diff options
Diffstat (limited to 'node_modules/hash-base/index.js')
-rw-r--r-- | node_modules/hash-base/index.js | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/node_modules/hash-base/index.js b/node_modules/hash-base/index.js new file mode 100644 index 000000000..9cd6a7005 --- /dev/null +++ b/node_modules/hash-base/index.js @@ -0,0 +1,83 @@ +'use strict' +var Transform = require('stream').Transform +var inherits = require('inherits') + +function HashBase (blockSize) { + Transform.call(this) + + this._block = new Buffer(blockSize) + this._blockSize = blockSize + this._blockOffset = 0 + this._length = [0, 0, 0, 0] + + this._finalized = false +} + +inherits(HashBase, Transform) + +HashBase.prototype._transform = function (chunk, encoding, callback) { + var error = null + try { + if (encoding !== 'buffer') chunk = new Buffer(chunk, encoding) + this.update(chunk) + } catch (err) { + error = err + } + + callback(error) +} + +HashBase.prototype._flush = function (callback) { + var error = null + try { + this.push(this._digest()) + } catch (err) { + error = err + } + + callback(error) +} + +HashBase.prototype.update = function (data, encoding) { + if (!Buffer.isBuffer(data) && typeof data !== 'string') throw new TypeError('Data must be a string or a buffer') + if (this._finalized) throw new Error('Digest already called') + if (!Buffer.isBuffer(data)) data = new Buffer(data, encoding || 'binary') + + // consume data + var block = this._block + var offset = 0 + while (this._blockOffset + data.length - offset >= this._blockSize) { + for (var i = this._blockOffset; i < this._blockSize;) block[i++] = data[offset++] + this._update() + this._blockOffset = 0 + } + while (offset < data.length) block[this._blockOffset++] = data[offset++] + + // update length + for (var j = 0, carry = data.length * 8; carry > 0; ++j) { + this._length[j] += carry + carry = (this._length[j] / 0x0100000000) | 0 + if (carry > 0) this._length[j] -= 0x0100000000 * carry + } + + return this +} + +HashBase.prototype._update = function (data) { + throw new Error('_update is not implemented') +} + +HashBase.prototype.digest = function (encoding) { + if (this._finalized) throw new Error('Digest already called') + this._finalized = true + + var digest = this._digest() + if (encoding !== undefined) digest = digest.toString(encoding) + return digest +} + +HashBase.prototype._digest = function () { + throw new Error('_digest is not implemented') +} + +module.exports = HashBase |