Synnefo » Pithos MS Client

using System.Security.Cryptography;

       /// <summary>

       ///Calculates a simple hash for an entire file

       /// </summary>

       /// <param name="info">The file to hash</param>

       /// <param name="hasher">The hash algorithm to use</param>

       /// <returns>A hash value for the entire file. An empty string if the file does not exist.</returns>

       public static string ComputeShortHash(this FileInfo info, HashAlgorithm hasher)

       {

           Contract.Requires(info != null);

           Contract.Requires(hasher!= null);           

           if (!info.Exists)

               return String.Empty;

           using (var stream = info.Open(FileMode.Open, FileAccess.Read, FileShare.Read))

           {

               var hash = hasher.ComputeHash(stream);

               var hashString = hash.ToHashString();

               return hashString;

           }

       }

        public static string ComputeShortHash(this FileInfo info)

       {

           Contract.Requires(info != null);           

           using (var hasher=HashAlgorithm.Create("sha1"))

           {               

               return ComputeShortHash(info,hasher);

           }

       }