Added decode error codes and exceptions

include/jwt/base64.hpp

@@ -282,7 +282,8 @@ std::string base64_uri_decode(const char* data, size_t len)
 
   size_t i = 0;
 
-  for (; i < len; ++i) {
+  for (; i < len; ++i) 
+  {
     switch (data[i]) {
     case '-':
       uri_dec[i] = '+';

include/jwt/error_codes.hpp

@@ -21,11 +21,25 @@ enum class AlgorithmFailureSource
 {
 };
 
+/**
+ * Decode error conditions
+ */
+enum class DecodeErrc
+{
+  JsonParseError = 1,
+  AlgHeaderMiss,
+  TypHeaderMiss,
+  TypMismatch,
+};
 
 /**
  */
 std::error_code make_error_code(AlgorithmErrc err);
 
+/**
+ */
+std::error_code make_error_code(DecodeErrc err);
+
 } // END namespace jwt
 
 
@@ -37,6 +51,9 @@ namespace std
 {
   template <>
   struct is_error_code_enum<jwt::AlgorithmErrc> : true_type {};
+
+  template <>
+  struct is_error_code_enum<jwt::DecodeErrc>: true_type {};
 }
 
 #include "jwt/impl/error_codes.ipp"

include/jwt/exceptions.hpp

@@ -29,6 +29,19 @@ private:
   const char* msg_ = nullptr;
 };
 
+/**
+ */
+class DecodeError final: public std::runtime_error
+{
+public:
+  /**
+   */
+  DecodeError(std::string msg)
+    : std::runtime_error(std::move(msg))
+  {
+  }
+};
+
 
 } // END namespace jwt
 

include/jwt/impl/error_codes.ipp

@@ -30,9 +30,38 @@ struct AlgorithmErrCategory: std::error_category
   }
 };
 
+/**
+ */
+struct DecodeErrorCategory: std::error_category
+{
+  const char* name() const noexcept override
+  {
+    return "decode";
+  }
+
+  std::string message(int ev) const override
+  {
+    switch (static_cast<DecodeErrc>(ev))
+    {
+    case DecodeErrc::AlgHeaderMiss:
+      return "missing algorithm header";
+    case DecodeErrc::TypHeaderMiss:
+      return "missing type header";
+    case DecodeErrc::TypMismatch:
+      return "type mismatch";
+    case DecodeErrc::JsonParseError:
+      return "json parse failed";
+    };
+
+    assert (0 && "Code not reached");
+  }
+};
+
 // Create global object for the error categories
 const AlgorithmErrCategory theAlgorithmErrCategory {};
 
+const DecodeErrorCategory theDecodeErrorCategory {};
+
 }
 
 
@@ -42,6 +71,11 @@ std::error_code make_error_code(AlgorithmErrc err)
   return { static_cast<int>(err), theAlgorithmErrCategory };
 }
 
+std::error_code make_error_code(DecodeErrc err)
+{
+  return { static_cast<int>(err), theDecodeErrorCategory };
+}
+
 
 } // END namespace jwt
 

include/jwt/impl/jwt.ipp

@@ -36,40 +36,80 @@ std::ostream& operator<< (std::ostream& os, const T& obj)
 
 //========================================================================
 
-void jwt_header::decode(const string_view enc_str)
+void jwt_header::decode(const string_view enc_str, std::error_code& ec) noexcept
 {
+  ec.clear();
   std::string json_str = base64_decode(enc_str);
-  json_t obj = json_t::parse(std::move(json_str));
+  json_t obj;
+
+  try {
+    obj = json_t::parse(std::move(json_str));
+  } catch(const std::exception& e) {
+    ec = DecodeErrc::JsonParseError;
+    return;
+  }
 
   //Look for the algorithm field
   auto alg_itr = obj.find("alg");
-  assert (alg_itr != obj.end() && "Algorithm header is missing");
-  std::error_code ec;
+  if (alg_itr == obj.end()) {
+    ec = DecodeErrc::AlgHeaderMiss;
+    return;
+  }
 
   alg_ = str_to_alg(alg_itr.value().get<std::string>());
 
-  if (alg_ != algorithm::NONE) {
+  if (alg_ != algorithm::NONE)
+  {
     auto itr = obj.find("typ");
     if (itr == obj.end()) {
-      //TODO: set error code
+      ec = DecodeErrc::TypHeaderMiss;
       return;
     }
-    auto typ = itr.value().get<std::string>();
+
+    const auto& typ = itr.value().get<std::string>();
     if (strcasecmp(typ.c_str(), "JWT")) {
-      //TODO: set error code
+      ec = DecodeErrc::TypMismatch;
       return;
     }
+
     typ_ = str_to_type(typ);
+  } else {
+    //TODO:
   }
 
   return;
 }
 
-
-void jwt_payload::decode(const string_view enc_str)
+void jwt_header::decode(const string_view enc_str) throw(DecodeError)
 {
+  std::error_code ec;
+  decode(enc_str, ec);
+  if (ec) {
+    throw DecodeError(ec.message());
+  }
+  return;
+}
+
+void jwt_payload::decode(const string_view enc_str, std::error_code& ec) noexcept
+{
+  ec.clear();
   std::string json_str = base64_decode(enc_str);
+  try {
     payload_ = json_t::parse(std::move(json_str));
+  } catch(const std::exception& e) {
+    ec = DecodeErrc::JsonParseError;
+    return;
+  }
+  return;
+}
+
+void jwt_payload::decode(const string_view enc_str) throw(DecodeError)
+{
+  std::error_code ec;
+  decode(enc_str, ec);
+  if (ec) {
+    throw DecodeError(ec.message());
+  }
   return;
 }
 
@@ -306,9 +346,9 @@ jwt_object jwt_decode(const string_view encoded_str, const string_view key, bool
 
   auto parts = jwt_object::three_parts(encoded_str);
 
-  //throws verification error
+  //throws decode error
   jobj.header(jwt_header{parts[0]});
-  //throws verification error
+  //throws decode error
   jobj.payload(jwt_payload{parts[1]});
 
   jwt_signature jsign{key};

include/jwt/jwt.hpp

@@ -12,6 +12,7 @@
 #include "jwt/algorithm.hpp"
 #include "jwt/string_view.hpp"
 #include "jwt/parameters.hpp"
+#include "jwt/exceptions.hpp"
 #include "jwt/json/json.hpp"
 
 // For convenience
@@ -237,9 +238,13 @@ public: // Exposed APIs
     return base64_encode(pprint);
   }
 
-  /*!
+  /**
    */
-  void decode(const string_view enc_str);
+  void decode(const string_view enc_str, std::error_code& ec) noexcept;
+
+  /**
+   */
+  void decode(const string_view enc_str) throw(DecodeError);
 
   /*!
    */
@@ -350,8 +355,11 @@ public: // Exposed APIs
 
   /**
    */
-  //TODO: what about error_code ?
-  void decode(const string_view enc_str);
+  void decode(const string_view enc_str, std::error_code& ec) noexcept;
+
+  /**
+   */
+  void decode(const string_view enc_str) throw(DecodeError);
 
   /**
    */