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using System.Security.Cryptography;

namespace MySql.Data.MySqlClient.Authentication
{
  /// <summary>
  /// The SCRAM-SHA-1 SASL mechanism.
  /// </summary>
  /// <remarks>
  /// A salted challenge/response SASL mechanism that uses the HMAC SHA-1 algorithm.
  /// </remarks>
  internal class ScramSha1Mechanism : ScramBase
  {
    /// <summary>
		/// Initializes a new instance of the <see cref="ScramSha1Mechanism"/> class.
		/// </summary>
		/// <remarks>
		/// Creates a new SCRAM-SHA-1 SASL context.
		/// </remarks>
		/// <param name="username">The user name.</param>
		/// <param name="password">The password.</param>
    /// <param name="host">The host.</param>
    internal ScramSha1Mechanism(string username, string password, string host) : base(username, password, host) { }

    /// <summary>
    /// Gets the name of the method.
    /// </summary>
    internal override string MechanismName
    {
      get { return "SCRAM-SHA-1"; }
    }

    protected override KeyedHashAlgorithm CreateHMAC(byte[] key)
    {
      return new HMACSHA1(key);
    }

    protected override byte[] Hash(byte[] str)
    {
      using (var sha1 = SHA1.Create())
        return sha1.ComputeHash(str);
    }
  }
}