update agent

default.nix

@@ -3,8 +3,8 @@ with pkgs;
 let
   agent_src = fetchgit {
     url = "https://gitea.rixxc.de/rixxc/x25519_agent.git";
-    rev = "de022e4c6b6fa0086a9f5c4fad1340b75ccceba1";
+    rev = "36ae72a8d90d94b5b0d1fd01adf50a33edd80e80";
-    hash = "sha256-oe8ngvtEcu6O6FWm0ImTS4DTsQx78VRs9bQx672aUbI=";
+    hash = "sha256-SxXZ/1CRi4J6Neq1uXIbue0bFa8WzdXPBnoXCjekOy8=";
   };
 
   agent = callPackage "${agent_src}/default.nix" { };

src/main.rs

@@ -1,6 +1,8 @@
 use libc::{
-    c_int, c_void, mmap, MAP_ANON, MAP_FAILED, MAP_PRIVATE, MAP_SHARED, PROT_READ, PROT_WRITE,
+    c_char, c_int, c_void, mmap, perror, MAP_FAILED, MAP_PRIVATE, MAP_SHARED, PROT_READ, PROT_WRITE,
 };
+use std::fs::File;
+use std::os::fd::AsRawFd;
 use std::{env, ptr};
 
 const SHARED_MEMORY_SIZE: usize = 1024;
@@ -45,19 +47,24 @@ fn main() {
     } as *mut u8;
     assert_ne!(sync_memory, MAP_FAILED as *mut u8);
 
+    let private_file = File::options()
+        .read(true)
+        .write(true)
+        .open(&args[2])
+        .expect("Cannot open KEY_FILE");
+
     let private_mem = unsafe {
         mmap(
             ptr::null_mut() as *mut c_void,
             32 * 100,
             PROT_READ | PROT_WRITE,
-            MAP_PRIVATE | MAP_ANON,
+            MAP_SHARED,
-            0,
+            private_file.as_raw_fd(),
             0,
         )
     } as *mut u8;
     assert_ne!(private_mem, MAP_FAILED as *mut u8);
 
-    println!("Agent: starting agent...");
     unsafe {
         agent_start(shared_memory, sync_memory, private_mem);
     }