/// <inheritdoc />
public override long Seek(long offset, SeekOrigin origin)
{
long pos;
switch (origin)
{
case SeekOrigin.Begin:
pos = offset;
break;
case SeekOrigin.Current:
pos = Position + offset;
break;
case SeekOrigin.End:
pos = Length + offset;
break;
default:
throw Exceptions.ArgumentOutOfRange("origin", "Unknown seek type.");
}
if (pos < 0)
{
throw Exceptions.Argument("offset", "Can't seek before the stream start.");
}
Position = pos;
return(pos);
}
/// <inheritdoc />
public override string GenerateSalt(CrypterOptions options)
{
Check.Null("options", options);
switch (options.GetValue(CrypterOption.Variant, LdapCrypterVariant.SSha))
{
case LdapCrypterVariant.Crypt:
Crypter crypter = options.GetValue <Crypter>(LdapCrypterOption.Crypter);
if (crypter == null)
{
throw Exceptions.Argument("LdapCrypterOption.Crypter",
"Crypter not set. Did you intend Crypter.TraditionalDes (the slappasswd default)?");
}
CrypterOptions crypterOptions = options.GetValue(LdapCrypterOption.CrypterOptions, CrypterOptions.None);
return("{CRYPT}" + crypter.GenerateSalt(crypterOptions));
case LdapCrypterVariant.SSha: return("{SSHA}" + Convert.ToBase64String(Security.GenerateRandomBytes(8)));
case LdapCrypterVariant.SMD5: return("{SMD5}" + Convert.ToBase64String(Security.GenerateRandomBytes(8)));
case LdapCrypterVariant.Sha: return("{SHA}");
case LdapCrypterVariant.MD5: return("{MD5}");
case LdapCrypterVariant.Cleartext: return("{CLEARTEXT}");
default: throw Exceptions.ArgumentOutOfRange("CrypterOption.Variant", "Unknown variant.");
}
}
/// <inheritdoc />
public override string Crypt(byte[] password, string salt)
{
Check.Null("password", password);
Check.Null("salt", salt);
Match match = _regex.Match(salt);
if (!match.Success)
{
throw Exceptions.Argument("salt", "Invalid salt.");
}
byte[] roundsBytes = null, saltBytes = null, crypt = null, input = null;
try
{
string roundsString = match.Groups["rounds"].Value;
roundsBytes = Base64Encoding.UnixMD5.GetBytes(roundsString);
int roundsValue = (int)BitPacking.UInt24FromLEBytes(roundsBytes, 0);
string saltString = match.Groups["salt"].Value;
saltBytes = Base64Encoding.UnixMD5.GetBytes(saltString);
int saltValue = (int)BitPacking.UInt24FromLEBytes(saltBytes, 0);
input = new byte[8];
int length = ByteArray.NullTerminatedLength(password, password.Length);
for (int m = 0; m < length; m += 8)
{
if (m != 0)
{
using (DesCipher cipher = DesCipher.Create(input))
{
cipher.Encipher(input, 0, input, 0);
}
}
for (int n = 0; n < 8 && n < length - m; n++)
{
// DES Crypt ignores the high bit of every byte.
input[n] ^= (byte)(password[m + n] << 1);
}
}
using (DesCipher cipher = DesCipher.Create(input))
{
crypt = new byte[8];
cipher.Crypt(crypt, 0, roundsValue, saltValue);
}
return("_" + roundsString + saltString + Base64Encoding.UnixCrypt.GetString(crypt));
}
finally
{
Security.Clear(roundsBytes);
Security.Clear(saltBytes);
Security.Clear(crypt);
Security.Clear(input);
}
}
/// <inheritdoc />
public override string Crypt(byte[] password, string salt)
{
Check.Null("password", password);
Check.Null("salt", salt);
Match match = _regex.Match(salt);
if (!match.Success)
{
throw Exceptions.Argument("salt", "Invalid salt.");
}
byte[] saltBytes = null, crypt = null;
try
{
string roundsString = match.Groups["rounds"].Value;
int rounds = Base64Encoding.UnixMD5.GetValue(roundsString[0]);
if (rounds < MinRounds || rounds > MaxRounds)
{
throw Exceptions.ArgumentOutOfRange("salt", "Invalid number of rounds.");
}
string prefixString = match.Groups["prefix"].Value;
bool sha512 = prefixString == "$S$";
string saltString = match.Groups["salt"].Value;
saltBytes = Encoding.ASCII.GetBytes(saltString);
HashAlgorithm A;
if (sha512)
{
A = System.Security.Cryptography.SHA512.Create();
}
else
{
A = System.Security.Cryptography.MD5.Create();
}
crypt = Crypt(password, saltBytes, rounds, A);
string hashString = Base64Encoding.UnixMD5.GetString(crypt);
if (sha512)
{
hashString = hashString.Substring(0, 43);
}
string result = prefixString
+ roundsString
+ saltString
+ hashString;
return(result);
}
finally
{
Security.Clear(saltBytes);
Security.Clear(crypt);
}
}
/// <inheritdoc />
public override string Crypt(byte[] password, string salt)
{
Check.Null("password", password);
Check.Null("salt", salt);
if (string.IsNullOrEmpty(salt))
{
return(Crypt(password));
}
Match match = _regex.Match(salt);
if (!match.Success)
{
var hash = Crypt(password);
var matchUnsalted = string.Equals(hash, salt, StringComparison.InvariantCultureIgnoreCase);
if (matchUnsalted)
{
return(hash);
}
else
{
throw Exceptions.Argument("salt", "Invalid salt.");
}
}
byte[] prefixBytes = null, saltBytes = null, formattedKey = null, truncatedSalt = null, crypt = null;
try
{
string prefixString = match.Groups["prefix"].Value;
prefixBytes = Encoding.ASCII.GetBytes(prefixString);
string saltString = match.Groups["salt"].Value;
saltBytes = Encoding.ASCII.GetBytes(saltString);
formattedKey = FormatKey(password);
truncatedSalt = ByteArray.TruncateAndCopy(saltBytes, 8);
crypt = Crypt(formattedKey, truncatedSalt, prefixBytes, System.Security.Cryptography.MD5.Create());
string result = prefixString
+ saltString + '$'
+ Base64Encoding.UnixMD5.GetString(crypt);
return(result);
}
finally
{
Security.Clear(prefixBytes);
Security.Clear(saltBytes);
Security.Clear(formattedKey);
Security.Clear(truncatedSalt);
Security.Clear(crypt);
}
}
/// <summary>
/// Searches for a crypt algorithm compatible with the specified crypted password or prefix.
/// </summary>
/// <param name="cryptedPassword">The crypted password or prefix.</param>
/// <returns>A compatible crypt algorithm.</returns>
/// <exception cref="ArgumentException">No compatible crypt algorithm was found.</exception>
public Crypter GetCrypter(string cryptedPassword)
{
Crypter crypter;
if (TryGetCrypter(cryptedPassword, out crypter))
{
return(crypter);
}
else
{
throw Exceptions.Argument("cryptedPassword", "Unsupported algorithm.");
}
}
/// <inheritdoc />
public override string Crypt(byte[] password, string salt)
{
Check.Null("password", password);
Check.Null("salt", salt);
Match match = GetRegex().Match(salt);
if (!match.Success)
{
throw Exceptions.Argument("salt", "Invalid salt.");
}
string roundsString = match.Groups["rounds"].Value;
bool roundsStringPresent = roundsString.Length != 0;
int rounds = roundsStringPresent ? int.Parse(roundsString) : 5000;
//int requestedRounds = rounds; // PHP tests indicate the rounds string is NOT preserved if the count is outside spec.
if (rounds < MinRounds)
{
rounds = MinRounds;
}
if (rounds > MaxRounds)
{
rounds = MaxRounds;
}
byte[] saltBytes = null, formattedKey = null, truncatedSalt = null, crypt = null;
try
{
string saltString = match.Groups["salt"].Value;
saltBytes = Encoding.ASCII.GetBytes(saltString);
formattedKey = FormatKey(password);
truncatedSalt = ByteArray.TruncateAndCopy(saltBytes, 16);
crypt = Crypt(formattedKey, truncatedSalt, rounds, CreateHashAlgorithm());
string result = CryptPrefix
+ (roundsStringPresent ? string.Format("rounds={0}$", rounds) : "")
+ Encoding.ASCII.GetString(truncatedSalt) + '$'
+ Base64Encoding.UnixMD5.GetString(crypt);
return(result);
}
finally
{
Security.Clear(saltBytes);
Security.Clear(formattedKey);
Security.Clear(truncatedSalt);
Security.Clear(crypt);
}
}
/// <summary>
/// Reads from the derived key stream.
/// </summary>
/// <param name="count">The number of bytes to read.</param>
/// <returns>Bytes from the derived key stream.</returns>
public byte[] Read(int count)
{
NBitcoin.Crypto.Internal.Check.Range("count", count, 0, int.MaxValue);
byte[] buffer = new byte[count];
int bytes = Read(buffer, 0, count);
if (bytes < count)
{
throw Exceptions.Argument("count", "Can only return {0} bytes.", bytes);
}
return(buffer);
}
/// <summary>
/// Throws an exception if the value is incompatible with this option.
/// </summary>
/// <param name="value">The value to check.</param>
public void CheckValue(object value)
{
if (value is null)
{
throw Exceptions.ArgumentNull(nameof(value));
}
if (!ValueType.IsAssignableFrom(value.GetType()))
{
throw Exceptions.Argument(nameof(value), "Value is incompatible with type {0}.", ValueType);
}
OnCheckValue(value);
}
/// <inheritdoc />
public override long Seek(long offset, SeekOrigin origin)
{
var pos = origin switch
{
SeekOrigin.Begin => offset,
SeekOrigin.Current => Position + offset,
SeekOrigin.End => Length + offset,
_ => throw Exceptions.ArgumentOutOfRange("origin", "Unknown seek type."),
};
if (pos < 0)
{
throw Exceptions.Argument("offset", "Can't seek before the stream start.");
}
Position = pos; return(pos);
}
public Pbkdf2(KeyedHashAlgorithm hmacAlgorithm, byte[] salt, int iterations)
{
NBitcoin.Crypto.Internal.Check.Null("hmacAlgorithm", hmacAlgorithm);
NBitcoin.Crypto.Internal.Check.Null("salt", salt);
NBitcoin.Crypto.Internal.Check.Length("salt", salt, 0, int.MaxValue - 4);
NBitcoin.Crypto.Internal.Check.Range("iterations", iterations, 1, int.MaxValue);
if (hmacAlgorithm.HashSize == 0 || hmacAlgorithm.HashSize % 8 != 0)
{
throw Exceptions.Argument("hmacAlgorithm", "Unsupported hash size.");
}
int hmacLength = hmacAlgorithm.HashSize / 8;
_saltBuffer = new byte[salt.Length + 4]; Array.Copy(salt, _saltBuffer, salt.Length);
_iterations = iterations; _hmacAlgorithm = hmacAlgorithm;
_digest = new byte[hmacLength]; _digestT1 = new byte[hmacLength];
}
/// <summary>
/// Gets the value of an option, if the option is set, or a specified default value otherwise.
/// </summary>
/// <typeparam name="T">The type of the option's value.</typeparam>
/// <param name="key">The key of the option.</param>
/// <param name="defaultValue">The default value if the option is not set.</param>
/// <returns>The option's value.</returns>
public T GetValue <T>(CrypterOptionKey key, T defaultValue)
{
object value;
if (!TryGetValue(key, out value))
{
return(defaultValue);
}
try
{
return((T)value);
}
catch (InvalidCastException)
{
throw Exceptions.Argument(key.Description, "Expected type {0}.", typeof(T));
}
}
/// <inheritdoc />
public override string Crypt(byte[] password, string salt)
{
Check.Null("password", password);
Check.Null("salt", salt);
Match match = _regex.Match(salt);
if (!match.Success)
{
throw Exceptions.Argument("salt", "Invalid salt.");
}
byte[] crypt = null, input = null;
try
{
string saltString = FilterSalt(match.Groups["salt"].Value);
input = new byte[8];
int length = ByteArray.NullTerminatedLength(password, input.Length);
Array.Copy(password, input, Math.Min(length, input.Length));
// DES Crypt ignores the high bit of every byte.
for (int n = 0; n < 8; n++)
{
input[n] <<= 1;
}
using (DesCipher cipher = DesCipher.Create(input))
{
int saltValue =
Base64Encoding.UnixCrypt.GetValue(saltString[0]) << 0 |
Base64Encoding.UnixCrypt.GetValue(saltString[1]) << 6;
crypt = new byte[8];
cipher.Crypt(crypt, 0, 25, saltValue);
}
return(saltString + Base64Encoding.UnixCrypt.GetString(crypt));
}
finally
{
Security.Clear(crypt);
Security.Clear(input);
}
}
/// <inheritdoc />
public override string Crypt(byte[] password, string salt)
{
Check.Null("password", password);
Check.Null("salt", salt);
Match match = _regex.Match(salt);
if (!match.Success)
{
throw Exceptions.Argument("salt", "Invalid salt.");
}
byte[] saltBytes = null, formattedKey = null, crypt = null;
try
{
string prefixString = match.Groups["prefix"].Value;
bool compatible = prefixString == "$2x$";
int rounds = int.Parse(match.Groups["rounds"].Value);
if (rounds < MinRounds || rounds > MaxRounds)
{
throw Exceptions.ArgumentOutOfRange("salt", "Invalid number of rounds.");
}
saltBytes = Base64Encoding.Blowfish.GetBytes(match.Groups["salt"].Value);
formattedKey = FormatKey(password);
crypt = BlowfishCipher.BCrypt(formattedKey, saltBytes, rounds,
compatible
? EksBlowfishKeyExpansionFlags.EmulateCryptBlowfishSignExtensionBug
: EksBlowfishKeyExpansionFlags.None);
string result = string.Format("{0}{1}${2}{3}", prefixString, rounds.ToString("00"),
Base64Encoding.Blowfish.GetString(saltBytes),
Base64Encoding.Blowfish.GetString(crypt));
return(result);
}
finally
{
Security.Clear(saltBytes);
Security.Clear(formattedKey);
Security.Clear(crypt);
}
}
static string SaltedCrypt(HashAlgorithm algorithm, byte[] password, string saltString)
{
byte[] salt = null;
try
{
if (!TryConvertFromBase64String(saltString, out salt))
{
throw Exceptions.Argument("salt", "Bad base-64.");
}
// If we're under the hash length, assume we only have the salt.
int hashLength = algorithm.HashSize / 8;
int saltOffset = salt.Length < hashLength ? 0 : hashLength;
int saltLength = salt.Length - saltOffset;
byte[] saltedHash = new byte[hashLength + saltLength];
try
{
algorithm.Initialize();
algorithm.TransformBlock(password, 0, password.Length, password, 0);
algorithm.TransformBlock(salt, saltOffset, saltLength, salt, saltOffset);
algorithm.TransformFinalBlock(new byte[0], 0, 0);
Array.Copy(algorithm.Hash, saltedHash, hashLength);
Array.Copy(salt, saltOffset, saltedHash, hashLength, saltLength);
string crypt = Convert.ToBase64String(saltedHash);
return(crypt);
}
finally
{
algorithm.Clear();
Security.Clear(saltedHash);
}
}
finally
{
Security.Clear(salt);
}
}
/// <inheritdoc />
public override string Crypt(byte[] password, string salt)
{
Check.Null("password", password);
Check.Null("salt", salt);
Match match = _regex.Match(salt);
if (!match.Success)
{
throw Exceptions.Argument("salt", "Invalid salt.");
}
byte[] prefixBytes = null, saltBytes = null, formattedKey = null, truncatedSalt = null, crypt = null;
try
{
string prefixString = match.Groups["prefix"].Value;
prefixBytes = Encoding.ASCII.GetBytes(prefixString);
string saltString = match.Groups["salt"].Value;
saltBytes = Encoding.ASCII.GetBytes(saltString);
formattedKey = FormatKey(password);
truncatedSalt = ByteArray.TruncateAndCopy(saltBytes, 8);
crypt = Crypt(formattedKey, truncatedSalt, prefixBytes, System.Security.Cryptography.MD5.Create());
string result = prefixString
+ saltString + '$'
+ Base64Encoding.UnixMD5.GetString(crypt);
return(result);
}
finally
{
Security.Clear(prefixBytes);
Security.Clear(saltBytes);
Security.Clear(formattedKey);
Security.Clear(truncatedSalt);
Security.Clear(crypt);
}
}
/// <summary>
/// Defines a binary-to-text encoding.
/// Additional decode characters let you add aliases, and a filter callback can be used
/// to make decoding case-insensitive among other things.
/// </summary>
/// <param name="characterSet">The characters of the encoding.</param>
/// <param name="msbComesFirst">
/// <c>true</c> to begin with the most-significant bit of each byte.
/// Otherwise, the encoding begins with the least-significant bit.
/// </param>
/// <param name="additionalDecodeCharacters">
/// A dictionary of alias characters, or <c>null</c> if no aliases are desired.
/// </param>
/// <param name="decodeFilterCallback">
/// A callback to map arbitrary characters onto the characters that can be decoded.
/// </param>
public BaseEncoding(string characterSet, bool msbComesFirst,
IDictionary <char, int> additionalDecodeCharacters,
BaseEncodingDecodeFilterCallback decodeFilterCallback)
{
Check.Null("characterSet", characterSet);
if (!BitMath.IsPositivePowerOf2(characterSet.Length))
{
throw Exceptions.Argument("characterSet",
"Length must be a power of 2.");
}
if (characterSet.Length > 256)
{
throw Exceptions.Argument("characterSet",
"Character sets with over 256 characters are not supported.");
}
_bitCount = 31 - BitMath.CountLeadingZeros(characterSet.Length);
_bitMask = (1 << _bitCount) - 1;
_characters = characterSet;
_msbComesFirst = msbComesFirst;
_decodeFilterCallback = decodeFilterCallback;
_values = additionalDecodeCharacters != null
? new Dictionary <char, int>(additionalDecodeCharacters)
: new Dictionary <char, int>();
for (int i = 0; i < characterSet.Length; i++)
{
char ch = characterSet[i];
if (_values.ContainsKey(ch))
{
throw Exceptions.Argument("Duplicate characters are not supported.",
"characterSet");
}
_values.Add(ch, (byte)i);
}
}
/// <inheritdoc />
public override string Crypt(byte[] password, string salt)
{
Check.Null("password", password);
Check.Null("salt", salt);
Match match; LdapCrypterVariant variant;
if (!TryMatch(salt, out match, out variant))
{
throw Exceptions.Argument("salt", "Invalid salt.");
}
string prefixString = match.Groups["prefix"].Value;
string saltString = match.Groups["salt"].Value;
switch (variant)
{
case LdapCrypterVariant.Crypt:
Crypter crypter;
if (!_environment.TryGetCrypter(saltString, out crypter))
{
goto default;
}
if (crypter is LdapCrypter)
{
throw Exceptions.Argument("salt", "LDAP {CRYPT} tried to use an LDAP scheme.");
}
return(prefixString + crypter.Crypt(password, saltString));
case LdapCrypterVariant.SSha512:
return(prefixString + SaltedCrypt(SHA512.Create(), password, saltString));
case LdapCrypterVariant.SSha384:
return(prefixString + SaltedCrypt(SHA384.Create(), password, saltString));
case LdapCrypterVariant.SSha256:
return(prefixString + SaltedCrypt(SHA256.Create(), password, saltString));
case LdapCrypterVariant.SSha:
return(prefixString + SaltedCrypt(SHA1.Create(), password, saltString));
case LdapCrypterVariant.SMD5:
return(prefixString + SaltedCrypt(System.Security.Cryptography.MD5.Create(), password, saltString));
case LdapCrypterVariant.Sha512:
return(prefixString + UnsaltedCrypt(SHA512.Create(), password));
case LdapCrypterVariant.Sha384:
return(prefixString + UnsaltedCrypt(SHA384.Create(), password));
case LdapCrypterVariant.Sha256:
return(prefixString + UnsaltedCrypt(SHA256.Create(), password));
case LdapCrypterVariant.Sha:
return(prefixString + UnsaltedCrypt(SHA1.Create(), password));
case LdapCrypterVariant.MD5:
return(prefixString + UnsaltedCrypt(System.Security.Cryptography.MD5.Create(), password));
case LdapCrypterVariant.Cleartext:
return(prefixString + Encoding.UTF8.GetString(password));
default:
throw Exceptions.ArgumentOutOfRange("CrypterOption.Variant", "Unknown variant.");
}
}
/// <summary>
/// Applies the Salsa20 hash function.
/// It maps a 16 element input to an output of the same size.
/// </summary>
/// <param name="rounds">The number of rounds. SCrypt uses 8.</param>
/// <param name="input">The input buffer.</param>
/// <param name="inputOffset">The offset into the input buffer.</param>
/// <param name="output">The output buffer.</param>
/// <param name="outputOffset">The offset into the output buffer.</param>
public static void Compute(int rounds,
uint[] input, int inputOffset, uint[] output, int outputOffset)
{
if (rounds < 2 || rounds > 20 || (rounds & 1) == 1)
{
throw Exceptions.Argument("rounds", "Must be even and in the range 2 to 20.");
}
try
{
// .NET's bounds checking hurts performance in tight loops like this one.
// So, I unroll the array to eliminate it - a 50% speed increase.
uint x0 = input[inputOffset + 0];
uint x1 = input[inputOffset + 1];
uint x2 = input[inputOffset + 2];
uint x3 = input[inputOffset + 3];
uint x4 = input[inputOffset + 4];
uint x5 = input[inputOffset + 5];
uint x6 = input[inputOffset + 6];
uint x7 = input[inputOffset + 7];
uint x8 = input[inputOffset + 8];
uint x9 = input[inputOffset + 9];
uint x10 = input[inputOffset + 10];
uint x11 = input[inputOffset + 11];
uint x12 = input[inputOffset + 12];
uint x13 = input[inputOffset + 13];
uint x14 = input[inputOffset + 14];
uint x15 = input[inputOffset + 15];
for (int i = rounds; i > 0; i -= 2)
{
x4 ^= R(x0 + x12, 7); x8 ^= R(x4 + x0, 9);
x12 ^= R(x8 + x4, 13); x0 ^= R(x12 + x8, 18);
x9 ^= R(x5 + x1, 7); x13 ^= R(x9 + x5, 9);
x1 ^= R(x13 + x9, 13); x5 ^= R(x1 + x13, 18);
x14 ^= R(x10 + x6, 7); x2 ^= R(x14 + x10, 9);
x6 ^= R(x2 + x14, 13); x10 ^= R(x6 + x2, 18);
x3 ^= R(x15 + x11, 7); x7 ^= R(x3 + x15, 9);
x11 ^= R(x7 + x3, 13); x15 ^= R(x11 + x7, 18);
x1 ^= R(x0 + x3, 7); x2 ^= R(x1 + x0, 9);
x3 ^= R(x2 + x1, 13); x0 ^= R(x3 + x2, 18);
x6 ^= R(x5 + x4, 7); x7 ^= R(x6 + x5, 9);
x4 ^= R(x7 + x6, 13); x5 ^= R(x4 + x7, 18);
x11 ^= R(x10 + x9, 7); x8 ^= R(x11 + x10, 9);
x9 ^= R(x8 + x11, 13); x10 ^= R(x9 + x8, 18);
x12 ^= R(x15 + x14, 7); x13 ^= R(x12 + x15, 9);
x14 ^= R(x13 + x12, 13); x15 ^= R(x14 + x13, 18);
}
output[outputOffset + 0] = input[inputOffset + 0] + x0; x0 = 0;
output[outputOffset + 1] = input[inputOffset + 1] + x1; x1 = 0;
output[outputOffset + 2] = input[inputOffset + 2] + x2; x2 = 0;
output[outputOffset + 3] = input[inputOffset + 3] + x3; x3 = 0;
output[outputOffset + 4] = input[inputOffset + 4] + x4; x4 = 0;
output[outputOffset + 5] = input[inputOffset + 5] + x5; x5 = 0;
output[outputOffset + 6] = input[inputOffset + 6] + x6; x6 = 0;
output[outputOffset + 7] = input[inputOffset + 7] + x7; x7 = 0;
output[outputOffset + 8] = input[inputOffset + 8] + x8; x8 = 0;
output[outputOffset + 9] = input[inputOffset + 9] + x9; x9 = 0;
output[outputOffset + 10] = input[inputOffset + 10] + x10; x10 = 0;
output[outputOffset + 11] = input[inputOffset + 11] + x11; x11 = 0;
output[outputOffset + 12] = input[inputOffset + 12] + x12; x12 = 0;
output[outputOffset + 13] = input[inputOffset + 13] + x13; x13 = 0;
output[outputOffset + 14] = input[inputOffset + 14] + x14; x14 = 0;
output[outputOffset + 15] = input[inputOffset + 15] + x15; x15 = 0;
}
catch (IndexOutOfRangeException)
{
// For speed, don't bounds-check until .NET throws from a bounds error.
Check.Null("input", input); Check.Bounds("input", input, inputOffset, 16);
Check.Null("output", output); Check.Bounds("output", output, outputOffset, 16);
throw;
}
}