[Workers] Adds New Rust Examples (#17302)

* feat: Adds rust example for websocket

* [Workers] Adds rust example logging-headers

* [Workers] Adds rust example basic-auth

* [Workers] Adds rust example security-headers

* [Workers] Adds rust example cors-header-proxy

Author: megaconfidence

src/content/docs/workers/examples/basic-auth.mdx

@@ -7,6 +7,7 @@ tags:
 languages:
   - JavaScript
   - TypeScript
+  - Rust
 preview:
   - true
 pcx_content_type: example
@@ -258,4 +259,75 @@ export default {
 } satisfies ExportedHandler<Env>;
 ```
 
-</TabItem> </Tabs>
+</TabItem> <TabItem label="Rust" icon="seti:rust">
+```rs
+use base64::prelude::*;
+use worker::*;
+
+#[event(fetch)]
+async fn fetch(req: Request, env: Env, _ctx: Context) -> Result<Response> {
+    let basic_user = "admin";
+    // You will need an admin password. This should be
+    // attached to your Worker as an encrypted secret.
+    // Refer to https://developers.cloudflare.com/workers/configuration/secrets/
+    let basic_pass = match env.secret("PASSWORD") {
+        Ok(s) => s.to_string(),
+        Err(_) => "password".to_string(),
+    };
+    let url = req.url()?;
+
+    match url.path() {
+        "/" => Response::ok("Anyone can access the homepage."),
+        // Invalidate the "Authorization" header by returning a HTTP 401.
+        // We do not send a "WWW-Authenticate" header, as this would trigger
+        // a popup in the browser, immediately asking for credentials again.
+        "/logout" => Response::error("Logged out.", 401),
+        "/admin" => {
+            // The "Authorization" header is sent when authenticated.
+            let authorization = req.headers().get("Authorization")?;
+            if authorization == None {
+                let mut headers = Headers::new();
+                // Prompts the user for credentials.
+                headers.set(
+                    "WWW-Authenticate",
+                    "Basic realm='my scope', charset='UTF-8'",
+                )?;
+                return Ok(Response::error("You need to login.", 401)?.with_headers(headers));
+            }
+            let authorization = authorization.unwrap();
+            let auth: Vec<&str> = authorization.split(" ").collect();
+            let scheme = auth[0];
+            let encoded = auth[1];
+
+            // The Authorization header must start with Basic, followed by a space.
+            if encoded == "" || scheme != "Basic" {
+                return Response::error("Malformed authorization header.", 400);
+            }
+
+            let buff = BASE64_STANDARD.decode(encoded).unwrap();
+            let credentials = String::from_utf8_lossy(&buff);
+            // The username & password are split by the first colon.
+            //=> example: "username:password"
+            let credentials: Vec<&str> = credentials.split(':').collect();
+            let user = credentials[0];
+            let pass = credentials[1];
+
+            if user != basic_user || pass != basic_pass {
+                let mut headers = Headers::new();
+                // Prompts the user for credentials.
+                headers.set(
+                    "WWW-Authenticate",
+                    "Basic realm='my scope', charset='UTF-8'",
+                )?;
+                return Ok(Response::error("You need to login.", 401)?.with_headers(headers));
+            }
+
+            let mut headers = Headers::new();
+            headers.set("Cache-Control", "no-store")?;
+            Ok(Response::ok("🎉 You have private access!")?.with_headers(headers))
+        }
+        _ => Response::error("Not Found.", 404),
+    }
+}
+```
+</TabItem> </Tabs>

src/content/docs/workers/examples/cors-header-proxy.mdx

@@ -8,6 +8,7 @@ languages:
   - JavaScript
   - TypeScript
   - Python
+  - Rust
 pcx_content_type: example
 title: CORS header proxy
 sidebar:
@@ -436,4 +437,128 @@ async def on_fetch(request):
     return raw_html_response(demo_page)
 ```
 
-</TabItem> </Tabs>
+</TabItem> <TabItem label="Rust" icon="seti:rust">
+```rs
+use std::{borrow::Cow, collections::HashMap};
+use worker::*;
+
+fn raw_html_response(html: &str) -> Result<Response> {
+    Response::from_html(html)
+}
+async fn handle_request(req: Request, api_url: &str) -> Result<Response> {
+    let url = req.url().unwrap();
+    let mut api_url2 = url
+        .query_pairs()
+        .find(|x| x.0 == Cow::Borrowed("apiurl"))
+        .unwrap()
+        .1
+        .to_string();
+    if api_url2 == String::from("") {
+        api_url2 = api_url.to_string();
+    }
+    let mut request = req.clone_mut()?;
+    *request.path_mut()? = api_url2.clone();
+    if let url::Origin::Tuple(origin, _, _) = Url::parse(&api_url2)?.origin() {
+        (*request.headers_mut()?).set("Origin", &origin)?;
+    }
+    let mut response = Fetch::Request(request).send().await?.cloned()?;
+    let headers = response.headers_mut();
+    if let url::Origin::Tuple(origin, _, _) = url.origin() {
+        headers.set("Access-Control-Allow-Origin", &origin)?;
+        headers.set("Vary", "Origin")?;
+    }
+
+    Ok(response)
+}
+
+fn handle_options(req: Request, cors_headers: &HashMap<&str, &str>) -> Result<Response> {
+    let headers: Vec<_> = req.headers().keys().collect();
+    if [
+        "access-control-request-method",
+        "access-control-request-headers",
+        "origin",
+    ]
+    .iter()
+    .all(|i| headers.contains(&i.to_string()))
+    {
+        let mut headers = Headers::new();
+        for (k, v) in cors_headers.iter() {
+            headers.set(k, v)?;
+        }
+        return Ok(Response::empty()?.with_headers(headers));
+    }
+    Response::empty()
+}
+#[event(fetch)]
+async fn fetch(req: Request, _env: Env, _ctx: Context) -> Result<Response> {
+    let cors_headers = HashMap::from([
+        ("Access-Control-Allow-Origin", "*"),
+        ("Access-Control-Allow-Methods", "GET,HEAD,POST,OPTIONS"),
+        ("Access-Control-Max-Age", "86400"),
+    ]);
+    let api_url = "https://examples.cloudflareworkers.com/demos/demoapi";
+    let proxy_endpoint = "/corsproxy/";
+    let demo_page = format!(
+        r#"
+    <!DOCTYPE html>
+    <html>
+    <body>
+    <h1>API GET without CORS Proxy</h1>
+    <a target="_blank" href="https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch#Checking_that_the_fetch_was_successful">Shows TypeError: Failed to fetch since CORS is misconfigured</a>
+    <p id="noproxy-status"/>
+    <code id="noproxy">Waiting</code>
+    <h1>API GET with CORS Proxy</h1>
+    <p id="proxy-status"/>
+    <code id="proxy">Waiting</code>
+    <h1>API POST with CORS Proxy + Preflight</h1>
+    <p id="proxypreflight-status"/>
+    <code id="proxypreflight">Waiting</code>
+    <script>
+    let reqs = {{}};
+    reqs.noproxy = () => {{
+        return fetch("{api_url}").then(r => r.json())
+    }}
+    reqs.proxy = async () => {{
+        let href = "{proxy_endpoint}?apiurl={api_url}"
+        return fetch(window.location.origin + href).then(r => r.json())
+    }}
+    reqs.proxypreflight = async () => {{
+        let href = "{proxy_endpoint}?apiurl={api_url}"
+        let response = await fetch(window.location.origin + href, {{
+        method: "POST",
+        headers: {{
+            "Content-Type": "application/json"
+        }},
+        body: JSON.stringify({{
+            msg: "Hello world!"
+        }})
+        }})
+        return response.json()
+    }}
+    (async () => {{
+    for (const [reqName, req] of Object.entries(reqs)) {{
+        try {{
+        let data = await req()
+        document.getElementById(reqName).innerHTML = JSON.stringify(data)
+        }} catch (e) {{
+        document.getElementById(reqName).innerHTML = e
+        }}
+    }}
+    }})()
+    </script>
+    </body>
+    </html>
+    "#
+    );
+
+    if req.url()?.path().starts_with(proxy_endpoint) {
+        match req.method() {
+            Method::Options => return handle_options(req, &cors_headers),
+            Method::Get | Method::Head | Method::Post => return handle_request(req, api_url).await,
+            _ => return Response::error("Method Not Allowed", 405),
+        }
+    }
+    raw_html_response(&demo_page)
+}
+```
+</TabItem> </Tabs>

src/content/docs/workers/examples/logging-headers.mdx

@@ -6,6 +6,7 @@ tags:
   - Headers
 languages:
   - JavaScript
+  - Rust
   - TypeScript
   - Python
 preview:
@@ -51,6 +52,16 @@ async def on_fetch(request):
     return Response.new('Hello world')
 ```
 
+</TabItem> <TabItem label="Rust" icon="seti:rust">
+```rs
+use worker::*;
+
+#[event(fetch)]
+async fn fetch(req: HttpRequest, _env: Env, _ctx: Context) -> Result<Response> {
+    console_log!("{:?}", req.headers());
+    Response::ok("hello world")
+}
+```
 </TabItem> </Tabs>
 
 ---
@@ -142,4 +153,4 @@ Request headers: {
   "cf-ipcountry": "US",
   // ...
 }"
-```
+```

src/content/docs/workers/examples/security-headers.mdx

@@ -10,6 +10,7 @@ languages:
   - JavaScript
   - TypeScript
   - Python
+  - Rust
 pcx_content_type: example
 title: Set security headers
 sidebar:
@@ -250,4 +251,75 @@ async def on_fetch(request):
     return Response.new(res.body, status=res.status, statusText=res.statusText, headers=new_headers)
 ```
 
-</TabItem> </Tabs>
+</TabItem> <TabItem label="Rust" icon="seti:rust">
+```rs
+use std::collections::HashMap;
+use worker::*;
+
+#[event(fetch)]
+async fn fetch(req: Request, _env: Env, _ctx: Context) -> Result<Response> {
+    let default_security_headers = HashMap::from([
+        //Secure your application with Content-Security-Policy headers.
+        //Enabling these headers will permit content from a trusted domain and all its subdomains.
+        //@see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
+        (
+            "Content-Security-Policy",
+            "default-src 'self' example.com *.example.com",
+        ),
+        //You can also set Strict-Transport-Security headers.
+        //These are not automatically set because your website might get added to Chrome's HSTS preload list.
+        //Here's the code if you want to apply it:
+        (
+            "Strict-Transport-Security",
+            "max-age=63072000; includeSubDomains; preload",
+        ),
+        //Permissions-Policy header provides the ability to allow or deny the use of browser features, such as opting out of FLoC - which you can use below:
+        ("Permissions-Policy", "interest-cohort=()"),
+        //X-XSS-Protection header prevents a page from loading if an XSS attack is detected.
+        //@see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-XSS-Protection
+        ("X-XSS-Protection", "0"),
+        //X-Frame-Options header prevents click-jacking attacks.
+        //@see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options
+        ("X-Frame-Options", "DENY"),
+        //X-Content-Type-Options header prevents MIME-sniffing.
+        //@see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Content-Type-Options
+        ("X-Content-Type-Options", "nosniff"),
+        ("Referrer-Policy", "strict-origin-when-cross-origin"),
+        (
+            "Cross-Origin-Embedder-Policy",
+            "require-corp; report-to='default';",
+        ),
+        (
+            "Cross-Origin-Opener-Policy",
+            "same-site; report-to='default';",
+        ),
+        ("Cross-Origin-Resource-Policy", "same-site"),
+    ]);
+    let blocked_headers = ["Public-Key-Pins", "X-Powered-By", "X-AspNet-Version"];
+    let tls = req.cf().unwrap().tls_version();
+    let res = Fetch::Request(req).send().await?;
+    let mut new_headers = res.headers().clone();
+
+    // This sets the headers for HTML responses
+    if Some(String::from("text/html")) == new_headers.get("Content-Type")? {
+        return Ok(Response::from_body(res.body().clone())?
+            .with_headers(new_headers)
+            .with_status(res.status_code()));
+    }
+    for (k, v) in default_security_headers {
+        new_headers.set(k, v)?;
+    }
+
+    for k in blocked_headers {
+        new_headers.delete(k)?;
+    }
+
+    if !vec!["TLSv1.2", "TLSv1.3"].contains(&tls.as_str()) {
+        return Response::error("You need to use TLS version 1.2 or higher.", 400);
+    }
+    Ok(Response::from_body(res.body().clone())?
+        .with_headers(new_headers)
+        .with_status(res.status_code()))
+}
+```
+</TabItem> </Tabs>