/// <summary>
/// Creates an instance of AeadAes256CbcHmac256Algorithm class with a given key
/// </summary>
/// <param name="encryptionKey">Root key</param>
/// <param name="encryptionType">Encryption Type. Expected values are either Determinitic or Randomized.</param>
/// <param name="encryptionAlgorithm">Encryption Algorithm.</param>
/// <returns></returns>
internal override SqlClientEncryptionAlgorithm Create(SqlClientSymmetricKey encryptionKey, SqlClientEncryptionType encryptionType, string encryptionAlgorithm)
{
// Callers should have validated the encryption algorithm and the encryption key
Debug.Assert(encryptionKey != null);
Debug.Assert(string.Equals(encryptionAlgorithm, SqlAeadAes256CbcHmac256Algorithm.AlgorithmName, StringComparison.OrdinalIgnoreCase) == true);
// Validate encryption type
if (!((encryptionType == SqlClientEncryptionType.Deterministic) || (encryptionType == SqlClientEncryptionType.Randomized)))
{
throw SQL.InvalidEncryptionType(SqlAeadAes256CbcHmac256Algorithm.AlgorithmName,
encryptionType,
SqlClientEncryptionType.Deterministic,
SqlClientEncryptionType.Randomized);
}
// Get the cached encryption algorithm if one exists or create a new one, add it to cache and use it
//
// For now, we only have one version. In future, we may need to parse the algorithm names to derive the version byte.
const byte algorithmVersion = 0x1;
StringBuilder algorithmKeyBuilder = new StringBuilder(Convert.ToBase64String(encryptionKey.RootKey), SqlSecurityUtility.GetBase64LengthFromByteLength(encryptionKey.RootKey.Length) + 4 /*separators, type and version*/);
#if DEBUG
int capacity = algorithmKeyBuilder.Capacity;
#endif //DEBUG
algorithmKeyBuilder.Append(":");
algorithmKeyBuilder.Append((int)encryptionType);
algorithmKeyBuilder.Append(":");
algorithmKeyBuilder.Append(algorithmVersion);
string algorithmKey = algorithmKeyBuilder.ToString();
#if DEBUG
Debug.Assert(algorithmKey.Length <= capacity, "We needed to allocate a larger array");
#endif //DEBUG
SqlAeadAes256CbcHmac256Algorithm aesAlgorithm;
if (!_encryptionAlgorithms.TryGetValue(algorithmKey, out aesAlgorithm))
{
SqlAeadAes256CbcHmac256EncryptionKey encryptedKey = new SqlAeadAes256CbcHmac256EncryptionKey(encryptionKey.RootKey, SqlAeadAes256CbcHmac256Algorithm.AlgorithmName);
aesAlgorithm = new SqlAeadAes256CbcHmac256Algorithm(encryptedKey, encryptionType, algorithmVersion);
// In case multiple threads reach here at the same time, the first one adds the value
// the second one will be a no-op, the allocated memory will be claimed by Garbage Collector.
_encryptionAlgorithms.TryAdd(algorithmKey, aesAlgorithm);
}
return(aesAlgorithm);
}
/// <summary>
/// Creates an instance of AeadAes256CbcHmac256Algorithm class with a given key
/// </summary>
/// <param name="encryptionKey">Root key</param>
/// <param name="encryptionType">Encryption Type. Expected values are either Determinitic or Randomized.</param>
/// <param name="encryptionAlgorithm">Encryption Algorithm.</param>
/// <returns></returns>
internal override SqlClientEncryptionAlgorithm Create(SqlClientSymmetricKey encryptionKey, SqlClientEncryptionType encryptionType, string encryptionAlgorithm) {
// Callers should have validated the encryption algorithm and the encryption key
Debug.Assert(encryptionKey != null);
Debug.Assert(string.Equals(encryptionAlgorithm, SqlAeadAes256CbcHmac256Algorithm.AlgorithmName, StringComparison.OrdinalIgnoreCase) == true);
// Validate encryption type
if (!((encryptionType == SqlClientEncryptionType.Deterministic) || (encryptionType == SqlClientEncryptionType.Randomized))) {
throw SQL.InvalidEncryptionType(SqlAeadAes256CbcHmac256Algorithm.AlgorithmName,
encryptionType,
SqlClientEncryptionType.Deterministic,
SqlClientEncryptionType.Randomized);
}
// Get the cached encryption algorithm if one exists or create a new one, add it to cache and use it
//
// For now, we only have one version. In future, we may need to parse the algorithm names to derive the version byte.
const byte algorithmVersion = 0x1;
StringBuilder algorithmKeyBuilder = new StringBuilder(Convert.ToBase64String(encryptionKey.RootKey), SqlSecurityUtility.GetBase64LengthFromByteLength(encryptionKey.RootKey.Length) + 4/*separators, type and version*/);
#if DEBUG
int capacity = algorithmKeyBuilder.Capacity;
#endif //DEBUG
algorithmKeyBuilder.Append(":");
algorithmKeyBuilder.Append((int)encryptionType);
algorithmKeyBuilder.Append(":");
algorithmKeyBuilder.Append(algorithmVersion);
string algorithmKey = algorithmKeyBuilder.ToString();
#if DEBUG
Debug.Assert(algorithmKey.Length <= capacity, "We needed to allocate a larger array");
#endif //DEBUG
SqlAeadAes256CbcHmac256Algorithm aesAlgorithm;
if (!_encryptionAlgorithms.TryGetValue(algorithmKey, out aesAlgorithm)) {
SqlAeadAes256CbcHmac256EncryptionKey encryptedKey = new SqlAeadAes256CbcHmac256EncryptionKey(encryptionKey.RootKey, SqlAeadAes256CbcHmac256Algorithm.AlgorithmName);
aesAlgorithm = new SqlAeadAes256CbcHmac256Algorithm(encryptedKey, encryptionType, algorithmVersion);
// In case multiple threads reach here at the same time, the first one adds the value
// the second one will be a no-op, the allocated memory will be claimed by Garbage Collector.
_encryptionAlgorithms.TryAdd(algorithmKey, aesAlgorithm);
}
return aesAlgorithm;
}
