Escape JSON strings correctly for error messages (microsoft#44)

* Escape JSON strings correctly * Add test examples with lots of carriage returns
tmccrmck · Apr 22, 2019 · 71227be · 71227be
1 parent 16cbbfa
commit 71227be
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Showing 3 changed files with 93 additions and 6 deletions.
diff --git a/onnxruntime/hosting/http/json_handling.cc b/onnxruntime/hosting/http/json_handling.cc
@@ -1,6 +1,9 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
+#include <sstream>
+#include <iomanip>
+
 #include <boost/beast/core.hpp>
 #include <google/protobuf/util/json_util.h>
 
@@ -32,7 +35,31 @@ protobufutil::Status GenerateResponseInJson(const onnxruntime::hosting::PredictR
 }
 
 std::string CreateJsonError(const http::status error_code, const std::string& error_message) {
- return R"({"error_code": )" + std::to_string(int(error_code)) + R"(, "error_message": ")" + error_message + R"(" })" + "\n";
+ auto escaped_message = escape_string(error_message);
+ return R"({"error_code": )" + std::to_string(int(error_code)) + R"(, "error_message": ")" + escaped_message + R"("})" + "\n";
+}
+
+std::string escape_string(const std::string& message) {
+ std::ostringstream o;
+ for (char c : message) {
+ switch (c) {
+ case '"': o << "\\\""; break;
+ case '\\': o << "\\\\"; break;
+ case '\b': o << "\\b"; break;
+ case '\f': o << "\\f"; break;
+ case '\n': o << "\\n"; break;
+ case '\r': o << "\\r"; break;
+ case '\t': o << "\\t"; break;
+ default:
+ if ('\x00' <= c && c <= '\x1f') {
+ o << "\\u"
+ << std::hex << std::setw(4) << std::setfill('0') << (int)c;
+ } else {
+ o << c;
+ }
+ }
+ }
+ return o.str();
 }
 
 } // namespace hosting

diff --git a/onnxruntime/hosting/http/json_handling.h b/onnxruntime/hosting/http/json_handling.h
@@ -25,6 +25,10 @@ google::protobuf::util::Status GenerateResponseInJson(const onnxruntime::hosting
 // Constructs JSON error message from error code object and error message
 std::string CreateJsonError(http::status error_code, const std::string& error_message);
 
+// Escapes a string following the JSON standard
+// Mostly taken from here: https://stackoverflow.com/questions/7724448/simple-json-string-escape-for-c/33799784#33799784
+std::string escape_string(const std::string& message);
+
 } // namespace hosting
 } // namespace onnxruntime