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Merge pull request #444 from eugeny-trunin/mem-opt

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Memory and speed optimization
This commit is contained in:
Adam Hathcock
2019-03-20 15:13:00 +00:00
committed by GitHub
parent bbb7c85ba7 c68eaa8397
commit 4e5b70dbfa
1 changed files with 11 additions and 19 deletions
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30
src/SharpCompress/Common/Rar/RarRijndael.cs
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@@ -1,7 +1,6 @@
#if !NO_CRYPTO
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using SharpCompress.Crypto;
@@ -23,12 +22,6 @@ namespace SharpCompress.Common.Rar
_salt = salt;
}
private byte[] ComputeHash(byte[] input)
{
var sha = SHA1.Create();
return sha.ComputeHash(input);
}
private void Initialize()
{
@@ -47,28 +40,27 @@ namespace SharpCompress.Common.Rar
rawPassword[i + rawLength] = _salt[i];
}
const int noOfRounds = (1 << 18);
IList<byte> bytes = new List<byte>();
const int iblock = 3;
byte[] digest;
byte[] data = new byte[(rawPassword.Length + iblock) * noOfRounds];
//TODO slow code below, find ways to optimize
for (int i = 0; i < noOfRounds; i++)
{
bytes.AddRange(rawPassword);
rawPassword.CopyTo(data, i * (rawPassword.Length + iblock));
bytes.AddRange(new[]
data[i * (rawPassword.Length + iblock) + rawPassword.Length + 0] = (byte)i;
data[i * (rawPassword.Length + iblock) + rawPassword.Length + 1] = (byte)(i >> 8);
data[i * (rawPassword.Length + iblock) + rawPassword.Length + 2] = (byte)(i >> CRYPTO_BLOCK_SIZE);
if (i % (noOfRounds / CRYPTO_BLOCK_SIZE) == 0)
{
(byte) i, (byte) (i >> 8), (byte) (i >> CRYPTO_BLOCK_SIZE)
});
if (i%(noOfRounds/CRYPTO_BLOCK_SIZE) == 0)
{
digest = ComputeHash(bytes.ToArray());
_aesInitializationVector[i/(noOfRounds/CRYPTO_BLOCK_SIZE)] = digest[19];
digest = SHA1.Create().ComputeHash(data, 0, (i + 1) * (rawPassword.Length + iblock));
_aesInitializationVector[i / (noOfRounds / CRYPTO_BLOCK_SIZE)] = digest[19];
}
}
digest = ComputeHash(bytes.ToArray());
digest = SHA1.Create().ComputeHash(data);
//slow code ends
byte[] aesKey = new byte[CRYPTO_BLOCK_SIZE];