J'ai besoin du code inversé CRC pour mon codage de somme de contrôle CRC64

Question

Quelqu'un peut-il me coder l'algorithme inverse CRC64 en C#? Je suis incapable de le coder, je ne peux rien comprendre. Merci,

J'ai copié le code Checksum CRC64 à partir de C++ et l'ai converti en C# .NET. Le code entier est affiché ci-dessous:

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 

namespace CRC64 
{ 
    public class cCRC64 
    { 
     public UInt64[] crc64_table = { 
      0x0000000000000000, 0x42F0E1EBA9EA3693, 
      0x85E1C3D753D46D26, 0xC711223CFA3E5BB5, 
      0x493366450E42ECDF, 0x0BC387AEA7A8DA4C, 
      0xCCD2A5925D9681F9, 0x8E224479F47CB76A, 
      0x9266CC8A1C85D9BE, 0xD0962D61B56FEF2D, 
      0x17870F5D4F51B498, 0x5577EEB6E6BB820B, 
      0xDB55AACF12C73561, 0x99A54B24BB2D03F2, 
      0x5EB4691841135847, 0x1C4488F3E8F96ED4, 
      0x663D78FF90E185EF, 0x24CD9914390BB37C, 
      0xE3DCBB28C335E8C9, 0xA12C5AC36ADFDE5A, 
      0x2F0E1EBA9EA36930, 0x6DFEFF5137495FA3, 
      0xAAEFDD6DCD770416, 0xE81F3C86649D3285, 
      0xF45BB4758C645C51, 0xB6AB559E258E6AC2, 
      0x71BA77A2DFB03177, 0x334A9649765A07E4, 
      0xBD68D2308226B08E, 0xFF9833DB2BCC861D, 
      0x388911E7D1F2DDA8, 0x7A79F00C7818EB3B, 
      0xCC7AF1FF21C30BDE, 0x8E8A101488293D4D, 
      0x499B3228721766F8, 0x0B6BD3C3DBFD506B, 
      0x854997BA2F81E701, 0xC7B97651866BD192, 
      0x00A8546D7C558A27, 0x4258B586D5BFBCB4, 
      0x5E1C3D753D46D260, 0x1CECDC9E94ACE4F3, 
      0xDBFDFEA26E92BF46, 0x990D1F49C77889D5, 
      0x172F5B3033043EBF, 0x55DFBADB9AEE082C, 
      0x92CE98E760D05399, 0xD03E790CC93A650A, 
      0xAA478900B1228E31, 0xE8B768EB18C8B8A2, 
      0x2FA64AD7E2F6E317, 0x6D56AB3C4B1CD584, 
      0xE374EF45BF6062EE, 0xA1840EAE168A547D, 
      0x66952C92ECB40FC8, 0x2465CD79455E395B, 
      0x3821458AADA7578F, 0x7AD1A461044D611C, 
      0xBDC0865DFE733AA9, 0xFF3067B657990C3A, 
      0x711223CFA3E5BB50, 0x33E2C2240A0F8DC3, 
      0xF4F3E018F031D676, 0xB60301F359DBE0E5, 
      0xDA050215EA6C212F, 0x98F5E3FE438617BC, 
      0x5FE4C1C2B9B84C09, 0x1D14202910527A9A, 
      0x93366450E42ECDF0, 0xD1C685BB4DC4FB63, 
      0x16D7A787B7FAA0D6, 0x5427466C1E109645, 
      0x4863CE9FF6E9F891, 0x0A932F745F03CE02, 
      0xCD820D48A53D95B7, 0x8F72ECA30CD7A324, 
      0x0150A8DAF8AB144E, 0x43A04931514122DD, 
      0x84B16B0DAB7F7968, 0xC6418AE602954FFB, 
      0xBC387AEA7A8DA4C0, 0xFEC89B01D3679253, 
      0x39D9B93D2959C9E6, 0x7B2958D680B3FF75, 
      0xF50B1CAF74CF481F, 0xB7FBFD44DD257E8C, 
      0x70EADF78271B2539, 0x321A3E938EF113AA, 
      0x2E5EB66066087D7E, 0x6CAE578BCFE24BED, 
      0xABBF75B735DC1058, 0xE94F945C9C3626CB, 
      0x676DD025684A91A1, 0x259D31CEC1A0A732, 
      0xE28C13F23B9EFC87, 0xA07CF2199274CA14, 
      0x167FF3EACBAF2AF1, 0x548F120162451C62, 
      0x939E303D987B47D7, 0xD16ED1D631917144, 
      0x5F4C95AFC5EDC62E, 0x1DBC74446C07F0BD, 
      0xDAAD56789639AB08, 0x985DB7933FD39D9B, 
      0x84193F60D72AF34F, 0xC6E9DE8B7EC0C5DC, 
      0x01F8FCB784FE9E69, 0x43081D5C2D14A8FA, 
      0xCD2A5925D9681F90, 0x8FDAB8CE70822903, 
      0x48CB9AF28ABC72B6, 0x0A3B7B1923564425, 
      0x70428B155B4EAF1E, 0x32B26AFEF2A4998D, 
      0xF5A348C2089AC238, 0xB753A929A170F4AB, 
      0x3971ED50550C43C1, 0x7B810CBBFCE67552, 
      0xBC902E8706D82EE7, 0xFE60CF6CAF321874, 
      0xE224479F47CB76A0, 0xA0D4A674EE214033, 
      0x67C58448141F1B86, 0x253565A3BDF52D15, 
      0xAB1721DA49899A7F, 0xE9E7C031E063ACEC, 
      0x2EF6E20D1A5DF759, 0x6C0603E6B3B7C1CA, 
      0xF6FAE5C07D3274CD, 0xB40A042BD4D8425E, 
      0x731B26172EE619EB, 0x31EBC7FC870C2F78, 
      0xBFC9838573709812, 0xFD39626EDA9AAE81, 
      0x3A28405220A4F534, 0x78D8A1B9894EC3A7, 
      0x649C294A61B7AD73, 0x266CC8A1C85D9BE0, 
      0xE17DEA9D3263C055, 0xA38D0B769B89F6C6, 
      0x2DAF4F0F6FF541AC, 0x6F5FAEE4C61F773F, 
      0xA84E8CD83C212C8A, 0xEABE6D3395CB1A19, 
      0x90C79D3FEDD3F122, 0xD2377CD44439C7B1, 
      0x15265EE8BE079C04, 0x57D6BF0317EDAA97, 
      0xD9F4FB7AE3911DFD, 0x9B041A914A7B2B6E, 
      0x5C1538ADB04570DB, 0x1EE5D94619AF4648, 
      0x02A151B5F156289C, 0x4051B05E58BC1E0F, 
      0x87409262A28245BA, 0xC5B073890B687329, 
      0x4B9237F0FF14C443, 0x0962D61B56FEF2D0, 
      0xCE73F427ACC0A965, 0x8C8315CC052A9FF6, 
      0x3A80143F5CF17F13, 0x7870F5D4F51B4980, 
      0xBF61D7E80F251235, 0xFD913603A6CF24A6, 
      0x73B3727A52B393CC, 0x31439391FB59A55F, 
      0xF652B1AD0167FEEA, 0xB4A25046A88DC879, 
      0xA8E6D8B54074A6AD, 0xEA16395EE99E903E, 
      0x2D071B6213A0CB8B, 0x6FF7FA89BA4AFD18, 
      0xE1D5BEF04E364A72, 0xA3255F1BE7DC7CE1, 
      0x64347D271DE22754, 0x26C49CCCB40811C7, 
      0x5CBD6CC0CC10FAFC, 0x1E4D8D2B65FACC6F, 
      0xD95CAF179FC497DA, 0x9BAC4EFC362EA149, 
      0x158E0A85C2521623, 0x577EEB6E6BB820B0, 
      0x906FC95291867B05, 0xD29F28B9386C4D96, 
      0xCEDBA04AD0952342, 0x8C2B41A1797F15D1, 
      0x4B3A639D83414E64, 0x09CA82762AAB78F7, 
      0x87E8C60FDED7CF9D, 0xC51827E4773DF90E, 
      0x020905D88D03A2BB, 0x40F9E43324E99428, 
      0x2CFFE7D5975E55E2, 0x6E0F063E3EB46371, 
      0xA91E2402C48A38C4, 0xEBEEC5E96D600E57, 
      0x65CC8190991CB93D, 0x273C607B30F68FAE, 
      0xE02D4247CAC8D41B, 0xA2DDA3AC6322E288, 
      0xBE992B5F8BDB8C5C, 0xFC69CAB42231BACF, 
      0x3B78E888D80FE17A, 0x7988096371E5D7E9, 
      0xF7AA4D1A85996083, 0xB55AACF12C735610, 
      0x724B8ECDD64D0DA5, 0x30BB6F267FA73B36, 
      0x4AC29F2A07BFD00D, 0x08327EC1AE55E69E, 
      0xCF235CFD546BBD2B, 0x8DD3BD16FD818BB8, 
      0x03F1F96F09FD3CD2, 0x41011884A0170A41, 
      0x86103AB85A2951F4, 0xC4E0DB53F3C36767, 
      0xD8A453A01B3A09B3, 0x9A54B24BB2D03F20, 
      0x5D45907748EE6495, 0x1FB5719CE1045206, 
      0x919735E51578E56C, 0xD367D40EBC92D3FF, 
      0x1476F63246AC884A, 0x568617D9EF46BED9, 
      0xE085162AB69D5E3C, 0xA275F7C11F7768AF, 
      0x6564D5FDE549331A, 0x279434164CA30589, 
      0xA9B6706FB8DFB2E3, 0xEB46918411358470, 
      0x2C57B3B8EB0BDFC5, 0x6EA7525342E1E956, 
      0x72E3DAA0AA188782, 0x30133B4B03F2B111, 
      0xF7021977F9CCEAA4, 0xB5F2F89C5026DC37, 
      0x3BD0BCE5A45A6B5D, 0x79205D0E0DB05DCE, 
      0xBE317F32F78E067B, 0xFCC19ED95E6430E8, 
      0x86B86ED5267CDBD3, 0xC4488F3E8F96ED40, 
      0x0359AD0275A8B6F5, 0x41A94CE9DC428066, 
      0xCF8B0890283E370C, 0x8D7BE97B81D4019F, 
      0x4A6ACB477BEA5A2A, 0x089A2AACD2006CB9, 
      0x14DEA25F3AF9026D, 0x562E43B4931334FE, 
      0x913F6188692D6F4B, 0xD3CF8063C0C759D8, 
      0x5DEDC41A34BBEEB2, 0x1F1D25F19D51D821, 
      0xD80C07CD676F8394, 0x9AFCE626CE85B507 
     }; 

     /* Initialize a CRC accumulator */ 
     public void Init_crc(ref UInt64 crc) 
     { 
      crc = 0xffffffffffffffff; 
     } 

     /* Finish a CRC calculation */ 
     public void Fin_crc(ref UInt64 crc) 
     { 
      crc ^= 0xffffffffffffffff; 
     } 

     /* Accumulate some (more) bytes into a CRC */ 
     public void Calc_crc(ref UInt64 crc, Byte[] pbData, uint len) 
     { 
      /* Constant table for CRC calculation */ 
      uint __len = len; 
      uint pos = 0; 
      byte byteInput = 0; 

      while (__len-- > 0) 
      { 
       uint __tab_index = ((uint) (crc >> 56)^pbData[pos++]) & 0xFF; 
       crc = crc64_table[__tab_index]^(crc << 8); 
      } 
     } 
    } 
} 

En attente d'aide!

Answer 1

n °

algorithmes de hachage ne sont pas réversibles. Vous ne pouvez pas récupérer les données d'origine, mais vous pouvez obtenir tous les ensembles possibles d'une longueur spécifique en calculant le hachage pour toutes les combinaisons possibles et en les comparant au hachage que vous avez.

Il s'agit bien sûr d'un calcul intensif. Juste dix octets par exemple vous donne 1 208 925 819 614 629 174 706 176 combinaisons pour tester ...