fix(NODE-6300): make expressionMode required in C++ in makeExplicitEncryptionContext (mongodb-js#37)

Author: baileympearson

addon/mongocrypt.cc

@@ -589,13 +589,29 @@ Value MongoCrypt::MakeEncryptionContext(const CallbackInfo& info) {
 }
 
 Value MongoCrypt::MakeExplicitEncryptionContext(const CallbackInfo& info) {
-    std::unique_ptr<mongocrypt_ctx_t, MongoCryptContextDeleter> context(
-        mongocrypt_ctx_new(_mongo_crypt.get()));
-
     Uint8Array valueBuffer = Uint8ArrayFromValue(info[0], "value");
 
     Object options = info.Length() > 1 ? info[1].ToObject() : Object::New(info.Env());
 
+    if (!options.Get("expressionMode").IsBoolean()) {
+        throw TypeError::New(Env(), "option `expressionMode` is required.");
+    }
+
+    bool expression_mode = options.Get("expressionMode").ToBoolean();
+    ExplicitEncryptionContextInitFunction context_init_function =
+        expression_mode ? mongocrypt_ctx_explicit_encrypt_expression_init
+                        : mongocrypt_ctx_explicit_encrypt_init;
+
+    return MakeExplicitEncryptionContextInternal(context_init_function, valueBuffer, options);
+}
+
+Value MongoCrypt::MakeExplicitEncryptionContextInternal(
+    ExplicitEncryptionContextInitFunction context_init_function,
+    const Uint8Array& valueBuffer,
+    const Object& options) {
+    std::unique_ptr<mongocrypt_ctx_t, MongoCryptContextDeleter> context(
+        mongocrypt_ctx_new(_mongo_crypt.get()));
+
     if (!options.Get("keyId").IsUndefined()) {
         Uint8Array keyId = Uint8ArrayFromValue(options["keyId"], "keyId");
 
@@ -658,12 +674,7 @@ Value MongoCrypt::MakeExplicitEncryptionContext(const CallbackInfo& info) {
     std::unique_ptr<mongocrypt_binary_t, MongoCryptBinaryDeleter> binaryValue(
         Uint8ArrayToBinary(valueBuffer));
 
-    const bool isExpressionMode = options.Get("expressionMode").ToBoolean();
-
-    const bool status =
-        isExpressionMode
-            ? mongocrypt_ctx_explicit_encrypt_expression_init(context.get(), binaryValue.get())
-            : mongocrypt_ctx_explicit_encrypt_init(context.get(), binaryValue.get());
+    const bool status = context_init_function(context.get(), binaryValue.get());
 
     if (!status) {
         throw TypeError::New(Env(), errorStringFromStatus(context.get()));

addon/mongocrypt.h

@@ -56,6 +56,8 @@ namespace opensslcrypto {
 std::unique_ptr<CryptoHooks> createOpenSSLCryptoHooks();
 }
 
+typedef bool (*ExplicitEncryptionContextInitFunction)(mongocrypt_ctx_t*, mongocrypt_binary_t*);
+
 class MongoCrypt : public Napi::ObjectWrap<MongoCrypt> {
    public:
     static Napi::Function Init(Napi::Env env);
@@ -67,6 +69,9 @@ class MongoCrypt : public Napi::ObjectWrap<MongoCrypt> {
     Napi::Value MakeExplicitDecryptionContext(const Napi::CallbackInfo& info);
     Napi::Value MakeDataKeyContext(const Napi::CallbackInfo& info);
     Napi::Value MakeRewrapManyDataKeyContext(const Napi::CallbackInfo& info);
+    Napi::Value MakeExplicitEncryptionContextInternal(ExplicitEncryptionContextInitFunction init_fn,
+                                                      const Napi::Uint8Array& value,
+                                                      const Napi::Object& options);
 
     Napi::Value Status(const Napi::CallbackInfo& info);
     Napi::Value CryptSharedLibVersionInfo(const Napi::CallbackInfo& info);

package.json

@@ -23,6 +23,7 @@
     "check:clang-format": "clang-format --style=file:.clang-format --dry-run --Werror addon/*",
     "test": "mocha test",
     "prepare": "tsc",
+    "rebuild": "node-gyp rebuild",
     "prebuild": "prebuild --runtime napi --strip --verbose --all"
   },
   "author": {

test/bindings.test.ts

@@ -387,6 +387,20 @@ describe('MongoCryptConstructor', () => {
         ).to.be.instanceOf(MongoCryptContextCtor);
       });
     });
+
+    describe('options.expressionMode', function () {
+      it('throws if `expressionMode` is not defined', function () {
+        expect(() =>
+          mc.makeExplicitEncryptionContext(value, {
+            // minimum required arguments from libmongocrypt
+            keyId: keyId.buffer,
+            algorithm: 'Unindexed'
+          })
+        )
+          .to.throw(/option `expressionMode` is required./)
+          .to.be.instanceOf(TypeError);
+      });
+    });
   });
 });
 

test/crypto.test.ts

@@ -38,7 +38,8 @@ function createEncryptedDocument(mongoCrypt: MongoCrypt) {
 
   const ctx = mongoCrypt.makeExplicitEncryptionContext(BSON.serialize({ v }), {
     keyId: keyId.buffer,
-    algorithm
+    algorithm,
+    expressionMode: false
   });
 
   const getState = () => ctx.state;