121 lines
3.4 KiB
TypeScript
121 lines
3.4 KiB
TypeScript
/**
|
|
* Pure JavaScript SHA256 implementation
|
|
* Used as fallback when crypto.subtle is not available (non-HTTPS contexts)
|
|
*/
|
|
|
|
/**
|
|
* SHA256 constants
|
|
*/
|
|
const K: number[] = [
|
|
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
|
|
];
|
|
|
|
/**
|
|
* Initial hash values
|
|
*/
|
|
const H: number[] = [
|
|
0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
|
|
0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
|
|
];
|
|
|
|
/**
|
|
* Rotate right
|
|
*/
|
|
function rotr(n: number, b: number): number {
|
|
return (n >>> b) | (n << (32 - b));
|
|
}
|
|
|
|
/**
|
|
* SHA256 compression function
|
|
*/
|
|
function sha256Transform(W: number[], H: number[]): void {
|
|
let a = H[0];
|
|
let b = H[1];
|
|
let c = H[2];
|
|
let d = H[3];
|
|
let e = H[4];
|
|
let f = H[5];
|
|
let g = H[6];
|
|
let h = H[7];
|
|
|
|
for (let j = 0; j < 64; j++) {
|
|
if (j >= 16) {
|
|
const s0 = rotr(W[j - 15], 7) ^ rotr(W[j - 15], 18) ^ (W[j - 15] >>> 3);
|
|
const s1 = rotr(W[j - 2], 17) ^ rotr(W[j - 2], 19) ^ (W[j - 2] >>> 10);
|
|
W[j] = (W[j - 16] + s0 + W[j - 7] + s1) >>> 0;
|
|
}
|
|
|
|
const S1 = rotr(e, 6) ^ rotr(e, 11) ^ rotr(e, 25);
|
|
const ch = (e & f) ^ ((~e) & g);
|
|
const temp1 = (h + S1 + ch + K[j] + W[j]) >>> 0;
|
|
|
|
const S0 = rotr(a, 2) ^ rotr(a, 13) ^ rotr(a, 22);
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* Calculate SHA256 hash from bytes
|
|
*/
|
|
export function sha256Fallback(bytes: Uint8Array): string {
|
|
const H_copy = [...H];
|
|
const msgLen = bytes.length;
|
|
const msgBitLen = msgLen * 8;
|
|
|
|
// Padding
|
|
const padLen = (msgLen % 64 < 56) ? 56 - (msgLen % 64) : 120 - (msgLen % 64);
|
|
const padded = new Uint8Array(msgLen + padLen + 8);
|
|
padded.set(bytes);
|
|
padded[msgLen] = 0x80;
|
|
|
|
// Append length (64-bit big-endian)
|
|
const dataView = new DataView(padded.buffer);
|
|
dataView.setUint32(padded.length - 8, 0, false); // high 32 bits
|
|
dataView.setUint32(padded.length - 4, msgBitLen >>> 0, false); // low 32 bits
|
|
|
|
// Process blocks
|
|
for (let offset = 0; offset < padded.length; offset += 64) {
|
|
const W = new Array(64);
|
|
|
|
// Copy block into W[0..15]
|
|
for (let i = 0; i < 16; i++) {
|
|
W[i] = dataView.getUint32(offset + i * 4, false);
|
|
}
|
|
|
|
sha256Transform(W, H_copy);
|
|
}
|
|
|
|
// Convert to hex string
|
|
let hex = '';
|
|
for (let i = 0; i < 8; i++) {
|
|
hex += H_copy[i].toString(16).padStart(8, '0');
|
|
}
|
|
|
|
return hex;
|
|
} |