Add support for logging to JSON.

Source/common/SNTCommonEnums.h

@@ -121,6 +121,7 @@ typedef NS_ENUM(NSInteger, SNTEventLogType) {
   SNTEventLogTypeSyslog,
   SNTEventLogTypeFilelog,
   SNTEventLogTypeProtobuf,
+  SNTEventLogTypeJSON,
   SNTEventLogTypeNull,
 };
 

Source/common/SNTConfigurator.m

@@ -794,6 +794,8 @@ - (SNTEventLogType)eventLogType {
     return SNTEventLogTypeSyslog;
   } else if ([logType isEqualToString:@"null"]) {
     return SNTEventLogTypeNull;
+  } else if ([logType isEqualToString:@"json"]) {
+    return SNTEventLogTypeFilelog;
   } else if ([logType isEqualToString:@"file"]) {
     return SNTEventLogTypeFilelog;
   } else {

Source/santad/Logs/EndpointSecurity/Logger.mm

@@ -72,6 +72,11 @@
         Protobuf::Create(esapi, std::move(decision_cache)),
         Spool::Create([spool_log_path UTF8String], spool_dir_size_threshold,
                       spool_file_size_threshold, spool_flush_timeout_ms));
+    case SNTEventLogTypeJSON:
+      return std::make_unique<Logger>(
+        Protobuf::Create(esapi, std::move(decision_cache), true),
+        File::Create(event_log_path, kFlushBufferTimeoutMS, kBufferBatchSizeBytes,
+                     kMaxExpectedWriteSizeBytes));
     default: LOGE(@"Invalid log type: %ld", log_type); return nullptr;
   }
 }

Source/santad/Logs/EndpointSecurity/LoggerTest.mm

@@ -125,6 +125,11 @@ LoggerPeer logger(
                                      @"/tmp/spool", 1, 1, 1));
   XCTAssertNotEqual(nullptr, std::dynamic_pointer_cast<Protobuf>(logger.Serializer()));
   XCTAssertNotEqual(nullptr, std::dynamic_pointer_cast<Spool>(logger.Writer()));
+
+  logger = LoggerPeer(Logger::Create(mockESApi, SNTEventLogTypeJSON, nil, @"/tmp/temppy",
+                                     @"/tmp/spool", 1, 1, 1));
+  XCTAssertNotEqual(nullptr, std::dynamic_pointer_cast<Protobuf>(logger.Serializer()));
+  XCTAssertNotEqual(nullptr, std::dynamic_pointer_cast<File>(logger.Writer()));
 }
 
 - (void)testLog {

Source/santad/Logs/EndpointSecurity/Serializers/Protobuf.h

@@ -33,11 +33,11 @@ class Protobuf : public Serializer {
  public:
   static std::shared_ptr<Protobuf> Create(
     std::shared_ptr<santa::santad::event_providers::endpoint_security::EndpointSecurityAPI> esapi,
-    SNTDecisionCache *decision_cache);
+    SNTDecisionCache *decision_cache, bool json = false);
 
   Protobuf(
     std::shared_ptr<santa::santad::event_providers::endpoint_security::EndpointSecurityAPI> esapi,
-    SNTDecisionCache *decision_cache);
+    SNTDecisionCache *decision_cache, bool json = false);
 
   std::vector<uint8_t> SerializeMessage(
     const santa::santad::event_providers::endpoint_security::EnrichedClose &) override;
@@ -87,6 +87,9 @@ class Protobuf : public Serializer {
   std::vector<uint8_t> FinalizeProto(::santa::pb::v1::SantaMessage *santa_msg);
 
   std::shared_ptr<santa::santad::event_providers::endpoint_security::EndpointSecurityAPI> esapi_;
+  // Toggle for transforming protobuf output to its JSON form.
+  // See https://protobuf.dev/programming-guides/proto3/#json
+  bool json_;
 };
 
 }  // namespace santa::santad::logs::endpoint_security::serializers

Source/santad/Logs/EndpointSecurity/Serializers/Protobuf.mm

@@ -38,6 +38,8 @@
 
 using google::protobuf::Arena;
 using google::protobuf::Timestamp;
+using google::protobuf::util::JsonPrintOptions;
+using google::protobuf::util::MessageToJsonString;
 
 using santa::common::NSStringToUTF8StringView;
 using santa::santad::event_providers::endpoint_security::EndpointSecurityAPI;
@@ -66,12 +68,12 @@
 namespace santa::santad::logs::endpoint_security::serializers {
 
 std::shared_ptr<Protobuf> Protobuf::Create(std::shared_ptr<EndpointSecurityAPI> esapi,
-                                           SNTDecisionCache *decision_cache) {
-  return std::make_shared<Protobuf>(esapi, std::move(decision_cache));
+                                           SNTDecisionCache *decision_cache, bool json) {
+  return std::make_shared<Protobuf>(esapi, std::move(decision_cache), json);
 }
 
-Protobuf::Protobuf(std::shared_ptr<EndpointSecurityAPI> esapi, SNTDecisionCache *decision_cache)
-    : Serializer(std::move(decision_cache)), esapi_(esapi) {}
+Protobuf::Protobuf(std::shared_ptr<EndpointSecurityAPI> esapi, SNTDecisionCache *decision_cache, bool json)
+    : Serializer(std::move(decision_cache)), esapi_(esapi), json_(json) {}
 
 static inline void EncodeTimestamp(Timestamp *timestamp, struct timespec ts) {
   timestamp->set_seconds(ts.tv_sec);
@@ -387,6 +389,26 @@ static inline void EncodeCertificateInfo(::pbv1::CertificateInfo *pb_cert_info,
 }
 
 std::vector<uint8_t> Protobuf::FinalizeProto(::pbv1::SantaMessage *santa_msg) {
+  if (this->_) {
+    //TODO: Profile this. It's probably not the most efficient way to do this.
+    JsonPrintOptions options;
+    options.always_print_enums_as_ints = false;
+    options.always_print_primitive_fields = true;
+    options.preserve_proto_field_names = true;
+    std::string json;
+
+    google::protobuf::util::Status status = MessageToJsonString(*santa_msg, &json, options);
+
+    if (!status.ok()) {
+      LOG(ERROR) << "Failed to convert protobuf to JSON: " << status.error_message();
+    }
+
+    std::vector<uint8_t> vec(json.begin(), json.end());
+    // Add a newline to the end of the JSON row.
+    vec.push_back('\n');
+    return vec;
+  }
+
   std::vector<uint8_t> vec(santa_msg->ByteSizeLong());
   santa_msg->SerializeWithCachedSizesToArray(vec.data());
   return vec;

docs/deployment/configuration.md

@@ -54,7 +54,8 @@ also known as mobileconfig files, which are in an Apple-specific XML format.
 | MachineOwnerKey                   | String     | The key to use on MachineOwnerPlist.     |
 | MachineIDPlist                    | String     | The path to a plist that contains the MachineOwnerKey / value pair. |
 | MachineIDKey                      | String     | The key to use on MachineIDPlist.        |
-| EventLogType                      | String     | Defines how event logs are stored. Options are 1) syslog: Sent to ASL or ULS (if built with the 10.12 SDK or later). 2) filelog: Sent to a file on disk. Use EventLogPath to specify a path. 3) protobuf (BETA): Sent to file on disk using a maildir-like format. 4) null: Don't output any event logs. Defaults to filelog.      |
+| EventLogType                      | String     | Defines how event logs are stored. Options are 1) syslog: Sent to ASL or ULS (if built with the 10.12 SDK or later). 2) filelog: Sent to a file on disk. Use EventLogPath to specify a path. 3) protobuf (BETA): Sent to file on disk using a maildir-like format. 4) json: Same as file but output is one JSON object per line 5) null: Don't output any event logs. Defaults to filelog.      |
+| EventLogPath                      | String     | If EventLogType is set to filelog or json, EventLogPath will provide the path to save logs. Defaults to /var/db/santa/santa.log. If you change this value ensure you also update com.google.santa.newsyslog.conf with the new path.        |
 | EventLogPath                      | String     | If EventLogType is set to filelog, EventLogPath will provide the path to save logs. Defaults to /var/db/santa/santa.log. If you change this value ensure you also update com.google.santa.newsyslog.conf with the new path.        |
 | SpoolDirectory                    | String     | If EventLogType is set to protobuf, SpoolDirectory will provide the the base directory used to save files according to a maildir-like format. Defaults to /var/db/santa/spool. |
 | SpoolDirectoryFileSizeThresholdKB  | Integer    | If EventLogType is set to protobuf, SpoolDirectoryFileSizeThresholdKB defines the per-file size limit for files stored in the spool directory. Events are buffered in memory until this threshold would be exceeded (or SpoolDirectoryEventMaxFlushTimeSec is exceeded). Defaults to 100. |