doipjs/src/keys.js

/*
Copyright 2020 Yarmo Mackenbach

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
const bent = require('bent')
const req = bent('GET')
const validUrl = require('valid-url')
const openpgp = require('openpgp')
const mergeOptions = require('merge-options')

const fetchHKP = async (identifier, keyserverBaseUrl) => {
  try {
    keyserverBaseUrl = keyserverBaseUrl
      ? keyserverBaseUrl
      : 'https://keys.openpgp.org/'

    const hkp = new openpgp.HKP(keyserverBaseUrl)
    const lookupOpts = {
      query: identifier,
    }
    let publicKey = await hkp.lookup(lookupOpts)
    publicKey = (await openpgp.key.readArmored(publicKey)).keys[0]

    return publicKey
  } catch (e) {
    console.error(e)
    return null
  }
}

const fetchWKD = async (identifier) => {
  try {
    const wkd = new openpgp.WKD()
    const lookupOpts = {
      email: identifier,
    }
    const publicKey = (await wkd.lookup(lookupOpts)).keys[0]

    return publicKey
  } catch (e) {
    console.error(e)
    return null
  }
}

const fetchKeybase = async (username, fingerprint) => {
  try {
    const keyLink = `https://keybase.io/${username}/pgp_keys.asc?fingerprint=${fingerprint}`
    try {
      const rawKeyContent = await req(opts.keyLink)
        .then(function (response) {
          if (response.status === 200) {
            return response
          }
        })
        .then((response) => response.text())
    } catch (e) {
      return null
    }
    const publicKey = (await openpgp.key.readArmored(rawKeyContent)).keys[0]

    return publicKey
  } catch (e) {
    console.error(e)
    return null
  }
}

const fetchPlaintext = async (rawKeyContent) => {
  try {
    const publicKey = (await openpgp.key.readArmored(rawKeyContent)).keys[0]

    return publicKey
  } catch (e) {
    console.error(e)
    return null
  }
}

const fetchSignature = async (rawSignatureContent, keyserverBaseUrl) => {
  try {
    let sig = await openpgp.signature.readArmored(rawSignatureContent)
    if ('compressed' in sig.packets[0]) {
      sig = sig.packets[0]
      let sigContent = await openpgp.stream.readToEnd(
        await sig.packets[1].getText()
      )
    }
    const sigUserId = sig.packets[0].signersUserId
    const sigKeyId = await sig.packets[0].issuerKeyId.toHex()

    return fetchHKP(sigUserId ? sigUserId : sigKeyId, keyserverBaseUrl)
  } catch (e) {
    console.error(e)
    return null
  }
}

const fetchURI = async (uri) => {
  try {
    if (!validUrl.isUri(uri)) {
      throw new Error('Invalid URI')
    }

    const re = /([a-zA-Z0-9]*):([a-zA-Z0-9@._=+\-]*)(\:[a-zA-Z0-9@._=+\-]*)?/
    const match = uri.match(re)

    if (!match[1]) {
      throw new Error('Invalid URI')
    }

    switch (match[1]) {
      case 'hkp':
        return fetchHKP(match[2], match.length >= 4 ? match[3] : null)
        break
      case 'wkd':
        return fetchWKD(match[2])
        break
      case 'kb':
        return fetchKeybase(match[2], match.length >= 4 ? match[3] : null)
        break
      default:
        throw new Error('Invalid URI protocol')
        break
    }
  } catch (e) {
    console.error(e)
    return null
  }
}

const process = async (publicKey) => {
  try {
    const fingerprint = await publicKey.primaryKey.getFingerprint()
    const user = await publicKey.getPrimaryUser()

    return {
      fingerprint: fingerprint,
      user: user,
    }
  } catch (e) {
    console.error(e)
    return null
  }
}

const getClaims = async (publicKey) => {
  try {
    const keyData = await process(publicKey)
    let notations = keyData.user.selfCertification.rawNotations

    notations = notations.map(({ name, value, humanReadable }) => {
      if (humanReadable && name === 'proof@metacode.biz') {
        return openpgp.util.decode_utf8(value)
      }
    })

    return notations
  } catch (e) {
    console.error(e)
    return null
  }
}

const getFingerprint = async (publicKey) => {
  try {
    const keyData = await process(publicKey)

    return keyData.fingerprint
  } catch (e) {
    console.error(e)
    return null
  }
}

exports.fetch = {
  uri: fetchURI,
  hkp: fetchHKP,
  wkd: fetchWKD,
  keybase: fetchKeybase,
  plaintext: fetchPlaintext,
  signature: fetchSignature,
}
exports.process = process
exports.getClaims = getClaims
exports.getFingerprint = getFingerprint