Use constant-time token verification in API (mimblewimble#1690)

Fixes mimblewimble#1641. The size of the token can be leaked, even if we pad or cut user's input we can't make it indistinguishable form the normal case.
brettcloward05 · Oct 9, 2018 · 8ee8043 · 8ee8043
1 parent 7e7697b
commit 8ee8043
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Showing 4 changed files with 8 additions and 2 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/api/Cargo.toml b/api/Cargo.toml
@@ -11,6 +11,7 @@ failure_derive = "0.1.1"
 hyper = "0.12"
 lazy_static = "1"
 regex = "1"
+ring = "0.13"
 serde = "1"
 serde_derive = "1"
 serde_json = "1"

diff --git a/api/src/auth.rs b/api/src/auth.rs
@@ -15,6 +15,7 @@
 use futures::future::ok;
 use hyper::header::{HeaderValue, AUTHORIZATION, WWW_AUTHENTICATE};
 use hyper::{Body, Request, Response, StatusCode};
+use ring::constant_time::verify_slices_are_equal;
 use router::{Handler, HandlerObj, ResponseFuture};
 
 // Basic Authentication Middleware
@@ -38,8 +39,10 @@ impl Handler for BasicAuthMiddleware {
 		req: Request<Body>,
 		mut handlers: Box<Iterator<Item = HandlerObj>>,
 	) -> ResponseFuture {
-		if req.headers().contains_key(AUTHORIZATION)
-			&& req.headers()[AUTHORIZATION] == self.api_basic_auth
+		if req.headers().contains_key(AUTHORIZATION) && verify_slices_are_equal(
+			req.headers()[AUTHORIZATION].as_bytes(),
+			&self.api_basic_auth.as_bytes(),
+		).is_ok()
 		{
 			handlers.next().unwrap().call(req, handlers)
 		} else {

diff --git a/api/src/lib.rs b/api/src/lib.rs
@@ -27,6 +27,7 @@ extern crate hyper;
 #[macro_use]
 extern crate lazy_static;
 extern crate regex;
+extern crate ring;
 extern crate serde;
 #[macro_use]
 extern crate serde_derive;