commit 91d6863edc98702536e087a1fd2db9a50f84ae6d
author David Brown <david.brown@linaro.org> Mon Jul 29 14:32:13 2019 -0600
committer David Brown <davidb@davidb.org> Tue Aug 06 11:26:09 2019 -0500
tree 25e4a6082f600149b6500d72c35369d82a90971a
parent 3b090212697e6e5a9473c5c1e8f0adb059df1b86

sim: Use byteorder for multi-byte values

Instead of manually expanding multi-byte encoding, use the byteorder
crate which has its own extension methods to do this.  This both makes
the code a bit clearer, and also makes it clear that these encodings are
specific to little endian platforms.

Signed-off-by: David Brown <david.brown@linaro.org>

sim/src/tlv.rs

diff --git a/sim/src/tlv.rs b/sim/src/tlv.rs
index 1af8618..f78c507 100644
--- a/sim/src/tlv.rs
+++ b/sim/src/tlv.rs
@@ -8,6 +8,9 @@
 //! Because of this header, we have to make two passes.  The first pass will compute the size of
 //! the TLV, and the second pass will build the data for the TLV.
 
+use byteorder::{
+    LittleEndian, WriteBytesExt,
+};
 use pem;
 use base64;
 use ring::{digest, rand};
@@ -200,8 +203,7 @@
         let size = self.get_size();
         result.push(0x07);
         result.push(0x69);
-        result.push((size & 0xFF) as u8);
-        result.push(((size >> 8) & 0xFF) as u8);
+        result.write_u16::<LittleEndian>(size).unwrap();
 
         if self.kinds.contains(&TlvKinds::SHA256) {
             let hash = digest::digest(&digest::SHA256, &self.payload);
@@ -259,8 +261,7 @@
                 result.push(TlvKinds::RSA3072 as u8);
             }
             result.push(0);
-            result.push((signature.len() & 0xFF) as u8);
-            result.push(((signature.len() >> 8) & 0xFF) as u8);
+            result.write_u16::<LittleEndian>(signature.len() as u16).unwrap();
             result.extend_from_slice(&signature);
         }
 
@@ -295,8 +296,7 @@
                 signature[1] += 1;
             }
 
-            result.push((signature.len() & 0xFF) as u8);
-            result.push(((signature.len() >> 8) & 0xFF) as u8);
+            result.write_u16::<LittleEndian>(signature.len() as u16).unwrap();
             result.extend_from_slice(signature.as_ref());
         }
 
@@ -327,8 +327,7 @@
             result.push(0);
 
             let signature = signature.as_ref().to_vec();
-            result.push((signature.len() & 0xFF) as u8);
-            result.push(((signature.len() >> 8) & 0xFF) as u8);
+            result.write_u16::<LittleEndian>(signature.len() as u16).unwrap();
             result.extend_from_slice(signature.as_ref());
         }