From 60b26344d6171d56dbbe4a610da5b3c2457169c6 Mon Sep 17 00:00:00 2001
From: ghe0 <gheorghe@gheo.tech>
Date: Thu, 15 Aug 2024 02:11:58 +0300
Subject: [PATCH] signing random messages from user

---
 src/database.rs    | 55 ++++++++++++++++++++++++++++++++++++++++++++--
 src/grpc.rs        |  6 +++--
 src/http_server.rs | 24 ++++++++++++++++++--
 3 files changed, 79 insertions(+), 6 deletions(-)

diff --git a/src/database.rs b/src/database.rs
index c270f5a..907033e 100644
--- a/src/database.rs
+++ b/src/database.rs
@@ -1,11 +1,44 @@
 #![allow(dead_code)]
-use ed25519_dalek::{SigningKey, VerifyingKey};
+use ed25519_dalek::{Signer, SigningKey, VerifyingKey};
 use once_cell::sync::Lazy;
 use std::collections::HashMap;
 use std::sync::Mutex;
 use std::time::SystemTime;
 use tabled::{Table, Tabled};
 
+pub enum SigningError {
+    CorruptedKey,
+    KeyNotFound,
+}
+
+impl std::fmt::Display for SigningError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let error_message = match self {
+            SigningError::CorruptedKey => "The public key is corrupted",
+            SigningError::KeyNotFound => "Did not find the public key",
+        };
+        write!(f, "{}", error_message)
+    }
+}
+
+impl From<hex::FromHexError> for SigningError {
+    fn from(_: hex::FromHexError) -> Self {
+        Self::CorruptedKey
+    }
+}
+
+impl From<ed25519_dalek::ed25519::Error> for SigningError {
+    fn from(_: ed25519_dalek::ed25519::Error) -> Self {
+        Self::CorruptedKey
+    }
+}
+
+impl From<std::array::TryFromSliceError> for SigningError {
+    fn from(_: std::array::TryFromSliceError) -> Self {
+        Self::CorruptedKey
+    }
+}
+
 #[derive(Clone)]
 pub struct NodeInfo {
     pub pubkey: VerifyingKey,
@@ -27,11 +60,29 @@ pub fn remove_key(pubkey: &VerifyingKey) {
     keys.remove(pubkey);
 }
 
-pub fn get_privkey(pubkey: &VerifyingKey) -> Option<SigningKey> {
+fn get_privkey(pubkey: &VerifyingKey) -> Option<SigningKey> {
     let keys = KEYS.lock().unwrap();
     keys.get(pubkey).cloned()
 }
 
+pub fn sign_message_with_key(pubkey: &str, message: &str) -> Result<String, SigningError> {
+    // Parse the hex string into a VerifyingKey
+    let key_bytes = hex::decode(pubkey)?;
+    let pubkey = VerifyingKey::from_bytes(&key_bytes.as_slice().try_into()?)?;
+
+    // Lock the hashmap and try to get the SigningKey
+    let key_store = KEYS.lock().unwrap();
+    let signing_key = match key_store.get(&pubkey) {
+        Some(k) => k,
+        None => return Err(SigningError::KeyNotFound),
+    };
+
+    // TODO: check if to_bytes returns the signature in a format that people can verify from bash
+    let signature = hex::encode(signing_key.sign(message.as_bytes()).to_bytes());
+
+    Ok(signature)
+}
+
 pub fn add_node(ip: String, info: NodeInfo) {
     let mut nodes = NODES.lock().unwrap();
     nodes.insert(ip, info);
diff --git a/src/grpc.rs b/src/grpc.rs
index a7c3ea4..483ec72 100644
--- a/src/grpc.rs
+++ b/src/grpc.rs
@@ -4,11 +4,13 @@ use rand::rngs::OsRng;
 
 pub fn add_node(ip: String) {
     let mut csprng = OsRng;
+    let privkey = ed25519_dalek::SigningKey::generate(&mut csprng);
     database::add_node(
         ip,
         NodeInfo {
-            pubkey: ed25519_dalek::SigningKey::generate(&mut csprng).verifying_key(),
+            pubkey: privkey.verifying_key(),
             updated_at: std::time::SystemTime::now(),
         },
-    )
+    );
+    database::add_key(privkey.verifying_key(), privkey);
 }
diff --git a/src/http_server.rs b/src/http_server.rs
index d9040d9..317751a 100644
--- a/src/http_server.rs
+++ b/src/http_server.rs
@@ -1,14 +1,34 @@
-use salvo::prelude::*;
 use crate::database::get_nodes_as_html_tabe;
+use salvo::prelude::*;
 
 #[handler]
 async fn homepage() -> String {
     get_nodes_as_html_tabe()
 }
 
+#[handler]
+async fn sign(req: &mut Request) -> String {
+    let pubkey = match req.query::<String>("pubkey") {
+        Some(k) => k,
+        None => return "pubkey must be specified as GET param".to_string(),
+    };
+
+    let something = match req.query::<String>("something") {
+        Some(k) => k,
+        None => return "something must be specified as GET param".to_string(),
+    };
+
+    match crate::database::sign_message_with_key(&pubkey, &something) {
+        Ok(s) => s,
+        Err(e) => e.to_string(),
+    }
+}
+
 pub async fn start() {
     let acceptor = TcpListener::new("0.0.0.0:5800").bind().await;
-    let router = Router::new().get(homepage);
+    let router = Router::new()
+        .get(homepage)
+        .push(Router::with_path("sign").get(sign));
     println!("{:?}", router);
     Server::new(acceptor).serve(router).await;
 }