buffer: use stricter `from()` input validation

So far we did not throw an error for all types of invalid input.
Functions do not return a buffer anymore and `number` and `symbol`
validation is also improved.

PR-URL: https://github.com/nodejs/node/pull/26825
Fixes: https://github.com/nodejs/node/issues/26741
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

1 files changed, 14 insertions, 24 deletions

diff --git a/lib/buffer.js b/lib/buffer.js
index 66c345885a..b5d89625b2 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -195,33 +195,23 @@ Buffer.from = function from(value, encodingOrOffset, length) {
   if (typeof value === 'string')
     return fromString(value, encodingOrOffset);
 
-  if (isAnyArrayBuffer(value))
-    return fromArrayBuffer(value, encodingOrOffset, length);
+  if (typeof value === 'object' && value !== null) {
+    if (isAnyArrayBuffer(value))
+      return fromArrayBuffer(value, encodingOrOffset, length);
 
-  if (value === null || value === undefined) {
-    throw new ERR_INVALID_ARG_TYPE(
-      'first argument',
-      ['string', 'Buffer', 'ArrayBuffer', 'Array', 'Array-like Object'],
-      value
-    );
-  }
-
-  if (typeof value === 'number') {
-    throw new ERR_INVALID_ARG_TYPE('value', 'not number', value);
-  }
+    const valueOf = value.valueOf && value.valueOf();
+    if (valueOf !== null && valueOf !== undefined && valueOf !== value)
+      return Buffer.from(valueOf, encodingOrOffset, length);
 
-  const valueOf = value.valueOf && value.valueOf();
-  if (valueOf !== null && valueOf !== undefined && valueOf !== value)
-    return Buffer.from(valueOf, encodingOrOffset, length);
-
-  const b = fromObject(value);
-  if (b)
-    return b;
+    const b = fromObject(value);
+    if (b)
+      return b;
 
-  if (typeof value[Symbol.toPrimitive] === 'function') {
-    return Buffer.from(value[Symbol.toPrimitive]('string'),
-                       encodingOrOffset,
-                       length);
+    if (typeof value[Symbol.toPrimitive] === 'function') {
+      return Buffer.from(value[Symbol.toPrimitive]('string'),
+                         encodingOrOffset,
+                         length);
+    }
   }
 
   throw new ERR_INVALID_ARG_TYPE(