Add config parameter to top-level functions (#1241)

Refactor functions to take the configuration as a parameter.

This allows setting a config option for a single function call, whereas
setting `openpgp.config` could lead to concurrency-related issues when
multiple async function calls are made at the same time.

`openpgp.config` is used as default for unset config values in top-level
functions.
`openpgp.config` is used as default config object in low-level functions
(i.e., when calling a low-level function, it may be required to pass
`{ ...openpgp.config, modifiedConfig: modifiedValue }`).

Also,

- remove `config.rsaBlinding`: blinding is now always applied to RSA decryption
- remove `config.debug`: debugging mode can be enabled by setting
  `process.env.NODE_ENV = 'development'`
- remove `config.useNative`: native crypto is always used when available

src/crypto/cfb.js

@@ -28,7 +28,6 @@ import { AES_CFB } from 'asmcrypto.js/dist_es8/aes/cfb';
 
 import stream from 'web-stream-tools';
 import * as cipher from './cipher';
-import config from '../config';
 import util from '../util';
 
 const webCrypto = util.getWebCrypto();
@@ -47,12 +46,12 @@ const nodeAlgos = {
   /* twofish is not implemented in OpenSSL */
 };
 
-export async function encrypt(algo, key, plaintext, iv) {
+export async function encrypt(algo, key, plaintext, iv, config) {
   if (util.getNodeCrypto() && nodeAlgos[algo]) { // Node crypto library.
     return nodeEncrypt(algo, key, plaintext, iv);
   }
   if (algo.substr(0, 3) === 'aes') {
-    return aesEncrypt(algo, key, plaintext, iv);
+    return aesEncrypt(algo, key, plaintext, iv, config);
   }
 
   const cipherfn = new cipher[algo](key);
@@ -113,7 +112,7 @@ export async function decrypt(algo, key, ciphertext, iv) {
   return stream.transform(ciphertext, process, process);
 }
 
-function aesEncrypt(algo, key, pt, iv) {
+function aesEncrypt(algo, key, pt, iv, config) {
   if (
     util.getWebCrypto() &&
     key.length !== 24 && // Chrome doesn't support 192 bit keys, see https://www.chromium.org/blink/webcrypto#TOC-AES-support

src/crypto/hash/index.js

@@ -6,7 +6,6 @@
  * @requires hash.js
  * @requires web-stream-tools
  * @requires crypto/hash/md5
- * @requires config
  * @requires util
  * @module crypto/hash
  */
@@ -19,8 +18,8 @@ import sha512 from 'hash.js/lib/hash/sha/512';
 import { ripemd160 } from 'hash.js/lib/hash/ripemd';
 import stream from 'web-stream-tools';
 import md5 from './md5';
-import config from '../../config';
 import util from '../../util';
+import defaultConfig from '../../config';
 
 const webCrypto = util.getWebCrypto();
 const nodeCrypto = util.getNodeCrypto();
@@ -36,7 +35,7 @@ function node_hash(type) {
 }
 
 function hashjs_hash(hash, webCryptoHash) {
-  return async function(data) {
+  return async function(data, config = defaultConfig) {
     if (!util.isStream(data) && webCrypto && webCryptoHash && data.length >= config.minBytesForWebCrypto) {
       return new Uint8Array(await webCrypto.digest(webCryptoHash, data));
     }
@@ -48,7 +47,7 @@ function hashjs_hash(hash, webCryptoHash) {
 }
 
 function asmcrypto_hash(hash, webCryptoHash) {
-  return async function(data) {
+  return async function(data, config = defaultConfig) {
     if (util.isStream(data)) {
       const hashInstance = new hash();
       return stream.transform(data, value => {

src/crypto/public_key/rsa.js

@@ -26,7 +26,6 @@
 
 import { randomProbablePrime } from './prime';
 import { getRandomBigInteger } from '../random';
-import config from '../../config';
 import util from '../../util';
 import { uint8ArrayToB64, b64ToUint8Array } from '../../encoding/base64';
 import { emsaEncode, emeEncode, emeDecode } from '../pkcs1';
@@ -528,13 +527,10 @@ async function bnDecrypt(data, n, e, d, p, q, u) {
   const dq = d.mod(q.dec()); // d mod (q-1)
   const dp = d.mod(p.dec()); // d mod (p-1)
 
-  let blinder;
-  let unblinder;
-  if (config.rsaBlinding) {
-    unblinder = (await getRandomBigInteger(new BigInteger(2), n)).mod(n);
-    blinder = unblinder.modInv(n).modExp(e, n);
-    data = data.mul(blinder).mod(n);
-  }
+  const unblinder = (await getRandomBigInteger(new BigInteger(2), n)).mod(n);
+  const blinder = unblinder.modInv(n).modExp(e, n);
+  data = data.mul(blinder).mod(n);
+
 
   const mp = data.modExp(dp, p); // data**{d mod (q-1)} mod p
   const mq = data.modExp(dq, q); // data**{d mod (p-1)} mod q
@@ -542,9 +538,8 @@ async function bnDecrypt(data, n, e, d, p, q, u) {
 
   let result = h.mul(p).add(mp); // result < n due to relations above
 
-  if (config.rsaBlinding) {
-    result = result.mul(unblinder).mod(n);
-  }
+  result = result.mul(unblinder).mod(n);
+
 
   return emeDecode(result.toUint8Array('be', n.byteLength()));
 }

src/crypto/random.js

@@ -24,8 +24,7 @@
  */
 import util from '../util';
 
-// Do not use util.getNodeCrypto because we need this regardless of useNative setting
-const nodeCrypto = util.detectNode() && require('crypto');
+const nodeCrypto = util.getNodeCrypto();
 
 /**
  * Buffer for secure random numbers