public override string Encode(string siteName, SiteType siteType, uint siteCounter, SiteVariant siteVariant, string siteContext = null)
{
if (siteCounter == 0)
{
siteCounter = (uint)(CurrentTimeMillis() / (300 * 1000)) * 300;
}
var siteScope = SiteVariantHelper.GetScope(siteVariant);
var siteNameBytes = Encoding.UTF8.GetBytes(siteName);
var siteNameLengthBytes = BytesForInt(siteName.Length);
var siteCounterBytes = BytesForInt(siteCounter);
var siteContextBytes = string.IsNullOrEmpty(siteContext) ? null : Encoding.UTF8.GetBytes(siteContext);
var siteContextLengthBytes = BytesForInt(siteContextBytes?.Length ?? 0);
var sitePasswordInfo = Concat(Encoding.UTF8.GetBytes(siteScope), siteNameLengthBytes, siteNameBytes, siteCounterBytes);
if (siteContextBytes != null)
{
sitePasswordInfo = Concat(sitePasswordInfo, siteContextLengthBytes, siteContextBytes);
}
var sitePasswordSeed = ComputeHmacOf(MasterKeyBytes, sitePasswordInfo);
var templateIndex = sitePasswordSeed[0] & 0xFF; // Mask the integer's sign.
var template = SiteTypeHelper.GetTemplateAtRollingIndex(siteType, templateIndex);
var password = new StringBuilder(template.TemplateString.Length);
for (var i = 0; i < template.TemplateString.Length; ++i)
{
var characterIndex = sitePasswordSeed[i + 1] & 0xFF; // Mask the integer's sign.
var characterClass = template.TemplateChars[i];
var passwordCharacter = TemplateCharacterClassHelper.GetCharacterAtRollingIndex(characterClass, characterIndex);
password.Append(passwordCharacter);
}
return(password.ToString());
}
public override string Encode(string siteName, SiteType siteType, uint siteCounter, SiteVariant siteVariant, string siteContext = null)
{
if (siteCounter == 0)
{
siteCounter = (uint)(CurrentTimeMillis() / (300 * 1000)) * 300;
}
var siteScope = SiteVariantHelper.GetScope(siteVariant);
var siteNameBytes = Encoding.UTF8.GetBytes(siteName);
var siteNameLengthBytes = BytesForInt(siteName.Length);
var siteCounterBytes = BytesForInt(siteCounter);
var siteContextBytes = string.IsNullOrEmpty(siteContext) ? null : Encoding.UTF8.GetBytes(siteContext);
var siteContextLengthBytes = BytesForInt(siteContextBytes?.Length ?? 0);
var sitePasswordInfo = Concat(Encoding.UTF8.GetBytes(siteScope), siteNameLengthBytes, siteNameBytes, siteCounterBytes);
if (siteContextBytes != null)
{
sitePasswordInfo = Concat(sitePasswordInfo, siteContextLengthBytes, siteContextBytes);
}
var sitePasswordSeedBytes = ComputeHmacOf(MasterKeyBytes, sitePasswordInfo);
var sitePasswordSeed = new int[sitePasswordSeedBytes.Length];
for (var i = 0; i < sitePasswordSeedBytes.Length; ++i)
{
var m = new MemoryStream(sizeof(int) / sizeof(byte));
m.SetLength(sizeof(int) / sizeof(byte));
Fill(m, (sbyte)sitePasswordSeedBytes[i] > 0 ? (byte)0x00 : (byte)0xFF);
var w = new BinaryWriter(m);
{
w.Seek(2, SeekOrigin.Begin);
w.Write(sitePasswordSeedBytes[i]);
w.Flush();
m.Position = 0;
}
// change byte order
m = new MemoryStream(ChangeByteOrder(m.ToArray(), ByteOrder.BigEndian));
using (var r = new BinaryReader(m))
{
sitePasswordSeed[i] = r.ReadInt32() & 0xFFFF;
}
}
var templateIndex = sitePasswordSeed[0];
var template = SiteTypeHelper.GetTemplateAtRollingIndex(siteType, templateIndex);
var password = new StringBuilder(template.TemplateString.Length);
for (var i = 0; i < template.TemplateString.Length; ++i)
{
var characterIndex = sitePasswordSeed[i + 1];
var characterClass = template.TemplateChars[i];
var passwordCharacter = TemplateCharacterClassHelper.GetCharacterAtRollingIndex(characterClass, characterIndex);
password.Append(passwordCharacter);
}
return(password.ToString());
}