﻿/*
 * Copyright 2014, 2015 Dominick Baier, Brock Allen
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using IdentityServer3.Core.Extensions;
using System;
using System.Security.Cryptography;
using System.Text;

namespace IdentityServer3.Core.Models
{
    /// <summary>
    /// Extension methods for hashing strings
    /// </summary>
    public static class HashExtensions
    {
        /// <summary>
        /// Creates a SHA256 hash of the specified input.
        /// </summary>
        /// <param name="input">The input.</param>
        /// <returns>A hash</returns>
        public static string Sha256(this string input)
        {
            if (input.IsMissing()) return string.Empty;

            using (var sha = SHA256.Create())
            {
                var bytes = Encoding.UTF8.GetBytes(input);
                var hash = sha.ComputeHash(bytes);

                return Convert.ToBase64String(hash);
            }
        }

        /// <summary>
        /// Creates a SHA512 hash of the specified input.
        /// </summary>
        /// <param name="input">The input.</param>
        /// <returns>A hash</returns>
        public static string Sha512(this string input)
        {
            if (input.IsMissing()) return string.Empty;

            using (var sha = SHA512.Create())
            {
                var bytes = Encoding.UTF8.GetBytes(input);
                var hash = sha.ComputeHash(bytes);

                return Convert.ToBase64String(hash);
            }
        }
    }
}