/// <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);
}
public static void Range(string valueName, int value, int minimum, int maximum)
{
if (value < minimum || value > maximum)
{
throw Exceptions.ArgumentOutOfRange(valueName,
"Value must be in the range [{0}, {1}].",
minimum, maximum);
}
}
public static void Length(string valueName, Array value, int minimum, int maximum)
{
Check.Null(valueName, value);
if (value.Length < minimum || value.Length > maximum)
{
throw Exceptions.ArgumentOutOfRange(valueName,
"Length must be in the range [{0}, {1}].",
minimum, maximum);
}
}
public static void Bounds(string valueName, Array value, int offset, int count)
{
Check.Null(valueName, value);
if (offset < 0 || count < 0 || count > value.Length - offset)
{
throw Exceptions.ArgumentOutOfRange(valueName,
"Range [{0}, {1}) is outside array bounds [0, {2}).",
offset, offset + count, value.Length);
}
}
static byte[] MFcrypt(byte[] P, byte[] S,
int cost, int blockSize, int parallel, int?maxThreads)
{
int MFLen = blockSize * 128;
if (maxThreads == null)
{
maxThreads = int.MaxValue;
}
if (!BitMath.IsPositivePowerOf2(cost))
{
throw Exceptions.ArgumentOutOfRange("cost", "Cost must be a positive power of 2.");
}
Check.Range("blockSize", blockSize, 1, int.MaxValue / 128);
Check.Range("parallel", parallel, 1, int.MaxValue / MFLen);
Check.Range("maxThreads", (int)maxThreads, 1, int.MaxValue);
#if !(USEBC || NETCORE)
byte[] B = Pbkdf2.ComputeDerivedKey(new HMACSHA256(P), S, 1, parallel * MFLen);
#else
var mac = new NBitcoin.BouncyCastle.Crypto.Macs.HMac(new NBitcoin.BouncyCastle.Crypto.Digests.Sha256Digest());
mac.Init(new KeyParameter(P));
byte[] B = Pbkdf2.ComputeDerivedKey(mac, S, 1, parallel * MFLen);
#endif
uint[] B0 = new uint[B.Length / 4];
for (int i = 0; i < B0.Length; i++)
{
B0[i] = BitPacking.UInt32FromLEBytes(B, i * 4);
} // code is easier with uint[]
ThreadSMixCalls(B0, MFLen, cost, blockSize, parallel, (int)maxThreads);
for (int i = 0; i < B0.Length; i++)
{
BitPacking.LEBytesFromUInt32(B0[i], B, i * 4);
}
Security.Clear(B0);
return(B);
}
