Completely reworked request handling to be able to serve SCGI

Multi ~~track~~ protocol ~~drifting~~ abstraction!!

Cargo.toml

@@ -12,24 +12,26 @@ readme = "README.md"
 include = ["src/**", "Cargo.*", "CHANGELOG.md", "LICENSE*", "README.md"]
 
 [features]
-default = ["certgen"]
+default = ["scgi_srv"]
 user_management = ["sled", "bincode", "serde/derive", "crc32fast", "lazy_static"]
 user_management_advanced = ["rust-argon2", "ring", "user_management"]
 user_management_routes = ["user_management"]
 serve_dir = ["mime_guess", "tokio/fs"]
 ratelimiting = ["dashmap"]
-certgen = ["rcgen"]
+certgen = ["rcgen", "gemini_srv"]
+gemini_srv = ["tokio-rustls", "webpki", "rustls"]
+scgi_srv = []
 
 [dependencies]
 anyhow = "1.0.33"
-rustls = { version = "0.18.1", features = ["dangerous_configuration"] }
-tokio-rustls = "0.20.0"
 tokio = { version = "0.3.1", features = ["io-util","net","time", "rt"] }
 uriparse = "0.6.3"
 percent-encoding = "2.1.0"
 log = "0.4.11"
-webpki = "0.21.0"
 lazy_static = { version = "1.4.0", optional = true }
+rustls = { version = "0.18.1", features = ["dangerous_configuration"], optional = true}
+webpki = { version = "0.21.0", optional = true}
+tokio-rustls = { version = "0.20.0", optional = true}
 mime_guess = { version = "2.0.3", optional = true }
 dashmap = { version = "3.11.10", optional = true }
 sled = { version = "0.34.6", optional = true }
@@ -39,6 +41,7 @@ rust-argon2 = { version = "0.8.2", optional = true }
 crc32fast = { version = "1.2.1", optional = true }
 ring = { version = "0.16.15", optional = true }
 rcgen = { version = "0.8.5", optional = true }
+squeegee = { git = "https://gitlab.com/Alch_Emi/squeegee.git", branch = "main", optional = true }
 
 [dev-dependencies]
 env_logger = "0.8.1"

examples/certificates.rs

@@ -1,7 +1,7 @@
 use anyhow::*;
 use log::LevelFilter;
 use tokio::sync::RwLock;
-use kochab::{Certificate, GEMINI_PORT, Request, Response, Server};
+use kochab::{Certificate, Request, Response, Server};
 use std::collections::HashMap;
 use std::sync::Arc;
 
@@ -16,9 +16,9 @@ async fn main() -> Result<()> {
 
     let users = Arc::<RwLock::<HashMap<CertBytes, String>>>::default();
 
-    Server::bind(("0.0.0.0", GEMINI_PORT))
+    Server::new()
         .add_route("/", move|req| handle_request(users.clone(), req))
-        .serve()
+        .serve_unix("kochab.sock")
         .await
 }
 

examples/document.rs

@@ -1,6 +1,6 @@
 use anyhow::*;
 use log::LevelFilter;
-use kochab::{Server, Response, GEMINI_PORT, Document};
+use kochab::{Server, Response, Document};
 use kochab::document::HeadingLevel::*;
 
 #[tokio::main]
@@ -38,8 +38,8 @@ async fn main() -> Result<()> {
         ))
         .into();
 
-    Server::bind(("localhost", GEMINI_PORT))
+    Server::new()
         .add_route("/", response)
-        .serve()
+        .serve_unix("kochab.sock")
         .await
 }

examples/ratelimiting.rs

@@ -2,7 +2,7 @@ use std::time::Duration;
 
 use anyhow::*;
 use log::LevelFilter;
-use kochab::{Server, Request, Response, GEMINI_PORT, Document};
+use kochab::{Server, Request, Response, Document};
 
 #[tokio::main]
 async fn main() -> Result<()> {
@@ -10,10 +10,10 @@ async fn main() -> Result<()> {
         .filter_module("kochab", LevelFilter::Debug)
         .init();
 
-    Server::bind(("localhost", GEMINI_PORT))
+    Server::new()
         .add_route("/", handle_request)
         .ratelimit("/limit", 2, Duration::from_secs(60))
-        .serve()
+        .serve_unix("kochab.sock")
         .await
 }
 

examples/routing.rs

@@ -1,6 +1,6 @@
 use anyhow::*;
 use log::LevelFilter;
-use kochab::{Document, document::HeadingLevel, Request, Response, GEMINI_PORT};
+use kochab::{Document, document::HeadingLevel, Request, Response};
 
 #[tokio::main]
 async fn main() -> Result<()> {
@@ -8,11 +8,11 @@ async fn main() -> Result<()> {
         .filter_module("kochab", LevelFilter::Debug)
         .init();
 
-    kochab::Server::bind(("localhost", GEMINI_PORT))
+    kochab::Server::new()
         .add_route("/", handle_base)
         .add_route("/route", handle_short)
         .add_route("/route/long", handle_long)
-        .serve()
+        .serve_unix("kochab.sock")
         .await
 }
 

examples/serve_dir.rs

@@ -2,7 +2,7 @@ use std::path::PathBuf;
 
 use anyhow::*;
 use log::LevelFilter;
-use kochab::{Server, GEMINI_PORT};
+use kochab::Server;
 
 #[tokio::main]
 async fn main() -> Result<()> {
@@ -10,9 +10,9 @@ async fn main() -> Result<()> {
         .filter_module("kochab", LevelFilter::Debug)
         .init();
 
-    Server::bind(("localhost", GEMINI_PORT))
+    Server::new()
         .add_route("/", PathBuf::from("public")) // Serve directory listings & file contents
         .add_route("/about", PathBuf::from("README.md")) // Serve a single file
-        .serve()
+        .serve_unix("kochab.sock")
         .await
 }

examples/user_management.rs

@@ -1,7 +1,6 @@
 use anyhow::*;
 use log::LevelFilter;
 use kochab::{
-    GEMINI_PORT,
     Document,
     Request,
     Response,
@@ -26,7 +25,7 @@ async fn main() -> Result<()> {
         .filter_module("kochab", LevelFilter::Debug)
         .init();
 
-    Server::bind(("0.0.0.0", GEMINI_PORT))
+    Server::new()
 
         // Add our main routes
         .add_authenticated_route("/", handle_main)
@@ -36,7 +35,7 @@ async fn main() -> Result<()> {
         .add_um_routes::<String>()
 
         // Start the server
-        .serve()
+        .serve_unix("kochab.sock")
         .await
 }
 

molly-brown.conf

@@ -0,0 +1,20 @@
+# This is a super simple molly brown config file for the purpose of testing SCGI
+# applications.  Although you are welcome to use this as a base for an actual webserver,
+# please find somewhere better for your production sockets.
+#
+# You can get a copy of molly brown and more information about configuring it from:
+# https://tildegit.org/solderpunk/molly-brown
+#
+# Once installed, run the test server using the command
+# molly-brown -c molly-brown.conf
+
+Port      = 1965
+Hostname  = "localhost"
+CertPath  = "cert/cert.pem"
+KeyPath   = "cert/key.pem"
+
+AccessLog = "/dev/stdout"
+ErrorLog  = "/dev/stderr"
+
+[SCGIPaths]
+"/" = "kochab.sock"

src/lib.rs

@@ -1,26 +1,43 @@
 #[macro_use] extern crate log;
 
 use std::{
-    convert::TryFrom,
-    io::BufReader,
     sync::Arc,
-    path::PathBuf,
     time::Duration,
 };
-#[cfg(feature = "ratelimiting")]
+#[cfg(feature = "gemini_srv")]
-use std::net::IpAddr;
+use std::{
+    convert::TryFrom,
+    path::PathBuf,
+};
+#[cfg(feature = "scgi_srv")]
+use std::{
+    collections::HashMap,
+    net::SocketAddr,
+    str::FromStr,
+};
 use tokio::{
+    io,
+    io::BufReader,
+    net::TcpListener,
+    net::ToSocketAddrs,
     prelude::*,
-    io::{self, BufStream},
+};
-    net::{TcpStream, ToSocketAddrs},
+#[cfg(feature = "scgi_srv")]
+use tokio::net::UnixListener;
+#[cfg(feature = "gemini_srv")]
+use tokio::{
     time::timeout,
+    net::TcpStream,
 };
 #[cfg(feature = "ratelimiting")]
 use tokio::time::interval;
-use tokio::net::TcpListener;
+#[cfg(feature = "gemini_srv")]
 use rustls::ClientCertVerifier;
+#[cfg(feature = "gemini_srv")]
 use rustls::internal::msgs::handshake::DigitallySignedStruct;
+#[cfg(feature = "gemini_srv")]
 use tokio_rustls::{rustls, TlsAcceptor};
+#[cfg(feature = "gemini_srv")]
 use rustls::*;
 use anyhow::*;
 use crate::util::opt_timeout;
@@ -54,6 +71,7 @@ use handling::Handler;
 
 #[derive(Clone)]
 struct ServerInner {
+    #[cfg(feature = "gemini_srv")]
     tls_acceptor: TlsAcceptor,
     routes: Arc<RoutingNode<Handler>>,
     timeout: Duration,
@@ -65,7 +83,7 @@ struct ServerInner {
 }
 
 impl ServerInner {
-    async fn serve(self, listener: TcpListener) -> Result<()> {
+    async fn serve_ip(self, listener: TcpListener) -> Result<()> {
         #[cfg(feature = "ratelimiting")]
         tokio::spawn(prune_ratelimit_log(self.rate_limits.clone()));
 
@@ -82,41 +100,102 @@ impl ServerInner {
         }
     }
 
-    async fn serve_client(self, stream: TcpStream) -> Result<()> {
+    #[cfg(feature = "scgi_srv")]
-        #[cfg(feature="ratelimiting")]
+    // Yeah it's code duplication, but I can't find a way around it, so this is what we're
-        let peer_addr = stream.peer_addr()?.ip();
+    // getting for now
+    async fn serve_unix(self, listener: UnixListener) -> Result<()> {
+        #[cfg(feature = "ratelimiting")]
+        tokio::spawn(prune_ratelimit_log(self.rate_limits.clone()));
 
+        loop {
+            let (stream, _addr) = listener.accept().await
+                .context("Failed to accept client")?;
+            let this = self.clone();
+
+            tokio::spawn(async move {
+                if let Err(err) = this.serve_client(stream).await {
+                    error!("{:?}", err);
+                }
+            });
+        }
+    }
+
+    async fn serve_client(
+        &self,
+        #[cfg(feature = "gemini_srv")]
+        stream: TcpStream,
+        #[cfg(feature = "scgi_srv")]
+        stream: impl AsyncWrite + AsyncRead + Unpin,
+    ) -> Result<()> {
         let fut_accept_request = async {
+            #[cfg(feature = "gemini_srv")]
             let stream = self.tls_acceptor.accept(stream).await
                 .context("Failed to establish TLS session")?;
-            let mut stream = BufStream::new(stream);
+            let mut stream = BufReader::new(stream);
 
-            #[cfg(feature="user_management")]
             let request = self.receive_request(&mut stream).await
                 .context("Failed to receive request")?;
-            #[cfg(not(feature="user_management"))]
-            let request = Self::receive_request(&mut stream).await
-                .context("Failed to receive request")?;
 
             Result::<_, anyhow::Error>::Ok((request, stream))
         };
 
+
+        // Wait for the request to be parsed
+        let (mut request, mut stream) = {
+            #[cfg(feature = "gemini_srv")] {
                 // Use a timeout for interacting with the client
                 let fut_accept_request = timeout(self.timeout, fut_accept_request);
-        let (mut request, mut stream) = fut_accept_request.await
+                fut_accept_request.await
-            .context("Client timed out while waiting for response")??;
+                    .context("Client timed out while waiting for response")??
+            }
+            #[cfg(feature = "scgi_srv")]
+            fut_accept_request.await?
+        };
 
-        #[cfg(feature="ratelimiting")]
+        // Determine the remote client's IP address for logging and ratelimiting
+        let peer_addr = {
+            #[cfg(feature = "gemini_srv")] {
+                stream.get_ref()
+                    .get_ref()
+                    .0
+                    .peer_addr()?
+                    .ip()
+            }
+            #[cfg(feature = "scgi_srv")] {
+                SocketAddr::from_str(
+                    request.headers()
+                        .get("REMOTE_ADDR")
+                        .ok_or(ParseError::Malformed("REMOTE_ADDR header not received"))?
+                        .as_str()
+                ).context("Received malformed IP address from upstream")?
+                 .ip()
+            }
+        };
+
+        #[cfg(feature = "ratelimiting")]
+        // Perform ratelimiting checks
         if let Some(resp) = self.check_rate_limits(peer_addr, &request) {
+
+            // Log warning
+            warn!(
+                "Client from {} requesting {} was turned away by ratelimiting",
+                peer_addr,
+                request.uri()
+            );
+
+            // Send error response
             self.send_response(resp, &mut stream).await
                 .context("Failed to send response")?;
+
+            // Exit
             return Ok(())
         }
 
-        debug!("Client requested: {}", request.uri());
+        info!("{} requested: {}", peer_addr, request.uri());
 
         // Identify the client certificate from the tls stream.  This is the first
         // certificate in the certificate chain.
+        #[cfg(feature = "gemini_srv")] { // This is done earlier for `scgi_srv`
             let client_cert = stream.get_ref()
                 .get_ref()
                 .1
@@ -124,6 +203,7 @@ impl ServerInner {
                 .and_then(|mut v| if v.is_empty() {None} else {Some(v.remove(0))});
 
             request.set_cert(client_cert);
+        }
 
         let response = if let Some((trailing, handler)) = self.routes.match_request(&request) {
             request.set_trailing(trailing);
@@ -197,13 +277,13 @@ impl ServerInner {
         None
     }
 
+    #[cfg(feature = "gemini_srv")]
     async fn receive_request(
-        #[cfg(feature="user_management")]
         &self,
-        stream: &mut (impl AsyncBufRead + Unpin)
+        stream: &mut (impl AsyncBufRead + Unpin),
     ) -> Result<Request> {
-        let limit = REQUEST_URI_MAX_LEN + "\r\n".len();
+        const HEADER_LIMIT: usize = REQUEST_URI_MAX_LEN + "\r\n".len();
-        let mut stream = stream.take(limit as u64);
+        let mut stream = stream.take(HEADER_LIMIT as u64);
         let mut uri = Vec::new();
 
         stream.read_until(b'\n', &mut uri).await?;
@@ -223,23 +303,123 @@ impl ServerInner {
         let uri = URIReference::try_from(&*uri)
             .context("Request URI is invalid")?
             .into_owned();
-        let request = Request::from_uri(
+
+        Request::new(
             uri,
             #[cfg(feature="user_management")]
             self.manager.clone(),
-        ) .context("Failed to create request from URI")?;
+        ).context("Failed to create request from URI")
+    }
 
-        Ok(request)
+    #[cfg(feature = "scgi_srv")]
+    async fn receive_request(
+        &self,
+        stream: &mut (impl AsyncBufRead + Unpin),
+    ) -> Result<Request> {
+        let mut buff = Vec::with_capacity(4);
+
+        #[allow(clippy::char_lit_as_u8)]
+        // Read the length of the header netstring (e.g. "120:")
+        stream.read_until(':' as u8, &mut buff).await?;
+
+        buff.pop(); // Remove the trailing ':'
+        let len = std::str::from_utf8(&*buff)
+            .ok()
+            .and_then(|s| usize::from_str(s).ok())
+            .ok_or(ParseError::Malformed("netstring length"))?;
+
+        // Read in the headers
+        buff.clear();
+        buff.resize(len + 1, 0);
+        stream.read_exact(buff.as_mut()).await?;
+        buff.truncate(len - 1); // Remove the final \x00,
+
+        // Parse the headers
+        let (maybe_trailing, headers) = buff.split(|b| *b == 0) // Headers are null delimiited
+            .map(|bytes| // Convert to an &str
+                 std::str::from_utf8(bytes)
+                    .map_err(|_| ParseError::Malformed("scgi headers"))
+                    .map(str::trim)
+             )
+            .try_fold( // Turn the array of [header, value, header, ...] into a map
+                (Option::<&str>::None, HashMap::<String, String>::with_capacity(16)),
+                |(last_header, mut headers), s| {
+                    s.map(|text| {
+                        match last_header {
+                            None => (Some(text), headers),
+                            Some(header) => {
+                                headers.insert(header.to_string(), text.to_string());
+                                (None, headers)
+                            }
+                        }
+                    })
+                }
+            )?;
+
+        // If there's not the same number of headers as values, that's a problem
+        if maybe_trailing.is_some() {
+            bail!(ParseError::Malformed("trailing header"));
+        }
+
+        // Check the content length info
+        let cont_len_val = headers.get("CONTENT_LENGTH")
+            .ok_or(ParseError::Malformed("No content length header!"))?;
+        let cont_len = usize::from_str(cont_len_val)
+            .map_err(|_| ParseError::Malformed("Malformed content length"))?;
+        if cont_len > 0 {
+            bail!(ParseError::Malformed("Gemini SCGI requests should not have a body"));
+        }
+
+        // Spec requires setting an SCGI header to one
+        if *headers.get("SCGI").ok_or(ParseError::Malformed("No SCGI header"))? != "1" {
+            bail!(ParseError::Malformed("SCGI header not set to \"1\""));
+        }
+
+        trace!("Headers received: {:?}", headers);
+
+        Ok(Request::new(headers)?)
     }
 }
 
-pub struct Server<A> {
+#[derive(Debug)]
-    addr: A,
+#[cfg(feature = "scgi_srv")]
-    cert_path: PathBuf,
+enum ParseError {
-    key_path: PathBuf,
+    IO(io::Error),
+    Malformed(&'static str),
+}
+
+#[cfg(feature = "scgi_srv")]
+impl From<io::Error> for ParseError {
+    fn from(e: io::Error) -> Self {
+        Self::IO(e)
+    }
+}
+
+#[cfg(feature = "scgi_srv")]
+impl std::fmt::Display for ParseError {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            Self::IO(e) => write!(f, "IO Error while parsing and responding SCGI: {}", e),
+            Self::Malformed(e) => write!(f, "SCGI request malformed at {}", e),
+        }
+    }
+}
+
+#[cfg(feature = "scgi_srv")]
+impl std::error::Error for ParseError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        if let Self::IO(e) = self { Some(e) } else { None }
+    }
+}
+
+pub struct Server {
     timeout: Duration,
     complex_body_timeout_override: Option<Duration>,
     routes: RoutingNode<Handler>,
+    #[cfg(feature = "gemini_srv")]
+    cert_path: PathBuf,
+    #[cfg(feature = "gemini_srv")]
+    key_path: PathBuf,
     #[cfg(feature="ratelimiting")]
     rate_limits: RoutingNode<RateLimiter<IpAddr>>,
     #[cfg(feature="user_management")]
@@ -250,15 +430,16 @@ pub struct Server<A> {
     certgen_mode: CertGenMode,
 }
 
-impl<A: ToSocketAddrs> Server<A> {
+impl Server {
-    pub fn bind(addr: A) -> Self {
+    pub fn new() -> Self {
         Self {
-            addr,
             timeout: Duration::from_secs(1),
             complex_body_timeout_override: Some(Duration::from_secs(30)),
-            cert_path: PathBuf::from("cert/cert.pem"),
-            key_path: PathBuf::from("cert/key.pem"),
             routes: RoutingNode::default(),
+            #[cfg(feature = "gemini_srv")]
+            cert_path: PathBuf::from("cert/cert.pem"),
+            #[cfg(feature = "gemini_srv")]
+            key_path: PathBuf::from("cert/key.pem"),
             #[cfg(feature="ratelimiting")]
             rate_limits: RoutingNode::default(),
             #[cfg(feature="user_management")]
@@ -309,6 +490,7 @@ impl<A: ToSocketAddrs> Server<A> {
         self
     }
 
+    #[cfg(feature = "gemini_srv")]
     /// Sets the directory that kochab should look for TLS certs and keys into
     ///
     /// Northstar will look for files called `cert.pem` and `key.pem` in the provided
@@ -324,6 +506,7 @@ impl<A: ToSocketAddrs> Server<A> {
             .set_key(dir.join("key.pem"))
     }
 
+    #[cfg(feature = "gemini_srv")]
     /// Set the path to the TLS certificate kochab will use
     ///
     /// This defaults to `cert/cert.pem`.
@@ -335,6 +518,7 @@ impl<A: ToSocketAddrs> Server<A> {
         self
     }
 
+    #[cfg(feature = "gemini_srv")]
     /// Set the path to the ertificate key kochab will use
     ///
     /// This defaults to `cert/key.pem`.
@@ -436,7 +620,8 @@ impl<A: ToSocketAddrs> Server<A> {
         self
     }
 
-    pub async fn serve(mut self) -> Result<()> {
+    fn build(mut self) -> Result<ServerInner> {
+        #[cfg(feature = "gemini_srv")]
         let config = tls_config(
             &self.cert_path,
             &self.key_path,
@@ -444,28 +629,51 @@ impl<A: ToSocketAddrs> Server<A> {
             self.certgen_mode
         ).context("Failed to create TLS config")?;
 
-        let listener = TcpListener::bind(self.addr).await
-            .context("Failed to create socket")?;
-
         self.routes.shrink();
 
         #[cfg(feature="user_management")]
         let data_dir = self.data_dir;
 
-        let server = ServerInner {
+        Ok(ServerInner {
-            tls_acceptor: TlsAcceptor::from(config),
             routes: Arc::new(self.routes),
             timeout: self.timeout,
             complex_timeout: self.complex_body_timeout_override,
+            #[cfg(feature = "gemini_srv")]
+            tls_acceptor: TlsAcceptor::from(config),
             #[cfg(feature="ratelimiting")]
             rate_limits: Arc::new(self.rate_limits),
             #[cfg(feature="user_management")]
             manager: UserManager::new(
                 self.database.unwrap_or_else(move|| sled::open(data_dir).unwrap())
             )?,
-        };
+        })
+    }
 
-        server.serve(listener).await
+    /// Start serving requests on a given bound address & port
+    ///
+    /// `addr` can be anything `tokio` can parse, including just a string like
+    /// "localhost:1965"
+    pub async fn serve_ip(self, addr: impl ToSocketAddrs) -> Result<()> {
+        let server = self.build()?;
+        let socket = TcpListener::bind(addr).await?;
+        server.serve_ip(socket).await
+    }
+
+    #[cfg(feature = "scgi_srv")]
+    /// Start serving requests on a given unix socket
+    ///
+    /// Requires an address in the form of a path to bind to.  This is only available when
+    /// in `scgi_srv` mode.
+    pub async fn serve_unix(self, addr: impl AsRef<std::path::Path>) -> Result<()> {
+        let server = self.build()?;
+        let socket = UnixListener::bind(addr)?;
+        server.serve_unix(socket).await
+    }
+}
+
+impl Default for Server {
+    fn default() -> Self {
+        Self::new()
     }
 }
 
@@ -512,6 +720,7 @@ async fn prune_ratelimit_log(rate_limits: Arc<RoutingNode<RateLimiter<IpAddr>>>)
     }
 }
 
+#[cfg(feature = "gemini_srv")]
 fn tls_config(
     cert_path: &PathBuf,
     key_path: &PathBuf,
@@ -535,20 +744,22 @@ fn tls_config(
     Ok(config.into())
 }
 
+#[cfg(feature = "gemini_srv")]
 fn load_cert_chain(cert_path: &PathBuf) -> Result<Vec<Certificate>> {
     let certs = std::fs::File::open(cert_path)
         .with_context(|| format!("Failed to open `{:?}`", cert_path))?;
-    let mut certs = BufReader::new(certs);
+    let mut certs = std::io::BufReader::new(certs);
     let certs = rustls::internal::pemfile::certs(&mut certs)
         .map_err(|_| anyhow!("failed to load certs `{:?}`", cert_path))?;
 
     Ok(certs)
 }
 
+#[cfg(feature = "gemini_srv")]
 fn load_key(key_path: &PathBuf) -> Result<PrivateKey> {
     let keys = std::fs::File::open(key_path)
         .with_context(|| format!("Failed to open `{:?}`", key_path))?;
-    let mut keys = BufReader::new(keys);
+    let mut keys = std::io::BufReader::new(keys);
     let mut keys = rustls::internal::pemfile::pkcs8_private_keys(&mut keys)
         .map_err(|_| anyhow!("failed to load key `{:?}`", key_path))?;
 
@@ -559,11 +770,14 @@ fn load_key(key_path: &PathBuf) -> Result<PrivateKey> {
     Ok(key)
 }
 
+#[cfg(feature = "gemini_srv")]
 /// A client cert verifier that accepts all connections
 ///
 /// Unfortunately, rustls doesn't provide a ClientCertVerifier that accepts self-signed
 /// certificates, so we need to implement this ourselves.
 struct AllowAnonOrSelfsignedClient { }
+
+#[cfg(feature = "gemini_srv")]
 impl AllowAnonOrSelfsignedClient {
 
     /// Create a new verifier
@@ -573,6 +787,7 @@ impl AllowAnonOrSelfsignedClient {
 
 }
 
+#[cfg(feature = "gemini_srv")]
 impl ClientCertVerifier for AllowAnonOrSelfsignedClient {
 
     fn client_auth_root_subjects(

src/types.rs

@@ -1,4 +1,7 @@
+#[cfg(feature = "gemini_srv")]
 pub use rustls::Certificate;
+#[cfg(feature = "scgi_srv")]
+pub type Certificate = String;
 pub use uriparse::URIReference;
 
 mod meta;

src/types/request.rs

@@ -1,8 +1,13 @@
 use std::ops;
+#[cfg(feature = "scgi_srv")]
+use std::{
+    collections::HashMap,
+    convert::TryFrom,
+};
 use anyhow::*;
 use percent_encoding::percent_decode_str;
 use uriparse::URIReference;
-use rustls::Certificate;
+use crate::types::Certificate;
 #[cfg(feature="user_management")]
 use serde::{Serialize, de::DeserializeOwned};
 
@@ -16,28 +21,37 @@ pub struct Request {
     trailing_segments: Option<Vec<String>>,
     #[cfg(feature="user_management")]
     manager: UserManager,
+    #[cfg(feature = "scgi_srv")]
+    headers: HashMap<String, String>,
 }
 
 impl Request {
-    pub fn from_uri(
+    pub fn new(
-        uri: URIReference<'static>,
+        #[cfg(feature = "gemini_srv")]
-        #[cfg(feature="user_management")]
-        manager: UserManager,
-    ) -> Result<Self> {
-        Self::with_certificate(
-            uri,
-            None,
-            #[cfg(feature="user_management")]
-            manager
-        )
-    }
-
-    pub fn with_certificate(
         mut uri: URIReference<'static>,
-        certificate: Option<Certificate>,
+        #[cfg(feature = "scgi_srv")]
+        headers: HashMap<String, String>,
         #[cfg(feature="user_management")]
         manager: UserManager,
     ) -> Result<Self> {
+        #[cfg(feature = "scgi_srv")]
+        let (mut uri, certificate) = (
+            URIReference::try_from(
+                format!(
+                    "{}{}",
+                    headers.get("PATH_INFO")
+                        .context("PATH_INFO header not received from SCGI client")?
+                        .as_str(),
+                    headers.get("QUERY_STRING")
+                        .map(|q| format!("?{}", q))
+                        .unwrap_or_else(String::new),
+                ).as_str()
+            )
+                .context("Request URI is invalid")?
+                .into_owned(),
+            headers.get("TLS_CLIENT_HASH").cloned(),
+        );
+
         uri.normalize();
 
         let input = match uri.query() {
@@ -54,8 +68,13 @@ impl Request {
         Ok(Self {
             uri,
             input,
+            #[cfg(feature = "scgi_srv")]
             certificate,
+            #[cfg(feature = "gemini_srv")]
+            certificate: None,
             trailing_segments: None,
+            #[cfg(feature = "scgi_srv")]
+            headers,
             #[cfg(feature="user_management")]
             manager,
         })
@@ -103,6 +122,24 @@ impl Request {
         self.input.as_deref()
     }
 
+    #[cfg(feature="scgi_srv")]
+    /// View any headers sent by the SCGI client
+    ///
+    /// When an SCGI client delivers a request (e.g. when your gemini server sends a
+    /// request to this app), it includes many headers which aren't always included in
+    /// the request otherwise.  Bear in mind that **not all SCGI clients send the same
+    /// headers**, and these are *never* available when operating in `gemini_srv` mode.
+    ///
+    /// Some examples of headers mollybrown sets are:
+    ///  - `REMOTE_ADDR` (The user's IP address and port)
+    ///  - `TLS_CLIENT_SUBJECT_CN` (The CommonName on the user's certificate, when present)
+    ///  - `SERVER_NAME` (The host name of the server the request was received on)
+    ///  - `SERVER_SOFTWARE` (= "MOLLY_BROWN")
+    ///  - `SCRIPT_PATH` (The prefix the script is being served on)
+    pub const fn headers(&self) -> &HashMap<String, String> {
+        &self.headers
+    }
+
     pub fn set_cert(&mut self, cert: Option<Certificate>) {
         self.certificate = cert;
     }