openclonk/thirdparty/blake2/csharp/Blake2Sharp/Blake2IvBuilder.cs

77 lines
2.7 KiB
C#

// BLAKE2 reference source code package - C# implementation
// Written in 2012 by Christian Winnerlein <codesinchaos@gmail.com>
// To the extent possible under law, the author(s) have dedicated all copyright
// and related and neighboring rights to this software to the public domain
// worldwide. This software is distributed without any warranty.
// You should have received a copy of the CC0 Public Domain Dedication along with
// this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
using System;
namespace Blake2Sharp
{
internal static class Blake2IvBuilder
{
private static readonly Blake2BTreeConfig SequentialTreeConfig = new Blake2BTreeConfig() { IntermediateHashSize = 0, LeafSize = 0, FanOut = 1, MaxHeight = 1 };
public static ulong[] ConfigB(Blake2BConfig config, Blake2BTreeConfig treeConfig)
{
bool isSequential = treeConfig == null;
if (isSequential)
treeConfig = SequentialTreeConfig;
var rawConfig = new ulong[8];
var result = new ulong[8];
//digest length
if (config.OutputSizeInBytes <= 0 | config.OutputSizeInBytes > 64)
throw new ArgumentOutOfRangeException("config.OutputSize");
rawConfig[0] |= (ulong)(uint)config.OutputSizeInBytes;
//Key length
if (config.Key != null)
{
if (config.Key.Length > 64)
throw new ArgumentException("config.Key", "Key too long");
rawConfig[0] |= (ulong)((uint)config.Key.Length << 8);
}
// FanOut
rawConfig[0] |= (uint)treeConfig.FanOut << 16;
// Depth
rawConfig[0] |= (uint)treeConfig.MaxHeight << 24;
// Leaf length
rawConfig[0] |= ((ulong)(uint)treeConfig.LeafSize) << 32;
// Inner length
if (!isSequential && (treeConfig.IntermediateHashSize <= 0 || treeConfig.IntermediateHashSize > 64))
throw new ArgumentOutOfRangeException("treeConfig.TreeIntermediateHashSize");
rawConfig[2] |= (uint)treeConfig.IntermediateHashSize << 8;
// Salt
if (config.Salt != null)
{
if (config.Salt.Length != 16)
throw new ArgumentException("config.Salt has invalid length");
rawConfig[4] = Blake2BCore.BytesToUInt64(config.Salt, 0);
rawConfig[5] = Blake2BCore.BytesToUInt64(config.Salt, 8);
}
// Personalization
if (config.Personalization != null)
{
if (config.Personalization.Length != 16)
throw new ArgumentException("config.Personalization has invalid length");
rawConfig[6] = Blake2BCore.BytesToUInt64(config.Personalization, 0);
rawConfig[7] = Blake2BCore.BytesToUInt64(config.Personalization, 8);
}
return rawConfig;
}
public static void ConfigBSetNode(ulong[] rawConfig, byte depth, ulong nodeOffset)
{
rawConfig[1] = nodeOffset;
rawConfig[2] = (rawConfig[2] & ~0xFFul) | depth;
}
}
}