crypto: DRY type checking

Factor out some common code.  The `checkUint()` function will also be
used in a follow-up commit that adds scrypt support to core.

PR-URL: #20816
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>

lib/internal/crypto/pbkdf2.js

@@ -4,19 +4,15 @@ const {
   ERR_INVALID_ARG_TYPE,
   ERR_INVALID_CALLBACK,
   ERR_CRYPTO_INVALID_DIGEST,
-  ERR_OUT_OF_RANGE
 } = require('internal/errors').codes;
 const {
   checkIsArrayBufferView,
+  checkIsUint,
   getDefaultEncoding,
-  toBuf
 } = require('internal/crypto/util');
 const {
   PBKDF2
 } = process.binding('crypto');
-const {
-  INT_MAX
-} = process.binding('constants').crypto;
 
 function pbkdf2(password, salt, iterations, keylen, digest, callback) {
   if (typeof digest === 'function') {
@@ -39,22 +35,12 @@ function _pbkdf2(password, salt, iterations, keylen, digest, callback) {
   if (digest !== null && typeof digest !== 'string')
     throw new ERR_INVALID_ARG_TYPE('digest', ['string', 'null'], digest);
 
-  password = checkIsArrayBufferView('password', toBuf(password));
-  salt = checkIsArrayBufferView('salt', toBuf(salt));
-
-  if (typeof iterations !== 'number')
-    throw new ERR_INVALID_ARG_TYPE('iterations', 'number', iterations);
-
-  if (iterations < 0)
-    throw new ERR_OUT_OF_RANGE('iterations',
-                               'a non-negative number',
-                               iterations);
-
-  if (typeof keylen !== 'number')
-    throw new ERR_INVALID_ARG_TYPE('keylen', 'number', keylen);
-
-  if (keylen < 0 || !Number.isInteger(keylen) || keylen > INT_MAX)
-    throw new ERR_OUT_OF_RANGE('keylen', `>= 0 && <= ${INT_MAX}`, keylen);
+  password = checkIsArrayBufferView('password', password);
+  salt = checkIsArrayBufferView('salt', salt);
+  // FIXME(bnoordhuis) The error message is in fact wrong since |iterations|
+  // cannot be > INT_MAX.  Adjust in the next major release.
+  iterations = checkIsUint('iterations', iterations, 'a non-negative number');
+  keylen = checkIsUint('keylen', keylen);
 
   const encoding = getDefaultEncoding();
 

lib/internal/crypto/sig.js

@@ -77,7 +77,7 @@ Sign.prototype.sign = function sign(options, encoding) {
 
   var pssSaltLength = getSaltLength(options);
 
-  key = checkIsArrayBufferView('key', toBuf(key));
+  key = checkIsArrayBufferView('key', key);
 
   var ret = this._handle.sign(key, passphrase, rsaPadding, pssSaltLength);
 
@@ -114,7 +114,7 @@ Verify.prototype.verify = function verify(options, signature, sigEncoding) {
 
   var pssSaltLength = getSaltLength(options);
 
-  key = checkIsArrayBufferView('key', toBuf(key));
+  key = checkIsArrayBufferView('key', key);
 
   signature = checkIsArrayBufferView('signature',
                                      toBuf(signature, sigEncoding));

lib/internal/crypto/util.js

@@ -15,7 +15,8 @@ const {
 const {
   ERR_CRYPTO_ENGINE_UNKNOWN,
   ERR_CRYPTO_TIMING_SAFE_EQUAL_LENGTH,
-  ERR_INVALID_ARG_TYPE
+  ERR_INVALID_ARG_TYPE,
+  ERR_OUT_OF_RANGE,
 } = require('internal/errors').codes;
 const { Buffer } = require('buffer');
 const {
@@ -25,6 +26,9 @@ const {
 const {
   isArrayBufferView
 } = require('internal/util/types');
+const {
+  INT_MAX
+} = process.binding('constants').crypto;
 
 var defaultEncoding = 'buffer';
 
@@ -84,6 +88,7 @@ function timingSafeEqual(buf1, buf2) {
 }
 
 function checkIsArrayBufferView(name, buffer) {
+  buffer = toBuf(buffer);
   if (!isArrayBufferView(buffer)) {
     throw new ERR_INVALID_ARG_TYPE(
       name,
@@ -94,8 +99,19 @@ function checkIsArrayBufferView(name, buffer) {
   return buffer;
 }
 
+function checkIsUint(name, value, errmsg = `>= 0 && <= ${INT_MAX}`) {
+  if (typeof value !== 'number')
+    throw new ERR_INVALID_ARG_TYPE(name, 'number', value);
+
+  if (value < 0 || !Number.isInteger(value) || value > INT_MAX)
+    throw new ERR_OUT_OF_RANGE(name, errmsg, value);
+
+  return value;
+}
+
 module.exports = {
   checkIsArrayBufferView,
+  checkIsUint,
   getCiphers,
   getCurves,
   getDefaultEncoding,