This commit is contained in:
Suzanne Soy 2021-07-25 19:58:54 +01:00
parent 5313ac877b
commit a2d7087b5b
2 changed files with 228 additions and 429 deletions

View File

@ -125,20 +125,39 @@ function ipfsBlockWithLinks(object) {
return result;
}
function ipfsBlockWithFile(fileHex) {
var size = fileHex.length / 2;
function ipfsBlockWithFile(object) {
var fileHex = object.File;
var result = '';
var totalSize = (fileHex || '').length / 2;
for (var i = 0; i < object.Links.length; i++) {
totalSize += object.Links[i].Size;
}
var encodedData = '';
encodedData += '08' + '02' + '12';
encodedData += integerToHexVarint(size);
encodedData += fileHex;
encodedData += '18' + '85' + '90' + '07';
encodedDataSize = encodedData.length / 2;
// '08' '02'
encodedData += '08' + '02';
// field 12 seems to be optional (for DAG nodes with links (groups of blocks and directories))
if (fileHex !== false) {
encodedData += '12';
encodedData += integerToHexVarint(totalSize);
encodedData += fileHex;
}
// '18' [8f b0 15 = total size of contents of the file = 35022300]
encodedData += '18' + integerToHexVarint(totalSize);
for (var j = 0; j < object.Links.length; j++) {
// 20 [80 80 10 = size of contents of block 1 = 262144]
// 20 [8f b0 05 = size of contents of block 2 = 88079]
encodedData += '20';
encodedData += integerToHexVarint(object.Links[j].Size);
}
var result = '';
// common bit
result += '0a'
encodedDataSize = encodedData.length / 2;
result += integerToHexVarint(encodedDataSize);
result += encodedData;
return result;
}
@ -149,6 +168,9 @@ document.write('<p>'+hexVarintToInteger('01')+'</p>');
document.write('<p>'+hexVarintToInteger('ac02')+'</p>');
document.write('<p>'+hexVarintToInteger('9db005')+'</p>');
document.write('<p>'+hexVarintToInteger('8e8010')+'</p>');
document.write('<p>'+hexVarintToInteger('8fb015')+'</p>');
document.write('<p>'+hexVarintToInteger('8fb005')+'</p>');
document.write('<p>'+hexVarintToInteger('808010')+'</p>');
document.write('<p>'+integerToHexVarint(262158)+'</p>');
document.write('<p>'+integerToHexVarint(88093)+'</p>');
@ -175,11 +197,13 @@ document.write('<p>'+ipfsBlockWithLinks({
"Size": 88093
}
],
"Data": "0802188fb01520808010208fb005"
"Data": "080218" + /* total size (sum of sizes) */ "8fb015" + "20808010208fb005"
})+'</p>');
// .ipfs/blocks/OD/CIQEZBBJX4QYOWN5PECDC2PGQXAXANXYF56NCX5JIPDWHR6HDJBAODY.data
document.write('<p>'+ipfsBlockWithFile(
document.write('<p>'+ipfsBlockWithFile({
"Links": [],
"File":
"3c21444f43545950452068746d6c3e0a3c68746d6c3e0a3c686561643e0a" +
"3c6d65746120687474702d65717569763d22436f6e74656e742d54797065" +
"2220636f6e74656e743d22746578742f68746d6c3b20636861727365743d" +
@ -4072,6 +4096,7 @@ document.write('<p>'+ipfsBlockWithFile(
"28736372697074293b0a20207d2928293b0a20205f5f5f6769745f747574" +
"6f7269616c5f6f6e6c6f616428290a3c2f7363726970743e0a3c2f626f64" +
"793e0a3c2f68746d6c3e0a"
}
)+'</p>');
document.write('<p>'+ipfsBlockWithLinks(

612
sha256.js
View File

@ -1,428 +1,202 @@
// https://github.com/dchest/fast-sha256-js Unlicense (Public Domain)
(function (root, factory) {
// Hack to make all exports of this module sha256 function object properties.
var exports = {};
factory(exports);
var sha256 = exports["default"];
for (var k in exports) {
sha256[k] = exports[k];
}
if (typeof module === 'object' && typeof module.exports === 'object') {
module.exports = sha256;
} else if (typeof define === 'function' && define.amd) {
define(function() { return sha256; });
} else {
root.sha256 = sha256;
}
})(this, function(exports) {
"use strict";
exports.__esModule = true;
// SHA-256 (+ HMAC and PBKDF2) for JavaScript.
//
// Written in 2014-2016 by Dmitry Chestnykh.
// Public domain, no warranty.
//
// Functions (accept and return Uint8Arrays):
//
// sha256(message) -> hash
// sha256.hmac(key, message) -> mac
// sha256.pbkdf2(password, salt, rounds, dkLen) -> dk
//
// Classes:
//
// new sha256.Hash()
// new sha256.HMAC(key)
//
exports.digestLength = 32;
exports.blockSize = 64;
// SHA-256 constants
var K = new Uint32Array([
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
]);
function hashBlocks(w, v, p, pos, len) {
var a, b, c, d, e, f, g, h, u, i, j, t1, t2;
while (len >= 64) {
a = v[0];
b = v[1];
c = v[2];
d = v[3];
e = v[4];
f = v[5];
g = v[6];
h = v[7];
for (i = 0; i < 16; i++) {
j = pos + i * 4;
w[i] = (((p[j] & 0xff) << 24) | ((p[j + 1] & 0xff) << 16) |
((p[j + 2] & 0xff) << 8) | (p[j + 3] & 0xff));
}
for (i = 16; i < 64; i++) {
u = w[i - 2];
t1 = (u >>> 17 | u << (32 - 17)) ^ (u >>> 19 | u << (32 - 19)) ^ (u >>> 10);
u = w[i - 15];
t2 = (u >>> 7 | u << (32 - 7)) ^ (u >>> 18 | u << (32 - 18)) ^ (u >>> 3);
w[i] = (t1 + w[i - 7] | 0) + (t2 + w[i - 16] | 0);
}
for (i = 0; i < 64; i++) {
t1 = (((((e >>> 6 | e << (32 - 6)) ^ (e >>> 11 | e << (32 - 11)) ^
(e >>> 25 | e << (32 - 25))) + ((e & f) ^ (~e & g))) | 0) +
((h + ((K[i] + w[i]) | 0)) | 0)) | 0;
t2 = (((a >>> 2 | a << (32 - 2)) ^ (a >>> 13 | a << (32 - 13)) ^
(a >>> 22 | a << (32 - 22))) + ((a & b) ^ (a & c) ^ (b & c))) | 0;
h = g;
g = f;
f = e;
e = (d + t1) | 0;
d = c;
c = b;
b = a;
a = (t1 + t2) | 0;
}
v[0] += a;
v[1] += b;
v[2] += c;
v[3] += d;
v[4] += e;
v[5] += f;
v[6] += g;
v[7] += h;
pos += 64;
len -= 64;
}
return pos;
}
// Hash implements SHA256 hash algorithm.
var Hash = /** @class */ (function () {
function Hash() {
this.digestLength = exports.digestLength;
this.blockSize = exports.blockSize;
// Note: Int32Array is used instead of Uint32Array for performance reasons.
this.state = new Int32Array(8); // hash state
this.temp = new Int32Array(64); // temporary state
this.buffer = new Uint8Array(128); // buffer for data to hash
this.bufferLength = 0; // number of bytes in buffer
this.bytesHashed = 0; // number of total bytes hashed
this.finished = false; // indicates whether the hash was finalized
this.reset();
}
// Resets hash state making it possible
// to re-use this instance to hash other data.
Hash.prototype.reset = function () {
this.state[0] = 0x6a09e667;
this.state[1] = 0xbb67ae85;
this.state[2] = 0x3c6ef372;
this.state[3] = 0xa54ff53a;
this.state[4] = 0x510e527f;
this.state[5] = 0x9b05688c;
this.state[6] = 0x1f83d9ab;
this.state[7] = 0x5be0cd19;
this.bufferLength = 0;
this.bytesHashed = 0;
this.finished = false;
return this;
};
// Cleans internal buffers and re-initializes hash state.
Hash.prototype.clean = function () {
for (var i = 0; i < this.buffer.length; i++) {
this.buffer[i] = 0;
}
for (var i = 0; i < this.temp.length; i++) {
this.temp[i] = 0;
}
this.reset();
};
// Updates hash state with the given data.
var sha256 = (function() {
// SHA-256 for JavaScript.
//
// Optionally, length of the data can be specified to hash
// fewer bytes than data.length.
// Written in 2014-2016 by Dmitry Chestnykh.
// Modified from https://github.com/dchest/fast-sha256-js/blob/2cee3ccb977bd4b10e8eeb7fa95036b1d08f2529/sha256.js in 2021 by Suzanne Soy
// Unlicense
// Public domain, no warranty.
//
// Throws error when trying to update already finalized hash:
// instance must be reset to use it again.
Hash.prototype.update = function (data, dataLength) {
if (dataLength === void 0) { dataLength = data.length; }
if (this.finished) {
throw new Error("SHA256: can't update because hash was finished.");
// Function sha256(message) -> hash accepts and returns an Uint8Array
var digestLength = 32;
var blockSize = 64;
// SHA-256 constants
var K = new Uint32Array([
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 hashBlocks = function(w, v, p, pos, len) {
var a, b, c, d, e, f, g, h, u, i, j, t1, t2;
while (len >= 64) {
a = v[0];
b = v[1];
c = v[2];
d = v[3];
e = v[4];
f = v[5];
g = v[6];
h = v[7];
for (i = 0; i < 16; i++) {
j = pos + i * 4;
w[i] = (((p[j] & 0xff) << 24) | ((p[j + 1] & 0xff) << 16) |
((p[j + 2] & 0xff) << 8) | (p[j + 3] & 0xff));
}
for (i = 16; i < 64; i++) {
u = w[i - 2];
t1 = (u >>> 17 | u << (32 - 17)) ^ (u >>> 19 | u << (32 - 19)) ^ (u >>> 10);
u = w[i - 15];
t2 = (u >>> 7 | u << (32 - 7)) ^ (u >>> 18 | u << (32 - 18)) ^ (u >>> 3);
w[i] = (t1 + w[i - 7] | 0) + (t2 + w[i - 16] | 0);
}
for (i = 0; i < 64; i++) {
t1 = (((((e >>> 6 | e << (32 - 6)) ^ (e >>> 11 | e << (32 - 11)) ^
(e >>> 25 | e << (32 - 25))) + ((e & f) ^ (~e & g))) | 0) +
((h + ((K[i] + w[i]) | 0)) | 0)) | 0;
t2 = (((a >>> 2 | a << (32 - 2)) ^ (a >>> 13 | a << (32 - 13)) ^
(a >>> 22 | a << (32 - 22))) + ((a & b) ^ (a & c) ^ (b & c))) | 0;
h = g;
g = f;
f = e;
e = (d + t1) | 0;
d = c;
c = b;
b = a;
a = (t1 + t2) | 0;
}
v[0] += a;
v[1] += b;
v[2] += c;
v[3] += d;
v[4] += e;
v[5] += f;
v[6] += g;
v[7] += h;
pos += 64;
len -= 64;
}
var dataPos = 0;
this.bytesHashed += dataLength;
if (this.bufferLength > 0) {
while (this.bufferLength < 64 && dataLength > 0) {
return pos;
}
// Hash implements SHA256 hash algorithm.
var Hash = /** @class */ (function () {
function Hash() {
this.digestLength = digestLength;
this.blockSize = blockSize;
// Note: Int32Array is used instead of Uint32Array for performance reasons.
this.state = new Int32Array(8); // hash state
this.temp = new Int32Array(64); // temporary state
this.buffer = new Uint8Array(128); // buffer for data to hash
this.bufferLength = 0; // number of bytes in buffer
this.bytesHashed = 0; // number of total bytes hashed
this.finished = false; // indicates whether the hash was finalized
this.reset();
}
// Resets hash state making it possible
// to re-use this instance to hash other data.
Hash.prototype.reset = function () {
this.state[0] = 0x6a09e667;
this.state[1] = 0xbb67ae85;
this.state[2] = 0x3c6ef372;
this.state[3] = 0xa54ff53a;
this.state[4] = 0x510e527f;
this.state[5] = 0x9b05688c;
this.state[6] = 0x1f83d9ab;
this.state[7] = 0x5be0cd19;
this.bufferLength = 0;
this.bytesHashed = 0;
this.finished = false;
return this;
};
// Cleans internal buffers and re-initializes hash state.
Hash.prototype.clean = function () {
for (var i = 0; i < this.buffer.length; i++) {
this.buffer[i] = 0;
}
for (var i = 0; i < this.temp.length; i++) {
this.temp[i] = 0;
}
this.reset();
};
// Updates hash state with the given data.
//
// Optionally, length of the data can be specified to hash
// fewer bytes than data.length.
//
// Throws error when trying to update already finalized hash:
// instance must be reset to use it again.
Hash.prototype.update = function (data, dataLength) {
if (dataLength === void 0) { dataLength = data.length; }
if (this.finished) {
throw new Error("SHA256: can't update because hash was finished.");
}
var dataPos = 0;
this.bytesHashed += dataLength;
if (this.bufferLength > 0) {
while (this.bufferLength < 64 && dataLength > 0) {
this.buffer[this.bufferLength++] = data[dataPos++];
dataLength--;
}
if (this.bufferLength === 64) {
hashBlocks(this.temp, this.state, this.buffer, 0, 64);
this.bufferLength = 0;
}
}
if (dataLength >= 64) {
dataPos = hashBlocks(this.temp, this.state, data, dataPos, dataLength);
dataLength %= 64;
}
while (dataLength > 0) {
this.buffer[this.bufferLength++] = data[dataPos++];
dataLength--;
}
if (this.bufferLength === 64) {
hashBlocks(this.temp, this.state, this.buffer, 0, 64);
this.bufferLength = 0;
return this;
};
// Finalizes hash state and puts hash into out.
//
// If hash was already finalized, puts the same value.
Hash.prototype.finish = function (out) {
if (!this.finished) {
var bytesHashed = this.bytesHashed;
var left = this.bufferLength;
var bitLenHi = (bytesHashed / 0x20000000) | 0;
var bitLenLo = bytesHashed << 3;
var padLength = (bytesHashed % 64 < 56) ? 64 : 128;
this.buffer[left] = 0x80;
for (var i = left + 1; i < padLength - 8; i++) {
this.buffer[i] = 0;
}
this.buffer[padLength - 8] = (bitLenHi >>> 24) & 0xff;
this.buffer[padLength - 7] = (bitLenHi >>> 16) & 0xff;
this.buffer[padLength - 6] = (bitLenHi >>> 8) & 0xff;
this.buffer[padLength - 5] = (bitLenHi >>> 0) & 0xff;
this.buffer[padLength - 4] = (bitLenLo >>> 24) & 0xff;
this.buffer[padLength - 3] = (bitLenLo >>> 16) & 0xff;
this.buffer[padLength - 2] = (bitLenLo >>> 8) & 0xff;
this.buffer[padLength - 1] = (bitLenLo >>> 0) & 0xff;
hashBlocks(this.temp, this.state, this.buffer, 0, padLength);
this.finished = true;
}
}
if (dataLength >= 64) {
dataPos = hashBlocks(this.temp, this.state, data, dataPos, dataLength);
dataLength %= 64;
}
while (dataLength > 0) {
this.buffer[this.bufferLength++] = data[dataPos++];
dataLength--;
}
return this;
};
// Finalizes hash state and puts hash into out.
//
// If hash was already finalized, puts the same value.
Hash.prototype.finish = function (out) {
if (!this.finished) {
var bytesHashed = this.bytesHashed;
var left = this.bufferLength;
var bitLenHi = (bytesHashed / 0x20000000) | 0;
var bitLenLo = bytesHashed << 3;
var padLength = (bytesHashed % 64 < 56) ? 64 : 128;
this.buffer[left] = 0x80;
for (var i = left + 1; i < padLength - 8; i++) {
this.buffer[i] = 0;
for (var i = 0; i < 8; i++) {
out[i * 4 + 0] = (this.state[i] >>> 24) & 0xff;
out[i * 4 + 1] = (this.state[i] >>> 16) & 0xff;
out[i * 4 + 2] = (this.state[i] >>> 8) & 0xff;
out[i * 4 + 3] = (this.state[i] >>> 0) & 0xff;
}
this.buffer[padLength - 8] = (bitLenHi >>> 24) & 0xff;
this.buffer[padLength - 7] = (bitLenHi >>> 16) & 0xff;
this.buffer[padLength - 6] = (bitLenHi >>> 8) & 0xff;
this.buffer[padLength - 5] = (bitLenHi >>> 0) & 0xff;
this.buffer[padLength - 4] = (bitLenLo >>> 24) & 0xff;
this.buffer[padLength - 3] = (bitLenLo >>> 16) & 0xff;
this.buffer[padLength - 2] = (bitLenLo >>> 8) & 0xff;
this.buffer[padLength - 1] = (bitLenLo >>> 0) & 0xff;
hashBlocks(this.temp, this.state, this.buffer, 0, padLength);
this.finished = true;
}
for (var i = 0; i < 8; i++) {
out[i * 4 + 0] = (this.state[i] >>> 24) & 0xff;
out[i * 4 + 1] = (this.state[i] >>> 16) & 0xff;
out[i * 4 + 2] = (this.state[i] >>> 8) & 0xff;
out[i * 4 + 3] = (this.state[i] >>> 0) & 0xff;
}
return this;
};
// Returns the final hash digest.
Hash.prototype.digest = function () {
var out = new Uint8Array(this.digestLength);
this.finish(out);
return out;
};
// Internal function for use in HMAC for optimization.
Hash.prototype._saveState = function (out) {
for (var i = 0; i < this.state.length; i++) {
out[i] = this.state[i];
}
};
// Internal function for use in HMAC for optimization.
Hash.prototype._restoreState = function (from, bytesHashed) {
for (var i = 0; i < this.state.length; i++) {
this.state[i] = from[i];
}
this.bytesHashed = bytesHashed;
this.finished = false;
this.bufferLength = 0;
};
return Hash;
}());
exports.Hash = Hash;
// HMAC implements HMAC-SHA256 message authentication algorithm.
var HMAC = /** @class */ (function () {
function HMAC(key) {
this.inner = new Hash();
this.outer = new Hash();
this.blockSize = this.inner.blockSize;
this.digestLength = this.inner.digestLength;
var pad = new Uint8Array(this.blockSize);
if (key.length > this.blockSize) {
(new Hash()).update(key).finish(pad).clean();
}
else {
for (var i = 0; i < key.length; i++) {
pad[i] = key[i];
}
}
for (var i = 0; i < pad.length; i++) {
pad[i] ^= 0x36;
}
this.inner.update(pad);
for (var i = 0; i < pad.length; i++) {
pad[i] ^= 0x36 ^ 0x5c;
}
this.outer.update(pad);
this.istate = new Uint32Array(8);
this.ostate = new Uint32Array(8);
this.inner._saveState(this.istate);
this.outer._saveState(this.ostate);
for (var i = 0; i < pad.length; i++) {
pad[i] = 0;
}
return this;
};
// Returns the final hash digest.
Hash.prototype.digest = function () {
var out = new Uint8Array(this.digestLength);
this.finish(out);
return out;
};
return Hash;
}());
// Returns SHA256 hash of data.
var hash = function(data) {
var h = (new Hash()).update(data);
var digest = h.digest();
h.clean();
return digest;
}
// Returns HMAC state to the state initialized with key
// to make it possible to run HMAC over the other data with the same
// key without creating a new instance.
HMAC.prototype.reset = function () {
this.inner._restoreState(this.istate, this.inner.blockSize);
this.outer._restoreState(this.ostate, this.outer.blockSize);
return this;
};
// Cleans HMAC state.
HMAC.prototype.clean = function () {
for (var i = 0; i < this.istate.length; i++) {
this.ostate[i] = this.istate[i] = 0;
}
this.inner.clean();
this.outer.clean();
};
// Updates state with provided data.
HMAC.prototype.update = function (data) {
this.inner.update(data);
return this;
};
// Finalizes HMAC and puts the result in out.
HMAC.prototype.finish = function (out) {
if (this.outer.finished) {
this.outer.finish(out);
}
else {
this.inner.finish(out);
this.outer.update(out, this.digestLength).finish(out);
}
return this;
};
// Returns message authentication code.
HMAC.prototype.digest = function () {
var out = new Uint8Array(this.digestLength);
this.finish(out);
return out;
};
return HMAC;
}());
exports.HMAC = HMAC;
// Returns SHA256 hash of data.
function hash(data) {
var h = (new Hash()).update(data);
var digest = h.digest();
h.clean();
return digest;
}
exports.hash = hash;
// Function hash is both available as module.hash and as default export.
exports["default"] = hash;
// Returns HMAC-SHA256 of data under the key.
function hmac(key, data) {
var h = (new HMAC(key)).update(data);
var digest = h.digest();
h.clean();
return digest;
}
exports.hmac = hmac;
// Fills hkdf buffer like this:
// T(1) = HMAC-Hash(PRK, T(0) | info | 0x01)
function fillBuffer(buffer, hmac, info, counter) {
// Counter is a byte value: check if it overflowed.
var num = counter[0];
if (num === 0) {
throw new Error("hkdf: cannot expand more");
}
// Prepare HMAC instance for new data with old key.
hmac.reset();
// Hash in previous output if it was generated
// (i.e. counter is greater than 1).
if (num > 1) {
hmac.update(buffer);
}
// Hash in info if it exists.
if (info) {
hmac.update(info);
}
// Hash in the counter.
hmac.update(counter);
// Output result to buffer and clean HMAC instance.
hmac.finish(buffer);
// Increment counter inside typed array, this works properly.
counter[0]++;
}
var hkdfSalt = new Uint8Array(exports.digestLength); // Filled with zeroes.
function hkdf(key, salt, info, length) {
if (salt === void 0) { salt = hkdfSalt; }
if (length === void 0) { length = 32; }
var counter = new Uint8Array([1]);
// HKDF-Extract uses salt as HMAC key, and key as data.
var okm = hmac(salt, key);
// Initialize HMAC for expanding with extracted key.
// Ensure no collisions with `hmac` function.
var hmac_ = new HMAC(okm);
// Allocate buffer.
var buffer = new Uint8Array(hmac_.digestLength);
var bufpos = buffer.length;
var out = new Uint8Array(length);
for (var i = 0; i < length; i++) {
if (bufpos === buffer.length) {
fillBuffer(buffer, hmac_, info, counter);
bufpos = 0;
}
out[i] = buffer[bufpos++];
}
hmac_.clean();
buffer.fill(0);
counter.fill(0);
return out;
}
exports.hkdf = hkdf;
// Derives a key from password and salt using PBKDF2-HMAC-SHA256
// with the given number of iterations.
//
// The number of bytes returned is equal to dkLen.
//
// (For better security, avoid dkLen greater than hash length - 32 bytes).
function pbkdf2(password, salt, iterations, dkLen) {
var prf = new HMAC(password);
var len = prf.digestLength;
var ctr = new Uint8Array(4);
var t = new Uint8Array(len);
var u = new Uint8Array(len);
var dk = new Uint8Array(dkLen);
for (var i = 0; i * len < dkLen; i++) {
var c = i + 1;
ctr[0] = (c >>> 24) & 0xff;
ctr[1] = (c >>> 16) & 0xff;
ctr[2] = (c >>> 8) & 0xff;
ctr[3] = (c >>> 0) & 0xff;
prf.reset();
prf.update(salt);
prf.update(ctr);
prf.finish(u);
for (var j = 0; j < len; j++) {
t[j] = u[j];
}
for (var j = 2; j <= iterations; j++) {
prf.reset();
prf.update(u).finish(u);
for (var k = 0; k < len; k++) {
t[k] ^= u[k];
}
}
for (var j = 0; j < len && i * len + j < dkLen; j++) {
dk[i * len + j] = t[j];
}
}
for (var i = 0; i < len; i++) {
t[i] = u[i] = 0;
}
for (var i = 0; i < 4; i++) {
ctr[i] = 0;
}
prf.clean();
return dk;
}
exports.pbkdf2 = pbkdf2;
});
return hash;
})();