crypto: fix output of privateDecrypt with zero-length data

deps/ncrypto/ncrypto.cc

@@ -215,7 +215,7 @@ Buffer<void> DataPointer::release() {
 DataPointer DataPointer::resize(size_t len) {
   size_t actual_len = std::min(len_, len);
   auto buf = release();
-  if (actual_len == len_) return DataPointer(buf);
+  if (actual_len == len_) return DataPointer(buf.data, actual_len);
   buf.data = OPENSSL_realloc(buf.data, actual_len);
   buf.len = actual_len;
   return DataPointer(buf);

test/parallel/test-crypto-zero-lengths.mjs

@@ -0,0 +1,51 @@
+import * as common from '../common/index.mjs';
+
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+
+import * as fixtures from '../common/fixtures.mjs';
+import assert from 'assert';
+import crypto from 'crypto';
+
+const { subtle } = globalThis.crypto;
+
+{
+  const privateKey = crypto.createPrivateKey(fixtures.readKey('rsa_private.pem', 'ascii'));
+  const publicKey = crypto.createPublicKey(fixtures.readKey('rsa_public.pem', 'ascii'));
+
+  const data = Buffer.alloc(0);
+  {
+
+    const ciphertext = crypto.publicEncrypt({
+      padding: crypto.constants.RSA_PKCS1_OAEP_PADDING,
+      key: publicKey,
+    }, data);
+
+    const plaintext = crypto.privateDecrypt({
+      padding: crypto.constants.RSA_PKCS1_OAEP_PADDING,
+      key: privateKey
+    }, ciphertext);
+
+    assert.deepStrictEqual(plaintext, data);
+  }
+
+  {
+    const ciphertext = crypto.publicEncrypt(publicKey, data);
+    const plaintext = crypto.privateDecrypt(privateKey, ciphertext);
+
+    assert.deepStrictEqual(plaintext, data);
+  }
+
+  {
+    const pkcs8 = privateKey.export({ format: 'der', type: 'pkcs8' });
+    const spki = publicKey.export({ format: 'der', type: 'spki' });
+    const kp = {
+      privateKey: await subtle.importKey('pkcs8', pkcs8, { name: 'RSA-OAEP', hash: 'SHA-1' }, false, ['decrypt']),
+      publicKey: await subtle.importKey('spki', spki, { name: 'RSA-OAEP', hash: 'SHA-1' }, false, ['encrypt']),
+    };
+
+    const ciphertext = await subtle.encrypt('RSA-OAEP', kp.publicKey, data);
+    const plaintext = await subtle.decrypt('RSA-OAEP', kp.privateKey, ciphertext);
+    assert.deepStrictEqual(plaintext, data.buffer);
+  }
+}