crypto: implement randomuuid

jasnell · danielleadams · commit 4e4deca90d5b · 2021-01-12T07:10:48.000-05:00
Signed-off-by: James M Snell <jasnell@gmail.com> PR-URL: #36729 Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Michaël Zasso <targos@protonmail.com> Reviewed-By: Filip Skokan <panva.ip@gmail.com> Reviewed-By: Ben Coe <bencoe@gmail.com>
diff --git a/benchmark/crypto/randomUUID.js b/benchmark/crypto/randomUUID.js
@@ -0,0 +1,17 @@
+'use strict';
+
+const common = require('../common.js');
+const { randomUUID } = require('crypto');
+
+const bench = common.createBenchmark(main, {
+  n: [1e7],
+  disableEntropyCache: [0, 1],
+});
+
+function main({ n, disableEntropyCache }) {
+  disableEntropyCache = !!disableEntropyCache;
+  bench.start();
+  for (let i = 0; i < n; ++i)
+    randomUUID({ disableEntropyCache });
+  bench.end(n);
+}
diff --git a/doc/api/crypto.md b/doc/api/crypto.md
@@ -3160,6 +3160,21 @@ const n = crypto.randomInt(1, 7);
 console.log(`The dice rolled: ${n}`);
 ```
 
+### `crypto.randomUUID([options])`
+<!-- YAML
+added: REPLACEME
+-->
+
+* `options` {Object}
+  * `disableEntropyCache` {boolean} By default, to improve performance,
+    Node.js will pre-emptively generate and persistently cache enough
+    random data to generate up to 128 random UUIDs. To generate a UUID
+    without using the cache, set `disableEntropyCache` to `true`.
+    **Defaults**: `false`.
+* Returns: {string}
+
+Generates a random [RFC 4122][] Version 4 UUID.
+
 ### `crypto.scrypt(password, salt, keylen[, options], callback)`
 <!-- YAML
 added: v10.5.0
@@ -3929,6 +3944,7 @@ See the [list of SSL OP Flags][] for details.
 [RFC 3526]: https://www.rfc-editor.org/rfc/rfc3526.txt
 [RFC 3610]: https://www.rfc-editor.org/rfc/rfc3610.txt
 [RFC 4055]: https://www.rfc-editor.org/rfc/rfc4055.txt
+[RFC 4122]: https://www.rfc-editor.org/rfc/rfc4122.txt
 [RFC 5208]: https://www.rfc-editor.org/rfc/rfc5208.txt
 [Web Crypto API documentation]: webcrypto.md
 [`Buffer`]: buffer.md
diff --git a/lib/crypto.js b/lib/crypto.js
@@ -53,7 +53,8 @@ const {
   randomBytes,
   randomFill,
   randomFillSync,
-  randomInt
+  randomInt,
+  randomUUID,
 } = require('internal/crypto/random');
 const {
   pbkdf2,
@@ -199,6 +200,7 @@ module.exports = {
   randomFill,
   randomFillSync,
   randomInt,
+  randomUUID,
   scrypt,
   scryptSync,
   sign: signOneShot,
diff --git a/lib/internal/crypto/random.js b/lib/internal/crypto/random.js
@@ -12,24 +12,28 @@ const {
   RandomBytesJob,
   kCryptoJobAsync,
   kCryptoJobSync,
+  secureBuffer,
 } = internalBinding('crypto');
 
 const {
   lazyDOMException,
 } = require('internal/crypto/util');
 
-const { kMaxLength } = require('buffer');
+const { Buffer, kMaxLength } = require('buffer');
 
 const {
   codes: {
     ERR_INVALID_ARG_TYPE,
     ERR_OUT_OF_RANGE,
+    ERR_OPERATION_FAILED,
   }
 } = require('internal/errors');
 
 const {
   validateNumber,
+  validateBoolean,
   validateCallback,
+  validateObject,
 } = require('internal/validators');
 
 const {
@@ -281,10 +285,114 @@ function getRandomValues(data) {
   return data;
 }
 
+// Implements an RFC 4122 version 4 random UUID.
+// To improve performance, random data is generated in batches
+// large enough to cover kBatchSize UUID's at a time. The uuidData
+// and uuid buffers are reused. Each call to randomUUID() consumes
+// 16 bytes from the buffer.
+
+const kHexDigits = [
+  48, 49, 50, 51, 52, 53, 54, 55,
+  56, 57, 97, 98, 99, 100, 101, 102
+];
+
+const kBatchSize = 128;
+let uuidData;
+let uuidNotBuffered;
+let uuid;
+let uuidBatch = 0;
+
+function getBufferedUUID() {
+  if (uuidData === undefined) {
+    uuidData = secureBuffer(16 * kBatchSize);
+    if (uuidData === undefined)
+      throw new ERR_OPERATION_FAILED('Out of memory');
+  }
+
+  if (uuidBatch === 0) randomFillSync(uuidData);
+  uuidBatch = (uuidBatch + 1) % kBatchSize;
+  return uuidData.slice(uuidBatch * 16, (uuidBatch * 16) + 16);
+}
+
+function randomUUID(options) {
+  if (options !== undefined)
+    validateObject(options, 'options');
+  const {
+    disableEntropyCache = false,
+  } = { ...options };
+
+  validateBoolean(disableEntropyCache, 'options.disableEntropyCache');
+
+  if (uuid === undefined) {
+    uuid = Buffer.alloc(36, '-');
+    uuid[14] = 52; // '4', identifies the UUID version
+  }
+
+  let uuidBuf;
+  if (!disableEntropyCache) {
+    uuidBuf = getBufferedUUID();
+  } else {
+    uuidBuf = uuidNotBuffered;
+    if (uuidBuf === undefined)
+      uuidBuf = uuidNotBuffered = secureBuffer(16);
+    if (uuidBuf === undefined)
+      throw new ERR_OPERATION_FAILED('Out of memory');
+    randomFillSync(uuidBuf);
+  }
+
+  // Variant byte: 10xxxxxx (variant 1)
+  uuidBuf[8] = (uuidBuf[8] & 0x3f) | 0x80;
+
+  // This function is structured the way it is for performance.
+  // The uuid buffer stores the serialization of the random
+  // bytes from uuidData.
+  // xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
+  let n = 0;
+  uuid[0] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[1] = kHexDigits[uuidBuf[n++] & 0xf];
+  uuid[2] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[3] = kHexDigits[uuidBuf[n++] & 0xf];
+  uuid[4] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[5] = kHexDigits[uuidBuf[n++] & 0xf];
+  uuid[6] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[7] = kHexDigits[uuidBuf[n++] & 0xf];
+  // -
+  uuid[9] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[10] = kHexDigits[uuidBuf[n++] & 0xf];
+  uuid[11] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[12] = kHexDigits[uuidBuf[n++] & 0xf];
+  // -
+  // 4, uuid[14] is set already...
+  uuid[15] = kHexDigits[uuidBuf[n++] & 0xf];
+  uuid[16] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[17] = kHexDigits[uuidBuf[n++] & 0xf];
+  // -
+  uuid[19] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[20] = kHexDigits[uuidBuf[n++] & 0xf];
+  uuid[21] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[22] = kHexDigits[uuidBuf[n++] & 0xf];
+  // -
+  uuid[24] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[25] = kHexDigits[uuidBuf[n++] & 0xf];
+  uuid[26] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[27] = kHexDigits[uuidBuf[n++] & 0xf];
+  uuid[28] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[29] = kHexDigits[uuidBuf[n++] & 0xf];
+  uuid[30] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[31] = kHexDigits[uuidBuf[n++] & 0xf];
+  uuid[32] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[33] = kHexDigits[uuidBuf[n++] & 0xf];
+  uuid[34] = kHexDigits[uuidBuf[n] >> 4];
+  uuid[35] = kHexDigits[uuidBuf[n] & 0xf];
+
+  return uuid.latin1Slice(0, 36);
+}
+
 module.exports = {
   randomBytes,
   randomFill,
   randomFillSync,
   randomInt,
   getRandomValues,
+  randomUUID,
 };
diff --git a/src/crypto/crypto_util.cc b/src/crypto/crypto_util.cc
@@ -31,6 +31,8 @@ using v8::NewStringType;
 using v8::Nothing;
 using v8::Object;
 using v8::String;
+using v8::Uint32;
+using v8::Uint8Array;
 using v8::Value;
 
 namespace crypto {
@@ -587,6 +589,36 @@ CryptoJobMode GetCryptoJobMode(v8::Local<v8::Value> args) {
   return static_cast<CryptoJobMode>(mode);
 }
 
+namespace {
+// SecureBuffer uses openssl to allocate a Uint8Array using
+// OPENSSL_secure_malloc. Because we do not yet actually
+// make use of secure heap, this has the same semantics as
+// using OPENSSL_malloc. However, if the secure heap is
+// initialized, SecureBuffer will automatically use it.
+void SecureBuffer(const FunctionCallbackInfo<Value>& args) {
+  CHECK(args[0]->IsUint32());
+  Environment* env = Environment::GetCurrent(args);
+  uint32_t len = args[0].As<Uint32>()->Value();
+  char* data = static_cast<char*>(OPENSSL_secure_malloc(len));
+  if (data == nullptr) {
+    // There's no memory available for the allocation.
+    // Return nothing.
+    return;
+  }
+  memset(data, 0, len);
+  std::shared_ptr<BackingStore> store =
+      ArrayBuffer::NewBackingStore(
+          data,
+          len,
+          [](void* data, size_t len, void* deleter_data) {
+            OPENSSL_secure_clear_free(data, len);
+          },
+          data);
+  Local<ArrayBuffer> buffer = ArrayBuffer::New(env->isolate(), store);
+  args.GetReturnValue().Set(Uint8Array::New(buffer, 0, len));
+}
+}  // namespace
+
 namespace Util {
 void Initialize(Environment* env, Local<Object> target) {
 #ifndef OPENSSL_NO_ENGINE
@@ -600,6 +632,8 @@ void Initialize(Environment* env, Local<Object> target) {
 
   NODE_DEFINE_CONSTANT(target, kCryptoJobAsync);
   NODE_DEFINE_CONSTANT(target, kCryptoJobSync);
+
+  env->SetMethod(target, "secureBuffer", SecureBuffer);
 }
 }  // namespace Util
 
diff --git a/test/parallel/test-crypto-randomuuid.js b/test/parallel/test-crypto-randomuuid.js
@@ -0,0 +1,58 @@
+'use strict';
+
+const common = require('../common');
+
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+
+const assert = require('assert');
+const {
+  randomUUID,
+} = require('crypto');
+
+const last = new Set([
+  '00000000-0000-0000-0000-000000000000'
+]);
+
+function testMatch(uuid) {
+  assert.match(
+    uuid,
+    /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/);
+}
+
+// Generate a number of UUID's to make sure we're
+// not just generating the same value over and over
+// and to make sure the batching changes the random
+// bytes.
+for (let n = 0; n < 130; n++) {
+  const uuid = randomUUID();
+  assert(!last.has(uuid));
+  last.add(uuid);
+  assert.strictEqual(typeof uuid, 'string');
+  assert.strictEqual(uuid.length, 36);
+  testMatch(uuid);
+
+  // Check that version 4 identifier was populated.
+  assert.strictEqual(
+    Buffer.from(uuid.substr(14, 2), 'hex')[0] & 0x40, 0x40);
+
+  // Check that clock_seq_hi_and_reserved was populated with reserved bits.
+  assert.strictEqual(
+    Buffer.from(uuid.substr(19, 2), 'hex')[0] & 0b1100_0000, 0b1000_0000);
+}
+
+// Test non-buffered UUID's
+{
+  testMatch(randomUUID({ disableEntropyCache: true }));
+  testMatch(randomUUID({ disableEntropyCache: true }));
+  testMatch(randomUUID({ disableEntropyCache: true }));
+  testMatch(randomUUID({ disableEntropyCache: true }));
+
+  assert.throws(() => randomUUID(1), {
+    code: 'ERR_INVALID_ARG_TYPE'
+  });
+
+  assert.throws(() => randomUUID({ disableEntropyCache: '' }), {
+    code: 'ERR_INVALID_ARG_TYPE'
+  });
+}
