internal SymmetricAlgorithmVerifier(SymmetricAlgorithm verificationAlgorithm,
SymmetricEncryptionState encryptionState,
Predicate <CryptographyLockContext <SymmetricAlgorithm> > lockCheckCallback,
object lockCheckParameter)
: base(verificationAlgorithm, lockCheckCallback, lockCheckParameter)
{
Debug.Assert(encryptionState != null, "encryptionState != null");
m_encryptionState = encryptionState;
}
protected override void OnDecryptorCreated(byte[] key, byte[] iv)
{
base.OnDecryptorCreated(key, iv);
using (SymmetricEncryptionState decryptionState = new SymmetricEncryptionState(key, iv, WrappedAlgorithm))
{
m_encryptionState.VerifyDecryptionState(decryptionState);
}
}
/// <summary>
/// Create a SymmetricAlgorithm which verifies the decryption operations done on it have state
/// which matches captured encryption state. This overload does not monitor for thread safe
/// access to the object.
/// </summary>
public static SymmetricAlgorithm EnableDecryptionVerification(this SymmetricAlgorithm loggedAlgorithm,
SymmetricEncryptionState encryptionState)
{
if (encryptionState == null)
{
throw new ArgumentNullException("encryptionState");
}
return(loggedAlgorithm.EnableDecryptionVerification(encryptionState,
new SymmetricAlgorithmDiagnosticOptions()
{
CheckThreadSafety = false
}));
}
/// <summary>
/// Verify that the input decryption state matches our encryption state, throwing an error if
/// they do not.
/// </summary>
internal override void VerifyDecryptionState(SymmetricEncryptionState decryptionState)
{
Debug.Assert(decryptionState != null, "decryptionState != null");
// All of the symmetric algorithm comparisons need to match
base.VerifyDecryptionState(decryptionState);
AuthenticatedSymmetricEncryptionState authenticatedDecryptionState =
decryptionState as AuthenticatedSymmetricEncryptionState;
// The base verify decryption state should have caught an algorithm mismatch, which would be the
// only way that we could be encrypting with an authenticated symmetric algortihm but decrypting
// with an unauthenticated algorithm.
Debug.Assert(authenticatedDecryptionState != null, "authenticatedDecryptionState != null");
// If we have authenticated data, make sure it matches
if (m_authenticatedData != null)
{
// If we have authenticated data, then the decryption state also needs to have authenticated
// data, and that data needs to match.
if (authenticatedDecryptionState.m_authenticatedData == null ||
!CompareBytes(m_authenticatedData, authenticatedDecryptionState.m_authenticatedData))
{
ThrowDiagnosticException(Resources.AuthenticatedDataMismatch,
m_authenticatedData.Length * 8,
HexString(m_authenticatedData),
authenticatedDecryptionState.m_authenticatedData != null ? authenticatedDecryptionState.m_authenticatedData.Length * 8 : 0,
HexString(authenticatedDecryptionState.m_authenticatedData));
}
}
else if (authenticatedDecryptionState.m_authenticatedData != null)
{
// We had no authenticated data during encryption, but we have some during decryption, so we
// have a mismatch.
ThrowDiagnosticException(Resources.AuthenticatedDataMismatch,
0,
HexString(null),
authenticatedDecryptionState.m_authenticatedData.Length * 8,
HexString(authenticatedDecryptionState.m_authenticatedData));
}
// Make sure the CNG chaining modes match
if (m_cngChainingMode != authenticatedDecryptionState.m_cngChainingMode)
{
ThrowDiagnosticException(Resources.CngChainingModeMismatch,
m_cngChainingMode,
authenticatedDecryptionState.m_cngChainingMode);
}
}
protected override void OnEncryptorCreated(byte[] key, byte[] iv)
{
base.OnEncryptorCreated(key, iv);
// An encryptor is being created, which means that all of the encryption parameters must be set at
// this point. Capture them so that they can be extracted for later verification.
if (m_lastCapturedEncryptionState != null)
{
m_lastCapturedEncryptionState.Dispose();
}
m_lastCapturedEncryptionState = new SymmetricEncryptionState(key,
iv,
WrappedAlgorithm);
}
/// <summary>
/// Create a SymmetricAlgorithm which verifies the decryption operations done on it have state
/// which matches captured encryption state.
/// </summary>
public static SymmetricAlgorithm EnableDecryptionVerification(this SymmetricAlgorithm loggedAlgorithm,
SymmetricEncryptionState encryptionState,
SymmetricAlgorithmDiagnosticOptions options)
{
if (encryptionState == null)
{
throw new ArgumentNullException("encryptionState");
}
if (options == null)
{
throw new ArgumentNullException("options");
}
#if !FXONLY_BUILD
AuthenticatedSymmetricAlgorithm authenticatedLoggedAlgorithm =
loggedAlgorithm as AuthenticatedSymmetricAlgorithm;
if (authenticatedLoggedAlgorithm != null)
{
AuthenticatedSymmetricEncryptionState authenticatedEncryptionState =
encryptionState as AuthenticatedSymmetricEncryptionState;
if (authenticatedEncryptionState == null)
{
throw new ArgumentException(Resources.NeedAuthenticatedEncryptionState, "encryptionState");
}
return(new AuthenticatedSymmetricAlgorithmVerifier(authenticatedLoggedAlgorithm,
authenticatedEncryptionState,
options.CheckThreadSafety ? options.LockCheckCallback : null,
options.CheckThreadSafety ? options.LockCheckParameter : null));
}
else
#endif // !FXONLY_BUILD
{
return(new SymmetricAlgorithmVerifier(loggedAlgorithm,
encryptionState,
options.CheckThreadSafety ? options.LockCheckCallback : null,
options.CheckThreadSafety ? options.LockCheckParameter : null));
}
}
/// <summary>
/// Perform a deep copy of another symmetric encryption state
/// </summary>
protected SymmetricEncryptionState(SymmetricEncryptionState other)
{
if (other == null)
{
throw new ArgumentNullException("other");
}
m_baseAlgorithmType = other.m_baseAlgorithmType;
m_compareCipherModes = other.m_compareCipherModes;
m_blockSize = other.m_blockSize;
m_cipherMode = other.m_cipherMode;
m_feedbackSize = other.m_feedbackSize;
m_paddingMode = other.m_paddingMode;
m_algorithm = other.m_algorithm;
m_iv = new byte[other.m_iv.Length];
Array.Copy(other.m_iv, m_iv, m_iv.Length);
m_key = new byte[other.m_key.Length];
Array.Copy(other.m_key, m_key, m_key.Length);
}
/// <summary>
/// Verify that the input decryption state matches our encryption state, throwing an error if
/// they do not.
/// </summary>
internal virtual void VerifyDecryptionState(SymmetricEncryptionState decryptionState)
{
Debug.Assert(decryptionState != null, "decryptionState != null");
// Make sure the algorithms match
if (m_algorithm != decryptionState.m_algorithm)
{
ThrowDiagnosticException(Properties.Resources.AlgorithmMismatch,
m_algorithm,
decryptionState.m_algorithm);
}
// Check the block sizes
if (m_blockSize != decryptionState.m_blockSize)
{
ThrowDiagnosticException(Properties.Resources.BlockSizeMismatch,
m_blockSize,
decryptionState.m_blockSize);
}
// Check the ciper modes
if (m_compareCipherModes && m_cipherMode != decryptionState.m_cipherMode)
{
ThrowDiagnosticException(Properties.Resources.CipherModeMismatch,
m_cipherMode,
decryptionState.m_cipherMode);
}
// Check the feedback
if (CipherModeUsesFeedback(m_cipherMode) && m_feedbackSize != decryptionState.m_feedbackSize)
{
ThrowDiagnosticException(Properties.Resources.FeedbackSizeMismatch,
m_feedbackSize,
decryptionState.m_feedbackSize);
}
// Check the IVs
if (!CompareBytes(m_iv, decryptionState.m_iv))
{
ThrowDiagnosticException(Properties.Resources.IVMismatch,
m_iv.Length * 8,
HexString(m_iv),
decryptionState.m_iv.Length * 8,
HexString(decryptionState.m_iv));
}
// Check the keys
if (!CompareBytes(m_key, decryptionState.m_key))
{
ThrowDiagnosticException(Properties.Resources.KeyMismatch,
m_key.Length * 8,
HexString(m_key),
decryptionState.m_key.Length * 8,
HexString(decryptionState.m_key));
}
// Check the padding modes
if (m_paddingMode != decryptionState.m_paddingMode)
{
ThrowDiagnosticException(Properties.Resources.PaddingModeMismatch,
m_paddingMode,
decryptionState.m_paddingMode);
}
}
