update print statements for clearer device logs

library/src/cache/signing.rs

@@ -4,7 +4,7 @@ use ring::signature;
 use std::path::Path;
 // https://stackoverflow.com/questions/67087597/is-it-possible-to-use-rusts-log-info-for-tests
 #[cfg(test)]
-use std::println as info; // Workaround to use println! for logs.
+use std::{println as info, println as debug}; // Workaround to use println! for logs.
 
 /// Reads the file at `path` and returns the SHA-256 hash of its contents as a String.
 pub fn hash_file<P: AsRef<Path>>(path: P) -> Result<String> {
@@ -25,32 +25,34 @@ pub fn hash_file<P: AsRef<Path>>(path: P) -> Result<String> {
 ///     -outform DER \
 ///     -out public_key.der
 pub fn check_signature(message: &str, signature: &str, public_key: &str) -> Result<()> {
-    // public.pem
+    debug!("Message is {}", message);
+    debug!("Public key is {:?}", public_key);
+    debug!("Signature is {}", signature);
+
+    // public.der
     let public_key_bytes = base64::prelude::BASE64_STANDARD
         .decode(public_key)
         .with_context(|| format!("Failed to decode public_key: {}", public_key))?;
 
     let public_key =
         signature::UnparsedPublicKey::new(&signature::RSA_PKCS1_2048_8192_SHA256, public_key_bytes);
-    info!("Public key is {:?}", public_key);
-    info!("Signature is {}", signature);
     let decoded_sig = match base64::prelude::BASE64_STANDARD.decode(signature) {
         Ok(sig) => sig,
         Err(e) => {
             bail!("Failed to decode signature: {:?}", e);
         }
     };
 
-    info!("Verifying signature...");
+    info!("Verifying patch signature...");
     match public_key.verify(message.as_bytes(), &decoded_sig) {
         Ok(_) => {
-            info!("Signature is valid");
+            info!("Patch signature is valid");
             Ok(())
         }
         Err(_) => {
             // The error provided by `verify` is (by design) not helpful, so we ignore it.
             // See https://docs.rs/ring/latest/ring/error/struct.Unspecified.html
-            bail!("Signature is invalid")
+            bail!("Patch signature is invalid")
         }
     }
 }