/// <summary>
/// Gets the length that an Iv value must have for the encryption algorithm specified by the method's argument.
/// </summary>
/// <param name="alg">Type of encryption algorithm.</param>
/// <returns>Int value representing string length.</returns>
public static int GetEncryptionKeyIvStringLength(pfEncryptionAlgorithm alg)
{
int stringLength = 16;
switch (alg)
{
case pfEncryptionAlgorithm.AES:
stringLength = 16;
break;
case pfEncryptionAlgorithm.DES:
stringLength = 8;
break;
case pfEncryptionAlgorithm.TripleDES:
stringLength = 16;
break;
default:
//default to AES
stringLength = 16;
break;
}
return(stringLength);
}
private int _statusReportIntervalSeconds = 5; //in seconds
//constructor
/// <summary>
/// Constructor initializes the Key and Iv values to defaults upon object creation.
/// Use Key and Iv properties to customize values to your application's requirements.
/// </summary>
/// <param name="alg">Encryption algorithm to use for this instance.</param>
public PFFileEncryptor(pfEncryptionAlgorithm alg)
{
switch (alg)
{
case pfEncryptionAlgorithm.AES:
_cryptoProvider = new AesCryptoServiceProvider();
break;
case pfEncryptionAlgorithm.DES:
_cryptoProvider = new DESCryptoServiceProvider();
break;
case pfEncryptionAlgorithm.TripleDES:
_cryptoProvider = new TripleDESCryptoServiceProvider();
break;
default:
_msg.Length = 0;
_msg.Append("Invalid or unexpected encryption algorithm: ");
_msg.Append(alg.ToString());
throw new System.Exception(_msg.ToString());
}
_encryptionAlgorithm = alg;
Initialize();
}
/// <summary>
/// Translates text description to a pfEncryptionAlgorithm enum value.
/// </summary>
/// <param name="typeDescription">String specifying the name of the algorithm.</param>
/// <returns>pfEncryptionAlgorithm value.</returns>
public static pfEncryptionAlgorithm GetEncryptionAlgorithm(string typeDescription)
{
pfEncryptionAlgorithm ret = pfEncryptionAlgorithm.NotSpecified;
switch (typeDescription)
{
case "AES":
ret = pfEncryptionAlgorithm.AES;
break;
case "DES":
ret = pfEncryptionAlgorithm.DES;
break;
case "TripleDES":
ret = pfEncryptionAlgorithm.TripleDES;
break;
default:
ret = pfEncryptionAlgorithm.Invalid;
break;
}
return(ret);
}
/// <summary>
/// Generate randomized Key and Iv values for symmetric encryption processing.
/// </summary>
/// <param name="typeEncryption">See <see cref="pfEncryptionAlgorithm"/> for list of valid values.</param>
/// <returns>pfKeyIvPair value.</returns>
public static pfKeyIvPair GenerateKeyIvPair(pfEncryptionAlgorithm typeEncryption)
{
int keyLength = 8;
int ivLength = 8;
pfKeyIvPair keyIvPair = new pfKeyIvPair();
RandomString randstr = new RandomString();
switch (typeEncryption)
{
case pfEncryptionAlgorithm.AES:
keyLength = 16;
ivLength = 16;
break;
case pfEncryptionAlgorithm.DES:
keyLength = 8;
ivLength = 8;
break;
case pfEncryptionAlgorithm.TripleDES:
keyLength = 16;
ivLength = 8;
break;
default:
//default to AES
keyLength = 16;
ivLength = 16;
break;
}
keyIvPair.key = randstr.GetStringNoSpaces(keyLength);
keyIvPair.IV = randstr.GetStringNoSpaces(ivLength);
return(keyIvPair);
}
/// <summary>
/// Factory method for creating instances of file encryption objects.
/// </summary>
/// <param name="alg">Type of encryption algorithm.</param>
/// <returns>IFileEncryptor interface for the chosen file encryptor.</returns>
public static IFileEncryptor GetFileEncryptor(pfEncryptionAlgorithm alg)
{
IFileEncryptor enc;
switch (alg)
{
case pfEncryptionAlgorithm.AES:
enc = new FileEncryptorAES();
break;
case pfEncryptionAlgorithm.DES:
enc = new FileEncryptorDES();
break;
case pfEncryptionAlgorithm.TripleDES:
enc = new FileEncryptorTripleDES();
break;
default:
enc = new FileEncryptorAES();
break;
}
return(enc);
}
/// <summary>
/// Saves the public property values contained in the current instance to an encrypted file. Key and IV parameters are used
/// to specify an AES encryption. Serialization is used to get the object values into an XML string that will be encrypted and
/// written to the output file.
/// </summary>
/// <param name="filePath">Full path for output file.</param>
/// <param name="key">AES encryption key.</param>
/// <param name="iv">AES IV value.</param>
/// <remarks>Only AES encryption is supported by this routine.</remarks>
public void SaveToXmlFile(string filePath, string key, string iv)
{
pfEncryptionAlgorithm alg = pfEncryptionAlgorithm.AES;
IStringEncryptor enc2 = PFEncryption.GetStringEncryptor(alg);
//store xml data in a string
string xmldata = this.ToXmlString();
//encrypt the xml data string
enc2.Key = key;
enc2.IV = iv;
string encryptedXML = enc2.Encrypt(xmldata);
//save encrypted xml to file
File.WriteAllText(filePath, encryptedXML);
}
/// <summary>
/// Creates and initializes an instance of the class by loading a serialized version of the instance stored in an encrypted file.
/// The file is first decrypted into an XML string and the XML string is then used to create an instance of the class.
/// </summary>
/// <param name="filePath">Full path for the input file.</param>
/// <param name="key">AES encryption key.</param>
/// <param name="iv">AES IV value.</param>
/// <returns>An instance of PFKeyValueListEx.</returns>
/// <remarks>Only AES encryption is supported by this routine.</remarks>
public static PFKeyValueListExSorted <K, V> LoadFromXmlFile(string filePath, string key, string iv)
{
pfEncryptionAlgorithm alg = pfEncryptionAlgorithm.AES;
IStringEncryptor enc2 = PFEncryption.GetStringEncryptor(alg);
PFKeyValueListExSorted <K, V> listElements;
//first: load the encrypted data from the specified file
string encryptedXML = File.ReadAllText(filePath);
//next: decrypt the encrypted data
enc2.Key = key;
enc2.IV = iv;
string xmldata = enc2.Decrypt(encryptedXML);
//step 3: create a PFLIcense object from the decrypted string
listElements = LoadFromXmlString(xmldata);
//finally: return to caller
return(listElements);
}
public void SaveKeyIVPair(pfEncryptionAlgorithm alg, pfKeyIvPair kvp, string filePath)
{
try
{
PFKeyIVValues kvv = new PFKeyIVValues(kvp.key, kvp.IV);
kvv.Algorithm = alg;
kvv.SaveToXmlFile(filePath);
}
catch (System.Exception ex)
{
_msg.Length = 0;
_msg.Append(AppGlobals.AppMessages.FormatErrorMessage(ex));
DisplayErrorMessage(_msg.ToString(), _saveErrorMessagesToAppLog);
}
finally
{
;
}
}
/// <summary>
/// Constructor.
/// </summary>
public PFKeyIVValues(pfEncryptionAlgorithm alg, string key, string iv)
{
_alg = alg;
_key = key;
_iv = iv;
}
public pfKeyIvPair GenerateKeyIVPair(pfEncryptionAlgorithm alg)
{
pfKeyIvPair ki = PFEncryption.GenerateKeyIvPair(alg);
return(ki);
}
