server/helpers/peertube-crypto.ts

   1 import { Request } from 'express'
   2 import { BCRYPT_SALT_SIZE, HTTP_SIGNATURE, PRIVATE_RSA_KEY_SIZE } from '../initializers/constants'
   3 import { ActorModel } from '../models/activitypub/actor'
   4 import { bcryptComparePromise, bcryptGenSaltPromise, bcryptHashPromise, createPrivateKey, getPublicKey, sha256 } from './core-utils'
   5 import { jsig, jsonld } from './custom-jsonld-signature'
   6 import { logger } from './logger'
   7 import { cloneDeep } from 'lodash'
   8 import { createVerify } from 'crypto'
   9 import { buildDigest } from '../lib/job-queue/handlers/utils/activitypub-http-utils'
  10
  11 const httpSignature = require('http-signature')
  12
  13 async function createPrivateAndPublicKeys () {
  14   logger.info('Generating a RSA key...')
  15
  16   const { key } = await createPrivateKey(PRIVATE_RSA_KEY_SIZE)
  17   const { publicKey } = await getPublicKey(key)
  18
  19   return { privateKey: key, publicKey }
  20 }
  21
  22 // User password checks
  23
  24 function comparePassword (plainPassword: string, hashPassword: string) {
  25   return bcryptComparePromise(plainPassword, hashPassword)
  26 }
  27
  28 async function cryptPassword (password: string) {
  29   const salt = await bcryptGenSaltPromise(BCRYPT_SALT_SIZE)
  30
  31   return bcryptHashPromise(password, salt)
  32 }
  33
  34 // HTTP Signature
  35
  36 function isHTTPSignatureDigestValid (rawBody: Buffer, req: Request): boolean {
  37   if (req.headers[HTTP_SIGNATURE.HEADER_NAME] && req.headers['digest']) {
  38     return buildDigest(rawBody.toString()) === req.headers['digest']
  39   }
  40
  41   return true
  42 }
  43
  44 function isHTTPSignatureVerified (httpSignatureParsed: any, actor: ActorModel): boolean {
  45   return httpSignature.verifySignature(httpSignatureParsed, actor.publicKey) === true
  46 }
  47
  48 function parseHTTPSignature (req: Request, clockSkew?: number) {
  49   return httpSignature.parse(req, { authorizationHeaderName: HTTP_SIGNATURE.HEADER_NAME, clockSkew })
  50 }
  51
  52 // JSONLD
  53
  54 async function isJsonLDSignatureVerified (fromActor: ActorModel, signedDocument: any): Promise<boolean> {
  55   if (signedDocument.signature.type === 'RsaSignature2017') {
  56     // Mastodon algorithm
  57     const res = await isJsonLDRSA2017Verified(fromActor, signedDocument)
  58     // Success? If no, try with our library
  59     if (res === true) return true
  60   }
  61
  62   const publicKeyObject = {
  63     '@context': jsig.SECURITY_CONTEXT_URL,
  64     id: fromActor.url,
  65     type: 'CryptographicKey',
  66     owner: fromActor.url,
  67     publicKeyPem: fromActor.publicKey
  68   }
  69
  70   const publicKeyOwnerObject = {
  71     '@context': jsig.SECURITY_CONTEXT_URL,
  72     id: fromActor.url,
  73     publicKey: [ publicKeyObject ]
  74   }
  75
  76   const options = {
  77     publicKey: publicKeyObject,
  78     publicKeyOwner: publicKeyOwnerObject
  79   }
  80
  81   return jsig.promises
  82              .verify(signedDocument, options)
  83              .then((result: { verified: boolean }) => result.verified)
  84              .catch(err => {
  85                logger.error('Cannot check signature.', { err })
  86                return false
  87              })
  88 }
  89
  90 // Backward compatibility with "other" implementations
  91 async function isJsonLDRSA2017Verified (fromActor: ActorModel, signedDocument: any) {
  92   function hash (obj: any): Promise<any> {
  93     return jsonld.promises
  94                  .normalize(obj, {
  95                    algorithm: 'URDNA2015',
  96                    format: 'application/n-quads'
  97                  })
  98                  .then(res => sha256(res))
  99   }
 100
 101   const signatureCopy = cloneDeep(signedDocument.signature)
 102   Object.assign(signatureCopy, {
 103     '@context': [
 104       'https://w3id.org/security/v1',
 105       { RsaSignature2017: 'https://w3id.org/security#RsaSignature2017' }
 106     ]
 107   })
 108   delete signatureCopy.type
 109   delete signatureCopy.id
 110   delete signatureCopy.signatureValue
 111
 112   const docWithoutSignature = cloneDeep(signedDocument)
 113   delete docWithoutSignature.signature
 114
 115   const [ documentHash, optionsHash ] = await Promise.all([
 116     hash(docWithoutSignature),
 117     hash(signatureCopy)
 118   ])
 119
 120   const toVerify = optionsHash + documentHash
 121
 122   const verify = createVerify('RSA-SHA256')
 123   verify.update(toVerify, 'utf8')
 124
 125   return verify.verify(fromActor.publicKey, signedDocument.signature.signatureValue, 'base64')
 126 }
 127
 128 function signJsonLDObject (byActor: ActorModel, data: any) {
 129   const options = {
 130     privateKeyPem: byActor.privateKey,
 131     creator: byActor.url,
 132     algorithm: 'RsaSignature2017'
 133   }
 134
 135   return jsig.promises.sign(data, options)
 136 }
 137
 138 // ---------------------------------------------------------------------------
 139
 140 export {
 141   isHTTPSignatureDigestValid,
 142   parseHTTPSignature,
 143   isHTTPSignatureVerified,
 144   isJsonLDSignatureVerified,
 145   comparePassword,
 146   createPrivateAndPublicKeys,
 147   cryptPassword,
 148   signJsonLDObject
 149 }