/// <summary>
/// encrypt the stream symmetrically using the security profile
/// information stored in the configuration file
/// </summary>
/// <param name="data">stream data</param>
/// <param name="profile">profile name</param>
/// <returns>stream data</returns>
public static Stream Encrypt(Stream data, string profile)
{
SAF.Configuration.ConfigurationManager cm = (SAF.Configuration.ConfigurationManager)System.Configuration.ConfigurationManager.GetSection("Framework");
CryptographyConfiguration cc = cm.CryptographyConfig;
//retrieve security profile information
XmlNode cryptoInfo = cc.SearchCryptoInfoByProfileName(profile);
bool symmetric = Boolean.Parse(cryptoInfo.Attributes["symmetric"].Value);
ICryptoTransform encryptor = null;
SymmetricAlgorithm provider = null;
if (symmetric != true)
{
throw new System.Exception("This method id not intended for asymmetric encryption");
}
//retrive the secret key and iv information
provider = cc.GetSymmetricAlgorithmProvider(profile);
string key = cryptoInfo.SelectSingleNode("SecretKey").InnerText;
string iv = cryptoInfo.SelectSingleNode("IV").InnerText;
provider.Key = Encoding.Default.GetBytes(key);
provider.IV = Encoding.Default.GetBytes(iv);
encryptor = provider.CreateEncryptor();
MemoryStream encrypted = new MemoryStream();
//encrypt the stream symmetrically
CryptoStream encStream = new CryptoStream(encrypted, encryptor, CryptoStreamMode.Write);
byte[] buffer = new byte[1024];
int count = 0;
while ((count = data.Read(buffer, 0, 1024)) > 0)
{
encStream.Write(buffer, 0, count);
}
encStream.FlushFinalBlock();
encrypted.Position = 0;
return((Stream)encrypted);
}
/// <summary>
/// decrypt the stream data symmetrically using the security profile
/// information stored in the configuration file
/// </summary>
/// <param name="data">stream data</param>
/// <param name="profile">security profile name</param>
/// <returns>decrypted stream</returns>
public static Stream Decrypt(Stream data, string profile)
{
SAF.Configuration.ConfigurationManager cm = (SAF.Configuration.ConfigurationManager)System.Configuration.ConfigurationManager.GetSection("Framework");
CryptographyConfiguration cc = cm.CryptographyConfig;
//retrieve the security profile information for configuration file
XmlNode cryptoInfo = cc.SearchCryptoInfoByProfileName(profile);
bool symmetric = Boolean.Parse(cryptoInfo.Attributes["symmetric"].Value);
ICryptoTransform decryptor = null;
SymmetricAlgorithm provider = null;
if (symmetric != true)
{
throw new System.Exception("This method id not intended for asymmetric encryption");
}
//retrieve the secret key and iv from the configuration file
provider = cc.GetSymmetricAlgorithmProvider(profile);
string key = cryptoInfo.SelectSingleNode("SecretKey").InnerText;
string iv = cryptoInfo.SelectSingleNode("IV").InnerText;
provider.Key = Encoding.Default.GetBytes(key);
provider.IV = Encoding.Default.GetBytes(iv);
decryptor = provider.CreateDecryptor();
//decrypt the stream
CryptoStream decStream = new CryptoStream(data, decryptor, CryptoStreamMode.Read);
MemoryStream decrypted = new MemoryStream();
byte[] buffer = new byte[2048];
int count = 0;
while ((count = decStream.Read(buffer, 0, buffer.Length)) != 0)
{
decrypted.Write(buffer, 0, count);
}
decrypted.Position = 0;
return((Stream)decrypted);
}
