C# Hashing utility, as used in Monkey.CMS.

HashUtility.cs

using System;
using System.Linq;
using System.Security.Cryptography;
using System.Text;

namespace Utilities
{
    /// <summary>
    /// Simple utility class for generating hashes for string values.
    /// </summary>
    public class HashUtility
    {
        /// <summary>
        /// Gets the hash.
        /// </summary>
        /// <remarks>This method uses UTF-8 encoding and is hashed using the SHA1 algorithm.</remarks>
        /// <param name="text">The text.</param>
        /// <returns></returns>
        public static string GetHash(string text)
        {
            return GetHash(text, HashType.SHA1, false, true);
        }

        /// <summary>
        /// Gets the hash.
        /// </summary>
        /// <param name="text">The text.</param>
        /// <param name="hashType">
        /// Type of hash algorithm used to hash the text. Integer value is cast to an enumerated value; <see cref="HashType"/>
        /// </param>
        /// <returns></returns>
        public static string GetHash(string text, int hashType)
        {
            return GetHash(text, (HashType)hashType, false, true);
        }

        /// <summary>
        /// Gets the hash.
        /// </summary>
        /// <param name="text">The text.</param>
        /// <param name="hashType">
        /// Type of hash algorithm used to hash the text; <see cref="HashType"/>
        /// </param>
        /// <param name="forceUpperCase">if set to <c>true</c>, forces uppercase characters in the hash-string.</param>
        /// <returns></returns>
        /// <remarks>
        /// This method uses UTF-8 encoding.
        /// </remarks>
        public static string GetHash(string text, HashType hashType, bool forceUpperCase = false)
        {
            return GetHash(text, hashType, forceUpperCase, true);
        }

        /// <summary>
        /// Gets the hash.
        /// </summary>
        /// <param name="text">The text.</param>
        /// <param name="hashType">Type of hash algorithm used to hash the text.</param>
        /// <param name="forceUpperCase">if set to <c>true</c>, forces uppercase characters in the hash-string.</param>
        /// <param name="unicode">if set to <c>true</c>, UTF-8 encoded bytes are extracted from the source string; otherwise, bytes are ASCII encoded.</param>
        /// <returns></returns>
        /// <exception cref="System.ArgumentException">Invalid hash type;hashType</exception>
        /// <remarks>
        /// This method uses UTF-8 encoding by default.
        /// </remarks>
        public static string GetHash(string text, HashType hashType, bool forceUpperCase = false, bool unicode = true)
        {
            HashAlgorithm _algorithm;
            switch (hashType)
            {
                case HashType.MD5:
                    _algorithm = MD5.Create();
                    break;
                case HashType.SHA1:
                    _algorithm = SHA1.Create();
                    break;
                case HashType.SHA256:
                    _algorithm = SHA256.Create();
                    break;
                case HashType.SHA512:
                    _algorithm = SHA512.Create();
                    break;
                default:
                    throw new ArgumentException("Invalid hash type", "hashType");
            }
            byte[] bytes = unicode ? Encoding.UTF8.GetBytes(text) : Encoding.ASCII.GetBytes(text);
            byte[] hash = _algorithm.ComputeHash(bytes);

            return string.Concat(hash.Select(b => b.ToString(forceUpperCase ? "X2" : "x2")));
        }
    }
    
    public enum HashType
    {
        NONE,
        MD5,
        SHA1,
        SHA256,
        SHA512
    }
}