How to convert crypto.WordArray to Uint8Array?

Question

The crypto-es library uses its own format for hash the WordArray

WordArray {
  // The number of significant bytes in the words.
  sigBytes: 16

  // An array of 32-bit words.
  words: [1013011610, 748842083, 565183709, -233379442]
}

How this WordArray could be converted to Uint8Array?

I need this because I have some converting hash to string that expect Uint8Array as an input. And I can't use it with WordArray hash.

Answer 1

This seems to work

function convert_word_array_to_uint8Array(wordArray: any) {
    var len = wordArray.words.length,
        u8_array = new Uint8Array(len << 2),
        offset = 0, word, i
    ;
    for (i=0; i<len; i++) {
        word = wordArray.words[i];
        u8_array[offset++] = word >> 24;
        u8_array[offset++] = (word >> 16) & 0xff;
        u8_array[offset++] = (word >> 8) & 0xff;
        u8_array[offset++] = word & 0xff;
    }
    return u8_array;
}

Answer 2

var data = {
  "sigBytes": 16,
  "words": [1013011610, 748842083, 565183709, -233379442]
}

const dataArray = new Uint8Array(data.sigBytes);
for (let i = 0x0; i < data.sigBytes; i++) {
  dataArray[i] = data.words[i >>> 0x2] >>> 0x18 - i % 0x4 * 0x8 & 0xff;
}
data = new Uint8Array(dataArray);

console.log(data);
/*
Uint8Array(16) [
   60, 97,  84, 154, 44, 162,
  108, 99,  33, 176,  4, 221,
  242, 22, 233, 142
]
*/