private static BCryptAlgorithmHandle GetAesAlgorithm(string chainingMode)
{
var algHandle = BCryptAlgorithmHandle.OpenAlgorithmHandle(Constants.BCRYPT_AES_ALGORITHM);
algHandle.SetChainingMode(chainingMode);
return(algHandle);
}
private static BCryptAlgorithmHandle GetEncryptionAlgorithmHandleAndCheckKeySize(string encryptionAlgorithm, string encryptionAlgorithmProvider, uint keyLengthInBits)
{
BCryptAlgorithmHandle algorithmHandle = null;
// Special-case cached providers
if (encryptionAlgorithmProvider == null)
{
if (encryptionAlgorithm == Constants.BCRYPT_AES_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.AES_GCM;
}
}
// Look up the provider dynamically if we couldn't fetch a cached instance
if (algorithmHandle == null)
{
algorithmHandle = BCryptAlgorithmHandle.OpenAlgorithmHandle(encryptionAlgorithm, encryptionAlgorithmProvider);
algorithmHandle.SetChainingMode(Constants.BCRYPT_CHAIN_MODE_GCM);
}
// make sure we're using a block cipher with an appropriate block size
uint cipherBlockSizeInBytes = algorithmHandle.GetCipherBlockLength();
CryptoUtil.Assert(cipherBlockSizeInBytes == 128 / 8, "cipherBlockSizeInBytes == 128 / 8");
// make sure the provided key length is valid
algorithmHandle.GetSupportedKeyLengths().EnsureValidKeyLength(keyLengthInBits);
// all good!
return(algorithmHandle);
}
private BCryptAlgorithmHandle GetHmacAlgorithmHandle(ILogger logger)
{
// basic argument checking
if (String.IsNullOrEmpty(HashAlgorithm))
{
throw Error.Common_PropertyCannotBeNullOrEmpty(nameof(HashAlgorithm));
}
if (logger.IsVerboseLevelEnabled())
{
logger.LogVerboseF($"Opening CNG algorithm '{HashAlgorithm}' from provider '{HashAlgorithmProvider}' with HMAC.");
}
BCryptAlgorithmHandle algorithmHandle = null;
// Special-case cached providers
if (HashAlgorithmProvider == null)
{
if (HashAlgorithm == Constants.BCRYPT_SHA1_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.HMAC_SHA1;
}
else if (HashAlgorithm == Constants.BCRYPT_SHA256_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.HMAC_SHA256;
}
else if (HashAlgorithm == Constants.BCRYPT_SHA512_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.HMAC_SHA512;
}
}
// Look up the provider dynamically if we couldn't fetch a cached instance
if (algorithmHandle == null)
{
algorithmHandle = BCryptAlgorithmHandle.OpenAlgorithmHandle(HashAlgorithm, HashAlgorithmProvider, hmac: true);
}
// Make sure we're using a hash algorithm. We require a minimum 128-bit digest.
uint digestSize = algorithmHandle.GetHashDigestLength();
AlgorithmAssert.IsAllowableValidationAlgorithmDigestSize(checked (digestSize * 8));
// all good!
return(algorithmHandle);
}
private BCryptAlgorithmHandle GetSymmetricBlockCipherAlgorithmHandle(ILogger logger)
{
// basic argument checking
if (String.IsNullOrEmpty(EncryptionAlgorithm))
{
throw Error.Common_PropertyCannotBeNullOrEmpty(nameof(EncryptionAlgorithm));
}
if (EncryptionAlgorithmKeySize < 0)
{
throw Error.Common_PropertyMustBeNonNegative(nameof(EncryptionAlgorithmKeySize));
}
BCryptAlgorithmHandle algorithmHandle = null;
if (logger.IsVerboseLevelEnabled())
{
logger.LogVerboseF($"Opening CNG algorithm '{EncryptionAlgorithm}' from provider '{EncryptionAlgorithmProvider}' with chaining mode GCM.");
}
// Special-case cached providers
if (EncryptionAlgorithmProvider == null)
{
if (EncryptionAlgorithm == Constants.BCRYPT_AES_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.AES_GCM;
}
}
// Look up the provider dynamically if we couldn't fetch a cached instance
if (algorithmHandle == null)
{
algorithmHandle = BCryptAlgorithmHandle.OpenAlgorithmHandle(EncryptionAlgorithm, EncryptionAlgorithmProvider);
algorithmHandle.SetChainingMode(Constants.BCRYPT_CHAIN_MODE_GCM);
}
// make sure we're using a block cipher with an appropriate key size & block size
CryptoUtil.Assert(algorithmHandle.GetCipherBlockLength() == 128 / 8, "GCM requires a block cipher algorithm with a 128-bit block size.");
AlgorithmAssert.IsAllowableSymmetricAlgorithmKeySize(checked ((uint)EncryptionAlgorithmKeySize));
// make sure the provided key length is valid
algorithmHandle.GetSupportedKeyLengths().EnsureValidKeyLength((uint)EncryptionAlgorithmKeySize);
// all good!
return(algorithmHandle);
}
private BCryptAlgorithmHandle GetHmacAlgorithmHandle(CngCbcAuthenticatedEncryptorConfiguration configuration)
{
// basic argument checking
if (String.IsNullOrEmpty(configuration.HashAlgorithm))
{
throw Error.Common_PropertyCannotBeNullOrEmpty(nameof(configuration.HashAlgorithm));
}
_logger.OpeningCNGAlgorithmFromProviderWithHMAC(configuration.HashAlgorithm, configuration.HashAlgorithmProvider);
BCryptAlgorithmHandle?algorithmHandle = null;
// Special-case cached providers
if (configuration.HashAlgorithmProvider == null)
{
if (configuration.HashAlgorithm == Constants.BCRYPT_SHA1_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.HMAC_SHA1;
}
else if (configuration.HashAlgorithm == Constants.BCRYPT_SHA256_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.HMAC_SHA256;
}
else if (configuration.HashAlgorithm == Constants.BCRYPT_SHA512_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.HMAC_SHA512;
}
}
// Look up the provider dynamically if we couldn't fetch a cached instance
if (algorithmHandle == null)
{
algorithmHandle = BCryptAlgorithmHandle.OpenAlgorithmHandle(configuration.HashAlgorithm, configuration.HashAlgorithmProvider, hmac: true);
}
// Make sure we're using a hash algorithm. We require a minimum 128-bit digest.
uint digestSize = algorithmHandle.GetHashDigestLength();
AlgorithmAssert.IsAllowableValidationAlgorithmDigestSize(checked (digestSize * 8));
// all good!
return(algorithmHandle);
}
private BCryptAlgorithmHandle GetSymmetricBlockCipherAlgorithmHandle(CngCbcAuthenticatedEncryptorConfiguration configuration)
{
// basic argument checking
if (String.IsNullOrEmpty(configuration.EncryptionAlgorithm))
{
throw Error.Common_PropertyCannotBeNullOrEmpty(nameof(EncryptionAlgorithm));
}
if (configuration.EncryptionAlgorithmKeySize < 0)
{
throw Error.Common_PropertyMustBeNonNegative(nameof(configuration.EncryptionAlgorithmKeySize));
}
_logger.OpeningCNGAlgorithmFromProviderWithChainingModeCBC(configuration.EncryptionAlgorithm, configuration.EncryptionAlgorithmProvider);
BCryptAlgorithmHandle?algorithmHandle = null;
// Special-case cached providers
if (configuration.EncryptionAlgorithmProvider == null)
{
if (configuration.EncryptionAlgorithm == Constants.BCRYPT_AES_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.AES_CBC;
}
}
// Look up the provider dynamically if we couldn't fetch a cached instance
if (algorithmHandle == null)
{
algorithmHandle = BCryptAlgorithmHandle.OpenAlgorithmHandle(configuration.EncryptionAlgorithm, configuration.EncryptionAlgorithmProvider);
algorithmHandle.SetChainingMode(Constants.BCRYPT_CHAIN_MODE_CBC);
}
// make sure we're using a block cipher with an appropriate key size & block size
AlgorithmAssert.IsAllowableSymmetricAlgorithmBlockSize(checked (algorithmHandle.GetCipherBlockLength() * 8));
AlgorithmAssert.IsAllowableSymmetricAlgorithmKeySize(checked ((uint)configuration.EncryptionAlgorithmKeySize));
// make sure the provided key length is valid
algorithmHandle.GetSupportedKeyLengths().EnsureValidKeyLength((uint)configuration.EncryptionAlgorithmKeySize);
// all good!
return(algorithmHandle);
}
public void CreateAuthenticatedEncryptor_RoundTripsData_CngCbcImplementation(EncryptionAlgorithm encryptionAlgorithm, ValidationAlgorithm validationAlgorithm)
{
// Parse test input
int keyLengthInBits = Int32.Parse(Regex.Match(encryptionAlgorithm.ToString(), @"^AES_(?<keyLength>\d{3})_CBC$").Groups["keyLength"].Value, CultureInfo.InvariantCulture);
string hashAlgorithm = Regex.Match(validationAlgorithm.ToString(), @"^HMAC(?<hashAlgorithm>.*)$").Groups["hashAlgorithm"].Value;
// Arrange
var masterKey = Secret.Random(512 / 8);
var control = new CbcAuthenticatedEncryptor(
keyDerivationKey: masterKey,
symmetricAlgorithmHandle: CachedAlgorithmHandles.AES_CBC,
symmetricAlgorithmKeySizeInBytes: (uint)(keyLengthInBits / 8),
hmacAlgorithmHandle: BCryptAlgorithmHandle.OpenAlgorithmHandle(hashAlgorithm, hmac: true));
var test = CreateEncryptorInstanceFromDescriptor(CreateDescriptor(encryptionAlgorithm, validationAlgorithm, masterKey));
// Act & assert - data round trips properly from control to test
byte[] plaintext = new byte[] { 1, 2, 3, 4, 5 };
byte[] aad = new byte[] { 2, 4, 6, 8, 0 };
byte[] ciphertext = control.Encrypt(new ArraySegment <byte>(plaintext), new ArraySegment <byte>(aad));
byte[] roundTripPlaintext = test.Decrypt(new ArraySegment <byte>(ciphertext), new ArraySegment <byte>(aad));
Assert.Equal(plaintext, roundTripPlaintext);
}
private static BCryptAlgorithmHandle GetHashAlgorithmHandle(string hashAlgorithm, string hashAlgorithmProvider)
{
BCryptAlgorithmHandle algorithmHandle = null;
// Special-case cached providers
if (hashAlgorithmProvider == null)
{
if (hashAlgorithm == Constants.BCRYPT_SHA1_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.HMAC_SHA1;
}
else if (hashAlgorithm == Constants.BCRYPT_SHA256_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.HMAC_SHA256;
}
else if (hashAlgorithm == Constants.BCRYPT_SHA512_ALGORITHM)
{
algorithmHandle = CachedAlgorithmHandles.HMAC_SHA512;
}
}
// Look up the provider dynamically if we couldn't fetch a cached instance
if (algorithmHandle == null)
{
algorithmHandle = BCryptAlgorithmHandle.OpenAlgorithmHandle(hashAlgorithm, hashAlgorithmProvider, hmac: true);
}
// Make sure we're using a hash algorithm. We require a minimum 128-bit digest.
uint digestSize = algorithmHandle.GetHashDigestLength();
CryptoUtil.Assert(digestSize >= CbcAuthenticatedEncryptor.HASH_ALG_MIN_DIGEST_LENGTH_IN_BYTES,
"digestSize >= CbcAuthenticatedEncryptor.HASH_ALG_MIN_DIGEST_LENGTH_IN_BYTES");
// all good!
return(algorithmHandle);
}
private static BCryptAlgorithmHandle GetSP800_108_CTR_HMACAlgorithm()
{
return(BCryptAlgorithmHandle.OpenAlgorithmHandle(Constants.BCRYPT_SP800108_CTR_HMAC_ALGORITHM, implementation: Constants.MS_PRIMITIVE_PROVIDER));
}
private static BCryptAlgorithmHandle GetPbkdf2Algorithm()
{
return(BCryptAlgorithmHandle.OpenAlgorithmHandle(Constants.BCRYPT_PBKDF2_ALGORITHM, implementation: Constants.MS_PRIMITIVE_PROVIDER));
}
private static BCryptAlgorithmHandle GetHmacAlgorithm(string algorithm)
{
return(BCryptAlgorithmHandle.OpenAlgorithmHandle(algorithm, hmac: true));
}
private static BCryptAlgorithmHandle GetHashAlgorithm(string algorithm)
{
return(BCryptAlgorithmHandle.OpenAlgorithmHandle(algorithm, hmac: false));
}
