js实现哈希计算

sha256(message) {
            function rightRotate(n, x) {
                return (x >>> n) | (x << (32 - n));
            }

            const K = new Uint32Array([
                0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
                0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
                0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
                0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
                0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
                0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
                0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
                0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
                0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
                0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
                0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
                0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
                0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
                0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
                0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
                0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
            ]);

            function sha256(message) {
                const blocks = prepareBlocks(message);
                const H = new Uint32Array([
                    0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
                    0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
                ]);

                for (let block of blocks) {
                    const words = new Uint32Array(64);

                    for (let i = 0; i < 16; i++) {
                        words[i] = (block[i * 4] << 24) |
                            (block[i * 4 + 1] << 16) |
                            (block[i * 4 + 2] << 8) |
                            (block[i * 4 + 3]);
                    }

                    for (let i = 16; i < 64; i++) {
                        const s0 = rightRotate(7, words[i - 15]) ^ rightRotate(18, words[i - 15]) ^ (words[i - 15] >>> 3);
                        const s1 = rightRotate(17, words[i - 2]) ^ rightRotate(19, words[i - 2]) ^ (words[i - 2] >>> 10);
                        words[i] = (words[i - 16] + s0 + words[i - 7] + s1) >>> 0;
                    }

                    let [a, b, c, d, e, f, g, h] = H;

                    for (let i = 0; i < 64; i++) {
                        const S1 = rightRotate(6, e) ^ rightRotate(11, e) ^ rightRotate(25, e);
                        const ch = (e & f) ^ (~e & g);
                        const temp1 = (h + S1 + ch + K[i] + words[i]) >>> 0;
                        const S0 = rightRotate(2, a) ^ rightRotate(13, a) ^ rightRotate(22, a);
                        const maj = (a & b) ^ (a & c) ^ (b & c);
                        const temp2 = (S0 + maj) >>> 0;

                        h = g;
                        g = f;
                        f = e;
                        e = (d + temp1) >>> 0;
                        d = c;
                        c = b;
                        b = a;
                        a = (temp1 + temp2) >>> 0;
                    }

                    H[0] = (H[0] + a) >>> 0;
                    H[1] = (H[1] + b) >>> 0;
                    H[2] = (H[2] + c) >>> 0;
                    H[3] = (H[3] + d) >>> 0;
                    H[4] = (H[4] + e) >>> 0;
                    H[5] = (H[5] + f) >>> 0;
                    H[6] = (H[6] + g) >>> 0;
                    H[7] = (H[7] + h) >>> 0;
                }

                const hash = new Uint8Array(32);
                for (let i = 0; i < 8; i++) {
                    hash[i * 4] = (H[i] >>> 24) & 0xff;
                    hash[i * 4 + 1] = (H[i] >>> 16) & 0xff;
                    hash[i * 4 + 2] = (H[i] >>> 8) & 0xff;
                    hash[i * 4 + 3] = H[i] & 0xff;
                }

                return Array.prototype.map.call(hash, x => ('00' + x.toString(16)).slice(-2)).join('');
            }

            function prepareBlocks(message) {
                const bytes = new Uint8Array(message.length);
                for (let i = 0; i < message.length; i++) {
                    bytes[i] = message.charCodeAt(i);
                }

                const bitLength = bytes.length * 8;
                const extraLength = (bitLength + 1 + 64) % 512 === 0 ? 0 : (512 - ((bitLength + 1 + 64) % 512)) / 8;
                const totalLength = bytes.length + 1 + extraLength + 8;
                const result = new Uint8Array(totalLength);
                result.set(bytes);

                result[bytes.length] = 0x80;

                const lengthBytes = new DataView(new ArrayBuffer(8));
                lengthBytes.setBigUint64(0, BigInt(bitLength), false);
                for (let i = 0; i < 8; i++) {
                    result[result.length - 8 + i] = lengthBytes.getUint8(i);
                }

                const blocks = [];
                for (let i = 0; i < result.length; i += 64) {
                    blocks.push(result.subarray(i, i + 64));
                }

                return blocks;
            }
            const hash = sha256(message);
            return hash;
        }