feat: backport enc/dec (#160)

* feat: add (rsa)pubKey.encrypt and (rsa)privKey.decrypt

nodeJS only for now

* feat: browser enc/dec

* fix: browser rsa enc/dec

* refactor: cleanup

* fix: lint

* fix: use direct buffers instead of converting to hex

* fix: padding error

* test: add interop test

* feat: use forge to convert jwk2forge

* fix: jwk var naming

* fix: missing cbwrap

package.json

@@ -45,7 +45,7 @@
     "keypair": "^1.0.1",
     "libp2p-crypto-secp256k1": "~0.3.0",
     "multihashing-async": "~0.5.1",
-    "node-forge": "^0.8.5",
+    "node-forge": "~0.9.1",
     "pem-jwk": "^2.0.0",
     "protons": "^1.0.1",
     "rsa-pem-to-jwk": "^1.1.3",

src/keys/jwk2pem.js

@@ -0,0 +1,42 @@
+'use strict'
+
+const forge = {
+  util: require('node-forge/lib/util'),
+  pki: require('node-forge/lib/pki'),
+  jsbn: require('node-forge/lib/jsbn')
+}
+
+function base64urlToBigInteger (str) {
+  var bytes = forge.util.decode64(
+    (str + '==='.slice((str.length + 3) % 4))
+      .replace(/-/g, '+')
+      .replace(/_/g, '/'))
+  return new forge.jsbn.BigInteger(forge.util.bytesToHex(bytes), 16)
+}
+
+function convert (key, types) {
+  return types.map(t => base64urlToBigInteger(key[t]))
+}
+
+function jwk2priv (key) {
+  return forge.pki.setRsaPrivateKey(...convert(key, ['n', 'e', 'd', 'p', 'q', 'dp', 'dq', 'qi']))
+}
+
+function jwk2privPem (key) {
+  return forge.pki.privateKeyToPem(jwk2priv(key))
+}
+
+function jwk2pub (key) {
+  return forge.pki.setRsaPublicKey(...convert(key, ['n', 'e']))
+}
+
+function jwk2pubPem (key) {
+  return forge.pki.publicKeyToPem(jwk2pub(key))
+}
+
+module.exports = {
+  jwk2pub,
+  jwk2pubPem,
+  jwk2priv,
+  jwk2privPem
+}

src/keys/rsa-browser.js

@@ -113,3 +113,32 @@ function derivePublicFromPrivate (jwKey) {
     ['verify']
   )
 }
+
+/*
+
+RSA encryption/decryption for the browser with webcrypto workarround
+"bloody dark magic. webcrypto's why."
+
+Explanation:
+  - Convert JWK to nodeForge
+  - Convert msg buffer to nodeForge buffer: ByteBuffer is a "binary-string backed buffer", so let's make our buffer a binary string
+  - Convert resulting nodeForge buffer to buffer: it returns a binary string, turn that into a uint8array(buffer)
+
+*/
+
+const { jwk2pub, jwk2priv } = require('./jwk2pem')
+
+function convertKey (key, pub, msg, handle) {
+  const fkey = pub ? jwk2pub(key) : jwk2priv(key)
+  const fmsg = Buffer.from(msg).toString('binary')
+  const fomsg = handle(fmsg, fkey)
+  return Buffer.from(fomsg, 'binary')
+}
+
+exports.encrypt = function (key, msg) {
+  return convertKey(key, true, msg, (msg, key) => key.encrypt(msg))
+}
+
+exports.decrypt = function (key, msg) {
+  return convertKey(key, false, msg, (msg, key) => key.decrypt(msg))
+}

src/keys/rsa-class.js

@@ -32,8 +32,8 @@ class RsaPublicKey {
     })
   }
 
-  encrypt (bytes) {
-    return this._key.encrypt(bytes, 'RSAES-PKCS1-V1_5')
+  encrypt (bytes, cb) {
+    return cbWrap(() => crypto.encrypt(this._key, bytes), cb)
   }
 
   equals (key) {
@@ -46,6 +46,17 @@ class RsaPublicKey {
   }
 }
 
+function cbWrap (f, cb) {
+  let res
+  try {
+    res = f()
+  } catch (err) {
+    cb(err)
+  }
+
+  return cb(null, res)
+}
+
 class RsaPrivateKey {
   // key       - Object of the jwk format
   // publicKey - Buffer of the spki format
@@ -71,8 +82,8 @@ class RsaPrivateKey {
     return new RsaPublicKey(this._publicKey)
   }
 
-  decrypt (msg, callback) {
-    crypto.decrypt(this._key, msg, callback)
+  decrypt (bytes, cb) {
+    cbWrap(() => crypto.decrypt(this._key, bytes), cb)
   }
 
   marshal () {

src/keys/rsa.js

@@ -97,3 +97,13 @@ exports.hashAndVerify = function (key, sig, msg, callback) {
     callback(null, result)
   })
 }
+
+const padding = crypto.constants.RSA_PKCS1_PADDING
+
+exports.encrypt = function (key, bytes) {
+  return crypto.publicEncrypt({ key: jwkToPem(key), padding }, bytes)
+}
+
+exports.decrypt = function (key, bytes) {
+  return crypto.privateDecrypt({ key: jwkToPem(key), padding }, bytes)
+}

test/keys/rsa.spec.js

@@ -128,6 +128,41 @@ describe('RSA', function () {
     })
   })
 
+  it('encrypt and decrypt', (done) => {
+    const data = Buffer.from('hello world')
+    key.public.encrypt(data, (err, enc) => {
+      if (err) { return done(err) }
+
+      key.decrypt(enc, (err, dec) => {
+        if (err) { return done(err) }
+        expect(dec).to.be.eql(data)
+
+        done()
+      })
+    })
+  })
+
+  it('encrypt decrypt browser/node interop', (done) => {
+    crypto.keys.unmarshalPrivateKey(Buffer.from('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', 'base64'), (err, id) => {
+      if (err) { return done(err) }
+
+      const msg = Buffer.from('hello')
+      // browser
+      id.decrypt(Buffer.from('YRFUDx8UjbWSfDS84cDA4WowaaOmd1qFNAv5QutodCKYb9uPtU/tDiAvJzOGu5DCJRo2J0l/35P2weiB4/C2Cb1aZgXKMx/QQC+2jSJiymhqcZaYerjTvkCFwkjCaqthoVo/YXxsaFZ1q7bdTZUDH1TaJR7hWfSyzyPcA8c0w43MIsw16pY8ZaPSclvnCwhoTg1JGjMk6te3we7+wR8QU7VrPhs54mZWxrpu3NQ8xZ6xQqIedsEiNhBUccrCSzYghgsP0Ae/8iKyGyl3U6IegsJNn8jcocvzOJrmU03rgIFPjvuBdaqB38xDSTjbA123KadB28jNoSZh18q/yH3ZIg==', 'base64'), (err, dec1) => {
+        if (err) { return done(err) }
+        expect(dec1).to.be.eql(msg)
+
+        // node
+        id.decrypt(Buffer.from('e6yxssqXsWc27ozDy0PGKtMkCS28KwFyES2Ijz89yiz+w6bSFkNOhHPKplpPzgQEuNoUGdbseKlJFyRYHjIT8FQFBHZM8UgSkgoimbY5on4xSxXs7E5/+twjqKdB7oNveTaTf7JCwaeUYnKSjbiYFEawtMiQE91F8sTT7TmSzOZ48tUhnddAAZ3Ac/O3Z9MSAKOCDipi+JdZtXRT8KimGt36/7hjjosYmPuHR1Xy/yMTL6SMbXtBM3yAuEgbQgP+q/7kHMHji3/JvTpYdIUU+LVtkMusXNasRA+UWG2zAht18vqjFMsm9JTiihZw9jRHD4vxAhf75M992tnC+0ZuQg==', 'base64'), (err, dec2) => {
+          if (err) { return done(err) }
+          expect(dec2).to.be.eql(msg)
+
+          done()
+        })
+      })
+    })
+  })
+
   it('fails to verify for different data', (done) => {
     const data = Buffer.from('hello world')
     key.sign(data, (err, sig) => {