MONGOCRYPT-463 check the collMod command for validator.$jsonSchema (

#441)

src/mongocrypt-ctx-encrypt.c

@@ -1935,8 +1935,9 @@ _try_empty_schema_for_create (mongocrypt_ctx_t *ctx)
    return true;
 }
 
-/* _try_schema_from_create_cmd tries to find a JSON schema included in a create
- * command by checking for "validator.$jsonSchema". Example:
+/* _try_schema_from_create_or_collMod_cmd tries to find a JSON schema included
+ * in a create or collMod command by checking for "validator.$jsonSchema".
+ * Example:
  * {
  *     "create" : "coll",
  *     "validator" : {
@@ -1947,18 +1948,23 @@ _try_empty_schema_for_create (mongocrypt_ctx_t *ctx)
  * }
  * If the "create" command does not include a JSON schema, an empty JSON schema
  * is returned. This is to avoid an unnecessary 'listCollections' command for
- * create. */
+ * create.
+ *
+ * If the "collMod" command does not include a JSON schema, a schema is later
+ * requested by entering the MONGOCRYPT_CTX_NEED_MONGO_COLLINFO state.
+ * This is because a "collMod" command may have sensitive data in the
+ * "validator" field.
+ */
 static bool
-_try_schema_from_create_cmd (mongocrypt_ctx_t *ctx)
+_try_schema_from_create_or_collMod_cmd (mongocrypt_ctx_t *ctx)
 {
    _mongocrypt_ctx_encrypt_t *ectx;
    mongocrypt_status_t *status = ctx->status;
 
    ectx = (_mongocrypt_ctx_encrypt_t *) ctx;
-   /* As a special case, use an empty schema for the 'create' command. */
    const char *cmd_name = ectx->cmd_name;
 
-   if (0 != strcmp (cmd_name, "create")) {
+   if (0 != strcmp (cmd_name, "create") && 0 != strcmp (cmd_name, "collMod")) {
       return true;
    }
 
@@ -2138,7 +2144,8 @@ mongocrypt_ctx_explicit_encrypt_init (mongocrypt_ctx_t *ctx,
    if (ctx->opts.index_type.set &&
        ctx->opts.index_type.value == MONGOCRYPT_INDEX_TYPE_EQUALITY &&
        !ctx->opts.contention_factor.set) {
-      return _mongocrypt_ctx_fail_w_msg (ctx, "contention factor is required for indexed algorithm");
+      return _mongocrypt_ctx_fail_w_msg (
+         ctx, "contention factor is required for indexed algorithm");
    }
 
    ectx = (_mongocrypt_ctx_encrypt_t *) ctx;
@@ -2523,7 +2530,7 @@ mongocrypt_ctx_encrypt_ismaster_done (mongocrypt_ctx_t *ctx)
       return false;
    }
    if (_mongocrypt_buffer_empty (&ectx->encrypted_field_config)) {
-      if (!_try_schema_from_create_cmd (ctx)) {
+      if (!_try_schema_from_create_or_collMod_cmd (ctx)) {
          return false;
       }
 

test/data/fle1-collMod/cmd-to-mongocryptd.json

@@ -0,0 +1,12 @@
+{
+    "collMod": "encryptedCollection",
+    "validator": {
+        "$jsonSchema": {
+            "bsonType": "object"
+        }
+    },
+    "jsonSchema": {
+        "bsonType": "object"
+    },
+    "isRemoteSchema": true
+}

test/data/fle1-collMod/cmd.json

@@ -0,0 +1,8 @@
+{
+    "collMod": "encryptedCollection",
+    "validator": {
+        "$jsonSchema": {
+            "bsonType": "object"
+        }
+    }
+}

test/data/fle1-collMod/insert/cmd.json

@@ -0,0 +1,8 @@
+{
+    "insert": "encryptedCollection",
+    "documents": [
+        {
+            "x": 1
+        }
+    ]
+}

test/data/fle1-collMod/insert/collinfo.json

@@ -0,0 +1,9 @@
+{
+    "options": {
+        "validator": {
+            "$jsonSchema": {
+                "bsonType": "object"
+            }
+        }
+    }
+}

test/data/fle1-collMod/mongocryptd-reply.json

@@ -0,0 +1,14 @@
+{
+    "ok": {
+        "$numberInt": "1"
+    },
+    "result": {
+        "collMod": "encryptedCollection",
+        "validator": {
+            "$jsonSchema": {
+                "bsonType": "object"
+            }
+        }
+    },
+    "hasEncryptedPlaceholders": false
+}

test/test-mongocrypt-ctx-encrypt.c

@@ -4379,6 +4379,64 @@ _test_encrypt_macos_no_ctr (_mongocrypt_tester_t *tester)
    mongocrypt_destroy (crypt);
 }
 
+/* If collMod contains a $jsonSchema, expect the same $jsonSchema to be used in
+ * the command to mongocryptd. This is a regression test for MONGOCRYPT-463. */
+static void
+_test_fle1_collmod_with_jsonSchema (_mongocrypt_tester_t *tester)
+{
+   mongocrypt_t *crypt =
+      _mongocrypt_tester_mongocrypt (TESTER_MONGOCRYPT_DEFAULT);
+
+   mongocrypt_ctx_t *ctx = mongocrypt_ctx_new (crypt);
+
+   ASSERT_OK (
+      mongocrypt_ctx_encrypt_init (
+         ctx, "db", -1, TEST_FILE ("./test/data/fle1-collMod/cmd.json")),
+      ctx);
+
+   ASSERT_STATE_EQUAL (mongocrypt_ctx_state (ctx),
+                       MONGOCRYPT_CTX_NEED_MONGO_MARKINGS);
+   {
+      mongocrypt_binary_t *cmd_to_mongocryptd = mongocrypt_binary_new ();
+
+      ASSERT_OK (mongocrypt_ctx_mongo_op (ctx, cmd_to_mongocryptd), ctx);
+      ASSERT_MONGOCRYPT_BINARY_EQUAL_BSON (
+         TEST_FILE ("./test/data/fle1-collMod/cmd-to-mongocryptd.json"),
+         cmd_to_mongocryptd);
+      mongocrypt_binary_destroy (cmd_to_mongocryptd);
+      ASSERT_OK (
+         mongocrypt_ctx_mongo_feed (
+            ctx, TEST_FILE ("./test/data/fle1-collMod/mongocryptd-reply.json")),
+         ctx);
+      ASSERT_OK (mongocrypt_ctx_mongo_done (ctx), ctx);
+   }
+
+   mongocrypt_ctx_destroy (ctx);
+   mongocrypt_destroy (crypt);
+}
+
+/* If collMod does not contain a $jsonSchema, expect a schema to be requested.
+ */
+static void
+_test_fle1_collmod_without_jsonSchema (_mongocrypt_tester_t *tester)
+{
+   mongocrypt_t *crypt =
+      _mongocrypt_tester_mongocrypt (TESTER_MONGOCRYPT_DEFAULT);
+
+   mongocrypt_ctx_t *ctx = mongocrypt_ctx_new (crypt);
+
+   ASSERT_OK (
+      mongocrypt_ctx_encrypt_init (
+         ctx, "db", -1, TEST_BSON ("{'collMod': 'encryptedCollection'}")),
+      ctx);
+
+   ASSERT_STATE_EQUAL (mongocrypt_ctx_state (ctx),
+                       MONGOCRYPT_CTX_NEED_MONGO_COLLINFO);
+
+   mongocrypt_ctx_destroy (ctx);
+   mongocrypt_destroy (crypt);
+}
+
 void
 _mongocrypt_tester_install_ctx_encrypt (_mongocrypt_tester_t *tester)
 {
@@ -4438,4 +4496,6 @@ _mongocrypt_tester_install_ctx_encrypt (_mongocrypt_tester_t *tester)
    INSTALL_TEST (_test_fle2_create);
    INSTALL_TEST (_test_fle2_create_bypass_query_analysis);
    INSTALL_TEST (_test_encrypt_macos_no_ctr);
+   INSTALL_TEST (_test_fle1_collmod_with_jsonSchema);
+   INSTALL_TEST (_test_fle1_collmod_without_jsonSchema);
 }