chore: add error codes (#155)

* chore: add error codes

* chore: create errors with new Error()

* fix: better error testin

* refactor: simplify random bytes error checks

src/keys/ecdh-browser.js

@@ -1,8 +1,10 @@
 'use strict'
 
+const errcode = require('err-code')
 const webcrypto = require('../webcrypto.js')
 const BN = require('asn1.js').bignum
 const { toBase64, toBn } = require('../util')
+const validateCurveType = require('./validate-curve-type')
 
 const bits = {
   'P-256': 256,
@@ -11,6 +13,8 @@ const bits = {
 }
 
 exports.generateEphmeralKeyPair = async function (curve) {
+  validateCurveType(Object.keys(bits), curve)
+
   const pair = await webcrypto.subtle.generateKey(
     {
       name: 'ECDH',
@@ -96,7 +100,7 @@ function unmarshalPublicKey (curve, key) {
   const byteLen = curveLengths[curve]
 
   if (!key.slice(0, 1).equals(Buffer.from([4]))) {
-    throw new Error('Invalid key format')
+    throw errcode(new Error('Cannot unmarshal public key - invalid key format'), 'ERR_INVALID_KEY_FORMAT')
   }
   const x = new BN(key.slice(1, byteLen + 1))
   const y = new BN(key.slice(1 + byteLen))

src/keys/ecdh.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const crypto = require('crypto')
+const validateCurveType = require('./validate-curve-type')
 
 const curves = {
   'P-256': 'prime256v1',
@@ -9,9 +10,8 @@ const curves = {
 }
 
 exports.generateEphmeralKeyPair = async function (curve) { // eslint-disable-line require-await
-  if (!curves[curve]) {
-    throw new Error(`Unkown curve: ${curve}`)
-  }
+  validateCurveType(Object.keys(curves), curve)
+
   const ecdh = crypto.createECDH(curves[curve])
   ecdh.generateKeys()
 

src/keys/ed25519-class.js

@@ -3,6 +3,7 @@
 const multihashing = require('multihashing-async')
 const protobuf = require('protons')
 const bs58 = require('bs58')
+const errcode = require('err-code')
 
 const crypto = require('./ed25519')
 const pbm = protobuf(require('./keys.proto'))
@@ -49,10 +50,6 @@ class Ed25519PrivateKey {
   }
 
   get public () {
-    if (!this._publicKey) {
-      throw new Error('public key not provided')
-    }
-
     return new Ed25519PublicKey(this._publicKey)
   }
 
@@ -117,7 +114,7 @@ function ensureKey (key, length) {
     key = new Uint8Array(key)
   }
   if (!(key instanceof Uint8Array) || key.length !== length) {
-    throw new Error('Key must be a Uint8Array or Buffer of length ' + length)
+    throw errcode(new Error('Key must be a Uint8Array or Buffer of length ' + length), 'ERR_INVALID_KEY_TYPE')
   }
   return key
 }

src/keys/index.js

@@ -6,6 +6,7 @@ require('node-forge/lib/asn1')
 require('node-forge/lib/rsa')
 require('node-forge/lib/pbe')
 const forge = require('node-forge/lib/forge')
+const errcode = require('err-code')
 
 exports = module.exports
 
@@ -18,9 +19,18 @@ const supportedKeys = {
 exports.supportedKeys = supportedKeys
 exports.keysPBM = keysPBM
 
-function isValidKeyType (keyType) {
-  const key = supportedKeys[keyType.toLowerCase()]
-  return key !== undefined
+const ErrMissingSecp256K1 = {
+  message: 'secp256k1 support requires libp2p-crypto-secp256k1 package',
+  code: 'ERR_MISSING_PACKAGE'
+}
+
+function typeToKey (type) {
+  let key = supportedKeys[type.toLowerCase()]
+  if (!key) {
+    const supported = Object.keys(supportedKeys).join(' / ')
+    throw errcode(new Error(`invalid or unsupported key type ${type}. Must be ${supported}`), 'ERR_UNSUPPORTED_KEY_TYPE')
+  }
+  return key
 }
 
 exports.keyStretcher = require('./key-stretcher')
@@ -28,24 +38,15 @@ exports.generateEphemeralKeyPair = require('./ephemeral-keys')
 
 // Generates a keypair of the given type and bitsize
 exports.generateKeyPair = async (type, bits) => { // eslint-disable-line require-await
-  let key = supportedKeys[type.toLowerCase()]
-
-  if (!key) {
-    throw new Error('invalid or unsupported key type')
-  }
-
-  return key.generateKeyPair(bits)
+  return typeToKey(type).generateKeyPair(bits)
 }
 
 // Generates a keypair of the given type and bitsize
 // seed is a 32 byte uint8array
 exports.generateKeyPairFromSeed = async (type, seed, bits) => { // eslint-disable-line require-await
-  let key = supportedKeys[type.toLowerCase()]
-  if (!key) {
-    throw new Error('invalid or unsupported key type')
-  }
+  const key = typeToKey(type)
   if (type.toLowerCase() !== 'ed25519') {
-    throw new Error('Seed key derivation is unimplemented for RSA or secp256k1')
+    throw errcode(new Error('Seed key derivation is unimplemented for RSA or secp256k1'), 'ERR_UNSUPPORTED_KEY_DERIVATION_TYPE')
   }
   return key.generateKeyPairFromSeed(seed, bits)
 }
@@ -65,20 +66,17 @@ exports.unmarshalPublicKey = (buf) => {
       if (supportedKeys.secp256k1) {
         return supportedKeys.secp256k1.unmarshalSecp256k1PublicKey(data)
       } else {
-        throw new Error('secp256k1 support requires libp2p-crypto-secp256k1 package')
+        throw errcode(new Error(ErrMissingSecp256K1.message), ErrMissingSecp256K1.code)
       }
     default:
-      throw new Error('invalid or unsupported key type')
+      typeToKey(decoded.Type) // throws because type is not supported
   }
 }
 
 // Converts a public key object into a protobuf serialized public key
 exports.marshalPublicKey = (key, type) => {
   type = (type || 'rsa').toLowerCase()
-  if (!isValidKeyType(type)) {
-    throw new Error('invalid or unsupported key type')
-  }
-
+  typeToKey(type) // check type
   return key.bytes
 }
 
@@ -97,27 +95,24 @@ exports.unmarshalPrivateKey = async (buf) => { // eslint-disable-line require-aw
       if (supportedKeys.secp256k1) {
         return supportedKeys.secp256k1.unmarshalSecp256k1PrivateKey(data)
       } else {
-        throw new Error('secp256k1 support requires libp2p-crypto-secp256k1 package')
+        throw errcode(new Error(ErrMissingSecp256K1.message), ErrMissingSecp256K1.code)
       }
     default:
-      throw new Error('invalid or unsupported key type')
+      typeToKey(decoded.Type) // throws because type is not supported
   }
 }
 
 // Converts a private key object into a protobuf serialized private key
 exports.marshalPrivateKey = (key, type) => {
   type = (type || 'rsa').toLowerCase()
-  if (!isValidKeyType(type)) {
-    throw new Error('invalid or unsupported key type')
-  }
-
+  typeToKey(type) // check type
   return key.bytes
 }
 
 exports.import = async (pem, password) => { // eslint-disable-line require-await
   const key = forge.pki.decryptRsaPrivateKey(pem, password)
   if (key === null) {
-    throw new Error('Cannot read the key, most likely the password is wrong or not a RSA key')
+    throw errcode(new Error('Cannot read the key, most likely the password is wrong or not a RSA key'), 'ERR_CANNOT_DECRYPT_PEM')
   }
   let der = forge.asn1.toDer(forge.pki.privateKeyToAsn1(key))
   der = Buffer.from(der.getBytes(), 'binary')

src/keys/key-stretcher.js

@@ -1,5 +1,6 @@
 'use strict'
 
+const errcode = require('err-code')
 const hmac = require('../hmac')
 
 const cipherMap = {
@@ -23,11 +24,12 @@ module.exports = async (cipherType, hash, secret) => {
   const cipher = cipherMap[cipherType]
 
   if (!cipher) {
-    throw new Error('unkown cipherType passed')
+    const allowed = Object.keys(cipherMap).join(' / ')
+    throw errcode(new Error(`unknown cipher type '${cipherType}'. Must be ${allowed}`), 'ERR_INVALID_CIPHER_TYPE')
   }
 
   if (!hash) {
-    throw new Error('unkown hashType passed')
+    throw errcode(new Error(`missing hash type`), 'ERR_MISSING_HASH_TYPE')
   }
 
   const cipherKeySize = cipher.keySize

src/keys/rsa-class.js

@@ -3,6 +3,7 @@
 const multihashing = require('multihashing-async')
 const protobuf = require('protons')
 const bs58 = require('bs58')
+const errcode = require('err-code')
 
 const crypto = require('./rsa')
 const pbm = protobuf(require('./keys.proto'))
@@ -61,7 +62,7 @@ class RsaPrivateKey {
 
   get public () {
     if (!this._publicKey) {
-      throw new Error('public key not provided')
+      throw errcode(new Error('public key not provided'), 'ERR_PUBKEY_NOT_PROVIDED')
     }
 
     return new RsaPublicKey(this._publicKey)
@@ -123,7 +124,7 @@ class RsaPrivateKey {
       }
       pem = forge.pki.encryptRsaPrivateKey(privateKey, password, options)
     } else {
-      throw new Error(`Unknown export format '${format}'`)
+      throw errcode(new Error(`Unknown export format '${format}'. Must be pkcs-8`), 'ERR_INVALID_EXPORT_FORMAT')
     }
 
     return pem

src/keys/rsa.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const crypto = require('crypto')
+const errcode = require('err-code')
 const randomBytes = require('../random-bytes')
 
 let keypair
@@ -40,7 +41,7 @@ exports.generateKey = async function (bits) { // eslint-disable-line require-awa
 // Takes a jwk key
 exports.unmarshalPrivateKey = async function (key) { // eslint-disable-line require-await
   if (!key) {
-    throw new Error('Key is invalid')
+    throw errcode(new Error('Missing key parameter'), 'ERR_MISSING_KEY')
   }
   return {
     privateKey: key,

src/keys/validate-curve-type.js

@@ -0,0 +1,10 @@
+'use strict'
+
+const errcode = require('err-code')
+
+module.exports = function (curveTypes, type) {
+  if (!curveTypes.includes(type)) {
+    const names = curveTypes.join(' / ')
+    throw errcode(new Error(`Unknown curve: ${type}. Must be ${names}`), 'ERR_INVALID_CURVE')
+  }
+}