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javascript实现sha256算法，支持分多次计算

news 2025/7/1 17:06:40

概述：

本人前端需要实现sha256计算的功能，最好是能做到分多次计算，在网上找了很久，发现达不到预期的功能：
比如这里代码：http://www.webtoolkit.info/javascript_sha256.html和这里代码：https://blog.csdn.net/BHSZZY/article/details/127111589，是说的一步计算的，
这里的代码用的比较广泛：https://blog.csdn.net/qq_40164190/article/details/83384234，支持分多次计算，但是，分多次计算结果却是错的，即

sha256_init();
sha256_update(“1234”, 4);
sha256_final();
sha256_encode_hex();

结果是对的
但是分多次计算

sha256_init();
sha256_update(“12”, 2);
sha256_update(“34”, 2);
sha256_final();
sha256_encode_hex();

结果是错的
查找js中crypto库，发现过于庞大不适合微信小程序，基于此，本人在现有sha256的C++代码，反复测试对比计算过程参数，成功改造成sha256的javascript代码，并成功验证好分多次计算sha256数据。

测试平台：

已经在如下环境中测试通过，其他平台应该也不会有问题：
1、nodejs中node.exe运行
2、Microsoft Edge和GPT Chrome浏览器
3、微信小程序

功能代码：

function strSha256CtxParams() {this.state;this.data;this.datalen;this.bitlenhigh;this.bitlenlow;
};var K256 = new Array(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 ROTLEFT(a, b) {return (((a) << (b)) | ((a) >>> (32-(b))));
}function ROTRIGHT(a,b) {return (((a) >>> (b)) | ((a) << (32-(b))));
}function CH(x,y,z) {return (((x) & (y)) ^ (~(x) & (z)));
}function MAJ(x,y,z) {return (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)));
}function EP0(x) {return (ROTRIGHT(x,2) ^ ROTRIGHT(x,13) ^ ROTRIGHT(x,22));
}function EP1(x) {return (ROTRIGHT(x,6) ^ ROTRIGHT(x,11) ^ ROTRIGHT(x,25));
}function SIG0(x) {return (ROTRIGHT(x,7) ^ ROTRIGHT(x,18) ^ ((x) >>> 3));
}function SIG1(x) {return (ROTRIGHT(x,17) ^ ROTRIGHT(x,19) ^ ((x) >>> 10));
}function BitLenAdd(sha256CtxParams, add) {sha256CtxParams.bitlenlow += add;if (sha256CtxParams.bitlenlow >= 4294967296) {sha256CtxParams.bitlenhigh++;sha256CtxParams.bitlenlow = sha256CtxParams.bitlenlow & 0xffffffff;}
}function sha256_init() {var sha256CtxParams = new strSha256CtxParams();sha256CtxParams.state = new Array(8);sha256CtxParams.data = new Uint8Array(64);sha256CtxParams.state[0] = 0x6a09e667;sha256CtxParams.state[1] = 0xbb67ae85;sha256CtxParams.state[2] = 0x3c6ef372;sha256CtxParams.state[3] = 0xa54ff53a;sha256CtxParams.state[4] = 0x510e527f;sha256CtxParams.state[5] = 0x9b05688c;sha256CtxParams.state[6] = 0x1f83d9ab;sha256CtxParams.state[7] = 0x5be0cd19;sha256CtxParams.datalen = 0;sha256CtxParams.bitlenhigh = 0;sha256CtxParams.bitlenlow = 0;return sha256CtxParams;
}function sha256_update(sha256CtxParams, data, datalen) {var i = 0;for (i = 0; i < datalen; i++) {sha256CtxParams.data[sha256CtxParams.datalen] = data.charCodeAt(i);sha256CtxParams.datalen++;if (sha256CtxParams.datalen == 64) {sha256_transform(sha256CtxParams);BitLenAdd(sha256CtxParams, 512);sha256CtxParams.datalen = 0;}}
}function sha256_transform(sha256CtxParams) {var a, b, c, d, e, f, g, h, t1, t2;var i, j;var m = new Array(64);for (i = 0, j = 0; i < 16; ++i, j += 4) {m[i] = ((parseInt(sha256CtxParams.data[j]) & 0xff) << 24) | ((parseInt(sha256CtxParams.data[j + 1]) & 0xff) << 16) | ((parseInt(sha256CtxParams.data[j + 2]) & 0xff) << 8) | (parseInt(sha256CtxParams.data[j + 3]) & 0xff);m[i] &= m[i];}for ( ; i < 64; ++i) {m[i] = (SIG1(m[i - 2]) & 0xffffffff) + m[i - 7] + (SIG0(m[i - 15]) & 0xffffffff) + m[i - 16];m[i] &= m[i];}a = sha256CtxParams.state[0];b = sha256CtxParams.state[1];c = sha256CtxParams.state[2];d = sha256CtxParams.state[3];e = sha256CtxParams.state[4];f = sha256CtxParams.state[5];g = sha256CtxParams.state[6];h = sha256CtxParams.state[7];for (i = 0; i < 64; ++i) {t1 = h + EP1(e) + CH(e,f,g) + K256[i] + m[i];t2 = EP0(a) + MAJ(a,b,c);h = g;g = f;f = e;e = d + t1;d = c;c = b;b = a;a = t1 + t2;}sha256CtxParams.state[0] += a;sha256CtxParams.state[1] += b;sha256CtxParams.state[2] += c;sha256CtxParams.state[3] += d;sha256CtxParams.state[4] += e;sha256CtxParams.state[5] += f;sha256CtxParams.state[6] += g;sha256CtxParams.state[7] += h;for (i = 0; i < 8; i++) {sha256CtxParams.state[i] &= 0xffffffff;}
}function sha256_final(sha256CtxParams) {var i = 0;var j = 0;var result = new Uint8Array(32);i = sha256CtxParams.datalen;// Pad whatever data is left in the buffer.if (sha256CtxParams.datalen < 56) {sha256CtxParams.data[i] = 0x80;  // pad 10000000 = 0x80i++;while (i < 56) {sha256CtxParams.data[i] = 0x00;i++;}}else {sha256CtxParams.data[i] = 0x80;i++;while (i < 64) {sha256CtxParams.data[i] = 0x00;i++;}sha256_transform(sha256CtxParams);//memset(sha256CtxParams.data, 0, 56);for (j = 0; j < 56; j++) {sha256CtxParams.data[j] = 0x00;}}BitLenAdd(sha256CtxParams, sha256CtxParams.datalen * 8);sha256CtxParams.data[63] = sha256CtxParams.bitlenlow;sha256CtxParams.data[62] = sha256CtxParams.bitlenlow >> 8;sha256CtxParams.data[61] = sha256CtxParams.bitlenlow >> 16;sha256CtxParams.data[60] = sha256CtxParams.bitlenlow >> 24;sha256CtxParams.data[59] = sha256CtxParams.bitlenhigh >> 0;sha256CtxParams.data[58] = sha256CtxParams.bitlenhigh >> 8;sha256CtxParams.data[57] = sha256CtxParams.bitlenhigh >> 16;sha256CtxParams.data[56] = sha256CtxParams.bitlenhigh >> 24;	sha256_transform(sha256CtxParams);// copying the final state to the output hash(use big endian).for (i = 0; i < 4; ++i) {result[i]      = (sha256CtxParams.state[0] >>> (24 - i * 8)) & 0x000000ff;result[i + 4]  = (sha256CtxParams.state[1] >>> (24 - i * 8)) & 0x000000ff;result[i + 8]  = (sha256CtxParams.state[2] >>> (24 - i * 8)) & 0x000000ff;result[i + 12] = (sha256CtxParams.state[3] >>> (24 - i * 8)) & 0x000000ff;result[i + 16] = (sha256CtxParams.state[4] >>> (24 - i * 8)) & 0x000000ff;result[i + 20] = (sha256CtxParams.state[5] >>> (24 - i * 8)) & 0x000000ff;result[i + 24] = (sha256CtxParams.state[6] >>> (24 - i * 8)) & 0x000000ff;result[i + 28] = (sha256CtxParams.state[7] >>> (24 - i * 8)) & 0x000000ff;}return result;
}function sha256_encode_hex(result) {var sha256_hex_digits = "0123456789abcdef";var output = new String();var i = 0;for (i = 0; i < 32; i++) {output += sha256_hex_digits.charAt((result[i] >>> 4) & 0x0f);output += sha256_hex_digits.charAt((result[i]) & 0x0f);}return output;
}function sha256_digest(data) {var result = null;var sha256CtxParams = sha256_init();sha256_update(sha256CtxParams, data, data.length);result = sha256_final(sha256CtxParams);return sha256_encode_hex(result);
}

测试代码：

var tmpStr = null;
var result = null;
var sha256Ctx = null;sha256Ctx = sha256_init();
sha256_update(sha256Ctx, "00112233445566778899", 20);
sha256_update(sha256Ctx, "PP", 2);
result = sha256_final(sha256Ctx);
tmpStr = sha256_encode_hex(result);
console.log("sha256_final:" + tmpStr);