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- /**
- * A JavaScript implementation of the Secure Hash Algorithm, SHA-256, as defined
- * in FIPS 180-2
- * Version 2.2-beta Copyright Angel Marin, Paul Johnston 2000 - 2009.
- * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
- *
- */
-
- var helpers = require('./helpers');
-
- var safe_add = function (x, y) {
- var lsw = (x & 0xffff) + (y & 0xffff);
- var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
- return (msw << 16) | (lsw & 0xffff);
- };
-
- var S = function (X, n) {
- return (X >>> n) | (X << (32 - n));
- };
-
- var R = function (X, n) {
- return X >>> n;
- };
-
- var Ch = function (x, y, z) {
- return (x & y) ^ (~x & z);
- };
-
- var Maj = function (x, y, z) {
- return (x & y) ^ (x & z) ^ (y & z);
- };
-
- var Sigma0256 = function (x) {
- return S(x, 2) ^ S(x, 13) ^ S(x, 22);
- };
-
- var Sigma1256 = function (x) {
- return S(x, 6) ^ S(x, 11) ^ S(x, 25);
- };
-
- var Gamma0256 = function (x) {
- return S(x, 7) ^ S(x, 18) ^ R(x, 3);
- };
-
- var Gamma1256 = function (x) {
- return S(x, 17) ^ S(x, 19) ^ R(x, 10);
- };
-
- var core_sha256 = function (m, l) {
- var K = new Array(
- 0x428a2f98,
- 0x71374491,
- 0xb5c0fbcf,
- 0xe9b5dba5,
- 0x3956c25b,
- 0x59f111f1,
- 0x923f82a4,
- 0xab1c5ed5,
- 0xd807aa98,
- 0x12835b01,
- 0x243185be,
- 0x550c7dc3,
- 0x72be5d74,
- 0x80deb1fe,
- 0x9bdc06a7,
- 0xc19bf174,
- 0xe49b69c1,
- 0xefbe4786,
- 0xfc19dc6,
- 0x240ca1cc,
- 0x2de92c6f,
- 0x4a7484aa,
- 0x5cb0a9dc,
- 0x76f988da,
- 0x983e5152,
- 0xa831c66d,
- 0xb00327c8,
- 0xbf597fc7,
- 0xc6e00bf3,
- 0xd5a79147,
- 0x6ca6351,
- 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 HASH = new Array(0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19);
- var W = new Array(64);
- var a, b, c, d, e, f, g, h, i, j;
- var T1, T2;
- /* append padding */
- m[l >> 5] |= 0x80 << (24 - (l % 32));
- m[(((l + 64) >> 9) << 4) + 15] = l;
- for (var i = 0; i < m.length; i += 16) {
- a = HASH[0];
- b = HASH[1];
- c = HASH[2];
- d = HASH[3];
- e = HASH[4];
- f = HASH[5];
- g = HASH[6];
- h = HASH[7];
- for (var j = 0; j < 64; j++) {
- if (j < 16) {
- W[j] = m[j + i];
- } else {
- W[j] = safe_add(safe_add(safe_add(Gamma1256(W[j - 2]), W[j - 7]), Gamma0256(W[j - 15])), W[j - 16]);
- }
- T1 = safe_add(safe_add(safe_add(safe_add(h, Sigma1256(e)), Ch(e, f, g)), K[j]), W[j]);
- T2 = safe_add(Sigma0256(a), Maj(a, b, c));
- h = g;
- g = f;
- f = e;
- e = safe_add(d, T1);
- d = c;
- c = b;
- b = a;
- a = safe_add(T1, T2);
- }
- HASH[0] = safe_add(a, HASH[0]);
- HASH[1] = safe_add(b, HASH[1]);
- HASH[2] = safe_add(c, HASH[2]);
- HASH[3] = safe_add(d, HASH[3]);
- HASH[4] = safe_add(e, HASH[4]);
- HASH[5] = safe_add(f, HASH[5]);
- HASH[6] = safe_add(g, HASH[6]);
- HASH[7] = safe_add(h, HASH[7]);
- }
- return HASH;
- };
-
- module.exports = function sha256(buf) {
- return helpers.hash(buf, core_sha256, 32, true);
- };
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