CRC32 _ 다항식 0x04C11DB7 자바스크립트 소스

input이 String 인경우 

export const Crc32_String = (inputString) => {

   

    var poly = 0xEDB88320;     // 다항식 0x04C11DB7  reverse한 값이 0xEDB88320 이다.

    var init_crc = 0xFFFFFFFF; // 초기 CRC

    var final_xor =0xFFFFFFFF; // 최종 XOR 값

    var crcTable = [];

      // CRC32 테이블 생성

      for (var i = 0; i < 256; i++) {

        var crc = i;

        for (var j = 0; j < 8; j++) {

            crc = (crc & 1) ? ((crc >>> 1) ^ poly) : (crc >>> 1);

        }

        crcTable[i] = crc >>> 0;

    }

    var crc = init_crc;

    for (var k = 0; k < inputString.length; k++) {

        console.log("inputString.charCodeAt("+k+") : "+inputString.charCodeAt(k))

        var index = (crc ^ inputString.charCodeAt(k)) & 0xFF;

        crc = (crc >>> 8) ^ crcTable[index];

    }

    // 최종 XOR 적용

    crc = crc ^ final_xor;

    // 결과값을 16진수로 변환하고 0x를 제거하여 반환

    return (crc >>> 0).toString(16).toUpperCase();

   

}

 

 

input이 binary 인경우 

export const Crc32_Binary = (inputBytes) => {

    var poly = 0xEDB88320;     // 다항식 0x04C11DB7의 reverse 값이 0xEDB88320이다.

    var init_crc = 0xFFFFFFFF; // 초기 CRC

    var final_xor = 0xFFFFFFFF; // 최종 XOR 값

    var crcTable = [];

    // CRC32 테이블 생성

    for (var i = 0; i < 256; i++) {

        var crc = i;

        for (var j = 0; j < 8; j++) {

            crc = (crc & 1) ? ((crc >>> 1) ^ poly) : (crc >>> 1);

        }

        crcTable[i] = crc >>> 0;

    }

    var crc = init_crc;

    for (var k = 0; k < inputBytes.length; k++) {

        var index = (crc ^ inputBytes[k]) & 0xFF;

        crc = (crc >>> 8) ^ crcTable[index];

    }

    // 최종 XOR 적용

    crc = crc ^ final_xor;

    // 결과값을 16진수로 변환하고 0x를 제거하여 반환

    return (crc >>> 0).toString(16).toUpperCase();

}

 

---

성능 개선을 위해 미리 CRC_32_Table을 만들어 놓는 경우

const crc32Table = [

    0x00000000,0x77073096,0xEE0E612C,0x990951BA,0x076DC419,0x706AF48F,0xE963A535,0x9E6495A3,0x0EDB8832,0x79DCB8A4,

    0xE0D5E91E,0x97D2D988,0x09B64C2B,0x7EB17CBD,0xE7B82D07,0x90BF1D91,0x1DB71064,0x6AB020F2,0xF3B97148,0x84BE41DE,

    0x1ADAD47D,0x6DDDE4EB,0xF4D4B551,0x83D385C7,0x136C9856,0x646BA8C0,0xFD62F97A,0x8A65C9EC,0x14015C4F,0x63066CD9,

    0xFA0F3D63,0x8D080DF5,0x3B6E20C8,0x4C69105E,0xD56041E4,0xA2677172,0x3C03E4D1,0x4B04D447,0xD20D85FD,0xA50AB56B,

    0x35B5A8FA,0x42B2986C,0xDBBBC9D6,0xACBCF940,0x32D86CE3,0x45DF5C75,0xDCD60DCF,0xABD13D59,0x26D930AC,0x51DE003A,

    0xC8D75180,0xBFD06116,0x21B4F4B5,0x56B3C423,0xCFBA9599,0xB8BDA50F,0x2802B89E,0x5F058808,0xC60CD9B2,0xB10BE924,

    0x2F6F7C87,0x58684C11,0xC1611DAB,0xB6662D3D,0x76DC4190,0x01DB7106,0x98D220BC,0xEFD5102A,0x71B18589,0x06B6B51F,

    0x9FBFE4A5,0xE8B8D433,0x7807C9A2,0x0F00F934,0x9609A88E,0xE10E9818,0x7F6A0DBB,0x086D3D2D,0x91646C97,0xE6635C01,

    0x6B6B51F4,0x1C6C6162,0x856530D8,0xF262004E,0x6C0695ED,0x1B01A57B,0x8208F4C1,0xF50FC457,0x65B0D9C6,0x12B7E950,

    0x8BBEB8EA,0xFCB9887C,0x62DD1DDF,0x15DA2D49,0x8CD37CF3,0xFBD44C65,0x4DB26158,0x3AB551CE,0xA3BC0074,0xD4BB30E2,

    0x4ADFA541,0x3DD895D7,0xA4D1C46D,0xD3D6F4FB,0x4369E96A,0x346ED9FC,0xAD678846,0xDA60B8D0,0x44042D73,0x33031DE5,

    0xAA0A4C5F,0xDD0D7CC9,0x5005713C,0x270241AA,0xBE0B1010,0xC90C2086,0x5768B525,0x206F85B3,0xB966D409,0xCE61E49F,

    0x5EDEF90E,0x29D9C998,0xB0D09822,0xC7D7A8B4,0x59B33D17,0x2EB40D81,0xB7BD5C3B,0xC0BA6CAD,0xEDB88320,0x9ABFB3B6,

    0x03B6E20C,0x74B1D29A,0xEAD54739,0x9DD277AF,0x04DB2615,0x73DC1683,0xE3630B12,0x94643B84,0x0D6D6A3E,0x7A6A5AA8,

    0xE40ECF0B,0x9309FF9D,0x0A00AE27,0x7D079EB1,0xF00F9344,0x8708A3D2,0x1E01F268,0x6906C2FE,0xF762575D,0x806567CB,

    0x196C3671,0x6E6B06E7,0xFED41B76,0x89D32BE0,0x10DA7A5A,0x67DD4ACC,0xF9B9DF6F,0x8EBEEFF9,0x17B7BE43,0x60B08ED5,

    0xD6D6A3E8,0xA1D1937E,0x38D8C2C4,0x4FDFF252,0xD1BB67F1,0xA6BC5767,0x3FB506DD,0x48B2364B,0xD80D2BDA,0xAF0A1B4C,

    0x36034AF6,0x41047A60,0xDF60EFC3,0xA867DF55,0x316E8EEF,0x4669BE79,0xCB61B38C,0xBC66831A,0x256FD2A0,0x5268E236,

    0xCC0C7795,0xBB0B4703,0x220216B9,0x5505262F,0xC5BA3BBE,0xB2BD0B28,0x2BB45A92,0x5CB36A04,0xC2D7FFA7,0xB5D0CF31,

    0x2CD99E8B,0x5BDEAE1D,0x9B64C2B0,0xEC63F226,0x756AA39C,0x026D930A,0x9C0906A9,0xEB0E363F,0x72076785,0x05005713,

    0x95BF4A82,0xE2B87A14,0x7BB12BAE,0x0CB61B38,0x92D28E9B,0xE5D5BE0D,0x7CDCEFB7,0x0BDBDF21,0x86D3D2D4,0xF1D4E242,

    0x68DDB3F8,0x1FDA836E,0x81BE16CD,0xF6B9265B,0x6FB077E1,0x18B74777,0x88085AE6,0xFF0F6A70,0x66063BCA,0x11010B5C,

    0x8F659EFF,0xF862AE69,0x616BFFD3,0x166CCF45,0xA00AE278,0xD70DD2EE,0x4E048354,0x3903B3C2,0xA7672661,0xD06016F7,

    0x4969474D,0x3E6E77DB,0xAED16A4A,0xD9D65ADC,0x40DF0B66,0x37D83BF0,0xA9BCAE53,0xDEBB9EC5,0x47B2CF7F,0x30B5FFE9,

    0xBDBDF21C,0xCABAC28A,0x53B39330,0x24B4A3A6,0xBAD03605,0xCDD70693,0x54DE5729,0x23D967BF,0xB3667A2E,0xC4614AB8,

    0x5D681B02,0x2A6F2B94,0xB40BBE37,0xC30C8EA1,0x5A05DF1B,0x2D02EF8D,];

 

 

export const Crc32_String = (inputString) => {

    var init_crc = 0xFFFFFFFF; // 초기 CRC

    var final_xor =0xFFFFFFFF; // 최종 XOR 값

    var crc = init_crc;

    for (var k = 0; k < inputString.length; k++) {

        var index = (crc ^ inputString.charCodeAt(k)) & 0xFF;

        crc = (crc >>> 8) ^ crc32Table[index];

    }

    // 최종 XOR 적용

    crc = crc ^ final_xor;

    // 결과값을 16진수로 변환하고 0x를 제거하여 반환

    return (crc >>> 0).toString(16).toUpperCase();

   

}

 

 

 

export const Crc32_Binary = (inputBytes) => {

    var init_crc = 0xFFFFFFFF; // 초기 CRC

    var final_xor = 0xFFFFFFFF; // 최종 XOR 값

    var crc = init_crc;

    for (var k = 0; k < inputBytes.length; k++) {

        var index = (crc ^ inputBytes[k]) & 0xFF;

        crc = (crc >>> 8) ^ crc32Table[index];

    }

    // 최종 XOR 적용

    crc = crc ^ final_xor;

    // 결과값을 16진수로 변환하고 0x를 제거하여 반환

    return (crc >>> 0).toString(16).toUpperCase();

}

 

 

 

테이블을 생성하는 코드 

 var poly = 0xEDB88320;     // 다항식 0x04C11DB7의 reverse 값이 0xEDB88320이다.

    var crcTable = [];

    // CRC32 테이블 생성

    for (var i = 0; i < 256; i++) {

        var crc = i;

        for (var j = 0; j < 8; j++) {

            crc = (crc & 1) ? ((crc >>> 1) ^ poly) : (crc >>> 1);

        }

        crcTable[i] = crc >>> 0;

    }

---

참고 

https://eteo.tistory.com/557

CRC-32

http://www.sunshine2k.de/coding/javascript/crc/crc_js.html

Sunshine's Homepage - Online CRC Calculator Javascript