A header only library for creating and validating [JSON Web Tokens](https://tools.ietf.org/html/rfc7519) in C++11. For a great introduction, [read this](https://jwt.io/introduction/).
jwt-cpp supports all the algorithms defined by the specifications. The modular design allows to easily add additional algorithms without any problems. If you need any feel free to create a pull request or [open an issue](https://github.com/Thalhammer/jwt-cpp/issues/new).
For completeness, here is a list of all supported algorithms:
| HMSC | RSA | ECDSA | PSS | EdDSA |
| ----- | ----- | ----- | ----- | ------- |
| HS256 | RS256 | ES256 | PS256 | Ed25519 |
| HS384 | RS384 | ES384 | PS384 | Ed448 |
| HS512 | RS512 | ES512 | PS512 | |
## SSL Compatibility
In the name of flexibility and extensibility, jwt-cpp supports both [OpenSSL](https://github.com/openssl/openssl) and [LibreSSL](https://github.com/libressl-portable/portable). These are the version which are, or have been, tested:
There is no hard dependency on a JSON library. Instead, there's a generic `jwt::basic_claim` which is templated around type traits, which described the semantic [JSON types](https://json-schema.org/understanding-json-schema/reference/type.html) for a value, object, array, string, number, integer and boolean, as well as methods to translate between them.
This allows for complete freedom when picking which libraries you want to use. For more information, [see below](#providing-your-own-json-traits-your-traits).
In order to maintain compatibility, [picojson](https://github.com/kazuho/picojson) is still used to provide a specialized `jwt::claim` along with all helpers. Defining `JWT_DISABLE_PICOJSON` will remove this optional dependency.
As for the base64 requirements of JWTs, this libary provides `base.h` with all the required implentation; However base64 implementations are very common, with varying degrees of performance. When providing your own base64 implementation, you can define `JWT_DISABLE_BASE64` to remove the jwt-cpp implementation.
### Getting Started
Simple example of decoding a token and printing all [claims](https://tools.ietf.org/html/rfc7519#section-4) ([try it out](https://github.com/Thalhammer/jwt-cpp/tree/master/example/print-claims.cpp)):
> To see more examples working with RSA public and private keys, visit our [examples](https://github.com/Thalhammer/jwt-cpp/tree/master/example)!
### Providing your own JSON Traits
There are several key items that need to be provided to a `jwt::basic_claim` in order for it to be interoptable with you JSON library of choice.
* type specifications
* conversion from generic "value type" to a specific type
* serialization and parsing
If ever you are not sure, the traits are heavily checked against static asserts to make sure you provide everything that's required.
> :warning: Not all JSON libraries are a like, you may need to extent certain types such that it can be used by jwt-cpp. See this [example](https://github.com/Thalhammer/jwt-cpp/blob/ac3de9e69bc698a464dacb256a1b50512843f092/tests/jsoncons/JsonconsTest.cpp).
```cpp
struct my_favorite_json_library_traits {
// Type Specifications
using value_type = json; // The generic "value type" implementation, most libraries have one
using object_type = json::object_t; // The "map type" string to value
using array_type = json::array_t; // The "list type" array of values
using string_type = std::string; // The "list of chars", must be a narrow char
using number_type = double; // The "percision type"
using integer_type = int64_t; // The "integral type"
using boolean_type = bool; // The "boolean type"
// Translation between the implementation notion of type, to the jwt::json::type equivilant
If you have an improvement or found a bug feel free to [open an issue](https://github.com/Thalhammer/jwt-cpp/issues/new) or add the change and create a pull request. If you file a bug please make sure to include as much information about your environment (compiler version, etc.) as possible to help reproduce the issue. If you add a new feature please make sure to also include test cases for it.
