using System; using System.Collections.Generic; using System.IO; using System.Text; namespace MediaBrowser.Model.Cryptography { public class PasswordHash { // Defined from this hash storage spec // https://github.com/P-H-C/phc-string-format/blob/master/phc-sf-spec.md // $[$=(,=)*][$[$]] // with one slight amendment to ease the transition, we're writing out the bytes in hex // rather than making them a BASE64 string with stripped padding private string _id; private Dictionary _parameters = new Dictionary(); private byte[] _salt; private byte[] _hash; public PasswordHash(string storageString) { string[] splitted = storageString.Split('$'); // The string should at least contain the hash function and the hash itself if (splitted.Length < 3) { throw new ArgumentException("String doesn't contain enough segments", nameof(storageString)); } // Start at 1, the first index shouldn't contain any data int index = 1; // Name of the hash function _id = splitted[index++]; // Optional parameters if (splitted[index].IndexOf('=') != -1) { foreach (string paramset in splitted[index++].Split(',')) { if (string.IsNullOrEmpty(paramset)) { continue; } string[] fields = paramset.Split('='); if (fields.Length != 2) { throw new InvalidDataException($"Malformed parameter in password hash string {paramset}"); } _parameters.Add(fields[0], fields[1]); } } // Check if the string also contains a salt if (splitted.Length - index == 2) { _salt = ConvertFromByteString(splitted[index++]); _hash = ConvertFromByteString(splitted[index++]); } else { _salt = Array.Empty(); _hash = ConvertFromByteString(splitted[index++]); } } public string Id { get => _id; set => _id = value; } public Dictionary Parameters { get => _parameters; set => _parameters = value; } public byte[] Salt { get => _salt; set => _salt = value; } public byte[] Hash { get => _hash; set => _hash = value; } public PasswordHash(ICryptoProvider cryptoProvider) { _id = cryptoProvider.DefaultHashMethod; _salt = cryptoProvider.GenerateSalt(); _hash = Array.Empty(); } // TODO: move this class and use the HexHelper class public static byte[] ConvertFromByteString(string byteString) { byte[] bytes = new byte[byteString.Length / 2]; for (int i = 0; i < byteString.Length; i += 2) { // TODO: NetStandard2.1 switch this to use a span instead of a substring. bytes[i / 2] = Convert.ToByte(byteString.Substring(i, 2), 16); } return bytes; } public static string ConvertToByteString(byte[] bytes) => BitConverter.ToString(bytes).Replace("-", string.Empty); private void SerializeParameters(StringBuilder stringBuilder) { if (_parameters.Count == 0) { return; } stringBuilder.Append('$'); foreach (var pair in _parameters) { stringBuilder.Append(pair.Key); stringBuilder.Append('='); stringBuilder.Append(pair.Value); stringBuilder.Append(','); } // Remove last ',' stringBuilder.Length -= 1; } public override string ToString() { var str = new StringBuilder(); str.Append('$'); str.Append(_id); SerializeParameters(str); if (_salt.Length == 0) { str.Append('$'); str.Append(ConvertToByteString(_salt)); } str.Append('$'); str.Append(ConvertToByteString(_hash)); return str.ToString(); } } }