Implement CSRF protection fairing

Cargo.lock

@@ -97,6 +97,12 @@ version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3441f0f7b02788e948e47f457ca01f1d7e6d92c693bc132c22b087d3141c03ff"
 
+[[package]]
+name = "base64"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "904dfeac50f3cdaba28fc6f57fdcddb75f49ed61346676a78c4ffe55877802fd"
+
 [[package]]
 name = "bcrypt"
 version = "0.8.2"
@@ -299,10 +305,12 @@ checksum = "e88a8acf291dafb59c2d96e8f59828f3838bb1a70398823ade51a84de6a6deed"
 name = "fedihub-registry"
 version = "0.0.0"
 dependencies = [
+ "base64 0.13.0",
  "bcrypt",
  "diesel",
  "dotenv",
  "r2d2",
+ "rand",
  "regex",
  "rocket",
  "rocket_contrib",

Cargo.toml

@@ -13,9 +13,11 @@ categories = []
 publish = true
 
 [dependencies]
+base64 = "0.13.0"
 bcrypt = "0.8.2"
 dotenv = "0.15.0"
 r2d2 = "0.8.9"
+rand = "0.7.3"
 regex = "1.4.1"
 serde = "1.0"
 serde_derive = "1.0"

src/csrf.rs

@@ -1,7 +1,10 @@
+use rand::RngCore;
 use rocket::{Data, Request};
 use rocket::fairing::{Fairing as RocketFairing, Info, Kind};
+use rocket::http::Cookie;
 
 const COOKIE_NAME: &str = "csrf_token";
+const RAW_TOKEN_LENGTH: usize = 32;
 
 pub struct Fairing;
 
@@ -20,8 +23,13 @@ impl RocketFairing for Fairing {
     }
 
     fn on_request(&self, request: &mut Request, _: &Data) {
-        let _token: Option<String> = request.cookies()
-            .get_private(COOKIE_NAME)
-            .and_then(|cookie| Some(cookie.value().to_string()));
+        if request.cookies().get_private(COOKIE_NAME).is_some() { return };
+
+        let mut raw = [0u8; RAW_TOKEN_LENGTH];
+        rand::thread_rng().fill_bytes(&mut raw);
+
+        let encoded = base64::encode(raw);
+
+        request.cookies().add_private(Cookie::new(COOKIE_NAME, encoded));
     }
 }