crc64.py

# Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
# (Any use permitted, subject to terms of PostgreSQL license; see.)

# If we have a 64-bit integer type, then a 64-bit CRC looks just like the
# usual sort of implementation. (See Ross Williams' excellent introduction
# A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS, available from
# ftp://ftp.rocksoft.com/papers/crc_v3.txt or several other net sites.)
# If we have no working 64-bit type, then fake it with two 32-bit registers.
#
# The present implementation is a normal (not "reflected", in Williams'
# terms) 64-bit CRC, using initial all-ones register contents and a final
# bit inversion. The chosen polynomial is borrowed from the DLT1 spec
# (ECMA-182, available from http://www.ecma.ch/ecma1/STAND/ECMA-182.HTM):
#
# x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
# x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
# x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +

crc_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
]

class CRC64(object):

    def __init__(self):
        self.crc = 0xffffffffffffffff

    def append(self, buffer):
        for c in buffer:
            tab_index = ((self.crc >> 56) ^ c) & 0xFF
            self.crc = crc_table[tab_index] ^ ((self.crc << 8) &
                                               0xffffffffffffffff)

    def append_int(self, c):
        tab_index = ((self.crc >> 56) ^ c) & 0xFF
        self.crc = crc_table[tab_index] ^ ((self.crc << 8) &
                                           0xffffffffffffffff)

    def fini(self):
        return self.crc ^ 0xffffffffffffffff


def crc64(buffer):
    crc = CRC64()
    crc.append(buffer)

    return crc.fini()