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discovery-key.js
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discovery-key.js
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'use strict'
const isBuffer = require('is-buffer')
const alloc = require('buffer-alloc-unsafe')
const { kDefaultDiscoveryKeySize } = require('./constants')
const {
crypto_generichash,
crypto_generichash_KEYBYTES_MIN,
} = require('sodium-universal')
const defaultDiscoveryKeyMessageKey = alloc(
crypto_generichash_KEYBYTES_MIN
).fill('ara')
/**
* Generate a discovery digest useful for network
* keys. This function calls `crypto_generichash` internally.
* @public
* @param {Buffer|Array<Buffer>} buffer
* @param {?(Number)} [size = 32]
* @return {Buffer}
* @throws TypeError
*/
function discoveryKey(buffer, size, key) {
if (null == size || 'number' != typeof size) {
size = kDefaultDiscoveryKeySize
} else if (size <= 0) {
throw new TypeError("crypto.discoveryKey: Expecting size to be greater than 0.")
}
if (null == key) {
key = defaultDiscoveryKeyMessageKey
} else if (false == isBuffer(key)) {
throw new TypeError("crypto.discoveryKey: Expecting key to be a buffer")
}
if (false == isBuffer(buffer)) {
throw new TypeError("crypto.discoveryKey: Expecting buffer.")
}
const digest = alloc(size)
crypto_generichash(digest, buffer, key)
return digest
}
module.exports = {
discoveryKey
}