keyserver/src/service/pgp.js

275 lines
10 KiB
JavaScript

/**
* Mailvelope - secure email with OpenPGP encryption for Webmail
* Copyright (C) 2016 Mailvelope GmbH
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License version 3
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
'use strict';
const log = require('winston');
const util = require('./util');
const openpgp = require('openpgp');
const KEY_BEGIN = '-----BEGIN PGP PUBLIC KEY BLOCK-----';
const KEY_END = '-----END PGP PUBLIC KEY BLOCK-----';
/**
* A simple wrapper around OpenPGP.js
*/
class PGP {
constructor() {
openpgp.config.show_version = false;
openpgp.config.show_comment = false;
}
/**
* Parse an ascii armored pgp key block and get its parameters.
* @param {String} publicKeyArmored ascii armored pgp key block
* @return {Object} public key document to persist
*/
async parseKey(publicKeyArmored) {
publicKeyArmored = this.trimKey(publicKeyArmored);
const r = await openpgp.key.readArmored(publicKeyArmored);
if (r.err) {
const error = r.err[0];
log.error('pgp', 'Failed to parse PGP key:\n%s', publicKeyArmored, error);
util.throw(500, 'Failed to parse PGP key');
} else if (!r.keys || r.keys.length !== 1 || !r.keys[0].primaryKey) {
util.throw(400, 'Invalid PGP key: only one key can be uploaded');
}
// verify primary key
const key = r.keys[0];
const primaryKey = key.primaryKey;
const now = new Date();
const verifyDate = primaryKey.created > now ? primaryKey.created : now;
if (await key.verifyPrimaryKey(verifyDate) !== openpgp.enums.keyStatus.valid) {
util.throw(400, 'Invalid PGP key: primary key verification failed');
}
// accept version 4 keys only
const keyId = primaryKey.getKeyId().toHex();
const fingerprint = primaryKey.getFingerprint();
if (!util.isKeyId(keyId) || !util.isFingerPrint(fingerprint)) {
util.throw(400, 'Invalid PGP key: only v4 keys are accepted');
}
// check for at least one valid user id
const {userIds, status} = await this.parseUserIds(key.users, primaryKey, verifyDate);
if (!userIds.length) {
if (status == 1) {
util.throw(400, 'Invalid PGP key: no user ID comes from a valid organisation');
}
else {
util.throw(400, 'Invalid PGP key: invalid user IDs');
}
}
// get algorithm details from primary key
const keyInfo = key.primaryKey.getAlgorithmInfo();
// public key document that is stored in the database
return {
keyId,
fingerprint,
userIds,
created: primaryKey.created,
uploaded: new Date(),
algorithm: keyInfo.algorithm,
keySize: keyInfo.bits,
publicKeyArmored
};
}
/**
* Remove all characters before and after the ascii armored key block
* @param {string} data The ascii armored key
* @return {string} The trimmed key block
*/
trimKey(data) {
if (!this.validateKeyBlock(data)) {
util.throw(400, 'Invalid PGP key: key block not found');
}
return KEY_BEGIN + data.split(KEY_BEGIN)[1].split(KEY_END)[0] + KEY_END;
}
/**
* Validate an ascii armored public PGP key block.
* @param {string} data The armored key block
* @return {boolean} If the key is valid
*/
validateKeyBlock(data) {
if (!util.isString(data)) {
return false;
}
const begin = data.indexOf(KEY_BEGIN);
const end = data.indexOf(KEY_END);
return begin >= 0 && end > begin;
}
/**
* Parse an array of user ids and verify signatures
* @param {Array} users A list of openpgp.js user objects
* @param {Object} primaryKey The primary key packet of the key
* @param {Date} verifyDate Verify user IDs at this point in time
* @return {Array, integer} An array of user id objects and a satus indicator
* Values of status : 0 if no error, 1 if no address comes from a specific organisation.
*/
async parseUserIds(users, primaryKey, verifyDate = new Date()) {
if (!users || !users.length) {
util.throw(400, 'Invalid PGP key: no user ID found');
}
// at least one user id must be valid, revoked or expired
const result = [];
var isFromOrganisation = false;
for (const user of users) {
const userStatus = await user.verify(primaryKey, verifyDate);
if (userStatus !== openpgp.enums.keyStatus.invalid && user.userId && user.userId.userid) {
try {
const uid = openpgp.util.parseUserId(user.userId.userid);
if (util.isEmail(uid.email)) {
// map to local user id object format
result.push({
status: userStatus,
name: uid.name,
email: util.normalizeEmail(uid.email),
verified: false
});
if(util.isFromOrganisation(util.normalizeEmail(uid.email)))
isFromOrganisation = true;
}
} catch (e) {}
}
}
var status = 0;
if(!isFromOrganisation){
result.length = 0;
status = 1;
}
return {userIds: result, status: status};
}
/**
* Remove user IDs from armored key block which are not in array of user IDs
* @param {Array} userIds user IDs to be kept
* @param {String} armored armored key block to be filtered
* @return {String} filtered amored key block
*/
async filterKeyByUserIds(userIds, armored) {
const emails = userIds.map(({email}) => email);
const {keys: [key]} = await openpgp.key.readArmored(armored);
key.users = key.users.filter(({userId}) => !userId || emails.includes(util.normalizeEmail(userId.email)));
return key.armor();
}
/**
* Remove signatures from source armored key which are not in compared armored key
* @param {String} srcArmored armored key block to be filtered
* @param {String} cmpArmored armored key block to be compare with
* @return {String, newSigs} filterd armored key block, list of new signatures
*/
async filterKeyBySignatures(srcArmored, cmpArmored) {
const {keys: [srcKey], err: srcErr} = await openpgp.key.readArmored(srcArmored);
if (srcErr) {
log.error('pgp', 'Failed to parse source PGP key:\n%s', srcArmored, srcErr);
util.throw(500, 'Failed to parse PGP key');
}
const {keys: [cmpKey], err: cmpErr} = await openpgp.key.readArmored(cmpArmored);
if (cmpErr) {
log.error('pgp', 'Failed to parse destination PGP key:\n%s', cmpArmored, cmpErr);
util.throw(500, 'Failed to parse PGP key');
}
const newSigs=[];
if(cmpKey.hasSameFingerprintAs(srcKey)) {
await Promise.all(srcKey.users.map(async srcUser => {
await Promise.all(cmpKey.users.map(async dstUser => {
if ((srcUser.userId && dstUser.userId &&
(srcUser.userId.userid === dstUser.userId.userid)) ||
(srcUser.userAttribute && (srcUser.userAttribute.equals(dstUser.userAttribute)))) {
const source = srcUser.otherCertifications;
const dest = dstUser.otherCertifications;
for(let i = source.length-1; i >= 0; i--) {
const sourceSig = source[i];
if (!sourceSig.isExpired() && !dest.some(function(destSig) {
return util.equalsUint8Array(destSig.signature, sourceSig.signature);
})) {
// list new signatures
let userId = (srcUser.userId) ? srcUser.userId.userid : null;
let userAttribute = (srcUser.userAttribute) ? srcUser.userAttribute : null;
newSigs.push({user: {userId: userId, userAttribute: userAttribute}, signature: sourceSig});
// do not add new signatures
source.splice(i, 1);
}
}
}
}));
}));
}
return {armored: srcKey.armor(), newSigs: newSigs};
}
/**
* Merge (update) armored key blocks without adding new signatures
* @param {String} srcArmored source amored key block
* @param {String} dstArmored destination armored key block
* @return {String} merged amored key block
*/
async updateKey(srcArmored, dstArmored) {
const {keys: [srcKey], err: srcErr} = await openpgp.key.readArmored(srcArmored);
if (srcErr) {
log.error('pgp', 'Failed to parse source PGP key for update:\n%s', srcArmored, srcErr);
util.throw(500, 'Failed to parse PGP key');
}
const {keys: [dstKey], err: dstErr} = await openpgp.key.readArmored(dstArmored);
if (dstErr) {
log.error('pgp', 'Failed to parse destination PGP key for update:\n%s', dstArmored, dstErr);
util.throw(500, 'Failed to parse PGP key');
}
await dstKey.update(srcKey);
return dstKey.armor();
}
/**
* Returns primary user and most significant (latest valid) self signature
* - if multiple primary users exist, returns the one with the latest self signature
* - otherwise, returns the user with the latest self signature
* @return {Object} The primary userId
*/
async getPrimaryUser(publicKeyArmored) {
const {keys: [key], err: srcErr} = await openpgp.key.readArmored(publicKeyArmored);
if (srcErr) {
log.error('pgp', 'Failed to parse PGP key for getPrimaryUser:\n%s', publicKeyArmored, srcErr);
util.throw(500, 'Failed to parse PGP key');
}
const primaryUser = await key.getPrimaryUser();
return primaryUser;
}
/**
* Remove user ID from armored key block
* @param {String} email email of user ID to be removed
* @param {String} publicKeyArmored amored key block to be filtered
* @return {String} filtered armored key block
*/
async removeUserId(email, publicKeyArmored) {
const {keys: [key]} = await openpgp.key.readArmored(publicKeyArmored);
key.users = key.users.filter(({userId}) => !userId || util.normalizeEmail(userId.email) !== email);
return key.armor();
}
}
module.exports = PGP;