hscrypto: Make several types Readable+Writeable

Specifically, RendCookie, Subcredential, HsId, and HsBlindId.

Cargo.lock

@@ -3982,6 +3982,7 @@ dependencies = [
  "signature 1.6.4",
  "thiserror",
  "tor-basic-utils",
+ "tor-bytes",
  "tor-llcrypto",
  "tor-units",
 ]

crates/tor-hscrypto/Cargo.toml

@@ -22,6 +22,7 @@ rand_core = "0.6.2"
 serde = { version = "1.0.103", features = ["derive"] }
 signature = "1"
 thiserror = "1"
+tor-bytes = { version = "0.6.1", path = "../tor-bytes" }
 tor-llcrypto = { version = "0.4.2", path = "../tor-llcrypto", features = [
     "hsv3-client",
     "hsv3-service",

crates/tor-hscrypto/src/macros.rs

@@ -59,6 +59,17 @@ macro_rules! define_bytes {
             inp.0.into()
         }
     }
+    impl tor_bytes::Readable for $name {
+        fn take_from(r: &mut tor_bytes::Reader<'_>) -> tor_bytes::Result<Self> {
+            Ok(Self::new(r.extract()?))
+        }
+    }
+    impl tor_bytes::Writeable for $name {
+        fn write_onto<B:tor_bytes::Writer+?Sized>(&self, w: &mut B) -> tor_bytes::EncodeResult<()> {
+            w.write_all(&self.0.as_ref()[..]);
+            Ok(())
+        }
+    }
 }
 }