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🐛Move checksum initializers to instance constructors.

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This commit is contained in:
Natalia Portillo
2018-02-03 17:39:49 +00:00
parent 3768e7d077
commit 28c52ef664
13 changed files with 272 additions and 252 deletions
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2
Adler32Context.cs
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@@ -47,7 +47,7 @@ namespace DiscImageChef.Checksums
/// <summary>
/// Initializes the Adler-32 sums
/// </summary>
public void Init()
public Adler32Context()
{
sum1 = 1;
sum2 = 0;

24
CRC16Context.cs
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@@ -43,14 +43,14 @@ namespace DiscImageChef.Checksums
{
const ushort CRC16_POLY = 0xA001;
const ushort CRC16_SEED = 0x0000;
ushort hashInt;
ushort[] table;
readonly ushort[] table;
ushort hashInt;
/// <summary>
/// Initializes the CRC16 table and seed
/// </summary>
public void Init()
public Crc16Context()
{
hashInt = CRC16_SEED;
@@ -59,8 +59,10 @@ namespace DiscImageChef.Checksums
{
ushort entry = (ushort)i;
for(int j = 0; j < 8; j++)
if((entry & 1) == 1) entry = (ushort)((entry >> 1) ^ CRC16_POLY);
else entry = (ushort)(entry >> 1);
if((entry & 1) == 1)
entry = (ushort)((entry >> 1) ^ CRC16_POLY);
else
entry = (ushort)(entry >> 1);
table[i] = entry;
}
@@ -135,8 +137,10 @@ namespace DiscImageChef.Checksums
{
ushort entry = (ushort)i;
for(int j = 0; j < 8; j++)
if((entry & 1) == 1) entry = (ushort)((entry >> 1) ^ CRC16_POLY);
else entry = (ushort)(entry >> 1);
if((entry & 1) == 1)
entry = (ushort)((entry >> 1) ^ CRC16_POLY);
else
entry = (ushort)(entry >> 1);
localTable[i] = entry;
}
@@ -187,8 +191,10 @@ namespace DiscImageChef.Checksums
{
ushort entry = (ushort)i;
for(int j = 0; j < 8; j++)
if((entry & 1) == 1) entry = (ushort)((entry >> 1) ^ polynomial);
else entry = (ushort)(entry >> 1);
if((entry & 1) == 1)
entry = (ushort)((entry >> 1) ^ polynomial);
else
entry = (ushort)(entry >> 1);
localTable[i] = entry;
}

32
CRC32Context.cs
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@@ -43,14 +43,14 @@ namespace DiscImageChef.Checksums
{
const uint CRC32_POLY = 0xEDB88320;
const uint CRC32_SEED = 0xFFFFFFFF;
uint hashInt;
uint[] table;
readonly uint[] table;
uint hashInt;
/// <summary>
/// Initializes the CRC32 table and seed
/// </summary>
public void Init()
public Crc32Context()
{
hashInt = CRC32_SEED;
@@ -59,8 +59,10 @@ namespace DiscImageChef.Checksums
{
uint entry = (uint)i;
for(int j = 0; j < 8; j++)
if((entry & 1) == 1) entry = (entry >> 1) ^ CRC32_POLY;
else entry = entry >> 1;
if((entry & 1) == 1)
entry = (entry >> 1) ^ CRC32_POLY;
else
entry = entry >> 1;
table[i] = entry;
}
@@ -135,20 +137,22 @@ namespace DiscImageChef.Checksums
{
uint entry = (uint)i;
for(int j = 0; j < 8; j++)
if((entry & 1) == 1) entry = (entry >> 1) ^ CRC32_POLY;
else entry = entry >> 1;
if((entry & 1) == 1)
entry = (entry >> 1) ^ CRC32_POLY;
else
entry = entry >> 1;
localTable[i] = entry;
}
for(int i = 0; i < fileStream.Length; i++)
{
localhashInt = (localhashInt >> 8) ^ localTable[fileStream.ReadByte() ^ (localhashInt & 0xff)];
if((localhashInt ^ CRC32_SEED) == 0xB883C628 || (localhashInt ^CRC32_SEED) == 0x28C683B8)
{
localhashInt = (localhashInt >> 8) ^
localTable[fileStream.ReadByte() ^ (localhashInt & 0xff)];
if((localhashInt ^ CRC32_SEED) == 0xB883C628 ||
(localhashInt ^ CRC32_SEED) == 0x28C683B8)
System.Console.WriteLine("CRC found at position {0}", fileStream.Position);
}
}
localhashInt ^= CRC32_SEED;
BigEndianBitConverter.IsLittleEndian = BitConverter.IsLittleEndian;
@@ -193,8 +197,10 @@ namespace DiscImageChef.Checksums
{
uint entry = (uint)i;
for(int j = 0; j < 8; j++)
if((entry & 1) == 1) entry = (entry >> 1) ^ polynomial;
else entry = entry >> 1;
if((entry & 1) == 1)
entry = (entry >> 1) ^ polynomial;
else
entry = entry >> 1;
localTable[i] = entry;
}

24
CRC64Context.cs
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@@ -43,14 +43,14 @@ namespace DiscImageChef.Checksums
{
const ulong CRC64_POLY = 0xC96C5795D7870F42;
const ulong CRC64_SEED = 0xFFFFFFFFFFFFFFFF;
ulong hashInt;
ulong[] table;
readonly ulong[] table;
ulong hashInt;
/// <summary>
/// Initializes the CRC64 table and seed
/// </summary>
public void Init()
public Crc64Context()
{
hashInt = CRC64_SEED;
@@ -59,8 +59,10 @@ namespace DiscImageChef.Checksums
{
ulong entry = (ulong)i;
for(int j = 0; j < 8; j++)
if((entry & 1) == 1) entry = (entry >> 1) ^ CRC64_POLY;
else entry = entry >> 1;
if((entry & 1) == 1)
entry = (entry >> 1) ^ CRC64_POLY;
else
entry = entry >> 1;
table[i] = entry;
}
@@ -135,8 +137,10 @@ namespace DiscImageChef.Checksums
{
ulong entry = (ulong)i;
for(int j = 0; j < 8; j++)
if((entry & 1) == 1) entry = (entry >> 1) ^ CRC64_POLY;
else entry = entry >> 1;
if((entry & 1) == 1)
entry = (entry >> 1) ^ CRC64_POLY;
else
entry = entry >> 1;
localTable[i] = entry;
}
@@ -187,8 +191,10 @@ namespace DiscImageChef.Checksums
{
ulong entry = (ulong)i;
for(int j = 0; j < 8; j++)
if((entry & 1) == 1) entry = (entry >> 1) ^ polynomial;
else entry = entry >> 1;
if((entry & 1) == 1)
entry = (entry >> 1) ^ polynomial;
else
entry = entry >> 1;
localTable[i] = entry;
}

2
FletcherContext.cs
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@@ -47,7 +47,7 @@ namespace DiscImageChef.Checksums
/// <summary>
/// Initializes the Fletcher32 sums
/// </summary>
public void Init()
public Fletcher32Context()
{
sum1 = 0xFFFF;
sum2 = 0xFFFF;

5
IChecksum.cs
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@@ -34,11 +34,6 @@ namespace DiscImageChef.Checksums
{
public interface IChecksum
{
/// <summary>
/// Initializes the algorithm
/// </summary>
void Init();
/// <summary>
/// Updates the hash with data.
/// </summary>

2
MD5Context.cs
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@@ -46,7 +46,7 @@ namespace DiscImageChef.Checksums
/// <summary>
/// Initializes the MD5 hash provider
/// </summary>
public void Init()
public Md5Context()
{
md5Provider = MD5.Create();
}

2
RIPEMD160Context.cs
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@@ -46,7 +46,7 @@ namespace DiscImageChef.Checksums
/// <summary>
/// Initializes the RIPEMD160 hash provider
/// </summary>
public void Init()
public Ripemd160Context()
{
ripemd160Provider = RIPEMD160.Create();
}

2
SHA1Context.cs
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@@ -46,7 +46,7 @@ namespace DiscImageChef.Checksums
/// <summary>
/// Initializes the SHA1 hash provider
/// </summary>
public void Init()
public Sha1Context()
{
sha1Provider = SHA1.Create();
}

2
SHA256Context.cs
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@@ -46,7 +46,7 @@ namespace DiscImageChef.Checksums
/// <summary>
/// Initializes the SHA256 hash provider
/// </summary>
public void Init()
public Sha256Context()
{
sha256Provider = SHA256.Create();
}

2
SHA384Context.cs
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@@ -46,7 +46,7 @@ namespace DiscImageChef.Checksums
/// <summary>
/// Initializes the SHA384 hash provider
/// </summary>
public void Init()
public Sha384Context()
{
sha384Provider = SHA384.Create();
}

2
SHA512Context.cs
View File

@@ -46,7 +46,7 @@ namespace DiscImageChef.Checksums
/// <summary>
/// Initializes the SHA512 hash provider
/// </summary>
public void Init()
public Sha512Context()
{
sha512Provider = SHA512.Create();
}

109
SpamSumContext.cs
View File

@@ -67,17 +67,13 @@ namespace DiscImageChef.Checksums
FuzzyState self;
void roll_init()
{
self.Roll = new RollState {Window = new byte[ROLLING_WINDOW]};
}
/// <summary>
/// Initializes the SpamSum structures
/// </summary>
public void Init()
public SpamSumContext()
{
self = new FuzzyState {Bh = new BlockhashContext[NUM_BLOCKHASHES]};
self =
new FuzzyState {Bh = new BlockhashContext[NUM_BLOCKHASHES]};
for(int i = 0; i < NUM_BLOCKHASHES; i++) self.Bh[i].Digest = new byte[SPAMSUM_LENGTH];
self.Bhstart = 0;
@@ -91,6 +87,50 @@ namespace DiscImageChef.Checksums
roll_init();
}
/// <summary>
/// Updates the hash with data.
/// </summary>
/// <param name="data">Data buffer.</param>
/// <param name="len">Length of buffer to hash.</param>
public void Update(byte[] data, uint len)
{
self.TotalSize += len;
for(int i = 0; i < len; i++) fuzzy_engine_step(data[i]);
}
/// <summary>
/// Updates the hash with data.
/// </summary>
/// <param name="data">Data buffer.</param>
public void Update(byte[] data)
{
Update(data, (uint)data.Length);
}
/// <summary>
/// Returns a byte array of the hash value.
/// </summary>
public byte[] Final()
{
// SpamSum does not have a binary representation, or so it seems
throw new NotImplementedException("SpamSum does not have a binary representation.");
}
/// <summary>
/// Returns a base64 representation of the hash value.
/// </summary>
public string End()
{
FuzzyDigest(out byte[] result);
return CToString(result);
}
void roll_init()
{
self.Roll = new RollState {Window = new byte[ROLLING_WINDOW]};
}
/*
* a rolling hash, based on the Adler checksum. By using a rolling hash
* we can perform auto resynchronisation after inserts/deletes
@@ -165,6 +205,7 @@ namespace DiscImageChef.Checksums
* blocksize. */ return;
if(self.Bh[self.Bhstart + 1].Dlen < SPAMSUM_LENGTH / 2)
/* Estimate adjustment would select this blocksize. */ return;
/* At this point we are clearly no longer interested in the
* start_blocksize. Get rid of it. */
++self.Bhstart;
@@ -193,6 +234,7 @@ namespace DiscImageChef.Checksums
/* Once this condition is false for one bs, it is
* automatically false for all further bs. I.e. if
* h === -1 (mod 2*bs) then h === -1 (mod bs). */ break;
/* We have hit a reset point. We now emit hashes which are
* based on all characters in the piece of the message between
* the last reset point and this one */
@@ -218,26 +260,6 @@ namespace DiscImageChef.Checksums
}
}
/// <summary>
/// Updates the hash with data.
/// </summary>
/// <param name="data">Data buffer.</param>
/// <param name="len">Length of buffer to hash.</param>
public void Update(byte[] data, uint len)
{
self.TotalSize += len;
for(int i = 0; i < len; i++) fuzzy_engine_step(data[i]);
}
/// <summary>
/// Updates the hash with data.
/// </summary>
/// <param name="data">Data buffer.</param>
public void Update(byte[] data)
{
Update(data, (uint)data.Length);
}
// CLAUNIA: Flags seems to never be used in ssdeep, so I just removed it for code simplicity
uint FuzzyDigest(out byte[] result)
{
@@ -259,6 +281,7 @@ namespace DiscImageChef.Checksums
++bi;
if(bi >= NUM_BLOCKHASHES) throw new OverflowException("The input exceeds data types.");
}
/* Adapt blocksize guess to actual digest length. */
while(bi >= self.Bhend) --bi;
while(bi > self.Bhstart && self.Bh[bi].Dlen < SPAMSUM_LENGTH / 2) --bi;
@@ -288,7 +311,8 @@ namespace DiscImageChef.Checksums
if(remain <= 0) throw new Exception("Assertion failed");
result[resultOff] = b64[self.Bh[bi].H % 64];
if(i < 3 || result[resultOff] != result[resultOff - 1] || result[resultOff] != result[resultOff - 2] ||
if(i < 3 || result[resultOff] != result[resultOff - 1] ||
result[resultOff] != result[resultOff - 2] ||
result[resultOff] != result[resultOff - 3])
{
++resultOff;
@@ -300,7 +324,8 @@ namespace DiscImageChef.Checksums
if(remain <= 0) throw new Exception("Assertion failed");
result[resultOff] = self.Bh[bi].Digest[i];
if(i < 3 || result[resultOff] != result[resultOff - 1] || result[resultOff] != result[resultOff - 2] ||
if(i < 3 || result[resultOff] != result[resultOff - 1] ||
result[resultOff] != result[resultOff - 2] ||
result[resultOff] != result[resultOff - 3])
{
++resultOff;
@@ -329,7 +354,8 @@ namespace DiscImageChef.Checksums
h = self.Bh[bi].Halfh;
result[resultOff] = b64[h % 64];
if(i < 3 || result[resultOff] != result[resultOff - 1] ||
result[resultOff] != result[resultOff - 2] || result[resultOff] != result[resultOff - 3])
result[resultOff] != result[resultOff - 2] ||
result[resultOff] != result[resultOff - 3])
{
++resultOff;
--remain;
@@ -344,7 +370,8 @@ namespace DiscImageChef.Checksums
result[resultOff] = (byte)i;
if(i < 3 || result[resultOff] != result[resultOff - 1] ||
result[resultOff] != result[resultOff - 2] || result[resultOff] != result[resultOff - 3])
result[resultOff] != result[resultOff - 2] ||
result[resultOff] != result[resultOff - 3])
{
++resultOff;
--remain;
@@ -367,25 +394,6 @@ namespace DiscImageChef.Checksums
return 0;
}
/// <summary>
/// Returns a byte array of the hash value.
/// </summary>
public byte[] Final()
{
// SpamSum does not have a binary representation, or so it seems
throw new NotImplementedException("SpamSum does not have a binary representation.");
}
/// <summary>
/// Returns a base64 representation of the hash value.
/// </summary>
public string End()
{
FuzzyDigest(out byte[] result);
return CToString(result);
}
/// <summary>
/// Gets the hash of a file
/// </summary>
@@ -417,7 +425,6 @@ namespace DiscImageChef.Checksums
public static string Data(byte[] data, uint len, out byte[] hash)
{
SpamSumContext fuzzyContext = new SpamSumContext();
fuzzyContext.Init();
fuzzyContext.Update(data, len);