Delphi-CRC32 Verification

an online down unit. I changed it myself.

Unit utcrc32; interfaceuses windows, sysutils, classes; const // CRC32 table crc32tab: array [0 .. $ ff] of longint = ($00000000, $77073096, $ ee0e612c, $ 990951ba, $076dc419, $ 706af48f, $ scheme, $ scheme, $0edb8832, $79dcb8a4, $ scheme, $97d2d988, $ variable, $ 7eb17cbd, $ variable, $90bf1d91, $1db71064, $6ab020f2, $ f3b97148, $ 84be41de, $ variable, $83d1_c7, $ scheme, $646ba8c0, $ fd62f97a, $ 8a65c9ec, $ 14015c4f, $63066cd9, $ fa0f3d63, $ scheme, $ scheme, $ 4c69105e, $ d56041e4, $ scheme, $ Scheme, $ scheme, $ d20d85fd, $ a50ab56b, $ scheme, $ 42b2986c, $ dbbbc9d6, $ scheme, $ 32d86pushed, $45df5c75, $ scheme, $ scheme, $ 26d930ac, $ 51de003a, $ response, $ bfd06116, $ response, $56b3c423, $ cfba9599, $ response, $ 2802b89e, $5f058808, $ c60cd9b2, $ b10be924, $ response, $58684c11, $ response, $ scheme, $76dc4190, $01db7106, $ 98d220bc, $ efd5102a, $71b18589, $ scheme, $9fbfe4a5, $ scheme, $7807c9a2, $ scheme, $ scheme, $ e10e9818, $ region, $ 086d3d2d, $91646c97, $ e6635c01, $ region, $1c6c6162, $ region, $ f262004e, $ 6c0695ed, $ region, $ region, $ f50fc457, $65b0d9c6, $ response, $ 62dd1ddf, $15da2d49, $8cd37cf3, $ fbd44c65, $4db26158, $ 3ab551ce, $ a3bc0074, $ d4bb30e2, $ response, $ response, $ region, $ region, $ 4369e96a, $ 346ed9fc, $ ad678846, $ region, $ region 42d73, $33031de5, $ aa0a4c5f, $ region, $ 5005713c, $ 270241aa, $ be0b1010, $ scheme, $5768b525, $206f85b3, $ scheme, $ ce61e49f, $ scheme, $29d9c998, $ scheme, $ scheme, $59b33d17, $2eb40d81, $ b7bd5c3b, $ c0ba6cad, $ scheme, $9abfb3b6, $ scheme, $ scheme, $ ead54739, $ 9dd277af, $04db2615, $73dc1683, $ e3630b12, $94643b84, $ scheme, $ scheme, $ e40ecf0b, $ scheme, $0a00ae27, $ scheme, $ scheme, $8708a3d2, $ scheme, $ 6906c2fe, $ f762575d, $ 806567cb, $196c3671, $ scheme, $ fed41b76, $89d32be0, $ response, $ 67dd4acc, $ response, $8ebeeff9, $17b7be43, $60b08ed5, $ response, $ a1d1937e, $38d8c2c4, $4fdff252, $ d1bb67f1, $ response, $ response, $ 48b2364b, $ d80d2133, $ af0a1b4c, $36034af6, $10947a60, $ df60efc3, $ a867df55, $ 109e8eef, $4669be79, $ scheme, $ scheme, $ scheme, $220216b9, $ 5505262f, $ c5ba3bbe, $ b2bd0b28, $2bb45a92, $5cb36a04, $ c2d7ffa7, $ scheme, $ 2cd99e8b, $ scheme, $ Scheme, $ ec63f226, $ 756aa39c, $ 026d930a, $9c0906a9, $ hour, $72076785, $05005713, $95bf4a82, $ e2b87a14, $ 7bb12bae, $0cb61b38, $ hour, $ hour, $ videos, $0bdbdf21, $86d3d2d4, $ videos, $68ddb3f8, $ videos, $ 81be16cd, $ videos, $6fb077e1, $18b74777, $88085ae6, $ videos, $ 66063bca, $ 11010b5c, $ response, $ f862ae69, $616bffd3, $166ccf45, $ a00ae278, $ d70dd2ee, $ response, $3903b3c2, $ a7672661, $ response, $ 4969474d, $ response, $ scheme, $ d9d65adc, $40df0b66, $37d83bf0, $ scheme, $ debb9ec5, $ 47b2cf7f, $ scheme, $ bdbdf21c, $ cabac28a, $ scheme, $ scheme, $ bad03605, $ scheme, $54de5729, $ 23d967bf, $ b3667a2e, $ c4614ab8, $ scheme, $2a6f2b94, $ b40bbe37, $ scheme); Procedure getcrc32stream (astream: tstream; var CRC32: Cardinal); implementationfunction updatecrc32 (initcrc: longint; var buffer; {$ ifdef Win32} length: longint {$ else} length: Word {$ endif }): longint; begin ASM {$ ifdef Win32} Push ESI push EDI push eax push EBX push ECx push edX Lea EDI, crc32tab mov ESI, buffer mov ax, word PTR initcrc mov dx, word PTR initcrc + 2 mov ECx, length or ECX, ECx JZ @ done @ loop: xor ebx, EBX mov BL, Al lodsb xor bl, Al mov Al, ah mov ah, DL mov DL, dh xor dh, dh shl bx, 1 shl bx, 1 add EBX, edi xor ax, [EBX] XOR dx, [EBX + 2] loop @ done: mov word PTR result, ax mov word PTR result + 2, DX pop edX pop ECx pop EBX pop eax pop EDI pop ESI {$ else} push ds pop es push ds Lea Di, crc32tab lDs Si, buffer mov ax, word PTR initcrc mov dx, word PTR initcrc + 2 mov CX, length or CX, cx jz @ done @ loop: xor bh, BH mov BL, Al lodsb xor bl, Al mov Al, ah mov ah, DL mov DL, dh xor dh, dh shl bx, 1 shl bx, 1 XOR ax, ES: [di + BX] XOR dx, ES: [di + bx + 2] loop @ done: Pop DS mov word PTR result, ax mov word PTR result + 2, DX {$ endif} end; procedure getcrc32stream (astream: tstream; var CRC32: Cardinal); var Buffer: pbyte; N: int64; begin n: = astream. size; getmem (buffer, n); try CRC32: = updatecrc32 ($ ffffffff, buffer ^, n) Finally freemem (buffer, n); end; CRC32: = Not CRC32; end; end.