Unity_Web/Assets/Best HTTP/Source/SecureProtocol/crypto/digests/Blake2xsDigest.cs

373 lines
12 KiB
C#

#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
#pragma warning disable
using System;
using BestHTTP.SecureProtocol.Org.BouncyCastle.Utilities;
namespace BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto.Digests
{
/*
The BLAKE2 cryptographic hash function was designed by Jean-
Philippe Aumasson, Samuel Neves, Zooko Wilcox-O'Hearn, and Christian
Winnerlein.
Reference Implementation and Description can be found at: https://blake2.net/blake2x.pdf
*/
/**
* Implementation of the eXtendable Output Function (XOF) BLAKE2xs.
* <p/>
* BLAKE2xs offers a built-in keying mechanism to be used directly
* for authentication ("Prefix-MAC") rather than a HMAC construction.
* <p/>
* BLAKE2xs offers a built-in support for a salt for randomized hashing
* and a personal string for defining a unique hash function for each application.
* <p/>
* BLAKE2xs is optimized for 32-bit platforms and produces digests of any size
* between 1 and 2^16-2 bytes. The length can also be unknown and then the maximum
* length will be 2^32 blocks of 32 bytes.
*/
public sealed class Blake2xsDigest
: IXof
{
/**
* Magic number to indicate an unknown length of digest
*/
public const int UnknownDigestLength = 65535;
private const int DigestLength = 32;
private const long MaxNumberBlocks = 1L << 32;
/**
* Expected digest length for the xof. It can be unknown.
*/
private int digestLength;
/**
* Root hash that will take the updates
*/
private Blake2sDigest hash;
/**
* Digest of the root hash
*/
private byte[] h0 = null;
/**
* Digest of each round of the XOF
*/
private byte[] buf = new byte[32];
/**
* Current position for a round
*/
private int bufPos = 32;
/**
* Overall position of the digest. It is useful when the length is known
* in advance to get last block length.
*/
private int digestPos = 0;
/**
* Keep track of the round number to detect the end of the digest after
* 2^32 blocks of 32 bytes.
*/
private long blockPos = 0;
/**
* Current node offset incremented by 1 every round.
*/
private long nodeOffset;
/**
* BLAKE2xs for hashing with unknown digest length
*/
public Blake2xsDigest()
: this(UnknownDigestLength)
{
}
/**
* BLAKE2xs for hashing
*
* @param digestBytes The desired digest length in bytes. Must be above 1 and less than 2^16-1
*/
public Blake2xsDigest(int digestBytes)
: this(digestBytes, null, null, null)
{
}
/**
* BLAKE2xs with key
*
* @param digestBytes The desired digest length in bytes. Must be above 1 and less than 2^16-1
* @param key A key up to 32 bytes or null
*/
public Blake2xsDigest(int digestBytes, byte[] key)
: this(digestBytes, key, null, null)
{
}
/**
* BLAKE2xs with key, salt and personalization
*
* @param digestBytes The desired digest length in bytes. Must be above 1 and less than 2^16-1
* @param key A key up to 32 bytes or null
* @param salt 8 bytes or null
* @param personalization 8 bytes or null
*/
public Blake2xsDigest(int digestBytes, byte[] key, byte[] salt, byte[] personalization)
{
if (digestBytes < 1 || digestBytes > UnknownDigestLength)
throw new ArgumentException("BLAKE2xs digest length must be between 1 and 2^16-1");
digestLength = digestBytes;
nodeOffset = ComputeNodeOffset();
hash = new Blake2sDigest(DigestLength, key, salt, personalization, nodeOffset);
}
public Blake2xsDigest(Blake2xsDigest digest)
{
digestLength = digest.digestLength;
hash = new Blake2sDigest(digest.hash);
h0 = Arrays.Clone(digest.h0);
buf = Arrays.Clone(digest.buf);
bufPos = digest.bufPos;
digestPos = digest.digestPos;
blockPos = digest.blockPos;
nodeOffset = digest.nodeOffset;
}
/**
* Return the algorithm name.
*
* @return the algorithm name
*/
public string AlgorithmName => "BLAKE2xs";
/**
* Return the size in bytes of the digest produced by this message digest.
*
* @return the size in bytes of the digest produced by this message digest.
*/
public int GetDigestSize() => digestLength;
/**
* Return the size in bytes of the internal buffer the digest applies its
* compression function to.
*
* @return byte length of the digest's internal buffer.
*/
public int GetByteLength() => hash.GetByteLength();
/**
* Return the maximum size in bytes the digest can produce when the length
* is unknown
*
* @return byte length of the largest digest with unknown length
*/
public long GetUnknownMaxLength()
{
return MaxNumberBlocks * DigestLength;
}
/**
* Update the message digest with a single byte.
*
* @param in the input byte to be entered.
*/
public void Update(byte b)
{
hash.Update(b);
}
/**
* Update the message digest with a block of bytes.
*
* @param in the byte array containing the data.
* @param inOff the offset into the byte array where the data starts.
* @param len the length of the data.
*/
public void BlockUpdate(byte[] input, int inOff, int inLen)
{
hash.BlockUpdate(input, inOff, inLen);
}
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || _UNITY_2021_2_OR_NEWER_
public void BlockUpdate(ReadOnlySpan<byte> input)
{
hash.BlockUpdate(input);
}
#endif
/**
* Reset the digest back to its initial state. The key, the salt and the
* personal string will remain for further computations.
*/
public void Reset()
{
hash.Reset();
h0 = null;
bufPos = DigestLength;
digestPos = 0;
blockPos = 0;
nodeOffset = ComputeNodeOffset();
}
/**
* Close the digest, producing the final digest value. The doFinal() call
* leaves the digest reset. Key, salt and personal string remain.
*
* @param out the array the digest is to be copied into.
* @param outOffset the offset into the out array the digest is to start at.
*/
public int DoFinal(byte[] output, int outOff)
{
return OutputFinal(output, outOff, digestLength);
}
/**
* Close the digest, producing the final digest value. The doFinal() call
* leaves the digest reset. Key, salt, personal string remain.
*
* @param out output array to write the output bytes to.
* @param outOff offset to start writing the bytes at.
* @param outLen the number of output bytes requested.
*/
public int OutputFinal(byte[] output, int outOff, int outLen)
{
int ret = Output(output, outOff, outLen);
Reset();
return ret;
}
/**
* Start outputting the results of the final calculation for this digest. Unlike doFinal, this method
* will continue producing output until the Xof is explicitly reset, or signals otherwise.
*
* @param out output array to write the output bytes to.
* @param outOff offset to start writing the bytes at.
* @param outLen the number of output bytes requested.
* @return the number of bytes written
*/
public int Output(byte[] output, int outOff, int outLen)
{
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || _UNITY_2021_2_OR_NEWER_
return Output(output.AsSpan(outOff, outLen));
#else
if (h0 == null)
{
h0 = new byte[hash.GetDigestSize()];
hash.DoFinal(h0, 0);
}
if (digestLength != UnknownDigestLength)
{
if (digestPos + outLen > digestLength)
throw new ArgumentException("Output length is above the digest length");
}
else if (blockPos << 5 >= GetUnknownMaxLength())
{
throw new ArgumentException("Maximum length is 2^32 blocks of 32 bytes");
}
for (int i = 0; i < outLen; i++)
{
if (bufPos >= DigestLength)
{
Blake2sDigest h = new Blake2sDigest(ComputeStepLength(), DigestLength, nodeOffset);
h.BlockUpdate(h0, 0, h0.Length);
Arrays.Fill(buf, 0);
h.DoFinal(buf, 0);
bufPos = 0;
nodeOffset++;
blockPos++;
}
output[outOff + i] = buf[bufPos];
bufPos++;
digestPos++;
}
return outLen;
#endif
}
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || _UNITY_2021_2_OR_NEWER_
public int DoFinal(Span<byte> output)
{
return OutputFinal(output[..digestLength]);
}
public int OutputFinal(Span<byte> output)
{
int ret = Output(output);
Reset();
return ret;
}
public int Output(Span<byte> output)
{
int outLen = output.Length;
if (h0 == null)
{
h0 = new byte[hash.GetDigestSize()];
hash.DoFinal(h0);
}
if (digestLength != UnknownDigestLength)
{
if (digestPos + outLen > digestLength)
throw new ArgumentException("Output length is above the digest length");
}
else if (blockPos << 5 >= GetUnknownMaxLength())
{
throw new ArgumentException("Maximum length is 2^32 blocks of 32 bytes");
}
for (int i = 0; i < outLen; i++)
{
if (bufPos >= DigestLength)
{
Blake2sDigest h = new Blake2sDigest(ComputeStepLength(), DigestLength, nodeOffset);
h.BlockUpdate(h0);
Arrays.Fill(buf, 0);
h.DoFinal(buf);
bufPos = 0;
nodeOffset++;
blockPos++;
}
output[i] = buf[bufPos];
bufPos++;
digestPos++;
}
return outLen;
}
#endif
// get the next round length. If the length is unknown, the digest length is always the maximum.
private int ComputeStepLength()
{
if (digestLength == UnknownDigestLength)
return DigestLength;
return System.Math.Min(DigestLength, digestLength - digestPos);
}
private long ComputeNodeOffset()
{
return digestLength * 0x100000000L;
}
}
}
#pragma warning restore
#endif