Fix quality parse in Accept-Encoding HTTP header

This commit is contained in:
Arthur LE MOIGNE 2021-07-23 16:40:33 +02:00
parent c50eef6166
commit 73f412519d
No known key found for this signature in database
GPG Key ID: 25D15180A1D2E077
4 changed files with 211 additions and 69 deletions

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@ -1,6 +1,7 @@
//! Stream decoders.
use std::{
convert::TryFrom,
future::Future,
io::{self, Write as _},
pin::Pin,
@ -80,7 +81,7 @@ where
let encoding = headers
.get(&CONTENT_ENCODING)
.and_then(|val| val.to_str().ok())
.map(ContentEncoding::from)
.and_then(|x| ContentEncoding::try_from(x).ok())
.unwrap_or(ContentEncoding::Identity);
Self::new(stream, encoding)

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@ -1,4 +1,4 @@
use std::{convert::Infallible, str::FromStr};
use std::{convert::TryFrom, error, fmt, str::FromStr};
use http::header::InvalidHeaderValue;
@ -8,6 +8,20 @@ use crate::{
HttpMessage,
};
/// Error return when a content encoding is unknown.
///
/// Example: 'compress'
#[derive(Debug)]
pub struct ContentEncodingParseError;
impl fmt::Display for ContentEncodingParseError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "Unsupported content encoding")
}
}
impl error::Error for ContentEncodingParseError {}
/// Represents a supported content encoding.
#[derive(Copy, Clone, PartialEq, Debug)]
pub enum ContentEncoding {
@ -48,18 +62,6 @@ impl ContentEncoding {
ContentEncoding::Identity | ContentEncoding::Auto => "identity",
}
}
/// Default Q-factor (quality) value.
#[inline]
pub fn quality(self) -> f64 {
match self {
ContentEncoding::Br => 1.1,
ContentEncoding::Gzip => 1.0,
ContentEncoding::Deflate => 0.9,
ContentEncoding::Identity | ContentEncoding::Auto => 0.1,
ContentEncoding::Zstd => 0.0,
}
}
}
impl Default for ContentEncoding {
@ -69,27 +71,29 @@ impl Default for ContentEncoding {
}
impl FromStr for ContentEncoding {
type Err = Infallible;
type Err = ContentEncodingParseError;
fn from_str(val: &str) -> Result<Self, Self::Err> {
Ok(Self::from(val))
Self::try_from(val)
}
}
impl From<&str> for ContentEncoding {
fn from(val: &str) -> ContentEncoding {
impl TryFrom<&str> for ContentEncoding {
type Error = ContentEncodingParseError;
fn try_from(val: &str) -> Result<Self, Self::Error> {
let val = val.trim();
if val.eq_ignore_ascii_case("br") {
ContentEncoding::Br
Ok(ContentEncoding::Br)
} else if val.eq_ignore_ascii_case("gzip") {
ContentEncoding::Gzip
Ok(ContentEncoding::Gzip)
} else if val.eq_ignore_ascii_case("deflate") {
ContentEncoding::Deflate
Ok(ContentEncoding::Deflate)
} else if val.eq_ignore_ascii_case("zstd") {
ContentEncoding::Zstd
Ok(ContentEncoding::Zstd)
} else {
ContentEncoding::default()
Err(ContentEncodingParseError)
}
}
}

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@ -2,27 +2,27 @@
use std::{
cmp,
convert::TryFrom,
future::Future,
marker::PhantomData,
pin::Pin,
str::FromStr,
task::{Context, Poll},
};
use actix_http::{
body::{MessageBody, ResponseBody},
body::{AnyBody, ResponseBody},
encoding::Encoder,
http::header::{ContentEncoding, ACCEPT_ENCODING},
};
use actix_service::{Service, Transform};
use actix_utils::future::{ok, Ready};
use actix_utils::future::{ok, Either, Ready};
use futures_core::ready;
use pin_project::pin_project;
use crate::{
dev::BodyEncoding,
service::{ServiceRequest, ServiceResponse},
Error,
Error, HttpResponse,
};
/// Middleware for compressing response payloads.
@ -54,12 +54,11 @@ impl Default for Compress {
}
}
impl<S, B> Transform<S, ServiceRequest> for Compress
impl<S> Transform<S, ServiceRequest> for Compress
where
B: MessageBody,
S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
S: Service<ServiceRequest, Response = ServiceResponse<AnyBody>, Error = Error>,
{
type Response = ServiceResponse<ResponseBody<Encoder<B>>>;
type Response = ServiceResponse<ResponseBody<Encoder<AnyBody>>>;
type Error = Error;
type Transform = CompressMiddleware<S>;
type InitError = ();
@ -78,56 +77,69 @@ pub struct CompressMiddleware<S> {
encoding: ContentEncoding,
}
impl<S, B> Service<ServiceRequest> for CompressMiddleware<S>
impl<S> Service<ServiceRequest> for CompressMiddleware<S>
where
B: MessageBody,
S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
S: Service<ServiceRequest, Response = ServiceResponse<AnyBody>, Error = Error>,
{
type Response = ServiceResponse<ResponseBody<Encoder<B>>>;
type Response = ServiceResponse<ResponseBody<Encoder<AnyBody>>>;
type Error = Error;
type Future = CompressResponse<S, B>;
type Future = Either<CompressResponse<S>, Ready<Result<Self::Response, Self::Error>>>;
actix_service::forward_ready!(service);
#[allow(clippy::borrow_interior_mutable_const)]
fn call(&self, req: ServiceRequest) -> Self::Future {
// negotiate content-encoding
let encoding = if let Some(val) = req.headers().get(&ACCEPT_ENCODING) {
if let Ok(enc) = val.to_str() {
AcceptEncoding::parse(enc, self.encoding)
} else {
ContentEncoding::Identity
}
} else {
ContentEncoding::Identity
};
let encoding_result = req
.headers()
.get(&ACCEPT_ENCODING)
.and_then(|val| val.to_str().ok())
.map(|enc| AcceptEncoding::try_parse(enc, self.encoding));
CompressResponse {
encoding,
fut: self.service.call(req),
_phantom: PhantomData,
match encoding_result {
// Missing header => fallback to identity
None => Either::left(CompressResponse {
encoding: ContentEncoding::Identity,
fut: self.service.call(req),
_phantom: PhantomData,
}),
// Valid encoding
Some(Ok(encoding)) => Either::left(CompressResponse {
encoding,
fut: self.service.call(req),
_phantom: PhantomData,
}),
// There is an HTTP header but we cannot match what client as asked for
Some(Err(_)) => {
let res = HttpResponse::NotAcceptable().finish();
let enc = ContentEncoding::Identity;
Either::right(ok(req.into_response(res.map_body(move |head, body| {
Encoder::response(enc, head, ResponseBody::Body(body))
}))))
}
}
}
}
#[pin_project]
pub struct CompressResponse<S, B>
pub struct CompressResponse<S>
where
S: Service<ServiceRequest>,
B: MessageBody,
{
#[pin]
fut: S::Future,
encoding: ContentEncoding,
_phantom: PhantomData<B>,
_phantom: PhantomData<AnyBody>,
}
impl<S, B> Future for CompressResponse<S, B>
impl<S> Future for CompressResponse<S>
where
B: MessageBody,
S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
S: Service<ServiceRequest, Response = ServiceResponse<AnyBody>, Error = Error>,
{
type Output = Result<ServiceResponse<ResponseBody<Encoder<B>>>, Error>;
type Output = Result<ServiceResponse<ResponseBody<Encoder<AnyBody>>>, Error>;
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
let this = self.project();
@ -177,26 +189,56 @@ impl PartialOrd for AcceptEncoding {
impl PartialEq for AcceptEncoding {
fn eq(&self, other: &AcceptEncoding) -> bool {
self.quality == other.quality
self.quality == other.quality && self.encoding == other.encoding
}
}
/// Parse qfactor from HTTP header
///
/// If parse fail, then fallback to default value which is 1
/// More details available here: https://developer.mozilla.org/en-US/docs/Glossary/Quality_values
fn parse_quality(parts: &[&str]) -> f64 {
for part in parts {
if part.starts_with("q=") {
return part[2..].parse().unwrap_or(1.0);
}
}
1.0
}
#[derive(Debug, PartialEq, Eq)]
enum AcceptEncodingError {
/// This error occurs when client only support compressed response
/// and server do not have any algorithm that match client accepted
/// algorithms
CompressionAlgorithmMismatch,
}
impl AcceptEncoding {
fn new(tag: &str) -> Option<AcceptEncoding> {
let parts: Vec<&str> = tag.split(';').collect();
let encoding = match parts.len() {
0 => return None,
_ => ContentEncoding::from(parts[0]),
};
let quality = match parts.len() {
1 => encoding.quality(),
_ => f64::from_str(parts[1]).unwrap_or(0.0),
_ => match ContentEncoding::try_from(parts[0]) {
Err(_) => return None,
Ok(x) => x,
},
};
let quality = parse_quality(&parts[1..]);
if quality <= 0.0 || quality > 1.0 {
return None;
}
Some(AcceptEncoding { encoding, quality })
}
/// Parse a raw Accept-Encoding header value into an ordered list.
pub fn parse(raw: &str, encoding: ContentEncoding) -> ContentEncoding {
/// Parse a raw Accept-Encoding header value into an ordered list
/// then return the best match based on middleware configuration.
pub fn try_parse(
raw: &str,
encoding: ContentEncoding,
) -> Result<ContentEncoding, AcceptEncodingError> {
let mut encodings = raw
.replace(' ', "")
.split(',')
@ -206,13 +248,89 @@ impl AcceptEncoding {
encodings.sort();
for enc in encodings {
if encoding == ContentEncoding::Auto {
return enc.encoding;
} else if encoding == enc.encoding {
return encoding;
if encoding == ContentEncoding::Auto || encoding == enc.encoding {
return Ok(enc.encoding);
}
}
ContentEncoding::Identity
// Special case if user cannot accept uncompressed data
// See: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept-Encoding
if raw.contains("*;q=0") || raw.contains("identity;q=0") {
return Err(AcceptEncodingError::CompressionAlgorithmMismatch);
}
Ok(ContentEncoding::Identity)
}
}
#[cfg(test)]
mod tests {
use super::*;
macro_rules! assert_parse_eq {
($raw:expr, $result:expr) => {
assert_eq!(
AcceptEncoding::try_parse($raw, ContentEncoding::Auto),
Ok($result)
);
};
}
macro_rules! assert_parse_fail {
($raw:expr) => {
assert!(AcceptEncoding::try_parse($raw, ContentEncoding::Auto).is_err());
};
}
#[test]
fn test_parse_encoding() {
// Test simple case
assert_parse_eq!("br", ContentEncoding::Br);
assert_parse_eq!("gzip", ContentEncoding::Gzip);
assert_parse_eq!("deflate", ContentEncoding::Deflate);
assert_parse_eq!("zstd", ContentEncoding::Zstd);
// Test space, trim, missing values
assert_parse_eq!("br,,,,", ContentEncoding::Br);
assert_parse_eq!("gzip , br, zstd", ContentEncoding::Gzip);
// Test float number parsing
assert_parse_eq!("br;q=1 ,", ContentEncoding::Br);
assert_parse_eq!("br;q=1.0 , br", ContentEncoding::Br);
// Test wildcard
assert_parse_eq!("*", ContentEncoding::Identity);
assert_parse_eq!("*;q=1.0", ContentEncoding::Identity);
}
#[test]
fn test_parse_encoding_qfactor_ordering() {
assert_parse_eq!("gzip, br, zstd", ContentEncoding::Gzip);
assert_parse_eq!("zstd, br, gzip", ContentEncoding::Zstd);
assert_parse_eq!("gzip;q=0.4, br;q=0.6", ContentEncoding::Br);
assert_parse_eq!("gzip;q=0.8, br;q=0.4", ContentEncoding::Gzip);
}
#[test]
fn test_parse_encoding_qfactor_invalid() {
// Out of range
assert_parse_eq!("gzip;q=-5.0", ContentEncoding::Identity);
assert_parse_eq!("gzip;q=5.0", ContentEncoding::Identity);
// Disabled
assert_parse_eq!("gzip;q=0", ContentEncoding::Identity);
}
#[test]
fn test_parse_compression_required() {
// Check we fallback to identity if there is an unsuported compression algorithm
assert_parse_eq!("compress", ContentEncoding::Identity);
// User do not want any compression
assert_parse_fail!("compress, identity;q=0");
assert_parse_fail!("compress, identity;q=0.0");
assert_parse_fail!("compress, *;q=0");
assert_parse_fail!("compress, *;q=0.0");
}
}

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@ -1077,3 +1077,22 @@ async fn test_data_drop() {
assert_eq!(num.load(Ordering::SeqCst), 0);
}
#[actix_rt::test]
async fn test_accept_encoding_no_match() {
let srv = actix_test::start_with(actix_test::config().h1(), || {
App::new()
.wrap(Compress::default())
.service(web::resource("/").route(web::to(move || HttpResponse::Ok().finish())))
});
let response = srv
.get("/")
.append_header((ACCEPT_ENCODING, "compress, identity;q=0"))
.no_decompress()
.send()
.await
.unwrap();
assert_eq!(response.status().as_u16(), 406);
}