From 68e1eaf88da5d0197c478ff6967e51de56091a2e Mon Sep 17 00:00:00 2001
From: Rob Ede <robjtede@icloud.com>
Date: Wed, 27 Jul 2022 02:27:46 +0100
Subject: [PATCH] implement parsing for StrictTransportSecurity header

---
 actix-web-lab/CHANGELOG.md                    |   2 +
 actix-web-lab/README.md                       |   2 +-
 .../src/strict_transport_security.rs          | 103 +++++++++++++++++-
 3 files changed, 101 insertions(+), 6 deletions(-)

diff --git a/actix-web-lab/CHANGELOG.md b/actix-web-lab/CHANGELOG.md
index 51a87e7e..5e130559 100644
--- a/actix-web-lab/CHANGELOG.md
+++ b/actix-web-lab/CHANGELOG.md
@@ -1,6 +1,8 @@
 # Changelog
 
 ## Unreleased - 2022-xx-xx
+- Implement `FromStr` and `Header::parse` for `StrictTransportSecurity`.
+- Implement `PartialEq` and `Eq` for `StrictTransportSecurity`.
 
 
 ## 0.16.6 - 2022-07-27
diff --git a/actix-web-lab/README.md b/actix-web-lab/README.md
index 59bc058a..efc23f66 100644
--- a/actix-web-lab/README.md
+++ b/actix-web-lab/README.md
@@ -78,4 +78,4 @@
 - Breaking changes will likely happen on most 0.x version bumps.
 - Documentation might be limited for some items.
 - Items that graduate to Actix Web crate will be marked deprecated here for a reasonable amount of time so you can migrate.
-- Migrating will often be as easy as dropping the `_lab` suffix from imports when migrating.
+- Migrating will often be as easy as dropping the `_lab` suffix from imports.
diff --git a/actix-web-lab/src/strict_transport_security.rs b/actix-web-lab/src/strict_transport_security.rs
index 3f06e69c..42a235eb 100644
--- a/actix-web-lab/src/strict_transport_security.rs
+++ b/actix-web-lab/src/strict_transport_security.rs
@@ -2,11 +2,13 @@
 //!
 //! See [`StrictTransportSecurity`] docs.
 
-use std::{convert::Infallible, time::Duration};
+use std::{convert::Infallible, str, time::Duration};
 
 use actix_web::{
+    error::ParseError,
     http::header::{
-        Header, HeaderName, HeaderValue, TryIntoHeaderValue, STRICT_TRANSPORT_SECURITY,
+        from_one_raw_str, Header, HeaderName, HeaderValue, TryIntoHeaderValue,
+        STRICT_TRANSPORT_SECURITY,
     },
     HttpMessage,
 };
@@ -35,7 +37,7 @@ pub type Hsts = StrictTransportSecurity;
 /// See the [HSTS page on MDN] for more information.
 ///
 /// [HSTS page on MDN]: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Strict-Transport-Security
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[doc(alias = "hsts", alias = "sts")]
 pub struct StrictTransportSecurity {
     duration: Duration,
@@ -94,6 +96,49 @@ impl Default for StrictTransportSecurity {
     }
 }
 
+impl str::FromStr for StrictTransportSecurity {
+    type Err = ParseError;
+
+    fn from_str(val: &str) -> Result<Self, Self::Err> {
+        let mut parts = val.split(';').map(str::trim);
+
+        // parse max-age/duration from first part of header
+        let duration = parts
+            .next()
+            .ok_or(ParseError::Header)?
+            .split_once('=')
+            .and_then(|(key, max_age)| {
+                if key.trim() != "max-age" {
+                    return None;
+                }
+
+                max_age.trim().parse().ok()
+            })
+            .map(Duration::from_secs)
+            .ok_or(ParseError::Header)?;
+
+        let mut include_subdomains = false;
+        let mut preload = false;
+
+        // find known attributes in remaining parts
+        for part in parts {
+            if part == "includeSubdomains" {
+                include_subdomains = true;
+            }
+
+            if part == "preload" {
+                preload = true;
+            }
+        }
+
+        Ok(Self {
+            duration,
+            include_subdomains,
+            preload,
+        })
+    }
+}
+
 impl TryIntoHeaderValue for StrictTransportSecurity {
     type Error = Infallible;
 
@@ -119,8 +164,8 @@ impl Header for StrictTransportSecurity {
         STRICT_TRANSPORT_SECURITY
     }
 
-    fn parse<M: HttpMessage>(_msg: &M) -> Result<Self, actix_http::error::ParseError> {
-        unimplemented!("Strict-Transport-Security header cannot yet be parsed");
+    fn parse<M: HttpMessage>(msg: &M) -> Result<Self, ParseError> {
+        from_one_raw_str(msg.headers().get(Self::name()))
     }
 }
 
@@ -195,4 +240,52 @@ mod test {
             "max-age=63072000; includeSubDomains"
         );
     }
+
+    #[test]
+    fn parsing() {
+        assert!("".parse::<StrictTransportSecurity>().is_err());
+        assert!("duration=1".parse::<StrictTransportSecurity>().is_err());
+
+        assert_eq!(
+            "max-age=1".parse::<StrictTransportSecurity>().unwrap(),
+            StrictTransportSecurity {
+                duration: Duration::from_secs(1),
+                include_subdomains: false,
+                preload: false,
+            }
+        );
+
+        assert_eq!(
+            "max-age=1; includeSubdomains"
+                .parse::<StrictTransportSecurity>()
+                .unwrap(),
+            StrictTransportSecurity {
+                duration: Duration::from_secs(1),
+                include_subdomains: true,
+                preload: false,
+            }
+        );
+
+        assert_eq!(
+            "max-age=1; preload"
+                .parse::<StrictTransportSecurity>()
+                .unwrap(),
+            StrictTransportSecurity {
+                duration: Duration::from_secs(1),
+                include_subdomains: false,
+                preload: true,
+            }
+        );
+
+        assert_eq!(
+            "max-age=1; includeSubdomains; preload"
+                .parse::<StrictTransportSecurity>()
+                .unwrap(),
+            StrictTransportSecurity {
+                duration: Duration::from_secs(1),
+                include_subdomains: true,
+                preload: true,
+            }
+        );
+    }
 }