REFACTOR: Final cleanup of DiscImageChef.Checksums.

Adler32Context.cs

@@ -41,8 +41,8 @@ namespace DiscImageChef.Checksums
     /// </summary>
     public class Adler32Context
     {
-        ushort sum1, sum2;
         const ushort ADLER_MODULE = 65521;
+        ushort sum1, sum2;
 
         /// <summary>
         ///     Initializes the Adler-32 sums
@@ -95,7 +95,8 @@ namespace DiscImageChef.Checksums
             StringBuilder adlerOutput = new StringBuilder();
 
             BigEndianBitConverter.IsLittleEndian = BitConverter.IsLittleEndian;
-            for(int i = 0; i < BigEndianBitConverter.GetBytes(finalSum).Length; i++) adlerOutput.Append(BigEndianBitConverter.GetBytes(finalSum)[i].ToString("x2"));
+            for(int i = 0; i < BigEndianBitConverter.GetBytes(finalSum).Length; i++)
+                adlerOutput.Append(BigEndianBitConverter.GetBytes(finalSum)[i].ToString("x2"));
 
             return adlerOutput.ToString();
         }

CDChecksums.cs

@@ -42,10 +42,34 @@ namespace DiscImageChef.Checksums
     /// </summary>
     public static class CdChecksums
     {
-        static byte[] eccFTable;
-        static byte[] eccBTable;
         const uint CDCRC32_POLY = 0xD8018001;
         const uint CDCRC32_SEED = 0x00000000;
+        static byte[] eccFTable;
+        static byte[] eccBTable;
+
+        static readonly ushort[] CcittCrc16Table =
+        {
+            0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c,
+            0xd1ad, 0xe1ce, 0xf1ef, 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6, 0x9339, 0x8318,
+            0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4,
+            0x5485, 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d, 0x3653, 0x2672, 0x1611, 0x0630,
+            0x76d7, 0x66f6, 0x5695, 0x46b4, 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc, 0x48c4,
+            0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823, 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969,
+            0xa90a, 0xb92b, 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12, 0xdbfd, 0xcbdc, 0xfbbf,
+            0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
+            0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49, 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13,
+            0x2e32, 0x1e51, 0x0e70, 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78, 0x9188, 0x81a9,
+            0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f, 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046,
+            0x6067, 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e, 0x02b1, 0x1290, 0x22f3, 0x32d2,
+            0x4235, 0x5214, 0x6277, 0x7256, 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, 0x34e2,
+            0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e,
+            0xc71d, 0xd73c, 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634, 0xd94c, 0xc96d, 0xf90e,
+            0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab, 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
+            0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a, 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1,
+            0x1ad0, 0x2ab3, 0x3a92, 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9, 0x7c26, 0x6c07,
+            0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1, 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9,
+            0x9ff8, 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
+        };
 
         public static bool? CheckCdSector(byte[] buffer)
         {
@@ -64,10 +88,13 @@ namespace DiscImageChef.Checksums
                     bool? status = null;
 
                     if(channelStatus == false || subchannelStatus == false) status = false;
-                    switch(channelStatus) {
+                    switch(channelStatus)
-                        case null when subchannelStatus == true: status = true;
+                    {
+                        case null when subchannelStatus == true:
+                            status = true;
                             break;
-                        case true when subchannelStatus == null: status = true;
+                        case true when subchannelStatus == null:
+                            status = true;
                             break;
                     }
 
@@ -155,8 +182,7 @@ namespace DiscImageChef.Checksums
 
                 if(channel[0x814] != 0x00 || // reserved (8 bytes)
                    channel[0x815] != 0x00 || channel[0x816] != 0x00 || channel[0x817] != 0x00 ||
-                   channel[0x818] != 0x00 || channel[0x819] != 0x00 || channel[0x81A] != 0x00 ||
+                   channel[0x818] != 0x00 || channel[0x819] != 0x00 || channel[0x81A] != 0x00 || channel[0x81B] != 0x00)
-                   channel[0x81B] != 0x00)
                 {
                     DicConsole.DebugWriteLine("CD checksums",
                                               "Mode 1 sector with data in reserved bytes at address: {0:X2}:{1:X2}:{2:X2}",
@@ -287,8 +313,7 @@ namespace DiscImageChef.Checksums
                 return true;
             }
 
-            DicConsole.DebugWriteLine("CD checksums",
+            DicConsole.DebugWriteLine("CD checksums", "Unknown mode {0} sector at address: {1:X2}:{2:X2}:{3:X2}",
-                                      "Unknown mode {0} sector at address: {1:X2}:{2:X2}:{3:X2}",
                                       channel[0x00F], channel[0x00C], channel[0x00D], channel[0x00E]);
             return null;
         }
@@ -484,39 +509,18 @@ namespace DiscImageChef.Checksums
 
             if(cdTextPack4Crc == calculatedCdtp4Crc || cdTextPack4Crc == 0) return status;
 
-            DicConsole.DebugWriteLine("CD checksums", "CD-Text Pack 4 CRC 0x{0:X4}, expected 0x{1:X4}",
+            DicConsole.DebugWriteLine("CD checksums", "CD-Text Pack 4 CRC 0x{0:X4}, expected 0x{1:X4}", cdTextPack4Crc,
-                                      cdTextPack4Crc, calculatedCdtp4Crc);
+                                      calculatedCdtp4Crc);
 
             return false;
         }
 
-        static readonly ushort[] CcittCrc16Table =
-        {
-            0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c,
-            0xd1ad, 0xe1ce, 0xf1ef, 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6, 0x9339, 0x8318,
-            0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4,
-            0x5485, 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d, 0x3653, 0x2672, 0x1611, 0x0630,
-            0x76d7, 0x66f6, 0x5695, 0x46b4, 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc, 0x48c4,
-            0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823, 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969,
-            0xa90a, 0xb92b, 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12, 0xdbfd, 0xcbdc, 0xfbbf,
-            0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
-            0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49, 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13,
-            0x2e32, 0x1e51, 0x0e70, 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78, 0x9188, 0x81a9,
-            0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f, 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046,
-            0x6067, 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e, 0x02b1, 0x1290, 0x22f3, 0x32d2,
-            0x4235, 0x5214, 0x6277, 0x7256, 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, 0x34e2,
-            0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e,
-            0xc71d, 0xd73c, 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634, 0xd94c, 0xc96d, 0xf90e,
-            0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab, 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
-            0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a, 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1,
-            0x1ad0, 0x2ab3, 0x3a92, 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9, 0x7c26, 0x6c07,
-            0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1, 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9,
-            0x9ff8, 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
-        };
-
         static ushort CalculateCCITT_CRC16(byte[] buffer)
         {
-            ushort crc16 = buffer.Aggregate<byte, ushort>(0, (current, t) => (ushort)(CcittCrc16Table[(current >> 8) ^ t] ^ (current << 8)));
+            ushort crc16 =
+                buffer.Aggregate<byte, ushort>(0,
+                                               (current, t) =>
+                                                   (ushort)(CcittCrc16Table[(current >> 8) ^ t] ^ (current << 8)));
 
             crc16 = (ushort)~crc16;
 

CRC16Context.cs

@@ -43,9 +43,9 @@ namespace DiscImageChef.Checksums
     {
         const ushort CRC16_POLY = 0xA001;
         const ushort CRC16_SEED = 0x0000;
+        ushort hashInt;
 
         ushort[] table;
-        ushort hashInt;
 
         /// <summary>
         ///     Initializes the CRC16 table and seed
@@ -104,7 +104,8 @@ namespace DiscImageChef.Checksums
             StringBuilder crc16Output = new StringBuilder();
 
             BigEndianBitConverter.IsLittleEndian = BitConverter.IsLittleEndian;
-            for(int i = 0; i < BigEndianBitConverter.GetBytes(hashInt).Length; i++) crc16Output.Append(BigEndianBitConverter.GetBytes(hashInt)[i].ToString("x2"));
+            for(int i = 0; i < BigEndianBitConverter.GetBytes(hashInt).Length; i++)
+                crc16Output.Append(BigEndianBitConverter.GetBytes(hashInt)[i].ToString("x2"));
 
             return crc16Output.ToString();
         }
@@ -143,7 +144,8 @@ namespace DiscImageChef.Checksums
             }
 
             for(int i = 0; i < fileStream.Length; i++)
-                localhashInt = (ushort)((localhashInt >> 8) ^ localTable[fileStream.ReadByte() ^ (localhashInt & 0xff)]);
+                localhashInt =
+                    (ushort)((localhashInt >> 8) ^ localTable[fileStream.ReadByte() ^ (localhashInt & 0xff)]);
 
             BigEndianBitConverter.IsLittleEndian = BitConverter.IsLittleEndian;
             hash = BigEndianBitConverter.GetBytes(localhashInt);

CRC32Context.cs

@@ -43,9 +43,9 @@ namespace DiscImageChef.Checksums
     {
         const uint CRC32_POLY = 0xEDB88320;
         const uint CRC32_SEED = 0xFFFFFFFF;
+        uint hashInt;
 
         uint[] table;
-        uint hashInt;
 
         /// <summary>
         ///     Initializes the CRC32 table and seed
@@ -104,7 +104,8 @@ namespace DiscImageChef.Checksums
             StringBuilder crc32Output = new StringBuilder();
 
             BigEndianBitConverter.IsLittleEndian = BitConverter.IsLittleEndian;
-            for(int i = 0; i < BigEndianBitConverter.GetBytes(hashInt).Length; i++) crc32Output.Append(BigEndianBitConverter.GetBytes(hashInt)[i].ToString("x2"));
+            for(int i = 0; i < BigEndianBitConverter.GetBytes(hashInt).Length; i++)
+                crc32Output.Append(BigEndianBitConverter.GetBytes(hashInt)[i].ToString("x2"));
 
             return crc32Output.ToString();
         }
@@ -194,7 +195,8 @@ namespace DiscImageChef.Checksums
                 localTable[i] = entry;
             }
 
-            for(int i = 0; i < len; i++) localhashInt = (localhashInt >> 8) ^ localTable[data[i] ^ (localhashInt & 0xff)];
+            for(int i = 0; i < len; i++)
+                localhashInt = (localhashInt >> 8) ^ localTable[data[i] ^ (localhashInt & 0xff)];
 
             localhashInt ^= CRC32_SEED;
             BigEndianBitConverter.IsLittleEndian = BitConverter.IsLittleEndian;

CRC64Context.cs

@@ -42,9 +42,9 @@ namespace DiscImageChef.Checksums
     {
         const ulong CRC64_POLY = 0xC96C5795D7870F42;
         const ulong CRC64_SEED = 0xFFFFFFFFFFFFFFFF;
+        ulong hashInt;
 
         ulong[] table;
-        ulong hashInt;
 
         /// <summary>
         ///     Initializes the CRC64 table and seed
@@ -103,7 +103,8 @@ namespace DiscImageChef.Checksums
             StringBuilder crc64Output = new StringBuilder();
 
             BigEndianBitConverter.IsLittleEndian = BigEndianBitConverter.IsLittleEndian;
-            for(int i = 0; i < BigEndianBitConverter.GetBytes(hashInt).Length; i++) crc64Output.Append(BigEndianBitConverter.GetBytes(hashInt)[i].ToString("x2"));
+            for(int i = 0; i < BigEndianBitConverter.GetBytes(hashInt).Length; i++)
+                crc64Output.Append(BigEndianBitConverter.GetBytes(hashInt)[i].ToString("x2"));
 
             return crc64Output.ToString();
         }
@@ -193,7 +194,8 @@ namespace DiscImageChef.Checksums
                 localTable[i] = entry;
             }
 
-            for(int i = 0; i < len; i++) localhashInt = (localhashInt >> 8) ^ localTable[data[i] ^ (localhashInt & 0xff)];
+            for(int i = 0; i < len; i++)
+                localhashInt = (localhashInt >> 8) ^ localTable[data[i] ^ (localhashInt & 0xff)];
 
             localhashInt ^= CRC64_SEED;
             BigEndianBitConverter.IsLittleEndian = BigEndianBitConverter.IsLittleEndian;

ReedSolomon.cs

@@ -67,27 +67,33 @@ namespace DiscImageChef.Checksums
     /// </summary>
     public class ReedSolomon
     {
-        /* Primitive polynomials - see Lin & Costello, Error Control Coding Appendix A,
+        /// <summary>
-         * and  Lee & Messerschmitt, Digital Communication p. 453.
+        ///     Alpha exponent for the first root of the generator polynomial
-         */
+        /// </summary>
-        int[] pp;
-        /* index->polynomial form conversion table */
-        int[] alpha_to;
-        /* Polynomial->index form conversion table */
-        int[] index_of;
-        /* Generator polynomial g(x)
-         * Degree of g(x) = 2*TT
-         * has roots @**B0, @**(B0+1), ... ,@^(B0+2*TT-1)
-         */
-        int[] gg;
-        int mm, kk, nn;
-        /* No legal value in index form represents zero, so
-         * we need a special value for this purpose
-         */
-        int a0;
-        bool initialized;
-        /* Alpha exponent for the first root of the generator polynomial */
         const int B0 = 1;
+        /// <summary>
+        ///     No legal value in index form represents zero, so we need a special value for this purpose
+        /// </summary>
+        int a0;
+        /// <summary>
+        ///     index->polynomial form conversion table
+        /// </summary>
+        int[] alpha_to;
+        /// <summary>
+        ///     Generator polynomial g(x) Degree of g(x) = 2*TT has roots @**B0, @**(B0+1), ... ,@^(B0+2*TT-1)
+        /// </summary>
+        int[] gg;
+        /// <summary>
+        ///     Polynomial->index form conversion table
+        /// </summary>
+        int[] index_of;
+        bool initialized;
+        int mm, kk, nn;
+        /// <summary>
+        ///     Primitive polynomials - see Lin & Costello, Error Control Coding Appendix A, and  Lee & Messerschmitt, Digital
+        ///     Communication p. 453.
+        /// </summary>
+        int[] pp;
 
         /// <summary>
         ///     Initializes the Reed-Solomon with RS(n,k) with GF(2^m)
@@ -395,8 +401,7 @@ namespace DiscImageChef.Checksums
             {
                 tmp = 0;
                 for(j = 0; j < nn; j++)
-                    if(recd[j] != a0) /* recd[j] in index form */
+                    if(recd[j] != a0) /* recd[j] in index form */ tmp ^= alpha_to[Modnn(recd[j] + (B0 + i - 1) * j)];
-                        tmp ^= alpha_to[Modnn(recd[j] + (B0 + i - 1) * j)];
 
                 synError |= tmp; /* set flag if non-zero syndrome =>
                      * error */
@@ -473,7 +478,8 @@ namespace DiscImageChef.Checksums
                 /* r is the step number */
                 /* Compute discrepancy at the r-th step in poly-form */
                 int discrR = 0;
-                for(i = 0; i < r; i++) if(lambda[i] != 0 && s[r - i] != a0) discrR ^= alpha_to[Modnn(index_of[lambda[i]] + s[r - i])];
+                for(i = 0; i < r; i++)
+                    if(lambda[i] != 0 && s[r - i] != a0) discrR ^= alpha_to[Modnn(index_of[lambda[i]] + s[r - i])];
 
                 discrR = index_of[discrR]; /* Index form */
                 if(discrR == a0)
@@ -560,7 +566,8 @@ namespace DiscImageChef.Checksums
             {
                 tmp = 0;
                 j = degLambda < i ? degLambda : i;
-                for(; j >= 0; j--) if(s[i + 1 - j] != a0 && lambda[j] != a0) tmp ^= alpha_to[Modnn(s[i + 1 - j] + lambda[j])];
+                for(; j >= 0; j--)
+                    if(s[i + 1 - j] != a0 && lambda[j] != a0) tmp ^= alpha_to[Modnn(s[i + 1 - j] + lambda[j])];
 
                 if(tmp != 0) degOmega = i;
                 omega[i] = index_of[tmp];
@@ -581,7 +588,8 @@ namespace DiscImageChef.Checksums
                 int den = 0;
 
                 /* lambda[i+1] for i even is the formal derivative lambda_pr of lambda[i] */
-                for(i = Min(degLambda, nn - kk - 1) & ~1; i >= 0; i -= 2) if(lambda[i + 1] != a0) den ^= alpha_to[Modnn(lambda[i + 1] + i * root[j])];
+                for(i = Min(degLambda, nn - kk - 1) & ~1; i >= 0; i -= 2)
+                    if(lambda[i + 1] != a0) den ^= alpha_to[Modnn(lambda[i + 1] + i * root[j])];
 
                 if(den == 0)
                 {

SpamSumContext.cs

@@ -65,41 +65,6 @@ namespace DiscImageChef.Checksums
             0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x2B, 0x2F
         };
 
-        struct RollState
-        {
-            public byte[] Window;
-            // ROLLING_WINDOW
-            public uint H1;
-            public uint H2;
-            public uint H3;
-            public uint N;
-        }
-
-        /* A blockhash contains a signature state for a specific (implicit) blocksize.
-         * The blocksize is given by SSDEEP_BS(index). The h and halfh members are the
-         * FNV hashes, where halfh stops to be reset after digest is SPAMSUM_LENGTH/2
-         * long. The halfh hash is needed be able to truncate digest for the second
-         * output hash to stay compatible with ssdeep output. */
-        struct BlockhashContext
-        {
-            public uint H;
-            public uint Halfh;
-            public byte[] Digest;
-            // SPAMSUM_LENGTH
-            public byte Halfdigest;
-            public uint Dlen;
-        }
-
-        struct FuzzyState
-        {
-            public uint Bhstart;
-            public uint Bhend;
-            public BlockhashContext[] Bh;
-            //NUM_BLOCKHASHES
-            public ulong TotalSize;
-            public RollState Roll;
-        }
-
         FuzzyState self;
 
         void roll_init()
@@ -323,8 +288,8 @@ 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] ||
+                if(i < 3 || result[resultOff] != result[resultOff - 1] || result[resultOff] != result[resultOff - 2] ||
-                   result[resultOff] != result[resultOff - 2] || result[resultOff] != result[resultOff - 3])
+                   result[resultOff] != result[resultOff - 3])
                 {
                     ++resultOff;
                     --remain;
@@ -335,8 +300,8 @@ 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] ||
+                if(i < 3 || result[resultOff] != result[resultOff - 1] || result[resultOff] != result[resultOff - 2] ||
-                   result[resultOff] != result[resultOff - 2] || result[resultOff] != result[resultOff - 3])
+                   result[resultOff] != result[resultOff - 3])
                 {
                     ++resultOff;
                     --remain;
@@ -486,5 +451,40 @@ namespace DiscImageChef.Checksums
 
             return sb.ToString();
         }
+
+        struct RollState
+        {
+            public byte[] Window;
+            // ROLLING_WINDOW
+            public uint H1;
+            public uint H2;
+            public uint H3;
+            public uint N;
+        }
+
+        /* A blockhash contains a signature state for a specific (implicit) blocksize.
+         * The blocksize is given by SSDEEP_BS(index). The h and halfh members are the
+         * FNV hashes, where halfh stops to be reset after digest is SPAMSUM_LENGTH/2
+         * long. The halfh hash is needed be able to truncate digest for the second
+         * output hash to stay compatible with ssdeep output. */
+        struct BlockhashContext
+        {
+            public uint H;
+            public uint Halfh;
+            public byte[] Digest;
+            // SPAMSUM_LENGTH
+            public byte Halfdigest;
+            public uint Dlen;
+        }
+
+        struct FuzzyState
+        {
+            public uint Bhstart;
+            public uint Bhend;
+            public BlockhashContext[] Bh;
+            //NUM_BLOCKHASHES
+            public ulong TotalSize;
+            public RollState Roll;
+        }
     }
 }