Align string/buffer conversion behaviors to Node.js

Author: wh201906

example/src/tests/utils/encoding_tests.ts

@@ -45,12 +45,44 @@ test(SUITE, 'hex decode is case-insensitive', () => {
   expect(lower).to.deep.equal(upper);
 });
 
-test(SUITE, 'hex decode rejects odd-length string', () => {
-  expect(() => stringToBuffer('abc', 'hex')).to.throw();
+test(SUITE, '[Node.js] Test single hex character is discarded.', () => {
+  expect(toU8(stringToBuffer('A', 'hex'))).to.deep.equal(new Uint8Array([]));
 });
 
-test(SUITE, 'hex decode rejects invalid characters', () => {
-  expect(() => stringToBuffer('zzzz', 'hex')).to.throw();
+test(
+  SUITE,
+  '[Node.js] Test that if a trailing character is discarded, rest of string is processed.',
+  () => {
+    expect(toU8(stringToBuffer('Abx', 'hex'))).to.deep.equal(
+      new Uint8Array([0xab]),
+    );
+    expect(toU8(stringToBuffer('abc', 'hex'))).to.deep.equal(
+      new Uint8Array([0xab]),
+    );
+  },
+);
+
+test(SUITE, '[Node.js] Test hex strings and bad hex strings', () => {
+  expect(toU8(stringToBuffer('abcdxx', 'hex'))).to.deep.equal(
+    new Uint8Array([0xab, 0xcd]),
+  );
+  expect(toU8(stringToBuffer('xxabcd', 'hex'))).to.deep.equal(
+    new Uint8Array([]),
+  );
+  expect(toU8(stringToBuffer('cdxxab', 'hex'))).to.deep.equal(
+    new Uint8Array([0xcd]),
+  );
+
+  const bytes = new Uint8Array(256);
+  for (let i = 0; i < 256; i++) {
+    bytes[i] = i;
+  }
+
+  const hex = bufferToString(bytes.buffer as ArrayBuffer, 'hex');
+  const badHex = `${hex.slice(0, 256)}xx${hex.slice(256, 510)}`;
+  expect(toU8(stringToBuffer(badHex, 'hex'))).to.deep.equal(
+    bytes.slice(0, 128),
+  );
 });
 
 // --- Base64 ---
@@ -658,18 +690,22 @@ test(SUITE, 'ascii encode strips high bit', () => {
   expect(str.charCodeAt(1)).to.equal(0x48); // 0xC8 & 0x7F = 0x48
 });
 
-test(SUITE, 'ascii decode strips high bit', () => {
-  const str = String.fromCharCode(0xc8); // above 0x7F
-  const ab = stringToBuffer(str, 'ascii');
-  expect(toU8(ab)[0]).to.equal(0x48); // 0xC8 & 0x7F = 0x48
-});
-
 test(SUITE, 'ascii roundtrip printable ASCII', () => {
   const str = 'Hello, World! 123';
   const ab = stringToBuffer(str, 'ascii');
   expect(bufferToString(ab, 'ascii')).to.equal(str);
 });
 
+test(
+  SUITE,
+  '[Node.js] Test for proper ascii Encoding, length should be 4',
+  () => {
+    expect(toU8(stringToBuffer('\u00fcber', 'ascii'))).to.deep.equal(
+      new Uint8Array([252, 98, 101, 114]),
+    );
+  },
+);
+
 test(
   SUITE,
   "[Node.js] ASCII conversion in node.js simply masks off the high bits, it doesn't do transliteration.",

packages/react-native-quick-crypto/cpp/utils/HybridUtils.cpp

@@ -35,16 +35,13 @@ namespace {
   }
 
   std::vector<uint8_t> decodeHex(const std::string& hex) {
-    if (hex.length() % 2 != 0) {
-      throw std::runtime_error("Invalid hex string length");
-    }
     std::vector<uint8_t> result;
     result.reserve(hex.length() / 2);
-    for (size_t i = 0; i < hex.length(); i += 2) {
+    for (size_t i = 0; i + 1 < hex.length(); i += 2) {
       int hi = hexCharToVal(hex[i]);
       int lo = hexCharToVal(hex[i + 1]);
       if (hi < 0 || lo < 0) {
-        throw std::runtime_error("Invalid hex character");
+        break;
       }
       result.push_back(static_cast<uint8_t>((hi << 4) | lo));
     }
@@ -192,9 +189,6 @@ std::shared_ptr<ArrayBuffer> HybridUtils::stringToBuffer(const std::string& str,
   }
   if (encoding == "ascii") {
     auto decoded = decodeLatin1(str);
-    for (auto& b : decoded) {
-      b &= 0x7F;
-    }
     return ArrayBuffer::move(std::move(decoded));
   }
   throw std::runtime_error("Unsupported encoding: " + encoding);