🐛 fixing CBOR's indefinity length strings #961

Beside the fix discussed in #961, we also had to re-adjust a test case. It seems that it was failing before, and I "fixed" it to work with the broken implementation...

README.md

@@ -969,6 +969,8 @@ I deeply appreciate the help of the following people.
 - [zerodefect](https://github.com/zerodefect) fixed a compiler warning.
 - [Kert](https://github.com/kaidokert) allowed to template the string type in the serialization and added the possibility to override the exceptional behavior.
 - [mark-99](https://github.com/mark-99) helped fixing an ICC error.
+- [Patrik Huber](https://github.com/patrikhuber) fixed links in the README file.
+- [johnfb](https://github.com/johnfb) found a bug in the implementation of CBOR's indefinite length strings.
 
 Thanks a lot for helping out! Please [let me know](mailto:mail@nlohmann.me) if I forgot someone.
 

include/nlohmann/detail/input/binary_reader.hpp

@@ -948,8 +948,7 @@ class binary_reader
                 string_t result;
                 while (get() != 0xFF)
                 {
-                    unexpect_eof();
+                    result.append(get_cbor_string());
-                    result.push_back(static_cast<char>(current));
                 }
                 return result;
             }

single_include/nlohmann/json.hpp

@@ -5768,8 +5768,7 @@ class binary_reader
                 string_t result;
                 while (get() != 0xFF)
                 {
-                    unexpect_eof();
+                    result.append(get_cbor_string());
-                    result.push_back(static_cast<char>(current));
                 }
                 return result;
             }

test/src/unit-cbor.cpp

@@ -1381,7 +1381,7 @@ TEST_CASE("single CBOR roundtrip")
         std::ifstream f_json(filename);
         json j1 = json::parse(f_json);
 
-        // parse MessagePack file
+        // parse CBOR file
         std::ifstream f_cbor(filename + ".cbor", std::ios::binary);
         std::vector<uint8_t> packed((std::istreambuf_iterator<char>(f_cbor)),
                                     std::istreambuf_iterator<char>());
@@ -1921,7 +1921,7 @@ TEST_CASE("examples from RFC 7049 Appendix A")
         CHECK(json::parse("\"\\ud800\\udd51\"") == json::from_cbor(std::vector<uint8_t>({0x64, 0xf0, 0x90, 0x85, 0x91})));
 
         // indefinite length strings
-        CHECK(json::parse("\"streaming\"") == json::from_cbor(std::vector<uint8_t>({0x7f, 0x73, 0x74, 0x72, 0x65, 0x61, 0x6d, 0x69, 0x6e, 0x67, 0xff})));
+        CHECK(json::parse("\"streaming\"") == json::from_cbor(std::vector<uint8_t>({0x7f, 0x65, 0x73, 0x74, 0x72, 0x65, 0x61, 0x64, 0x6d, 0x69, 0x6e, 0x67, 0xff})));
     }
 
     SECTION("arrays")

test/src/unit-regression.cpp

@@ -1408,4 +1408,19 @@ TEST_CASE("regression tests")
                                  "path": "/a/b/c"}])"_json),
                           "[json.exception.out_of_range.403] key 'a' not found");
     }
+
+    SECTION("issue #961 - incorrect parsing of indefinite length CBOR strings")
+    {
+        std::vector<uint8_t> v_cbor =
+        {
+            0x7F,
+            0x64,
+            'a', 'b', 'c', 'd',
+            0x63,
+            '1', '2', '3',
+            0xFF
+        };
+        json j = json::from_cbor(v_cbor);
+        CHECK(j == "abcd123");
+    }
 }