Use postcard directly

Instead of using Trussed’s re-exports of postcard that will be removed
in Trussed 0.2.0, either use the public wrapper provided by Trussed or
postcard directly.

Cargo.toml

@@ -33,6 +33,7 @@ subtle = { version = "2.4.1", default-features = false }
 trussed = "0.1.0"
 trussed-rsa-alloc = { version = "0.1.0", optional = true }
 serde_repr = "0.1"
+postcard = "0.7.0"
 hex-literal = "0.3.4"
 trussed-auth = "0.2.1"
 

src/command/gen.rs

@@ -301,11 +301,10 @@ fn read_rsa_key<const R: usize, T: trussed::Client + AuthClient>(
                 Status::UnspecifiedNonpersistentExecutionError
             })?
             .serialized_key;
-    let parsed_pubkey_data: RsaPublicParts =
-        trussed::postcard_deserialize(&pubkey_data).map_err(|_err| {
-            error!("Failed to deserialize public key");
-            Status::UnspecifiedNonpersistentExecutionError
-        })?;
+    let parsed_pubkey_data = RsaPublicParts::deserialize(&pubkey_data).map_err(|_err| {
+        error!("Failed to deserialize public key");
+        Status::UnspecifiedNonpersistentExecutionError
+    })?;
     ctx.reply.expand(&[0x81])?;
     ctx.reply.append_len(parsed_pubkey_data.n.len())?;
     ctx.reply.expand(parsed_pubkey_data.n)?;

src/command/private_key_template.rs

@@ -208,17 +208,20 @@ fn put_rsa<const R: usize, T: trussed::Client + AuthClient>(
     ctx: LoadedContext<'_, R, T>,
     mechanism: Mechanism,
 ) -> Result<Option<(KeyId, KeyId)>, Status> {
-    use trussed::{postcard_serialize_bytes, types::SerializedKey};
+    use trussed::types::SerializedKey;
 
     let key_data = parse_rsa_template(ctx.data).ok_or_else(|| {
         warn!("Unable to parse RSA key");
         Status::IncorrectDataParameter
     })?;
 
-    let key_message: SerializedKey = postcard_serialize_bytes(&key_data).map_err(|_err| {
-        error!("Failed to serialize RSA key: {_err:?}");
-        Status::UnspecifiedNonpersistentExecutionError
-    })?;
+    // TODO: move serialization into trussed
+    let key_message = postcard::to_vec(&key_data)
+        .map(SerializedKey::from)
+        .map_err(|_err| {
+            error!("Failed to serialize RSA key: {_err:?}");
+            Status::UnspecifiedNonpersistentExecutionError
+        })?;
     let key = try_syscall!(ctx.backend.client_mut().unsafe_inject_key(
         mechanism,
         &key_message,