Add message signing

All messages are now signed by default with a randomly generated key.
TODO still is keyserver stuff, locking down the config file potentially
(or telling users to do it in the readme?), and doing any sort of
verification

src/cli.rs

@@ -1,4 +1,5 @@
 use clap::{Parser,Subcommand,ArgAction};
+use ed25519_dalek::SigningKey;
 use fedichat::client::{ClientMessage,SignedClientMessage,AuthMethod};
 use fedichat::ServerAddr;
 use fedichat::state::StatePath;
@@ -181,7 +182,7 @@ impl Command {
     }
     // If a command needs multiple messages, like an auth message first
     // then call this
-    pub fn generate_messages(self,username: String,token: Option<String>) 
+    pub fn generate_messages(self,username: String,token: Option<String>, key: SigningKey) 
         -> Result<Vec<SignedClientMessage>,MessageError>
     {
         let mut messages = Vec::with_capacity(2);
@@ -211,6 +212,11 @@ impl Command {
                 signature: Box::new([0])});
         }
 
+        // sign all the messages
+        for message in messages.iter_mut() {
+            message.sign(key.clone())?;
+        }
+
         Ok(messages)
     }
 }
@@ -223,6 +229,8 @@ pub enum MessageError {
     UuidError(#[from] uuid::Error),
     #[error("Error during file IO: {0}")]
     IoError(#[from] std::io::Error),
+    #[error("Error while processing signature: {0}")]
+    Signature(#[from] fedichat::client::SignatureError)
 
 }