1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371

//! Middlewares that mark headers as [sensitive].
//!
//! [sensitive]: https://docs.rs/http/latest/http/header/struct.HeaderValue.html#method.set_sensitive
//!
//! # Example
//!
//! ```
//! use tower_http::sensitive_headers::SetSensitiveHeadersLayer;
//! use tower::{Service, ServiceExt, ServiceBuilder, service_fn};
//! use http::{Request, Response, header::AUTHORIZATION};
//! use hyper::Body;
//! use std::{iter::once, convert::Infallible};
//!
//! async fn handle(req: Request<Body>) -> Result<Response<Body>, Infallible> {
//!     // ...
//!     # Ok(Response::new(Body::empty()))
//! }
//!
//! # #[tokio::main]
//! # async fn main() -> Result<(), Box<dyn std::error::Error>> {
//! let mut service = ServiceBuilder::new()
//!     // Mark the `Authorization` header as sensitive so it doesn't show in logs
//!     //
//!     // `SetSensitiveHeadersLayer` will mark the header as sensitive on both the
//!     // request and response.
//!     //
//!     // The middleware is constructed from an iterator of headers to easily mark
//!     // multiple headers at once.
//!     .layer(SetSensitiveHeadersLayer::new(once(AUTHORIZATION)))
//!     .service(service_fn(handle));
//!
//! // Call the service.
//! let response = service
//!     .ready()
//!     .await?
//!     .call(Request::new(Body::empty()))
//!     .await?;
//! # Ok(())
//! # }
//! ```
//!
//! Its important to think about the order in which requests and responses arrive at your
//! middleware. For example to hide headers both on requests and responses when using
//! [`TraceLayer`] you have to apply [`SetSensitiveRequestHeadersLayer`] before [`TraceLayer`]
//! and [`SetSensitiveResponseHeadersLayer`] afterwards.
//!
//! ```
//! use tower_http::{
//!     trace::TraceLayer,
//!     sensitive_headers::{
//!         SetSensitiveRequestHeadersLayer,
//!         SetSensitiveResponseHeadersLayer,
//!     },
//! };
//! use tower::{Service, ServiceExt, ServiceBuilder, service_fn};
//! use http::header;
//! use std::sync::Arc;
//! # use http::{Request, Response};
//! # use hyper::Body;
//! # use std::convert::Infallible;
//! # async fn handle(req: Request<Body>) -> Result<Response<Body>, Infallible> {
//! #     Ok(Response::new(Body::empty()))
//! # }
//!
//! # #[tokio::main]
//! # async fn main() -> Result<(), Box<dyn std::error::Error>> {
//! let headers: Arc<[_]> = Arc::new([
//!     header::AUTHORIZATION,
//!     header::PROXY_AUTHORIZATION,
//!     header::COOKIE,
//!     header::SET_COOKIE,
//! ]);
//!
//! let service = ServiceBuilder::new()
//!     .layer(SetSensitiveRequestHeadersLayer::from_shared(Arc::clone(&headers)))
//!     .layer(TraceLayer::new_for_http())
//!     .layer(SetSensitiveResponseHeadersLayer::from_shared(headers))
//!     .service_fn(handle);
//! # Ok(())
//! # }
//! ```
//!
//! [`TraceLayer`]: crate::trace::TraceLayer

use futures_util::ready;
use http::{header::HeaderName, Request, Response};
use pin_project::pin_project;
use std::{
    future::Future,
    pin::Pin,
    sync::Arc,
    task::{Context, Poll},
};
use tower_layer::Layer;
use tower_service::Service;

/// Mark headers as [sensitive] on both requests and responses.
///
/// Produces [`SetSensitiveHeaders`] services.
///
/// See the [module docs](crate::sensitive_headers) for more details.
///
/// [sensitive]: https://docs.rs/http/latest/http/header/struct.HeaderValue.html#method.set_sensitive
#[derive(Clone, Debug)]
pub struct SetSensitiveHeadersLayer {
    headers: Arc<[HeaderName]>,
}

impl SetSensitiveHeadersLayer {
    /// Create a new [`SetSensitiveHeadersLayer`].
    pub fn new<I>(headers: I) -> Self
    where
        I: IntoIterator<Item = HeaderName>,
    {
        let headers = headers.into_iter().collect::<Vec<_>>();
        Self::from_shared(headers.into())
    }

    /// Create a new [`SetSensitiveHeadersLayer`] from a shared slice of headers.
    pub fn from_shared(headers: Arc<[HeaderName]>) -> Self {
        Self { headers }
    }
}

impl<S> Layer<S> for SetSensitiveHeadersLayer {
    type Service = SetSensitiveHeaders<S>;

    fn layer(&self, inner: S) -> Self::Service {
        SetSensitiveRequestHeaders::from_shared(
            SetSensitiveResponseHeaders::from_shared(inner, self.headers.clone()),
            self.headers.clone(),
        )
    }
}

/// Mark headers as [sensitive] on both requests and responses.
///
/// See the [module docs](crate::sensitive_headers) for more details.
///
/// [sensitive]: https://docs.rs/http/latest/http/header/struct.HeaderValue.html#method.set_sensitive
pub type SetSensitiveHeaders<S> = SetSensitiveRequestHeaders<SetSensitiveResponseHeaders<S>>;

/// Mark request headers as [sensitive].
///
/// Produces [`SetSensitiveRequestHeaders`] services.
///
/// See the [module docs](crate::sensitive_headers) for more details.
///
/// [sensitive]: https://docs.rs/http/latest/http/header/struct.HeaderValue.html#method.set_sensitive
#[derive(Clone, Debug)]
pub struct SetSensitiveRequestHeadersLayer {
    headers: Arc<[HeaderName]>,
}

impl SetSensitiveRequestHeadersLayer {
    /// Create a new [`SetSensitiveRequestHeadersLayer`].
    pub fn new<I>(headers: I) -> Self
    where
        I: IntoIterator<Item = HeaderName>,
    {
        let headers = headers.into_iter().collect::<Vec<_>>();
        Self::from_shared(headers.into())
    }

    /// Create a new [`SetSensitiveRequestHeadersLayer`] from a shared slice of headers.
    pub fn from_shared(headers: Arc<[HeaderName]>) -> Self {
        Self { headers }
    }
}

impl<S> Layer<S> for SetSensitiveRequestHeadersLayer {
    type Service = SetSensitiveRequestHeaders<S>;

    fn layer(&self, inner: S) -> Self::Service {
        SetSensitiveRequestHeaders {
            inner,
            headers: self.headers.clone(),
        }
    }
}

/// Mark request headers as [sensitive].
///
/// See the [module docs](crate::sensitive_headers) for more details.
///
/// [sensitive]: https://docs.rs/http/latest/http/header/struct.HeaderValue.html#method.set_sensitive
#[derive(Clone, Debug)]
pub struct SetSensitiveRequestHeaders<S> {
    inner: S,
    headers: Arc<[HeaderName]>,
}

impl<S> SetSensitiveRequestHeaders<S> {
    /// Create a new [`SetSensitiveRequestHeaders`].
    pub fn new<I>(inner: S, headers: I) -> Self
    where
        I: IntoIterator<Item = HeaderName>,
    {
        let headers = headers.into_iter().collect::<Vec<_>>();
        Self::from_shared(inner, headers.into())
    }

    /// Create a new [`SetSensitiveRequestHeaders`] from a shared slice of headers.
    pub fn from_shared(inner: S, headers: Arc<[HeaderName]>) -> Self {
        Self { inner, headers }
    }

    define_inner_service_accessors!();

    /// Returns a new [`Layer`] that wraps services with a `SetSensitiveRequestHeaders` middleware.
    ///
    /// [`Layer`]: tower_layer::Layer
    pub fn layer<I>(headers: I) -> SetSensitiveRequestHeadersLayer
    where
        I: IntoIterator<Item = HeaderName>,
    {
        SetSensitiveRequestHeadersLayer::new(headers)
    }
}

impl<ReqBody, ResBody, S> Service<Request<ReqBody>> for SetSensitiveRequestHeaders<S>
where
    S: Service<Request<ReqBody>, Response = Response<ResBody>>,
{
    type Response = S::Response;
    type Error = S::Error;
    type Future = S::Future;

    #[inline]
    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        self.inner.poll_ready(cx)
    }

    fn call(&mut self, mut req: Request<ReqBody>) -> Self::Future {
        for header in &*self.headers {
            if let Some(value) = req.headers_mut().get_mut(header) {
                value.set_sensitive(true);
            }
        }

        self.inner.call(req)
    }
}

/// Mark response headers as [sensitive].
///
/// Produces [`SetSensitiveResponseHeaders`] services.
///
/// See the [module docs](crate::sensitive_headers) for more details.
///
/// [sensitive]: https://docs.rs/http/latest/http/header/struct.HeaderValue.html#method.set_sensitive
#[derive(Clone, Debug)]
pub struct SetSensitiveResponseHeadersLayer {
    headers: Arc<[HeaderName]>,
}

impl SetSensitiveResponseHeadersLayer {
    /// Create a new [`SetSensitiveResponseHeadersLayer`].
    pub fn new<I>(headers: I) -> Self
    where
        I: IntoIterator<Item = HeaderName>,
    {
        let headers = headers.into_iter().collect::<Vec<_>>();
        Self::from_shared(headers.into())
    }

    /// Create a new [`SetSensitiveResponseHeadersLayer`] from a shared slice of headers.
    pub fn from_shared(headers: Arc<[HeaderName]>) -> Self {
        Self { headers }
    }
}

impl<S> Layer<S> for SetSensitiveResponseHeadersLayer {
    type Service = SetSensitiveResponseHeaders<S>;

    fn layer(&self, inner: S) -> Self::Service {
        SetSensitiveResponseHeaders {
            inner,
            headers: self.headers.clone(),
        }
    }
}

/// Mark response headers as [sensitive].
///
/// See the [module docs](crate::sensitive_headers) for more details.
///
/// [sensitive]: https://docs.rs/http/latest/http/header/struct.HeaderValue.html#method.set_sensitive
#[derive(Clone, Debug)]
pub struct SetSensitiveResponseHeaders<S> {
    inner: S,
    headers: Arc<[HeaderName]>,
}

impl<S> SetSensitiveResponseHeaders<S> {
    /// Create a new [`SetSensitiveResponseHeaders`].
    pub fn new<I>(inner: S, headers: I) -> Self
    where
        I: IntoIterator<Item = HeaderName>,
    {
        let headers = headers.into_iter().collect::<Vec<_>>();
        Self::from_shared(inner, headers.into())
    }

    /// Create a new [`SetSensitiveResponseHeaders`] from a shared slice of headers.
    pub fn from_shared(inner: S, headers: Arc<[HeaderName]>) -> Self {
        Self { inner, headers }
    }

    define_inner_service_accessors!();

    /// Returns a new [`Layer`] that wraps services with a `SetSensitiveResponseHeaders` middleware.
    ///
    /// [`Layer`]: tower_layer::Layer
    pub fn layer<I>(headers: I) -> SetSensitiveResponseHeadersLayer
    where
        I: IntoIterator<Item = HeaderName>,
    {
        SetSensitiveResponseHeadersLayer::new(headers)
    }
}

impl<ReqBody, ResBody, S> Service<Request<ReqBody>> for SetSensitiveResponseHeaders<S>
where
    S: Service<Request<ReqBody>, Response = Response<ResBody>>,
{
    type Response = S::Response;
    type Error = S::Error;
    type Future = SetSensitiveResponseHeadersResponseFuture<S::Future>;

    #[inline]
    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        self.inner.poll_ready(cx)
    }

    fn call(&mut self, req: Request<ReqBody>) -> Self::Future {
        SetSensitiveResponseHeadersResponseFuture {
            future: self.inner.call(req),
            headers: self.headers.clone(),
        }
    }
}

/// Response future for [`SetSensitiveResponseHeaders`].
#[pin_project]
#[derive(Debug)]
pub struct SetSensitiveResponseHeadersResponseFuture<F> {
    #[pin]
    future: F,
    headers: Arc<[HeaderName]>,
}

impl<F, ResBody, E> Future for SetSensitiveResponseHeadersResponseFuture<F>
where
    F: Future<Output = Result<Response<ResBody>, E>>,
{
    type Output = F::Output;

    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
        let this = self.project();
        let mut res = ready!(this.future.poll(cx)?);

        for header in &**this.headers {
            if let Some(value) = res.headers_mut().get_mut(header) {
                value.set_sensitive(true);
            }
        }

        Poll::Ready(Ok(res))
    }
}