Crate poem_grants

A crate to protect your endpoints in poem.

For built-in configure see: GrantsMiddleware.

To check user access to specific services, you can use proc-macro or manual.

The library can also be integrated with third-party solutions or your custom middlewares, see authorities module.

You can find more examples in the git repository.

poem-grants

Authorization extension for poem to protect your endpoints.

To check user access to specific services, you can use built-in proc-macro or manual.

The library can also be integrated with third-party solutions or your custom middlewares (like jwt-auth example).

NOTE: Even under beta flag it’s ready-to-use library. However, I’m going to prepare large update of whole *-grants ecosystem with additional features soon.

How to use

1. Declare your own authorities extractor

The easiest way is to declare a function with the following signature (trait is already implemented for such Fn):

// You can use custom type instead of String
async fn extract(req: &poem::Request) -> poem::Result<HashSet<String>>

2. Add middleware to your application using the extractor defined in step 1

Route::new()
    .at("/endpoint", your_endpoint)
    .with(GrantsMiddleware::with_extractor(extract))

Steps 1 and 2 can be replaced by custom middleware or integration with another libraries. Take a look at an jwt-auth example

3. Protect your endpoints in any convenient way from the examples below:

Example of proc-macro way protection

use poem::{Response, http::StatusCode};

#[poem_grants::protect("OP_READ_SECURED_INFO")]
#[poem::handler]
async fn macro_secured() -> Response {
    Response::builder().status(StatusCode::OK).body("ADMIN_RESPONSE")
}

Or for poem-openapi:

use poem_openapi::{OpenApi, payload::PlainText};

struct Api;

#[poem_grants::open_api] // It's important to keep above of `OpenApi`
#[OpenApi]
impl Api {
    #[protect("OP_READ_ADMIN_INFO")]
    #[oai(path = "/admin", method = "get")]
    async fn macro_secured(&self) -> PlainText<String> {
        PlainText("ADMIN_RESPONSE".to_string())
    }
}

Example of ABAC-like protection and custom authority type

Here is an example using the ty and expr attributes. But these are independent features.

expr allows you to include some checks in the macro based on function params, it can be combined with authorities by using all/any.

ty allows you to use a custom type for th authorities (then the middleware needs to be configured). Take a look at an enum-role example

use poem::{Response, http::StatusCode, web};
use enums::Role::{self, ADMIN};
use dto::User;

#[poem_grants::protect("ADMIN", expr = "*user_id == user.id", ty = "Role")]
#[poem::handler]
async fn macro_secured(user_id: web::Path<i32>, user: web::Data<User>) -> Response {
    Response::builder().status(StatusCode::OK).body("some secured response")
}

#[poem_grants::protect(any("ADMIN", expr = "user.is_super_user()"), ty = "Role")]
#[poem::handler]
async fn admin_or_super_user(user_id: web::Path<i32>, user: web::Data<User>) -> Response {
    Response::builder().status(StatusCode::OK).body("some secured response")
}

Example of manual way protection

use poem::{Response, http::StatusCode};
use poem_grants::authorities::{AuthDetails, AuthoritiesCheck};

#[poem::handler]
async fn manual_secure(details: AuthDetails) -> Response {
    if details.has_authority("ROLE_ADMIN") {
        return Response::builder().status(StatusCode::OK).body("ADMIN_RESPONSE");
    }
    Response::builder().status(StatusCode::OK).body("OTHER_RESPONSE")
}

You can find more examples in the git repository folder and documentation.

Supported poem versions

• For poem-grants: 3.* supported version of poem is 3.*
• For poem-grants: 2.* supported version of poem is 2.*
• For poem-grants: 1.* supported version of poem is 1.*

Re-exports

• pub use proc_macro::*;

Modules

• authorities
  A set of traits and structures for custom integration.
• error
• proc_macro
  Procedural macros for checking user authorities (permissions or roles).

Structs

• GrantsMiddleware
  Built-in middleware for extracting user authorities.