Merge pull request #292 from blackbeam/tls-domain-override

Allow overriding domain used for TLS hostname verification

src/conn/mod.rs

@@ -550,7 +550,10 @@ impl Conn {
             self.write_struct(&ssl_request).await?;
             let conn = self;
             let ssl_opts = conn.opts().ssl_opts().cloned().expect("unreachable");
-            let domain = conn.opts().ip_or_hostname().into();
+            let domain = ssl_opts
+                .tls_hostname_override()
+                .unwrap_or_else(|| conn.opts().ip_or_hostname())
+                .into();
             conn.stream_mut()?.make_secure(domain, ssl_opts).await?;
             Ok(())
         } else {

src/opts/mod.rs

@@ -195,6 +195,7 @@ pub struct SslOpts {
     root_certs: Vec<PathOrBuf<'static>>,
     skip_domain_validation: bool,
     accept_invalid_certs: bool,
+    tls_hostname_override: Option<Cow<'static, str>>,
 }
 
 impl SslOpts {
@@ -228,6 +229,18 @@ impl SslOpts {
         self
     }
 
+    /// If set, will override the hostname used to verify the server's certificate.
+    ///
+    /// This is useful when connecting to a server via a tunnel, where the server hostname is
+    /// different from the hostname used to connect to the tunnel.
+    pub fn with_danger_tls_hostname_override<T: Into<Cow<'static, str>>>(
+        mut self,
+        domain: Option<T>,
+    ) -> Self {
+        self.tls_hostname_override = domain.map(Into::into);
+        self
+    }
+
     #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
     pub fn client_identity(&self) -> Option<&ClientIdentity> {
         self.client_identity.as_ref()
@@ -244,6 +257,10 @@ impl SslOpts {
     pub fn accept_invalid_certs(&self) -> bool {
         self.accept_invalid_certs
     }
+
+    pub fn tls_hostname_override(&self) -> Option<&str> {
+        self.tls_hostname_override.as_deref()
+    }
 }
 
 /// Connection pool options.