// Token: 0x06000070 RID: 112 RVA: 0x00008B70 File Offset: 0x00006D70
public void Init(byte[] H)
{
this.M[0] = new uint[16][];
this.M[1] = new uint[16][];
this.M[0][0] = new uint[4];
this.M[1][0] = new uint[4];
this.M[1][8] = GcmUtilities.AsUints(H);
for (int i = 4; i >= 1; i >>= 1)
{
uint[] array = (uint[])this.M[1][i + i].Clone();
GcmUtilities.MultiplyP(array);
this.M[1][i] = array;
}
uint[] array2 = (uint[])this.M[1][1].Clone();
GcmUtilities.MultiplyP(array2);
this.M[0][8] = array2;
for (int j = 4; j >= 1; j >>= 1)
{
uint[] array3 = (uint[])this.M[0][j + j].Clone();
GcmUtilities.MultiplyP(array3);
this.M[0][j] = array3;
}
int num = 0;
for (;;)
{
for (int k = 2; k < 16; k += k)
{
for (int l = 1; l < k; l++)
{
uint[] array4 = (uint[])this.M[num][k].Clone();
GcmUtilities.Xor(array4, this.M[num][l]);
this.M[num][k + l] = array4;
}
}
if (++num == 32)
{
break;
}
if (num > 1)
{
this.M[num] = new uint[16][];
this.M[num][0] = new uint[4];
for (int m = 8; m > 0; m >>= 1)
{
uint[] array5 = (uint[])this.M[num - 2][m].Clone();
GcmUtilities.MultiplyP8(array5);
this.M[num][m] = array5;
}
}
}
}
// Token: 0x06000082 RID: 130 RVA: 0x00009464 File Offset: 0x00007664
private byte[] gHASH(byte[] b)
{
byte[] array = new byte[16];
for (int i = 0; i < b.Length; i += 16)
{
byte[] array2 = new byte[16];
int length = Math.Min(b.Length - i, 16);
Array.Copy(b, i, array2, 0, length);
GcmUtilities.Xor(array, array2);
this.multiplier.MultiplyH(array);
}
return(array);
}
// Token: 0x0600007E RID: 126 RVA: 0x000091C0 File Offset: 0x000073C0
public int DoFinal(byte[] output, int outOff)
{
int num = this.bufOff;
if (!this.forEncryption)
{
if (num < this.macSize)
{
throw new InvalidCipherTextException("data too short");
}
num -= this.macSize;
}
if (num > 0)
{
byte[] array = new byte[16];
Array.Copy(this.bufBlock, 0, array, 0, num);
this.gCTRBlock(array, num, output, outOff);
}
byte[] array2 = new byte[16];
GcmBlockCipher.packLength((ulong)((long)this.A.Length * 8L), array2, 0);
GcmBlockCipher.packLength(this.totalLength * 8UL, array2, 8);
GcmUtilities.Xor(this.S, array2);
this.multiplier.MultiplyH(this.S);
byte[] array3 = new byte[16];
this.cipher.ProcessBlock(this.J0, 0, array3, 0);
GcmUtilities.Xor(array3, this.S);
int num2 = num;
this.macBlock = new byte[this.macSize];
Array.Copy(array3, 0, this.macBlock, 0, this.macSize);
if (this.forEncryption)
{
Array.Copy(this.macBlock, 0, output, outOff + this.bufOff, this.macSize);
num2 += this.macSize;
}
else
{
byte[] array4 = new byte[this.macSize];
Array.Copy(this.bufBlock, num, array4, 0, this.macSize);
if (!Arrays.ConstantTimeAreEqual(this.macBlock, array4))
{
throw new InvalidCipherTextException("mac check in GCM failed");
}
}
this.Reset(false);
return(num2);
}
// Token: 0x06000081 RID: 129 RVA: 0x0000939C File Offset: 0x0000759C
private void gCTRBlock(byte[] buf, int bufCount, byte[] output, int outOff)
{
for (int i = 15; i >= 12; i--)
{
byte[] array = this.counter;
int num = i;
byte b = array[num] + 1;
array[num] = b;
if (b != 0)
{
break;
}
}
byte[] array2 = new byte[16];
this.cipher.ProcessBlock(this.counter, 0, array2, 0);
byte[] val;
if (this.forEncryption)
{
Array.Copy(GcmBlockCipher.Zeroes, bufCount, array2, bufCount, 16 - bufCount);
val = array2;
}
else
{
val = buf;
}
for (int j = bufCount - 1; j >= 0; j--)
{
byte[] array3 = array2;
int num2 = j;
array3[num2] ^= buf[j];
output[outOff + j] = array2[j];
}
GcmUtilities.Xor(this.S, val);
this.multiplier.MultiplyH(this.S);
this.totalLength += (ulong)((long)bufCount);
}
// Token: 0x06000077 RID: 119 RVA: 0x00008E70 File Offset: 0x00007070
public virtual void Init(bool forEncryption, ICipherParameters parameters)
{
this.forEncryption = forEncryption;
this.macBlock = null;
if (parameters is AeadParameters)
{
AeadParameters aeadParameters = (AeadParameters)parameters;
this.nonce = aeadParameters.GetNonce();
this.A = aeadParameters.GetAssociatedText();
int num = aeadParameters.MacSize;
if (num < 96 || num > 128 || num % 8 != 0)
{
throw new ArgumentException("Invalid value for MAC size: " + num.ToString());
}
this.macSize = num / 8;
this.keyParam = aeadParameters.Key;
}
else
{
if (!(parameters is ParametersWithIV))
{
throw new ArgumentException("invalid parameters passed to GCM");
}
ParametersWithIV parametersWithIV = (ParametersWithIV)parameters;
this.nonce = parametersWithIV.GetIV();
this.A = null;
this.macSize = 16;
this.keyParam = (KeyParameter)parametersWithIV.Parameters;
}
int num2 = forEncryption ? 16 : (16 + this.macSize);
this.bufBlock = new byte[num2];
if (this.nonce == null || this.nonce.Length < 1)
{
throw new ArgumentException("IV must be at least 1 byte");
}
if (this.A == null)
{
this.A = new byte[0];
}
this.cipher.Init(true, this.keyParam);
this.H = new byte[16];
this.cipher.ProcessBlock(this.H, 0, this.H, 0);
this.multiplier.Init(this.H);
this.initS = this.gHASH(this.A);
if (this.nonce.Length == 12)
{
this.J0 = new byte[16];
Array.Copy(this.nonce, 0, this.J0, 0, this.nonce.Length);
this.J0[15] = 1;
}
else
{
this.J0 = this.gHASH(this.nonce);
byte[] array = new byte[16];
GcmBlockCipher.packLength((ulong)((long)this.nonce.Length * 8L), array, 8);
GcmUtilities.Xor(this.J0, array);
this.multiplier.MultiplyH(this.J0);
}
this.S = Arrays.Clone(this.initS);
this.counter = Arrays.Clone(this.J0);
this.bufOff = 0;
this.totalLength = 0UL;
}
