internal BCryptAuthenticatedSymmetricAlgorithm(CngAlgorithm algorithm,
CngProvider implementation,
KeySizes[] legalBlockSizes,
KeySizes[] legalKeySizes)
{
Debug.Assert(algorithm != null, "algorithm != null");
Debug.Assert(implementation != null, "implementation != null");
Debug.Assert(legalBlockSizes != null, "legalBlockSizes != null");
Debug.Assert(legalKeySizes != null, "legalKeySizes != null");
m_algorithm = algorithm;
m_implementation = implementation;
m_chainingMode = CngChainingMode.Gcm;
LegalBlockSizesValue = legalBlockSizes;
LegalKeySizesValue = legalKeySizes;
// Create a temporary algorithm handle so that we can query it for some properties - such as the
// block and tag sizes.
using (SafeBCryptAlgorithmHandle algorithmHandle = SetupAlgorithm())
{
// Get block size in bits
BlockSize = BCryptNative.GetInt32Property(algorithmHandle, BCryptNative.ObjectPropertyName.BlockLength) * 8;
UpdateLegalTagSizes(algorithmHandle);
}
}
/// <summary>
/// Make a deep copy of the authenticated encryption state
/// </summary>
private AuthenticatedSymmetricEncryptionState(AuthenticatedSymmetricEncryptionState other)
: base(other)
{
Debug.Assert(other != null, "other != null");
m_cngChainingMode = other.m_cngChainingMode;
if (other.m_authenticatedData != null)
{
m_authenticatedData = new byte[other.m_authenticatedData.Length];
Array.Copy(other.m_authenticatedData, m_authenticatedData, m_authenticatedData.Length);
}
}
/// <summary>
/// Capture the parameters used for encryption, and verify that they make sense together
/// </summary>
internal AuthenticatedSymmetricEncryptionState(byte[] key,
byte[] iv,
byte[] authenticatedData,
AuthenticatedSymmetricAlgorithm algorithm)
: base(key, iv, algorithm, typeof(AuthenticatedSymmetricAlgorithm), false)
{
if (authenticatedData != null)
{
m_authenticatedData = new byte[authenticatedData.Length];
Array.Copy(authenticatedData, m_authenticatedData, m_authenticatedData.Length);
}
// Since CipherMode doesn't contain authenticated encryption modes, it's not very useful for
// debugging mode mismatches in authenticated symmetric algorithms. Our only current
// authenticated symmetric algorithm implementations ues CNG chaining modes, so we'll grab that
// if it's available to aid in debugging.
ICngSymmetricAlgorithm cngAlgorithm = algorithm as ICngSymmetricAlgorithm;
if (cngAlgorithm != null)
{
m_cngChainingMode = cngAlgorithm.CngMode;
}
}
