| 52 | }; |
| 53 | |
| 54 | uint32_t crc32_core(uint32_t *ptr, uint32_t len) |
| 55 | { |
| 56 | unsigned int xbit = 0; |
| 57 | unsigned int data = 0; |
| 58 | unsigned int CRC32 = 0xFFFFFFFF; |
| 59 | const unsigned int dwPolynomial = 0x04c11db7; |
| 60 | |
| 61 | for (unsigned int i = 0; i < len; i++) |
| 62 | { |
| 63 | xbit = 1 << 31; |
| 64 | data = ptr[i]; |
| 65 | for (unsigned int bits = 0; bits < 32; bits++) |
| 66 | { |
| 67 | if (CRC32 & 0x80000000) |
| 68 | { |
| 69 | CRC32 <<= 1; |
| 70 | CRC32 ^= dwPolynomial; |
| 71 | } |
| 72 | else |
| 73 | { |
| 74 | CRC32 <<= 1; |
| 75 | } |
| 76 | |
| 77 | if (data & xbit) |
| 78 | CRC32 ^= dwPolynomial; |
| 79 | xbit >>= 1; |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | return CRC32; |
| 84 | } |
| 85 | |
| 86 | void Custom::Init() |
| 87 | { |