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- function sha256(ascii) {
- function rightRotate(value, amount) {
- return (value >>> amount) | (value << (32 - amount));
- }
- var mathPow = Math.pow;
- var maxWord = mathPow(2, 32);
- var lengthProperty = 'length';
- var i, j; // Used as a counter across the whole file
- var result = '';
- var words = [];
- var asciiBitLength = ascii[lengthProperty] * 8;
- //* caching results is optional - remove/add slash from front of this line to toggle
- // Initial hash value: first 32 bits of the fractional parts of the square roots of the first 8 primes
- // (we actually calculate the first 64, but extra values are just ignored)
- // var hash = (sha256.h = sha256.h || []);
- // // Round constants: first 32 bits of the fractional parts of the cube roots of the first 64 primes
- // var k = (sha256.k = sha256.k || []);
- // var primeCounter = k[lengthProperty];
- var hash = [], k = [];
- var primeCounter = 0;
- var isComposite = {};
- for (var candidate = 2; primeCounter < 64; candidate++) {
- if (!isComposite[candidate]) {
- for (i = 0; i < 313; i += candidate) {
- isComposite[i] = candidate;
- }
- hash[primeCounter] = (mathPow(candidate, 0.5) * maxWord) | 0;
- k[primeCounter++] = (mathPow(candidate, 1 / 3) * maxWord) | 0;
- }
- }
- console.log('hash:', hash, 'iscom', isComposite);
- ascii += '\x80'; // Append '1' bit (plus zero padding)
- while (ascii[lengthProperty] % 64 - 56) ascii += '\x00'; // More zero padding
- for (i = 0; i < ascii[lengthProperty]; i++) {
- j = ascii.charCodeAt(i);
- if (j >> 8) return; // ASCII check: only accept characters in range 0-255
- words[i >> 2] |= j << (((3 - i) % 4) * 8);
- }
- words[words[lengthProperty]] = (asciiBitLength / maxWord) | 0;
- words[words[lengthProperty]] = asciiBitLength;
- // process each chunk
- for (j = 0; j < words[lengthProperty]; ) {
- var w = words.slice(j, (j += 16)); // The message is expanded into 64 words as part of the iteration
- var oldHash = hash;
- // This is now the "working hash", often labelled as variables a...g
- // (we have to truncate as well, otherwise extra entries at the end accumulate
- hash = hash.slice(0, 8);
- for (i = 0; i < 64; i++) {
- var i2 = i + j;
- // Expand the message into 64 words
- // Used below if
- var w15 = w[i - 15],
- w2 = w[i - 2];
- // Iterate
- var a = hash[0],
- e = hash[4];
- var temp1 =
- hash[7] +
- (rightRotate(e, 6) ^ rightRotate(e, 11) ^ rightRotate(e, 25)) + // S1
- ((e & hash[5]) ^ (~e & hash[6])) + // ch
- k[i] +
- // Expand the message schedule if needed
- (w[i] =
- i < 16
- ? w[i]
- : (w[i - 16] +
- (rightRotate(w15, 7) ^ rightRotate(w15, 18) ^ (w15 >>> 3)) + // s0
- w[i - 7] +
- (rightRotate(w2, 17) ^ rightRotate(w2, 19) ^ (w2 >>> 10))) | // s1
- 0);
- // This is only used once, so *could* be moved below, but it only saves 4 bytes and makes things unreadble
- var temp2 =
- (rightRotate(a, 2) ^ rightRotate(a, 13) ^ rightRotate(a, 22)) + // S0
- ((a & hash[1]) ^ (a & hash[2]) ^ (hash[1] & hash[2])); // maj
- hash = [ (temp1 + temp2) | 0 ].concat(hash); // We don't bother trimming off the extra ones, they're harmless as long as we're truncating when we do the slice()
- hash[4] = (hash[4] + temp1) | 0;
- }
- for (i = 0; i < 8; i++) {
- hash[i] = (hash[i] + oldHash[i]) | 0;
- }
- }
- for (i = 0; i < 8; i++) {
- for (j = 3; j + 1; j--) {
- var b = (hash[i] >> (j * 8)) & 255;
- result += (b < 16 ? 0 : '') + b.toString(16);
- }
- }
- console.log('hash:', hash);
- return result;
- }
- const digest = sha256('111');
- console.log(digest);
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