namespace System.Security.Cryptography
{
  /// <summary>
  /// An enumeration of the possible error codes which are returned from Daniel Dinu and
  /// Dmitry Khovratovich's Argon2 library.
  ///
  /// Some of these error conditions cannot be reached while using the C# PasswordHasher wrapper
  /// </summary>
  public enum Argon2Error
  {
    /// <summary>
    /// The operation was successful
    /// </summary>
    OK = 0,

    /// <summary>
    /// The output hash length is less than 4 bytes
    /// </summary>
    OUTPUT_TOO_SHORT = -2,

    /// <summary>
    /// The salt is less than 8 bytes
    /// </summary>
    SALT_TOO_SHORT = -6,

    /// <summary>
    /// The salt is too big
    /// </summary>
    SALT_TOO_LONG = -7,

    /// <summary>
    /// The time cost is less than 1
    /// </summary>
    TIME_TOO_SMALL = -12,

    /// <summary>
    /// The memory cost is less than 8 (KiB)
    /// </summary>
    MEMORY_TOO_LITTLE = -14,
    /// <summary>
    /// The memory cost is greater than 2^21 (KiB) (2 GiB)
    /// </summary>
    MEMORY_TOO_MUCH = -15,

    /// <summary>
    /// The parallelism is less than 1
    /// </summary>
    LANES_TOO_FEW = -16,
    /// <summary>
    /// The parallelism is greater than 16,777,215
    /// </summary>
    LANES_TOO_MANY = -17,

    /// <summary>
    /// Memory allocation failed
    /// </summary>
    MEMORY_ALLOCATION_ERROR = -22,

    /// <summary>
    /// The parallelism is less than 1
    /// </summary>
    THREADS_TOO_FEW = -28,
    /// <summary>
    /// The parallelism is greater than 16,777,215
    /// </summary>
    THREADS_TOO_MANY = -29,

    /// <summary>
    /// This will not be returned from the C# PasswordHasher wrapper
    /// </summary>
    DECODING_FAIL = -32,

    /// <summary>
    /// Unable to create the number of threads requested
    /// </summary>
    THREAD_FAIL = -33,

    /// <summary>
    /// This will not be returned from the C# PasswordHasher wrapper
    /// </summary>
    VERIFY_MISMATCH = -35
  }
}