download_sysext: read delta update file after downloading

Read delta update file after downloading, and do not store sigfiles.

src/bin/download_sysext.rs

@@ -4,7 +4,6 @@ use std::path::Path;
 use std::fs::File;
 use std::fs;
 use std::io;
-use std::io::Write;
 
 #[macro_use]
 extern crate log;
@@ -132,7 +131,6 @@ async fn main() -> Result<(), Box<dyn Error>> {
     println!();
 
     const PUBKEY_FILE: &str = "../src/testdata/public_key_test_pkcs8.pem";
-    const SIGFILE: &str = "./testsigfile";
 
     ////
     // download
@@ -145,9 +143,6 @@ async fn main() -> Result<(), Box<dyn Error>> {
         let path = unverified_dir.join(&*pkg.name);
         let mut file = File::create(path.clone())?;
 
-        // Read update payload from file, read delta update header from the payload.
-        let updata = io::read_to_string(file.try_clone().unwrap());
-
         println!("creating {}...", path.display());
 
         let res = ue_rs::download_and_hash(&client, pkg.url, &mut file).await?;
@@ -156,24 +151,21 @@ async fn main() -> Result<(), Box<dyn Error>> {
         println!("\tcalculated sha256: {}", res.hash);
         println!("\tsha256 match?      {}", pkg.hash == res.hash);
 
+        // Read update payload from file, read delta update header from the payload.
+        let updata = io::read_to_string(res.data.try_clone().unwrap());
+
         let header = delta_update::read_delta_update_header(res.data)?;
 
         // Extract signature from header.
         let sigbytes = delta_update::get_signatures_bytes(res.data, &header)?;
 
         // Parse signature data from the signature containing data, version, special fields.
-        let sigdata = match delta_update::parse_signature_data(updata.unwrap().as_bytes(), &sigbytes, PUBKEY_FILE) {
+        let _sigdata = match delta_update::parse_signature_data(updata.unwrap().as_bytes(), &sigbytes, PUBKEY_FILE) {
             Some(data) => Box::leak(data),
             _ => return Err("unable to parse signature data".into()),
         };
 
         println!("Parsed signature data from file {:?}", path);
-
-        // Store signature into a file.
-        let mut sigfile = File::create(SIGFILE.clone())?;
-        let _ = sigfile.write_all(sigdata);
-
-        println!("Wrote signature data into file {:?}", SIGFILE);
     }
 
     Ok(())