digest-headers

Crates.io	digest-headers
lib.rs	digest-headers
version	0.2.1
source	src
created_at	2018-01-13 23:03:46.307329
updated_at	2019-01-12 18:19:59.80106
description	A simple library to hash a request's body in the headers
homepage
repository	https://git.asonix.dog/asonix/digest-headers
max_upload_size
id	46714
size	84,876

asonix (asonix)

documentation

README

Digest Headers

A library to aid in the creation and verification of Digest Headers, Sha Digests of HTTP Request Bodies

crates.io documentation

Getting started

Add the following to your Cargo.toml

[dependencies.digest-headers]
version = "0.2"

Available Features

use_actix_web
use_hyper
use_reqwest
use_rocket

Usage

Here's some basic usage with all of the supported frameworks.

Building requests with Actix Web

#[derive(Debug, Fail)]
#[fail(display = "Could not build request")]
pub struct RequestBuildError;

fn main() -> Result<(), Error> {
    let json = r#"{"library":"actix"}"#;

    let req = post("http://localhost:5000")
        .content_type("application/json")
        .with_digest(json, ShaSize::TwoFiftySix)
        .map_err(|_| RequestBuildError)?;

    actix_web::actix::run(move || {
        req.send()
            .map_err(|_| ())
            .and_then(|res| {
                println!("POST: {}", res.status());

                res.verify_digest()
                    .map(|ActixWebVerifiedDigest| println!("Verified response!"))
                    .map_err(|_| ())
            })
            .map(|_| {
                actix_web::actix::System::current().stop();
            })
    });

    Ok(())
}

Handling requests with Actix Web

use actix_web::{server, App, HttpResponse};
use digest_headers::{prelude::*, ShaSize};

const PHRASE: &str = "Hewwo, Mr. Obama???";

fn index(_: ActixWebVerifiedDigest) -> HttpResponse {
    println!("Verified request!");

    HttpResponse::Ok()
        .content_type("text/plain")
        .force_close()
        .with_digest(PHRASE, ShaSize::TwoFiftySix)
}

fn main() {
    server::new(move || App::new().resource("/", |r| r.with(index)))
        .bind("127.0.0.1:5000")
        .expect("Can not bind to port 5000")
        .run();
}

Building requests with Hyper

use digest_headers::{prelude::*, ShaSize};

let client = Client::new();

let uri = "http://localhost:8000";
let json = r#"{"Library":"Hyper"}"#;

let req = Request::post(uri)
    .header(CONTENT_TYPE, "application/json")
    .header(CONNECTION, "close")
    .with_digest(json, ShaSize::TwoFiftySix)
    .unwrap();

let post = client.request(req).map_err(|_| ()).and_then(|res| {
    println!("POST: {}", res.status());

    res.verify_digest()
        .map(|_req| {
            println!("Verified resposne");
        })
        .map_err(|_| ())
});

hyper::rt::run(post)

Handling requests with Hyper

use digest_headers::{prelude::*, ShaSize};
use futures::Future;
use hyper::{service::service_fn, Body, Request, Response, Server};

type BoxResponse = Box<Future<Item = Response<Body>, Error = SomeError> + Send>;

fn verify_digest(req: Request<Body>) -> BoxResponse {
    let fut = req.verify_digest().map_err(|_| SomeError).and_then(|_req| {
        println!("Verified!");
        Response::builder()
            .with_digest("Verified", ShaSize::TwoFiftySix)
            .map_err(|_| SomeError)
    });

    Box::new(fut)
}

Building requests with Reqwest

use digest_headers::{prelude::*, ShaSize};
use reqwest::Client;

let payload = r#"{"Library":"Reqwest"}"#;
let client = Client::new();
let req = client
    .post("http://localhost:8000")
    .with_digest(payload, ShaSize::TwoFiftySix)
    .build()
    .unwrap();

let mut res = client.execute(req).unwrap();
println!("GET: {}", res.status());
let body = res.verify_digest().unwrap();
if let Ok(body) = std::str::from_utf8(&body) {
    println!("Verified, {}", body);
} else {
    println!("Verified");
}

Handling requests with Rocket

use digest_headers::{
    use_rocket::{ContentLengthHeader, DigestHeader, Error as DigestError, WithDigest},
    ShaSize,
};
use rocket::{
    config::{Config, Environment},
    data::{self, Data, FromData},
    http::Status,
    request::Request,
    response::Response,
    Outcome,
};

struct DigestVerifiedBody<T>(pub T);

impl<'a> FromData<'a> for DigestVerifiedBody<Vec<u8>> {
    type Owned = Vec<u8>;
    type Borrowed = Vec<u8>;
    type Error = Error;

    fn transform(
        req: &Request,
        data: Data,
    ) -> data::Transform<data::Outcome<Self::Owned, Self::Error>> {
        let outcome = req
            .guard::<DigestHeader>()
            .map(|digest_header| digest_header.0)
            .and_then(move |digest| {
                req.guard::<ContentLengthHeader>()
                    .map(|content_length_header| (digest, content_length_header.0))
            })
            .map_failure(|(s, e)| (s, e.into()))
            .and_then(move |(digest, content_length)| {
                println!("Provided Digest: {:?}", digest);

                let mut body = vec![0u8; content_length];
                // Ensure request is less than 2 MB. This is still likely way too large
                if content_length > 1024 * 1024 * 2 {
                    return Outcome::Failure((Status::BadRequest, Error::RequestTooBig));
                }

                println!("Content Length: {}", content_length);

                // Only read as much data as we expect to avoid DOS
                if data.open().read_exact(&mut body).is_err() {
                    return Outcome::Failure((Status::InternalServerError, Error::ReadFailed));
                }

                if digest.verify(&body).is_err() {
                    return Outcome::Failure((Status::BadRequest, Error::DigestMismatch));
                }

                Outcome::Success(body)
            });

        let outcome = match outcome {
            Outcome::Success(s) => Outcome::Success(s),
            Outcome::Forward(_) => Outcome::Failure((Status::BadRequest, Error::ReadFailed)),
            Outcome::Failure(f) => Outcome::Failure(f),
        };

        data::Transform::Borrowed(outcome)
    }

    fn from_data(
        _: &Request,
        outcome: data::Transformed<'a, Self>,
    ) -> data::Outcome<Self, Self::Error> {
        let body = outcome.borrowed()?;

        Outcome::Success(DigestVerifiedBody(body.to_vec()))
    }
}

#[post("/", data = "<data>")]
fn index(data: DigestVerifiedBody<Vec<u8>>) -> Response<'static> {
    let inner = data.0;
    if let Ok(data) = std::str::from_utf8(&inner) {
        println!("Verified {}", data);
    } else {
        println!("Verified");
    }

    Response::build()
        .with_digest(Cursor::new("woah"), ShaSize::TwoFiftySix)
        .unwrap()
        .finalize()
}

What this library supports

Creation of Digest Header strings
Verification of Digest Header strings
Adding Digest Headers to Requests and Responses for various libraries.

Examples

Actix Client example
Actix Server example
Hyper Client example
Hyper Server example
Request Client example
Rocket Server Example. This one is more in-depth. It implements rocket::request::FromRequest for two custom structs for the Digest and ContentLength headers, and implements FromData for a simple wrapper around a Vec<u8>. See the example for the full implementation.

Notes

The Actix Web Client and Server examples are configured to work with each other.
The Hyper Client and Server examples are configured to work with each other.
The Rocket and Reqwest examples are configured to work with each other.

Contributing

Please be aware that all code contributed to this project will be licensed under the GPL version 3.

License

Digest Headers is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Digest Headers is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. This file is part of Digest Headers

You should have received a copy of the GNU General Public License along with Digest Headers If not, see http://www.gnu.org/licenses/.

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