/// <summary>
/// Decrypts the given encrypted text with an AEAD encryption algorithm
/// </summary>
/// <param name="symmetricBlockAlgorithm">string SymmetricBlockAlgorithm enum, symmetric block algorithm name</param>
/// <param name="symmetricBlockMode">string SymmetricBlockModes enum, symmetric block mode name</param>
/// <param name="key">string Hexa key for the algorithm excecution</param>
/// <param name="macSize">int macSize in bits for MAC length for AEAD Encryption algorithm</param>
/// <param name="nonce">string Hexa nonce for MAC length for AEAD Encryption algorithm</param>
/// <param name="encryptedInput">string Base64 text to decrypt</param>
/// <returns></returns>
public string DoAEADDecrypt(string symmetricBlockAlgorithm, string symmetricBlockMode,
string key, int macSize, string nonce, string encryptedInput)
{
this.error.cleanError();
SymmetricBlockAlgorithm algorithm = SymmetricBlockAlgorithmUtils.getSymmetricBlockAlgorithm(symmetricBlockAlgorithm, this.error);
SymmetricBlockMode mode = SymmetricBlockModeUtils.getSymmetricBlockMode(symmetricBlockMode, this.error);
if (this.error.existsError())
{
return("");
}
IBlockCipher engine = getCipherEngine(algorithm);
IAeadBlockCipher bbc = getAEADCipherMode(engine, mode);
if (this.error.existsError() && !(string.Compare(this.error.Code, "SB016", true) == 0))
{
return("");
}
byte[] nonceBytes = SecurityUtils.GetHexa(nonce, "SB025", this.error);
byte[] keyBytes = SecurityUtils.GetHexa(key, "SB025", this.error);
if (this.HasError())
{
return("");
}
KeyParameter keyParam = new KeyParameter(keyBytes);
AeadParameters AEADparams = new AeadParameters(keyParam, macSize, nonceBytes);
try
{
bbc.Init(false, AEADparams);
}catch (Exception e)
{
this.error.setError("SB030", e.Message);
return("");
}
byte[] out2 = Base64.Decode(encryptedInput);
byte[] comparisonBytes = new byte[bbc.GetOutputSize(out2.Length)];
int length = bbc.ProcessBytes(out2, 0, out2.Length, comparisonBytes, 0);
try
{
bbc.DoFinal(comparisonBytes, length);
}
catch (Exception)
{
this.error.setError("SB012", "AEAD decryption exception");
return("");
}
this.error.cleanError();
// return System.Text.Encoding.UTF8.GetString(comparisonBytes).Trim();
EncodingUtil eu = new EncodingUtil();
this.error = eu.GetError();
return(eu.getString(comparisonBytes));
}
private bool isValidAlgorithm(string algorithm)
{
SymmetricBlockAlgorithm symmetricBlockAlgorithm = SymmetricBlockAlgorithmUtils.getSymmetricBlockAlgorithm(algorithm,
this.error);
int blockSize = SymmetricBlockAlgorithmUtils.getBlockSize(symmetricBlockAlgorithm, this.error);
if (this.HasError())
{
return(false);
}
if (blockSize != 64 && blockSize != 128)
{
return(false);
}
return(true);
}
/********EXTERNAL OBJECT PUBLIC METHODS - BEGIN ********/
/// <summary>
/// Encrypts the given text with an AEAD encryption algorithm
/// </summary>
/// <param name="symmetricBlockAlgorithm">string SymmetricBlockAlgorithm enum, symmetric block algorithm name</param>
/// <param name="symmetricBlockMode">string SymmetricBlockModes enum, symmetric block mode name</param>
/// <param name="key">string Hexa key for the algorithm excecution</param>
/// <param name="macSize">int macSize in bits for MAC length for AEAD Encryption algorithm</param>
/// <param name="nonce">string Hexa nonce for MAC length for AEAD Encryption algorithm</param>
/// <param name="plainText"> string UTF-8 plain text to encrypt</param>
/// <returns></returns>
public string DoAEADEncrypt(string symmetricBlockAlgorithm, string symmetricBlockMode,
string key, int macSize, string nonce, string plainText)
{
this.error.cleanError();
SymmetricBlockAlgorithm algorithm = SymmetricBlockAlgorithmUtils.getSymmetricBlockAlgorithm(symmetricBlockAlgorithm, this.error);
SymmetricBlockMode mode = SymmetricBlockModeUtils.getSymmetricBlockMode(symmetricBlockMode, this.error);
if (this.error.existsError())
{
return("");
}
IBlockCipher engine = getCipherEngine(algorithm);
IAeadBlockCipher bbc = getAEADCipherMode(engine, mode);
if (this.error.existsError() && !(string.Compare(this.error.Code, "SB016", true) == 0))
{
return("");
}
byte[] nonceBytes = SecurityUtils.GetHexa(nonce, "SB024", this.error);
byte[] keyBytes = SecurityUtils.GetHexa(key, "SB024", this.error);
if (this.HasError())
{
return("");
}
KeyParameter keyParam = new KeyParameter(keyBytes);
AeadParameters AEADparams = new AeadParameters(keyParam, macSize, nonceBytes);
try
{
bbc.Init(true, AEADparams);
}catch (Exception e)
{
this.error.setError("SB029", e.Message);
return("");
}
EncodingUtil eu = new EncodingUtil();
byte[] inputBytes = eu.getBytes(plainText);
if (eu.GetError().existsError())
{
this.error = eu.GetError();
return("");
}
byte[] outputBytes = new byte[bbc.GetOutputSize(inputBytes.Length)];
int length = bbc.ProcessBytes(inputBytes, 0, inputBytes.Length, outputBytes, 0);
try
{
bbc.DoFinal(outputBytes, length);
}
catch (Exception)
{
this.error.setError("SB010", "AEAD encryption exception");
return("");
}
string result = Base64.ToBase64String(outputBytes);
if (result == null || result.Length == 0)
{
this.error.setError("SB011", "Error encoding base64");
return("");
}
this.error.cleanError();
return(result);
}
public string DoDecrypt(string symmetricBlockAlgorithm, string symmetricBlockMode,
string symmetricBlockPadding, string key, string IV, string encryptedInput)
{
this.error.cleanError();
SymmetricBlockAlgorithm algorithm = SymmetricBlockAlgorithmUtils.getSymmetricBlockAlgorithm(symmetricBlockAlgorithm, this.error);
SymmetricBlockMode mode = SymmetricBlockModeUtils.getSymmetricBlockMode(symmetricBlockMode, this.error);
SymmetricBlockPadding padding = SymmetricBlockPaddingUtils.getSymmetricBlockPadding(symmetricBlockPadding, this.error);
if (this.error.existsError())
{
return("");
}
BufferedBlockCipher bbc = getCipher(algorithm, mode, padding);
if (this.error.existsError() && !(string.Compare(this.error.Code, "SB016", true) == 0))
{
return("");
}
byte[] bytesKey = SecurityUtils.GetHexa(key, "SB023", this.error);
byte[] bytesIV = SecurityUtils.GetHexa(IV, "SB023", this.error);
if (this.HasError())
{
return("");
}
KeyParameter keyParam = new KeyParameter(bytesKey);
if (SymmetricBlockMode.ECB != mode && SymmetricBlockMode.OPENPGPCFB != mode)
{
ParametersWithIV keyParamWithIV = new ParametersWithIV(keyParam, bytesIV);
try
{
bbc.Init(false, keyParamWithIV);
}catch (Exception e)
{
this.error.setError("SB027", e.Message);
return("");
}
}
else
{
try
{
bbc.Init(false, keyParam);
}catch (Exception e)
{
this.error.setError("SB028", e.Message);
return("");
}
}
byte[] out2 = Base64.Decode(encryptedInput);
byte[] comparisonBytes = new byte[bbc.GetOutputSize(out2.Length)];
int length = bbc.ProcessBytes(out2, 0, out2.Length, comparisonBytes, 0);
try
{
bbc.DoFinal(comparisonBytes, length);
}
catch (Exception)
{
this.error.setError("SB015", "Block decryption exception");
return("");
}
this.error.cleanError();
EncodingUtil eu = new EncodingUtil();
this.error = eu.GetError();
return(eu.getString(comparisonBytes));
}
public string DoEncrypt(string symmetricBlockAlgorithm, string symmetricBlockMode,
string symmetricBlockPadding, string key, string IV, string plainText)
{
this.error.cleanError();
SymmetricBlockAlgorithm algorithm = SymmetricBlockAlgorithmUtils.getSymmetricBlockAlgorithm(symmetricBlockAlgorithm, this.error);
SymmetricBlockMode mode = SymmetricBlockModeUtils.getSymmetricBlockMode(symmetricBlockMode, this.error);
SymmetricBlockPadding padding = SymmetricBlockPaddingUtils.getSymmetricBlockPadding(symmetricBlockPadding, this.error);
if (this.error.existsError())
{
return("");
}
BufferedBlockCipher bbc = getCipher(algorithm, mode, padding);
if (this.error.existsError() && !(string.Compare(this.error.Code, "SB016", true) == 0))
{
return("");
}
byte[] byteIV = SecurityUtils.GetHexa(IV, "SB022", this.error);
byte[] byteKey = SecurityUtils.GetHexa(key, "SB022", this.error);
if (this.HasError())
{
return("");
}
KeyParameter keyParam = new KeyParameter(byteKey);
if (SymmetricBlockMode.ECB != mode && SymmetricBlockMode.OPENPGPCFB != mode)
{
ParametersWithIV keyParamWithIV = new ParametersWithIV(keyParam, byteIV);
try{
bbc.Init(true, keyParamWithIV);
}catch (Exception e)
{
this.error.setError("SB025", e.Message);
return("");
}
}
else
{
try
{
bbc.Init(true, keyParam);
}catch (Exception e)
{
this.error.setError("SB026", e.Message);
return("");
}
}
EncodingUtil eu = new EncodingUtil();
byte[] inputBytes = eu.getBytes(plainText);
if (eu.GetError().existsError())
{
this.error = eu.GetError();
return("");
}
byte[] outputBytes = new byte[bbc.GetOutputSize(inputBytes.Length)];
int length = bbc.ProcessBytes(inputBytes, 0, inputBytes.Length, outputBytes, 0);
try
{
bbc.DoFinal(outputBytes, length);
}
catch (Exception)
{
this.error.setError("SB013", "Block encryption exception");
return("");
}
string result = Base64.ToBase64String(outputBytes);
if (result == null || result.Length == 0)
{
this.error.setError("SB014", "Error encoding base64");
return("");
}
this.error.cleanError();
return(result);
}
public string calculate(string plainText, string key, string algorithm, int macSize)
{
if (!isValidAlgorithm(algorithm))
{
this.error.setError("CM001", "Invalid Symmetric block algorithm for CMAC");
return("");
}
SymmetricBlockAlgorithm symmetricBlockAlgorithm = SymmetricBlockAlgorithmUtils.getSymmetricBlockAlgorithm(algorithm,
this.error);
SymmetricBlockCipher symCipher = new SymmetricBlockCipher();
IBlockCipher blockCipher = symCipher.getCipherEngine(symmetricBlockAlgorithm);
if (symCipher.HasError())
{
this.error = symCipher.GetError();
return("");
}
if (macSize > blockCipher.GetBlockSize() * 8)
{
this.error.setError("CM002", "The mac length must be less or equal than the algorithm block size.");
return("");
}
byte[] byteKey = SecurityUtils.GetHexa(key, "CM003", this.error);
if (this.HasError())
{
return("");
}
EncodingUtil eu = new EncodingUtil();
byte[] byteInput = eu.getBytes(plainText);
ICipherParameters parms = new KeyParameter(byteKey);
CMac mac = null;
if (macSize != 0)
{
mac = new CMac(blockCipher, macSize);
}
else
{
mac = new CMac(blockCipher);
}
try
{
mac.Init(parms);
}catch (Exception e)
{
this.error.setError("CM004", e.Message);
return("");
}
byte[] resBytes = new byte[mac.GetMacSize()];
mac.BlockUpdate(byteInput, 0, byteInput.Length);
mac.DoFinal(resBytes, 0);
string result = toHexastring(resBytes);
if (!this.error.existsError())
{
return(result);
}
return("");
}