我需要在浏览器内的文件（~6MB）中创建一个SHA-256摘要。到目前为止，我设法做到的唯一方法是：
var reader = new FileReader();
reader.onload = function() {
// this gets read of the mime-type data header
var actual_contents = reader.result.slice(reader.result.indexOf(',') + 1);
var what_i_need = new jsSHA(actual_contents, "B64").getHash("SHA-256", "HEX");
}
reader.readAsDataURL(some_file);
虽然这可以正常工作，但问题是它非常慢。 6MB文件需要2-3秒。我怎样才能改善这个？
答案 0 :(得分：16)
您可能需要查看Stanford JS加密库
来自网站：
SJCL很安全。它使用128,192或256位的行业标准AES算法; SHA256哈希函数; HMAC认证码; PBKDF2密码增强器;以及CCM和OCB认证加密模式。
SJCL有一个测试页面，显示需要多长时间。
SHA256迭代的184毫秒。来自catameringue的SHA-256为50毫秒。
测试page
示例代码：
加密数据：
sjcl.encrypt("password", "data")
解密数据：sjcl.decrypt("password", "encrypted-data")
答案 1 :(得分：6)
这是一个老问题，但我认为值得注意的是asmCrypto明显快于jsSHA，并且快于CryptoJS和SJCL
https://github.com/vibornoff/asmcrypto.js/
还有一个由OpenPGP.js
https://github.com/openpgpjs/asmcrypto-lite
其中仅包含SHA256和几个AES功能。
使用asmCrypto您只需执行以下操作：
var sha256HexValue = asmCrypto.SHA256.hex(myArraybuffer);
我可以在＆lt; 中散列 150MB + 文件Chrome中一致<2秒。
答案 2 :(得分：4)
使用加密库的emscripten编译版本可能会更快，
Q值。编译代码的速度有多快？
一个。 Emscripten的默认代码生成模式为asm.js格式， 这是JavaScript的一个子集，旨在使其成为可能 JavaScript引擎可以非常快速地执行。请看这里是最新的 基准结果。在许多情况下，asm.js可以非常接近原生 速度。
您可以找到Emscripten编译的NaCl加密库here。
答案 3 :(得分：3)
这是你要找的东西。我从SHA256算法的C版本中得到了这个。它还包括SHA256D。我不认为你会比javascript快得多。我尝试扩展循环，由于javascript解释器运行优化，它运行得很慢。
// From: https://github.com/Hartland/GPL-CPU-Miner/blob/master/sha2.c
if ("undefined" == typeof vnet) {
vnet = new Array();
}
if ("undefined" == typeof vnet.crypt) {
vnet.crypt = new Array();
}
vnet.crypt.sha2 = function() {
var sha256_h = [
0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
];
var sha256_k = [
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
];
var sha256_init = function(s) {
s.state = [
sha256_h[0],
sha256_h[1],
sha256_h[2],
sha256_h[3],
sha256_h[4],
sha256_h[5],
sha256_h[6],
sha256_h[7],
];
}; this.sha256_init = sha256_init;
/*
* SHA256 block compression function. The 256-bit state is transformed via
* the 512-bit input block to produce a new state.
*/
var sha256_transform = function(s, b, swap) {
var block = b.block;
var state = s.state;
var W;
var S;
var t0;
var t1;
var i;
/* 1. Prepare message schedule W. */
if (swap) {
W = [
((((block[0] ) << 24) & 0xff000000) | (((block[0] ) << 8) & 0x00ff0000) | (((block[0] ) >> 8) & 0x0000ff00) | (((block[0] ) >> 24) & 0x000000ff)),
((((block[1] ) << 24) & 0xff000000) | (((block[1] ) << 8) & 0x00ff0000) | (((block[1] ) >> 8) & 0x0000ff00) | (((block[1] ) >> 24) & 0x000000ff)),
((((block[2] ) << 24) & 0xff000000) | (((block[2] ) << 8) & 0x00ff0000) | (((block[2] ) >> 8) & 0x0000ff00) | (((block[2] ) >> 24) & 0x000000ff)),
((((block[3] ) << 24) & 0xff000000) | (((block[3] ) << 8) & 0x00ff0000) | (((block[3] ) >> 8) & 0x0000ff00) | (((block[3] ) >> 24) & 0x000000ff)),
((((block[4] ) << 24) & 0xff000000) | (((block[4] ) << 8) & 0x00ff0000) | (((block[4] ) >> 8) & 0x0000ff00) | (((block[4] ) >> 24) & 0x000000ff)),
((((block[5] ) << 24) & 0xff000000) | (((block[5] ) << 8) & 0x00ff0000) | (((block[5] ) >> 8) & 0x0000ff00) | (((block[5] ) >> 24) & 0x000000ff)),
((((block[6] ) << 24) & 0xff000000) | (((block[6] ) << 8) & 0x00ff0000) | (((block[6] ) >> 8) & 0x0000ff00) | (((block[6] ) >> 24) & 0x000000ff)),
((((block[7] ) << 24) & 0xff000000) | (((block[7] ) << 8) & 0x00ff0000) | (((block[7] ) >> 8) & 0x0000ff00) | (((block[7] ) >> 24) & 0x000000ff)),
((((block[8] ) << 24) & 0xff000000) | (((block[8] ) << 8) & 0x00ff0000) | (((block[8] ) >> 8) & 0x0000ff00) | (((block[8] ) >> 24) & 0x000000ff)),
((((block[9] ) << 24) & 0xff000000) | (((block[9] ) << 8) & 0x00ff0000) | (((block[9] ) >> 8) & 0x0000ff00) | (((block[9] ) >> 24) & 0x000000ff)),
((((block[10]) << 24) & 0xff000000) | (((block[10]) << 8) & 0x00ff0000) | (((block[10]) >> 8) & 0x0000ff00) | (((block[10]) >> 24) & 0x000000ff)),
((((block[11]) << 24) & 0xff000000) | (((block[11]) << 8) & 0x00ff0000) | (((block[11]) >> 8) & 0x0000ff00) | (((block[11]) >> 24) & 0x000000ff)),
((((block[12]) << 24) & 0xff000000) | (((block[12]) << 8) & 0x00ff0000) | (((block[12]) >> 8) & 0x0000ff00) | (((block[12]) >> 24) & 0x000000ff)),
((((block[13]) << 24) & 0xff000000) | (((block[13]) << 8) & 0x00ff0000) | (((block[13]) >> 8) & 0x0000ff00) | (((block[13]) >> 24) & 0x000000ff)),
((((block[14]) << 24) & 0xff000000) | (((block[14]) << 8) & 0x00ff0000) | (((block[14]) >> 8) & 0x0000ff00) | (((block[14]) >> 24) & 0x000000ff)),
((((block[15]) << 24) & 0xff000000) | (((block[15]) << 8) & 0x00ff0000) | (((block[15]) >> 8) & 0x0000ff00) | (((block[15]) >> 24) & 0x000000ff))
];
} else {
W = [
block[0],
block[1],
block[2],
block[3],
block[4],
block[5],
block[6],
block[7],
block[8],
block[9],
block[10],
block[11],
block[12],
block[13],
block[14],
block[15]
];
}
for (i = 16; i < 64; i += 2) {
W[i] = ((
((((W[i-2] >>> 17) | (W[i-2] << 15)) ^ ((W[i-2] >>> 19) | ((W[i-2] << 13)>>>0) ) ^ (W[i - 2] >>> 10)) >>> 0) + //s1 (W[i - 2]) +
W[i - 7] +
((((W[i - 15] >>> 7) | (W[i - 15] << 25)) ^ ((W[i - 15] >>> 18) | ((W[i - 15] << 14) >>> 0)) ^ (W[i - 15] >>> 3)) >>> 0) + //s0 (W[i - 15]) +
W[i - 16]
) & 0xffffffff) >>> 0;
W[i+1] = ((
((((W[i-1] >>> 17) | (W[i-1] << 15)) ^ ((W[i-1] >>> 19) | (W[i-1] << 13)) ^ (W[i - 1] >>> 10)) >>> 0)+ //s1 (W[i - 1]) +
W[i - 6] +
((((W[i - 14] >>> 7) | (W[i - 14] << 25)) ^ ((W[i - 14] >>> 18) | (W[i - 14] << 14)) ^ (W[i - 14] >>> 3)) >>> 0) + //s0 (W[i - 14]) +
W[i - 15]
) & 0xffffffff) >>> 0;
}
/* 2. Initialize working variables. */
S = [
state[0],
state[1],
state[2],
state[3],
state[4],
state[5],
state[6],
state[7],
];
/* 3. Mix. */
i=0;
for(;i<64;++i) {
//RNDr(S,W,i)
t0 = S[(71 - i) % 8] +
((((S[(68 - i) % 8] >>> 6) | (S[(68 - i) % 8] << 26)) ^ ((S[(68 - i) % 8] >>> 11) | (S[(68 - i) % 8] << 21)) ^ ((S[(68 - i) % 8] >>> 25) | (S[(68 - i) % 8] << 7)))) + //S1 (S[(68 - i) % 8]) +
(((S[(68 - i) % 8] & (S[(69 - i) % 8] ^ S[(70 - i) % 8])) ^ S[(70 - i) % 8]) ) + // Ch
W[i] +
sha256_k[i];
t1 = ((((S[(64 - i) % 8] >>> 2) | ((S[(64 - i) % 8] & 3) << 30)) ^ ((S[(64 - i) % 8] >>> 13) | (S[(64 - i) % 8] << 19)) ^ ((S[(64 - i) % 8] >>> 22) | (S[(64 - i) % 8] << 10)))) + //S0 (S[(64 - i) % 8]) +
(((S[(64 - i) % 8] & (S[(65 - i) % 8] | S[(66 - i) % 8])) | (S[(65 - i) % 8] & S[(66 - i) % 8]))); // Maj
S[(67 - i) % 8] = ((S[(67 - i) % 8] + t0) & 0xFFFFFFFF) >>> 0;
S[(71 - i) % 8] = ((t0 + t1) & 0xFFFFFFFF) >>> 0;
}
/* 4. Mix local working variables into global state */
i=0;
for(;i<8;++i) {
s.state[i] = (0xFFFFFFFF & (state[i] + S[i])) >>> 0;
}
}; this.sha256_transform = sha256_transform;
var sha256d_hash1 = [
0x00000000, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000000,
0x80000000, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000100
];
var sha256d_80_swap = function(hash, data)
{
var S = new Array();
var i;
var b1 = new Array();
var b2 = new Array();
var b3 = new Array();
b1.block = [
data[0],
data[1],
data[2],
data[3],
data[4],
data[5],
data[6],
data[7],
data[8],
data[9],
data[10],
data[11],
data[12],
data[13],
data[14],
data[15]
];
b2.block = [
data[16],
data[17],
data[18],
data[19],
data[20],
data[21],
data[22],
data[23],
data[24],
data[25],
data[26],
data[27],
data[28],
data[29],
data[30],
data[31]
];
sha256_init(S);
sha256_transform(S, b1, 0);
sha256_transform(S, b2, 0);
b3.block = [
S.state[0],
S.state[1],
S.state[2],
S.state[3],
S.state[4],
S.state[5],
S.state[6],
S.state[7],
sha256d_hash1[8],
sha256d_hash1[9],
sha256d_hash1[10],
sha256d_hash1[11],
sha256d_hash1[12],
sha256d_hash1[13],
sha256d_hash1[14],
sha256d_hash1[15]
];
sha256_init(hash);
sha256_transform(hash, b3, 0);
for (i = 0; i < 8; i++) {
hash.state[i] = ((((hash.state[i] ) << 24) & 0xff000000) | (((hash.state[i] ) << 8) & 0x00ff0000) | (((hash.state[i] ) >> 8) & 0x0000ff00) | (((hash.state[i] ) >> 24) & 0x000000ff)); //swab32(hash[i]);
}
}; this.sha256d_80_swap = sha256d_80_swap;
var sha256d = function(hash, data) {
var S;
var T;
var block_in;
S = new Array();
T = new Array();
T.block = [];
var i, r;
//hash.hash = new Array(32).join('0').split('').map(parseFloat);
sha256_init(S);
for (r = data.length; r > -9; r -= 64) {
if (r < 64) {
if (r > 0) {
block_in = data.slice(data.length - r,data.length);
block_in.push.apply(block_in, new Array(64-r).join('0').split('').map(parseFloat));
} else {
block_in = new Array(64).join('0').split('').map(parseFloat);
}
} else {
block_in = data.slice(data.length - r,data.length - r + 64);
}
//memcpy(T, data + len - r, r > 64 ? 64 : (r < 0 ? 0 : r));
if (r >= 0 && r < 64) {
block_in[r] = 0x80;
}
for (i = 0; i < 16; i++) {
T.block[i] = (((0xff & block_in[(i*4)]) << 24) | ((0xff & block_in[(i*4)+1]) << 16) | ((0xff & block_in[(i*4)+2]) << 8) | (0xff & block_in[(i*4)+3])) >>> 0;
}
if (r < 56) {
T.block[15] = 8 * data.length;
}
sha256_transform(S, T, 0);
}
//memcpy(S + 8, sha256d_hash1 + 8, 32);
S.block = S.state;
for(i=8;i<16;i++) {
S.block[i] = sha256d_hash1[i];
}
sha256_init(T);
sha256_transform(T, S, 0);
hash.hash = [
(T.state[0] >> 24) & 0xff,
(T.state[0] >> 16) & 0xff,
(T.state[0] >> 8) & 0xff,
T.state[0] & 0xff,
(T.state[1] >> 24) & 0xff,
(T.state[1] >> 16) & 0xff,
(T.state[1] >> 8) & 0xff,
T.state[1] & 0xff,
(T.state[2] >> 24) & 0xff,
(T.state[2] >> 16) & 0xff,
(T.state[2] >> 8) & 0xff,
T.state[2] & 0xff,
(T.state[3] >> 24) & 0xff,
(T.state[3] >> 16) & 0xff,
(T.state[3] >> 8) & 0xff,
T.state[3] & 0xff,
(T.state[4] >> 24) & 0xff,
(T.state[4] >> 16) & 0xff,
(T.state[4] >> 8) & 0xff,
T.state[4] & 0xff,
(T.state[5] >> 24) & 0xff,
(T.state[5] >> 16) & 0xff,
(T.state[5] >> 8) & 0xff,
T.state[5] & 0xff,
(T.state[6] >> 24) & 0xff,
(T.state[6] >> 16) & 0xff,
(T.state[6] >> 8) & 0xff,
T.state[6] & 0xff,
(T.state[7] >> 24) & 0xff,
(T.state[7] >> 16) & 0xff,
(T.state[7] >> 8) & 0xff,
T.state[7] & 0xff
];
}; this.sha256d = sha256d;
var sha256 = function(hash, data) {
var S;
var T;
var block_in;
S = new Array();
T = new Array();
T.block = [];
var i, r;
hash.hash = new Array(32).join('0').split('').map(parseFloat);
sha256_init(S);
for (r = data.length; r > -9; r -= 64) {
if (r < 64) {
if (r > 0) {
block_in = data.slice(data.length - r,data.length);
block_in.push.apply(block_in, new Array(64-r).join('0').split('').map(parseFloat));
} else {
block_in = new Array(64).join('0').split('').map(parseFloat);
}
} else {
block_in = data.slice(data.length - r,data.length - r + 64);
}
//memcpy(T, data + len - r, r > 64 ? 64 : (r < 0 ? 0 : r));
if (r >= 0 && r < 64) {
block_in[r] = 0x80;
}
for (i = 0; i < 16; i++) {
T.block[i] = (((0xff & block_in[(i*4)]) << 24) | ((0xff & block_in[(i*4)+1]) << 16) | ((0xff & block_in[(i*4)+2]) << 8) | (0xff & block_in[(i*4)+3])) >>> 0;
}
if (r < 56) {
T.block[15] = 8 * data.length;
}
sha256_transform(S, T, 0);
}
for (i = 0; i < 8; i++) {
//be32enc((uint32_t *)hash + i, T[i]);
hash.hash[(i * 4)] = (S.state[i] >> 24) & 0xff;
hash.hash[(i * 4)+1] = (S.state[i] >> 16) & 0xff
hash.hash[(i * 4)+2] = (S.state[i] >> 8) & 0xff
hash.hash[(i * 4)+3] = S.state[i] & 0xff;
}
}; this.sha256 = sha256;
};
答案 4 :(得分：0)
大约 85MB 的测试文件，不需要一秒钟就可以完成。
<input type="file" multiple/>
<input placeholder="Press `Enter` when done."/>
<script>
/**
* @param {"SHA-1"|"SHA-256"|"SHA-384"|"SHA-512"} algorithm https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest
* @param {string|Blob} data
*/
async function getHash(algorithm, data) {
const main = async (msgUint8) => { // https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest#converting_a_digest_to_a_hex_string
const hashBuffer = await crypto.subtle.digest(algorithm, msgUint8)
const hashArray = Array.from(new Uint8Array(hashBuffer))
return hashArray.map(b => b.toString(16).padStart(2, '0')).join(''); // convert bytes to hex string
}
if (data instanceof Blob) {
const arrayBuffer = await data.arrayBuffer()
const msgUint8 = new Uint8Array(arrayBuffer)
return await main(msgUint8)
}
const encoder = new TextEncoder()
const msgUint8 = encoder.encode(data)
return await main(msgUint8)
}
const inputFile = document.querySelector(`input[type="file"]`)
const inputText = document.querySelector(`input[placeholder^="Press"]`)
inputFile.onchange = async (event) => {
for (const file of event.target.files) {
console.log(file.name, file.type, file.size + "bytes")
const hashHex = await getHash("SHA-256", new Blob([file]))
console.log(hashHex)
}
}
inputText.onkeyup = async (keyboardEvent) => {
if (keyboardEvent.key === "Enter") {
const hashHex = await getHash("SHA-256", keyboardEvent.target.value)
console.log(hashHex)
}
}
</script>