/// <summary>
/// Generate a new digest and compute data hash.
/// </summary>
/// <param name="mode">MAC cipher mode.</param>
/// <param name="padding">MAC padding mode.</param>
/// <param name="parameters">Parameters.</param>
/// <param name="data">Data buffer bytes.</param>
/// <param name="offset">The starting offset to read.</param>
/// <param name="length">The length to read.</param>
/// <returns></returns>
public byte[] ComputeHash(MACCipherMode mode, MACPaddingMode padding, ICipherParameters parameters, byte[] data, int offset, int length)
{
IMac digest = GenerateDigest(mode, padding, parameters);
digest.BlockUpdate(data, offset, length);
byte[] hash = new byte[this.HashSize];
digest.DoFinal(hash, 0);
return(hash);
}
private static void Test4()
{
Array modes = Enum.GetValues(typeof(MACCipherMode));
Array paddings = Enum.GetValues(typeof(MACPaddingMode));
byte[] test = Utilities.ScoopBytes(123);
//
Type type = typeof(MACHelper);
PropertyInfo[] properties = type.GetProperties(BindingFlags.Static | BindingFlags.Public);
foreach (PropertyInfo property in properties)
{
if (property.GetValue(type, null) is IMAC algorithm)
{
foreach (int modeValue in modes)
{
MACCipherMode mode = (MACCipherMode)modeValue;
int keySize = GetQualitySize(algorithm.KeySizes);
byte[] key = Utilities.ScoopBytes(keySize / 8);
algorithm.TryGetIVSizes(mode, out KeySizes[] ivSizes);
int ivSize = GetQualitySize(ivSizes);
byte[] iv = Utilities.ScoopBytes(ivSize / 8);
ICipherParameters parameters = algorithm.GenerateParameters(key, iv);
foreach (int paddingValue in paddings)
{
_total++;
MACPaddingMode padding = (MACPaddingMode)paddingValue;
string mechanism = string.Format(CultureInfo.InvariantCulture, "{0}/{1}/{2}", algorithm.Mechanism, mode.ToString(), padding.ToString());
IMac digest = algorithm.GenerateDigest(mode, padding, parameters);
try
{
XTest(mechanism, digest, test);
_execute++;
}
catch (Exception)
{
Console.WriteLine("{0}-------- Ignored --------", mechanism.PadRight(32));
}
}
}
}
}
}
/// <summary>
/// Generate digest. The digest can be reused.
/// </summary>
/// <param name="mode">MAC cipher mode.</param>
/// <param name="padding">MAC padding mode.</param>
/// <param name="parameters">Parameters.</param>
/// <returns></returns>
/// <exception cref="Exception"/>
public IMac GenerateDigest(MACCipherMode mode, MACPaddingMode padding, ICipherParameters parameters)
{
IBlockCipherPadding pad;
switch (padding)
{
case MACPaddingMode.NoPadding: pad = null; break;
case MACPaddingMode.PKCS7: pad = Common.PKCS7Padding; break;
case MACPaddingMode.Zeros: pad = Common.ZEROBYTEPadding; break;
case MACPaddingMode.X923: pad = Common.X923Padding; break;
case MACPaddingMode.ISO7816_4: pad = Common.ISO7816d4Padding; break;
case MACPaddingMode.TBC: pad = Common.TBCPadding; break;
default: throw new CryptographicException("Unsupported padding mode.");
}
IMac digest;
switch (mode)
{
case MACCipherMode.CBC:
digest = pad is null ? new CbcBlockCipherMac(this.BlockAlgorithm.GenerateEngine(), this.HashSize)
: new CbcBlockCipherMac(this.BlockAlgorithm.GenerateEngine(), this.HashSize, pad);
break;
case MACCipherMode.CFB:
int cfbs = ((ParametersWithIV)parameters).GetIV().Length * 8;
digest = pad is null ? new CfbBlockCipherMac(this.BlockAlgorithm.GenerateEngine(), cfbs, this.HashSize)
: new CfbBlockCipherMac(this.BlockAlgorithm.GenerateEngine(), cfbs, this.HashSize, pad);
break;
default: throw new CryptographicException("Unsupported cipher mode.");
}
digest.Init(parameters);
return(digest);
}
/// <summary>
/// Generate a new digest and compute data hash.
/// </summary>
/// <param name="mode">MAC cipher mode.</param>
/// <param name="padding">MAC padding mode.</param>
/// <param name="parameters">Parameters.</param>
/// <param name="data">Data bytes.</param>
/// <returns></returns>
public byte[] ComputeHash(MACCipherMode mode, MACPaddingMode padding, ICipherParameters parameters, byte[] data)
{
return(ComputeHash(mode, padding, parameters, data, 0, data.Length));
}
