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87 lines
2.5 KiB
87 lines
2.5 KiB
2 years ago
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import stream from "stream";
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import { inherits as inherits$0 } from "util";
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'use strict';
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var Transform = stream.Transform;
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var inherits = { inherits: inherits$0 }.inherits;
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function throwIfNotStringOrBuffer(val, prefix) {
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if (!Buffer.isBuffer(val) && typeof val !== 'string') {
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throw new TypeError(prefix + ' must be a string or a buffer');
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}
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}
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function HashBase(blockSize) {
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Transform.call(this);
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this._block = Buffer.allocUnsafe(blockSize);
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this._blockSize = blockSize;
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this._blockOffset = 0;
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this._length = [0, 0, 0, 0];
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this._finalized = false;
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}
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inherits(HashBase, Transform);
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HashBase.prototype._transform = function (chunk, encoding, callback) {
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var error = null;
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try {
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this.update(chunk, encoding);
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}
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catch (err) {
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error = err;
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}
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callback(error);
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};
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HashBase.prototype._flush = function (callback) {
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var error = null;
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try {
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this.push(this.digest());
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}
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catch (err) {
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error = err;
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}
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callback(error);
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};
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HashBase.prototype.update = function (data, encoding) {
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throwIfNotStringOrBuffer(data, 'Data');
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if (this._finalized)
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throw new Error('Digest already called');
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if (!Buffer.isBuffer(data))
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data = Buffer.from(data, encoding);
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// consume data
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var block = this._block;
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var offset = 0;
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while (this._blockOffset + data.length - offset >= this._blockSize) {
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for (var i = this._blockOffset; i < this._blockSize;)
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block[i++] = data[offset++];
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this._update();
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this._blockOffset = 0;
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}
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while (offset < data.length)
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block[this._blockOffset++] = data[offset++];
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// update length
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for (var j = 0, carry = data.length * 8; carry > 0; ++j) {
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this._length[j] += carry;
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carry = (this._length[j] / 0x0100000000) | 0;
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if (carry > 0)
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this._length[j] -= 0x0100000000 * carry;
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}
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return this;
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};
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HashBase.prototype._update = function () {
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throw new Error('_update is not implemented');
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};
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HashBase.prototype.digest = function (encoding) {
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if (this._finalized)
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throw new Error('Digest already called');
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this._finalized = true;
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var digest = this._digest();
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if (encoding !== undefined)
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digest = digest.toString(encoding);
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// reset state
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this._block.fill(0);
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this._blockOffset = 0;
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for (var i = 0; i < 4; ++i)
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this._length[i] = 0;
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return digest;
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};
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HashBase.prototype._digest = function () {
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throw new Error('_digest is not implemented');
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};
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export default HashBase;
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