
ProcessAadBytes(inBytes.AsSpan(inOff, len));
#else
CheckStatus();
if (atBlockPos > 0)
{
int available = BlockSize - atBlockPos;
if (len < available)
{
Array.Copy(inBytes, inOff, atBlock, atBlockPos, len);
atBlockPos += len;
return;
}
Array.Copy(inBytes, inOff, atBlock, atBlockPos, available);
gHASHBlock(S_at, atBlock);
atLength += BlockSize;
inOff += available;
len -= available;
//atBlockPos = 0;
}
int inLimit = inOff + len - BlockSize;
while (inOff <= inLimit)
{
gHASHBlock(S_at, inBytes, inOff);
atLength += BlockSize;
inOff += BlockSize;
}
atBlockPos = BlockSize + inLimit - inOff;
Array.Copy(inBytes, inOff, atBlock, 0, atBlockPos);
#endif
}
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
public void ProcessAadBytes(ReadOnlySpan input)
{
CheckStatus();
if (atBlockPos > 0)
{
int available = BlockSize - atBlockPos;
if (input.Length < available)
{
input.CopyTo(atBlock.AsSpan(atBlockPos));
atBlockPos += input.Length;
return;
}
input[..available].CopyTo(atBlock.AsSpan(atBlockPos));
gHASHBlock(S_at, atBlock);
atLength += BlockSize;
input = input[available..];
//atBlockPos = 0;
}
while (input.Length >= BlockSize)
{
gHASHBlock(S_at, input);
atLength += BlockSize;
input = input[BlockSize..];
}
input.CopyTo(atBlock);
atBlockPos = input.Length;
}
#endif
private void InitCipher()
{
if (atLength > 0)
{
Array.Copy(S_at, 0, S_atPre, 0, BlockSize);
atLengthPre = atLength;
}
// Finish hash for partial AAD block
if (atBlockPos > 0)
{
gHASHPartial(S_atPre, atBlock, 0, atBlockPos);
atLengthPre += (uint)atBlockPos;
}
if (atLengthPre > 0)
{
Array.Copy(S_atPre, 0, S, 0, BlockSize);
}
}
public int ProcessByte(byte input, byte[] output, int outOff)
{
CheckStatus();
bufBlock[bufOff] = input;
if (++bufOff == bufBlock.Length)
{
if (forEncryption)
{
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
EncryptBlock(bufBlock, output.AsSpan(outOff));
#else
EncryptBlock(bufBlock, 0, output, outOff);
#endif
bufOff = 0;
}
else
{
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
DecryptBlock(bufBlock, output.AsSpan(outOff));
#else
DecryptBlock(bufBlock, 0, output, outOff);
#endif
Array.Copy(bufBlock, BlockSize, bufBlock, 0, macSize);
bufOff = macSize;
}
return BlockSize;
}
return 0;
}
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
public int ProcessByte(byte input, Span output)
{
CheckStatus();
bufBlock[bufOff] = input;
if (++bufOff == bufBlock.Length)
{
if (forEncryption)
{
EncryptBlock(bufBlock, output);
bufOff = 0;
}
else
{
DecryptBlock(bufBlock, output);
Array.Copy(bufBlock, BlockSize, bufBlock, 0, macSize);
bufOff = macSize;
}
return BlockSize;
}
return 0;
}
#endif
public int ProcessBytes(byte[] input, int inOff, int len, byte[] output, int outOff)
{
CheckStatus();
Check.DataLength(input, inOff, len, "input buffer too short");
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
return ProcessBytes(input.AsSpan(inOff, len), Spans.FromNullable(output, outOff));
#else
int resultLen = 0;
if (forEncryption)
{
if (bufOff > 0)
{
int available = BlockSize - bufOff;
if (len < available)
{
Array.Copy(input, inOff, bufBlock, bufOff, len);
bufOff += len;
return 0;
}
Array.Copy(input, inOff, bufBlock, bufOff, available);
EncryptBlock(bufBlock, 0, output, outOff);
inOff += available;
len -= available;
resultLen = BlockSize;
//bufOff = 0;
}
int inLimit1 = inOff + len - BlockSize;
int inLimit2 = inLimit1 - BlockSize;
while (inOff <= inLimit2)
{
EncryptBlocks2(input, inOff, output, outOff + resultLen);
inOff += BlockSize * 2;
resultLen += BlockSize * 2;
}
if (inOff <= inLimit1)
{
EncryptBlock(input, inOff, output, outOff + resultLen);
inOff += BlockSize;
resultLen += BlockSize;
}
bufOff = BlockSize + inLimit1 - inOff;
Array.Copy(input, inOff, bufBlock, 0, bufOff);
}
else
{
int available = bufBlock.Length - bufOff;
if (len < available)
{
Array.Copy(input, inOff, bufBlock, bufOff, len);
bufOff += len;
return 0;
}
if (bufOff >= BlockSize)
{
DecryptBlock(bufBlock, 0, output, outOff);
Array.Copy(bufBlock, BlockSize, bufBlock, 0, bufOff -= BlockSize);
resultLen = BlockSize;
available += BlockSize;
if (len < available)
{
Array.Copy(input, inOff, bufBlock, bufOff, len);
bufOff += len;
return resultLen;
}
}
int inLimit1 = inOff + len - bufBlock.Length;
int inLimit2 = inLimit1 - BlockSize;
available = BlockSize - bufOff;
Array.Copy(input, inOff, bufBlock, bufOff, available);
DecryptBlock(bufBlock, 0, output, outOff + resultLen);
inOff += available;
resultLen += BlockSize;
//bufOff = 0;
while (inOff <= inLimit2)
{
DecryptBlocks2(input, inOff, output, outOff + resultLen);
inOff += BlockSize * 2;
resultLen += BlockSize * 2;
}
if (inOff <= inLimit1)
{
DecryptBlock(input, inOff, output, outOff + resultLen);
inOff += BlockSize;
resultLen += BlockSize;
}
bufOff = bufBlock.Length + inLimit1 - inOff;
Array.Copy(input, inOff, bufBlock, 0, bufOff);
}
return resultLen;
#endif
}
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
public unsafe int ProcessBytes(ReadOnlySpan input, Span output)
{
CheckStatus();
int resultLen = 0;
if (forEncryption)
{
if (bufOff > 0)
{
int available = BlockSize - bufOff;
if (input.Length < available)
{
input.CopyTo(bufBlock.AsSpan(bufOff));
bufOff += input.Length;
return 0;
}
input[..available].CopyTo(bufBlock.AsSpan(bufOff));
EncryptBlock(bufBlock, output);
input = input[available..];
resultLen = BlockSize;
//bufOff = 0;
}
while (input.Length >= BlockSize * 2)
{
EncryptBlocks2(input, output[resultLen..]);
input = input[(BlockSize * 2)..];
resultLen += BlockSize * 2;
}
if (input.Length >= BlockSize)
{
EncryptBlock(input, output[resultLen..]);
input = input[BlockSize..];
resultLen += BlockSize;
}
bufOff = input.Length;
input.CopyTo(bufBlock);
}
else
{
int available = bufBlock.Length - bufOff;
if (input.Length < available)
{
input.CopyTo(bufBlock.AsSpan(bufOff));
bufOff += input.Length;
return 0;
}
if (bufOff >= BlockSize)
{
DecryptBlock(bufBlock, output);
Array.Copy(bufBlock, BlockSize, bufBlock, 0, bufOff -= BlockSize);
resultLen = BlockSize;
available += BlockSize;
if (input.Length < available)
{
input.CopyTo(bufBlock.AsSpan(bufOff));
bufOff += input.Length;
return resultLen;
}
}
int inLimit1 = bufBlock.Length;
int inLimit2 = inLimit1 + BlockSize;
available = BlockSize - bufOff;
input[..available].CopyTo(bufBlock.AsSpan(bufOff));
DecryptBlock(bufBlock, output[resultLen..]);
input = input[available..];
resultLen += BlockSize;
//bufOff = 0;
while (input.Length >= inLimit2)
{
//DecryptBlocks2(input, output[resultLen..]);
var outputSample = output[resultLen..];
if (totalLength == 0)
{
InitCipher();
}
Span ctrBlock = stackalloc byte[BlockSize];
//GetNextCtrBlock(ctrBlock);
if (blocksRemaining == 0)
throw new InvalidOperationException("Attempt to process too many blocks");
blocksRemaining--;
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
BinaryPrimitives.WriteUInt32BigEndian(counter.AsSpan(12), ++counter32);
#else
Pack.UInt32_To_BE(++counter32, counter, 12);
#endif
cipher.ProcessBlock(counter, ctrBlock);
ReadOnlySpan uInput = MemoryMarshal.Cast(input);
Span uS = MemoryMarshal.Cast(S);
ReadOnlySpan uCtrBlock = MemoryMarshal.Cast(ctrBlock);
Span uOutput = MemoryMarshal.Cast(outputSample);
uS[0] ^= uInput[0];
uOutput[0] = uInput[0] ^ uCtrBlock[0];
uS[1] ^= uInput[1];
uOutput[1] = uInput[1] ^ uCtrBlock[1];
uS[2] ^= uInput[2];
uOutput[2] = uInput[2] ^ uCtrBlock[2];
uS[3] ^= uInput[3];
uOutput[3] = uInput[3] ^ uCtrBlock[3];
multiplier.MultiplyH(S);
input = input[BlockSize..];
outputSample = outputSample[BlockSize..];
//GetNextCtrBlock(ctrBlock);
if (blocksRemaining == 0)
throw new InvalidOperationException("Attempt to process too many blocks");
blocksRemaining--;
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
BinaryPrimitives.WriteUInt32BigEndian(counter.AsSpan(12), ++counter32);
#else
Pack.UInt32_To_BE(++counter32, counter, 12);
#endif
cipher.ProcessBlock(counter, ctrBlock);
uInput = MemoryMarshal.Cast(input);
uS = MemoryMarshal.Cast(S);
uCtrBlock = MemoryMarshal.Cast(ctrBlock);
uOutput = MemoryMarshal.Cast(outputSample);
uS[0] ^= uInput[0];
uOutput[0] = uInput[0] ^ uCtrBlock[0];
uS[1] ^= uInput[1];
uOutput[1] = uInput[1] ^ uCtrBlock[1];
uS[2] ^= uInput[2];
uOutput[2] = uInput[2] ^ uCtrBlock[2];
uS[3] ^= uInput[3];
uOutput[3] = uInput[3] ^ uCtrBlock[3];
multiplier.MultiplyH(S);
totalLength += BlockSize * 2;
//input = input[(BlockSize * 2)..];
input = input[BlockSize..];
resultLen += BlockSize * 2;
}
if (input.Length >= inLimit1)
{
DecryptBlock(input, output[resultLen..]);
input = input[BlockSize..];
resultLen += BlockSize;
}
bufOff = input.Length;
input.CopyTo(bufBlock);
}
return resultLen;
}
#endif
public int DoFinal(byte[] output, int outOff)
{
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
return DoFinal(output.AsSpan(outOff));
#else
CheckStatus();
if (totalLength == 0)
{
InitCipher();
}
int extra = bufOff;
if (forEncryption)
{
Check.OutputLength(output, outOff, extra + macSize, "output buffer too short");
}
else
{
if (extra < macSize)
throw new InvalidCipherTextException("data too short");
extra -= macSize;
Check.OutputLength(output, outOff, extra, "output buffer too short");
}
if (extra > 0)
{
ProcessPartial(bufBlock, 0, extra, output, outOff);
}
atLength += (uint)atBlockPos;
if (atLength > atLengthPre)
{
/*
* Some AAD was sent after the cipher started. We determine the difference b/w the hash value
* we actually used when the cipher started (S_atPre) and the final hash value calculated (S_at).
* Then we carry this difference forward by multiplying by H^c, where c is the number of (full or
* partial) cipher-text blocks produced, and adjust the current hash.
*/
// Finish hash for partial AAD block
if (atBlockPos > 0)
{
gHASHPartial(S_at, atBlock, 0, atBlockPos);
}
// Find the difference between the AAD hashes
if (atLengthPre > 0)
{
GcmUtilities.Xor(S_at, S_atPre);
}
// Number of cipher-text blocks produced
long c = (long)(((totalLength * 8) + 127) >> 7);
// Calculate the adjustment factor
byte[] H_c = new byte[16];
if (exp == null)
{
exp = new BasicGcmExponentiator();
exp.Init(H);
}
exp.ExponentiateX(c, H_c);
// Carry the difference forward
GcmUtilities.Multiply(S_at, H_c);
// Adjust the current hash
GcmUtilities.Xor(S, S_at);
}
// Final gHASH
byte[] X = new byte[BlockSize];
Pack.UInt64_To_BE(atLength * 8UL, X, 0);
Pack.UInt64_To_BE(totalLength * 8UL, X, 8);
gHASHBlock(S, X);
// T = MSBt(GCTRk(J0,S))
byte[] tag = new byte[BlockSize];
cipher.ProcessBlock(J0, 0, tag, 0);
GcmUtilities.Xor(tag, S);
int resultLen = extra;
// We place into macBlock our calculated value for T
this.macBlock = new byte[macSize];
Array.Copy(tag, 0, macBlock, 0, macSize);
if (forEncryption)
{
// Append T to the message
Array.Copy(macBlock, 0, output, outOff + bufOff, macSize);
resultLen += macSize;
}
else
{
// Retrieve the T value from the message and compare to calculated one
byte[] msgMac = new byte[macSize];
Array.Copy(bufBlock, extra, msgMac, 0, macSize);
if (!Arrays.ConstantTimeAreEqual(this.macBlock, msgMac))
throw new InvalidCipherTextException("mac check in GCM failed");
}
Reset(false);
return resultLen;
#endif
}
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
public int DoFinal(Span output)
{
CheckStatus();
if (totalLength == 0)
{
InitCipher();
}
int extra = bufOff;
if (forEncryption)
{
Check.OutputLength(output, extra + macSize, "output buffer too short");
}
else
{
if (extra < macSize)
throw new InvalidCipherTextException("data too short");
extra -= macSize;
Check.OutputLength(output, extra, "output buffer too short");
}
if (extra > 0)
{
ProcessPartial(bufBlock.AsSpan(0, extra), output);
}
atLength += (uint)atBlockPos;
if (atLength > atLengthPre)
{
/*
* Some AAD was sent after the cipher started. We determine the difference b/w the hash value
* we actually used when the cipher started (S_atPre) and the final hash value calculated (S_at).
* Then we carry this difference forward by multiplying by H^c, where c is the number of (full or
* partial) cipher-text blocks produced, and adjust the current hash.
*/
// Finish hash for partial AAD block
if (atBlockPos > 0)
{
gHASHPartial(S_at, atBlock, 0, atBlockPos);
}
// Find the difference between the AAD hashes
if (atLengthPre > 0)
{
GcmUtilities.Xor(S_at, S_atPre);
}
// Number of cipher-text blocks produced
long c = (long)(((totalLength * 8) + 127) >> 7);
// Calculate the adjustment factor
byte[] H_c = new byte[16];
if (exp == null)
{
exp = new BasicGcmExponentiator();
exp.Init(H);
}
exp.ExponentiateX(c, H_c);
// Carry the difference forward
GcmUtilities.Multiply(S_at, H_c);
// Adjust the current hash
GcmUtilities.Xor(S, S_at);
}
// Final gHASH
Span X = stackalloc byte[BlockSize];
Pack.UInt64_To_BE(atLength * 8UL, X);
Pack.UInt64_To_BE(totalLength * 8UL, X[8..]);
gHASHBlock(S, X);
// T = MSBt(GCTRk(J0,S))
Span tag = stackalloc byte[BlockSize];
cipher.ProcessBlock(J0, tag);
GcmUtilities.Xor(tag, S);
int resultLen = extra;
// We place into macBlock our calculated value for T
this.macBlock = new byte[macSize];
tag[..macSize].CopyTo(macBlock);
if (forEncryption)
{
// Append T to the message
macBlock.CopyTo(output[bufOff..]);
resultLen += macSize;
}
else
{
// Retrieve the T value from the message and compare to calculated one
Span msgMac = stackalloc byte[macSize];
bufBlock.AsSpan(extra, macSize).CopyTo(msgMac);
if (!Arrays.ConstantTimeAreEqual(this.macBlock, msgMac))
throw new InvalidCipherTextException("mac check in GCM failed");
}
Reset(false);
return resultLen;
}
#endif
public void Reset()
{
Reset(true);
}
private void Reset(bool clearMac)
{
// note: we do not reset the nonce.
S = new byte[BlockSize];
S_at = new byte[BlockSize];
S_atPre = new byte[BlockSize];
atBlock = new byte[BlockSize];
atBlockPos = 0;
atLength = 0;
atLengthPre = 0;
counter = Arrays.Clone(J0);
counter32 = Pack.BE_To_UInt32(counter, 12);
blocksRemaining = uint.MaxValue - 1;
bufOff = 0;
totalLength = 0;
if (bufBlock != null)
{
Arrays.Fill(bufBlock, 0);
}
if (clearMac)
{
macBlock = null;
}
if (forEncryption)
{
initialised = false;
}
else
{
if (initialAssociatedText != null)
{
ProcessAadBytes(initialAssociatedText, 0, initialAssociatedText.Length);
}
}
}
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
private void DecryptBlock(ReadOnlySpan input, Span output)
{
Check.OutputLength(output, BlockSize, "output buffer too short");
if (totalLength == 0)
{
InitCipher();
}
Span ctrBlock = stackalloc byte[BlockSize];
GetNextCtrBlock(ctrBlock);
#if BESTHTTP_WITH_BURST
FastGcmBlockCipherHelper.DecryptBlock(input, output, ctrBlock, S.AsSpan(), BlockSize);
#elif NETCOREAPP3_0_OR_GREATER
if (Sse2.IsSupported && Unsafe.SizeOf>() == BlockSize)
{
var t0 = MemoryMarshal.Read>(input);
var t1 = MemoryMarshal.Read>(ctrBlock);
var t2 = MemoryMarshal.Read>(S.AsSpan());
t1 = Sse2.Xor(t1, t0);
t2 = Sse2.Xor(t2, t0);
MemoryMarshal.Write(output, ref t1);
MemoryMarshal.Write(S.AsSpan(), ref t2);
}
else
#else
{
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = input[i + 0];
byte c1 = input[i + 1];
byte c2 = input[i + 2];
byte c3 = input[i + 3];
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
output[i + 0] = (byte)(c0 ^ ctrBlock[i + 0]);
output[i + 1] = (byte)(c1 ^ ctrBlock[i + 1]);
output[i + 2] = (byte)(c2 ^ ctrBlock[i + 2]);
output[i + 3] = (byte)(c3 ^ ctrBlock[i + 3]);
}
}
#endif
multiplier.MultiplyH(S);
totalLength += BlockSize;
}
private void DecryptBlocks2(ReadOnlySpan input, Span outputSample)
{
Check.OutputLength(outputSample, BlockSize * 2, "output buffer too short");
if (totalLength == 0)
{
InitCipher();
}
Span ctrBlock = stackalloc byte[BlockSize];
GetNextCtrBlock(ctrBlock);
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = input[i + 0];
byte c1 = input[i + 1];
byte c2 = input[i + 2];
byte c3 = input[i + 3];
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
outputSample[i + 0] = (byte)(c0 ^ ctrBlock[i + 0]);
outputSample[i + 1] = (byte)(c1 ^ ctrBlock[i + 1]);
outputSample[i + 2] = (byte)(c2 ^ ctrBlock[i + 2]);
outputSample[i + 3] = (byte)(c3 ^ ctrBlock[i + 3]);
}
multiplier.MultiplyH(S);
input = input[BlockSize..];
outputSample = outputSample[BlockSize..];
GetNextCtrBlock(ctrBlock);
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = input[i + 0];
byte c1 = input[i + 1];
byte c2 = input[i + 2];
byte c3 = input[i + 3];
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
outputSample[i + 0] = (byte)(c0 ^ ctrBlock[i + 0]);
outputSample[i + 1] = (byte)(c1 ^ ctrBlock[i + 1]);
outputSample[i + 2] = (byte)(c2 ^ ctrBlock[i + 2]);
outputSample[i + 3] = (byte)(c3 ^ ctrBlock[i + 3]);
}
multiplier.MultiplyH(S);
totalLength += BlockSize * 2;
}
private void EncryptBlock(ReadOnlySpan input, Span output)
{
Check.OutputLength(output, BlockSize, "output buffer too short");
if (totalLength == 0)
{
InitCipher();
}
Span ctrBlock = stackalloc byte[BlockSize];
GetNextCtrBlock(ctrBlock);
#if NETCOREAPP3_0_OR_GREATER
if (Sse2.IsSupported && Unsafe.SizeOf>() == BlockSize)
{
var t0 = MemoryMarshal.Read>(input);
var t1 = MemoryMarshal.Read>(ctrBlock);
var t2 = MemoryMarshal.Read>(S.AsSpan());
t1 = Sse2.Xor(t1, t0);
t2 = Sse2.Xor(t2, t1);
MemoryMarshal.Write(output, ref t1);
MemoryMarshal.Write(S.AsSpan(), ref t2);
}
else
#endif
{
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = (byte)(ctrBlock[i + 0] ^ input[i + 0]);
byte c1 = (byte)(ctrBlock[i + 1] ^ input[i + 1]);
byte c2 = (byte)(ctrBlock[i + 2] ^ input[i + 2]);
byte c3 = (byte)(ctrBlock[i + 3] ^ input[i + 3]);
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
output[i + 0] = c0;
output[i + 1] = c1;
output[i + 2] = c2;
output[i + 3] = c3;
}
}
multiplier.MultiplyH(S);
totalLength += BlockSize;
}
private void EncryptBlocks2(ReadOnlySpan input, Span output)
{
Check.OutputLength(output, BlockSize * 2, "Output buffer too short");
if (totalLength == 0)
{
InitCipher();
}
Span ctrBlock = stackalloc byte[BlockSize];
GetNextCtrBlock(ctrBlock);
#if NETCOREAPP3_0_OR_GREATER
if (Sse2.IsSupported && Unsafe.SizeOf>() == BlockSize)
{
var t0 = MemoryMarshal.Read>(input);
var t1 = MemoryMarshal.Read>(ctrBlock);
var t2 = MemoryMarshal.Read>(S.AsSpan());
t1 = Sse2.Xor(t1, t0);
t2 = Sse2.Xor(t2, t1);
MemoryMarshal.Write(output, ref t1);
MemoryMarshal.Write(S.AsSpan(), ref t2);
}
else
#endif
{
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = (byte)(ctrBlock[i + 0] ^ input[i + 0]);
byte c1 = (byte)(ctrBlock[i + 1] ^ input[i + 1]);
byte c2 = (byte)(ctrBlock[i + 2] ^ input[i + 2]);
byte c3 = (byte)(ctrBlock[i + 3] ^ input[i + 3]);
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
output[i + 0] = c0;
output[i + 1] = c1;
output[i + 2] = c2;
output[i + 3] = c3;
}
}
multiplier.MultiplyH(S);
input = input[BlockSize..];
output = output[BlockSize..];
GetNextCtrBlock(ctrBlock);
#if NETCOREAPP3_0_OR_GREATER
if (Sse2.IsSupported && Unsafe.SizeOf>() == BlockSize)
{
var t0 = MemoryMarshal.Read>(input);
var t1 = MemoryMarshal.Read>(ctrBlock);
var t2 = MemoryMarshal.Read>(S.AsSpan());
t1 = Sse2.Xor(t1, t0);
t2 = Sse2.Xor(t2, t1);
MemoryMarshal.Write(output, ref t1);
MemoryMarshal.Write(S.AsSpan(), ref t2);
}
else
#endif
{
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = (byte)(ctrBlock[i + 0] ^ input[i + 0]);
byte c1 = (byte)(ctrBlock[i + 1] ^ input[i + 1]);
byte c2 = (byte)(ctrBlock[i + 2] ^ input[i + 2]);
byte c3 = (byte)(ctrBlock[i + 3] ^ input[i + 3]);
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
output[i + 0] = c0;
output[i + 1] = c1;
output[i + 2] = c2;
output[i + 3] = c3;
}
}
multiplier.MultiplyH(S);
totalLength += BlockSize * 2;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private void GetNextCtrBlock(Span block)
{
if (blocksRemaining == 0)
throw new InvalidOperationException("Attempt to process too many blocks");
blocksRemaining--;
Pack.UInt32_To_BE(++counter32, counter, 12);
cipher.ProcessBlock(counter, block);
}
private void ProcessPartial(Span partialBlock, Span output)
{
Span ctrBlock = stackalloc byte[BlockSize];
GetNextCtrBlock(ctrBlock);
if (forEncryption)
{
GcmUtilities.Xor(partialBlock, ctrBlock, partialBlock.Length);
gHASHPartial(S, partialBlock);
}
else
{
gHASHPartial(S, partialBlock);
GcmUtilities.Xor(partialBlock, ctrBlock, partialBlock.Length);
}
partialBlock.CopyTo(output);
totalLength += (uint)partialBlock.Length;
}
#else
private void DecryptBlock(byte[] inBuf, int inOff, byte[] outBuf, int outOff)
{
Check.OutputLength(outBuf, outOff, BlockSize, "Output buffer too short");
if (totalLength == 0)
{
InitCipher();
}
//byte[] ctrBlock = new byte[BlockSize];
GetNextCtrBlock(ctrBlock);
{
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = inBuf[inOff + i + 0];
byte c1 = inBuf[inOff + i + 1];
byte c2 = inBuf[inOff + i + 2];
byte c3 = inBuf[inOff + i + 3];
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
outBuf[outOff + i + 0] = (byte)(c0 ^ ctrBlock[i + 0]);
outBuf[outOff + i + 1] = (byte)(c1 ^ ctrBlock[i + 1]);
outBuf[outOff + i + 2] = (byte)(c2 ^ ctrBlock[i + 2]);
outBuf[outOff + i + 3] = (byte)(c3 ^ ctrBlock[i + 3]);
}
}
multiplier.MultiplyH(S);
totalLength += BlockSize;
}
private void DecryptBlocks2(byte[] inBuf, int inOff, byte[] outBuf, int outOff)
{
Check.OutputLength(outBuf, outOff, BlockSize * 2, "Output buffer too short");
if (totalLength == 0)
{
InitCipher();
}
//byte[] ctrBlock = new byte[BlockSize];
GetNextCtrBlock(ctrBlock);
{
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = inBuf[inOff + i + 0];
byte c1 = inBuf[inOff + i + 1];
byte c2 = inBuf[inOff + i + 2];
byte c3 = inBuf[inOff + i + 3];
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
outBuf[outOff + i + 0] = (byte)(c0 ^ ctrBlock[i + 0]);
outBuf[outOff + i + 1] = (byte)(c1 ^ ctrBlock[i + 1]);
outBuf[outOff + i + 2] = (byte)(c2 ^ ctrBlock[i + 2]);
outBuf[outOff + i + 3] = (byte)(c3 ^ ctrBlock[i + 3]);
}
}
multiplier.MultiplyH(S);
inOff += BlockSize;
outOff += BlockSize;
GetNextCtrBlock(ctrBlock);
{
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = inBuf[inOff + i + 0];
byte c1 = inBuf[inOff + i + 1];
byte c2 = inBuf[inOff + i + 2];
byte c3 = inBuf[inOff + i + 3];
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
outBuf[outOff + i + 0] = (byte)(c0 ^ ctrBlock[i + 0]);
outBuf[outOff + i + 1] = (byte)(c1 ^ ctrBlock[i + 1]);
outBuf[outOff + i + 2] = (byte)(c2 ^ ctrBlock[i + 2]);
outBuf[outOff + i + 3] = (byte)(c3 ^ ctrBlock[i + 3]);
}
}
multiplier.MultiplyH(S);
totalLength += BlockSize * 2;
}
private void EncryptBlock(byte[] inBuf, int inOff, byte[] outBuf, int outOff)
{
Check.OutputLength(outBuf, outOff, BlockSize, "Output buffer too short");
if (totalLength == 0)
{
InitCipher();
}
//byte[] ctrBlock = new byte[BlockSize];
GetNextCtrBlock(ctrBlock);
{
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = (byte)(ctrBlock[i + 0] ^ inBuf[inOff + i + 0]);
byte c1 = (byte)(ctrBlock[i + 1] ^ inBuf[inOff + i + 1]);
byte c2 = (byte)(ctrBlock[i + 2] ^ inBuf[inOff + i + 2]);
byte c3 = (byte)(ctrBlock[i + 3] ^ inBuf[inOff + i + 3]);
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
outBuf[outOff + i + 0] = c0;
outBuf[outOff + i + 1] = c1;
outBuf[outOff + i + 2] = c2;
outBuf[outOff + i + 3] = c3;
}
}
multiplier.MultiplyH(S);
totalLength += BlockSize;
}
private void EncryptBlocks2(byte[] inBuf, int inOff, byte[] outBuf, int outOff)
{
Check.OutputLength(outBuf, outOff, BlockSize * 2, "Output buffer too short");
if (totalLength == 0)
{
InitCipher();
}
//byte[] ctrBlock = new byte[BlockSize];
GetNextCtrBlock(ctrBlock);
{
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = (byte)(ctrBlock[i + 0] ^ inBuf[inOff + i + 0]);
byte c1 = (byte)(ctrBlock[i + 1] ^ inBuf[inOff + i + 1]);
byte c2 = (byte)(ctrBlock[i + 2] ^ inBuf[inOff + i + 2]);
byte c3 = (byte)(ctrBlock[i + 3] ^ inBuf[inOff + i + 3]);
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
outBuf[outOff + i + 0] = c0;
outBuf[outOff + i + 1] = c1;
outBuf[outOff + i + 2] = c2;
outBuf[outOff + i + 3] = c3;
}
}
multiplier.MultiplyH(S);
inOff += BlockSize;
outOff += BlockSize;
GetNextCtrBlock(ctrBlock);
{
for (int i = 0; i < BlockSize; i += 4)
{
byte c0 = (byte)(ctrBlock[i + 0] ^ inBuf[inOff + i + 0]);
byte c1 = (byte)(ctrBlock[i + 1] ^ inBuf[inOff + i + 1]);
byte c2 = (byte)(ctrBlock[i + 2] ^ inBuf[inOff + i + 2]);
byte c3 = (byte)(ctrBlock[i + 3] ^ inBuf[inOff + i + 3]);
S[i + 0] ^= c0;
S[i + 1] ^= c1;
S[i + 2] ^= c2;
S[i + 3] ^= c3;
outBuf[outOff + i + 0] = c0;
outBuf[outOff + i + 1] = c1;
outBuf[outOff + i + 2] = c2;
outBuf[outOff + i + 3] = c3;
}
}
multiplier.MultiplyH(S);
totalLength += BlockSize * 2;
}
private void GetNextCtrBlock(byte[] block)
{
if (blocksRemaining == 0)
throw new InvalidOperationException("Attempt to process too many blocks");
blocksRemaining--;
Pack.UInt32_To_BE(++counter32, counter, 12);
cipher.ProcessBlock(counter, 0, block, 0);
}
private void ProcessPartial(byte[] buf, int off, int len, byte[] output, int outOff)
{
//byte[] ctrBlock = new byte[BlockSize];
GetNextCtrBlock(ctrBlock);
if (forEncryption)
{
GcmUtilities.Xor(buf, off, ctrBlock, 0, len);
gHASHPartial(S, buf, off, len);
}
else
{
gHASHPartial(S, buf, off, len);
GcmUtilities.Xor(buf, off, ctrBlock, 0, len);
}
Array.Copy(buf, off, output, outOff, len);
totalLength += (uint)len;
}
#endif
private void gHASH(byte[] Y, byte[] b, int len)
{
for (int pos = 0; pos < len; pos += BlockSize)
{
int num = System.Math.Min(len - pos, BlockSize);
gHASHPartial(Y, b, pos, num);
}
}
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private void gHASHBlock(byte[] Y, ReadOnlySpan b)
{
GcmUtilities.Xor(Y, b);
multiplier.MultiplyH(Y);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private void gHASHPartial(byte[] Y, ReadOnlySpan b)
{
GcmUtilities.Xor(Y, b, b.Length);
multiplier.MultiplyH(Y);
}
#else
private void gHASHBlock(byte[] Y, byte[] b)
{
GcmUtilities.Xor(Y, b);
multiplier.MultiplyH(Y);
}
private void gHASHBlock(byte[] Y, byte[] b, int off)
{
GcmUtilities.Xor(Y, b, off);
multiplier.MultiplyH(Y);
}
#endif
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private void gHASHPartial(byte[] Y, byte[] b, int off, int len)
{
GcmUtilities.Xor(Y, b, off, len);
multiplier.MultiplyH(Y);
}
private void CheckStatus()
{
if (!initialised)
{
if (forEncryption)
{
throw new InvalidOperationException("GCM cipher cannot be reused for encryption");
}
throw new InvalidOperationException("GCM cipher needs to be initialised");
}
}
}
}
#pragma warning restore
#endif