diff --git a/native/native_rust_library/src/lib.rs b/native/native_rust_library/src/lib.rs
--- a/native/native_rust_library/src/lib.rs
+++ b/native/native_rust_library/src/lib.rs
@@ -7,6 +7,7 @@
 
 mod crypto_tools;
 mod identity_client;
+mod tunnelbroker_client;
 mod identity {
   tonic::include_proto!("identity");
 }
diff --git a/native/native_rust_library/src/tunnelbroker_client.rs b/native/native_rust_library/src/tunnelbroker_client.rs
new file mode 100644
--- /dev/null
+++ b/native/native_rust_library/src/tunnelbroker_client.rs
@@ -0,0 +1,17 @@
+use crate::TunnelbrokerClient;
+
+use crate::tunnelbroker::SessionSignatureRequest;
+
+pub async fn get_nonce_to_sign(
+  mut client: Box<TunnelbrokerClient>,
+  device_id: String,
+) -> Result<String, tonic::Status> {
+  Ok(
+    client
+      .tunnelbroker_client
+      .session_signature(SessionSignatureRequest { device_id })
+      .await?
+      .into_inner()
+      .to_sign,
+  )
+}