commit 8ed29ce59dfe6712a493faa86ab41c8fce6bb79e
author Alice Wang <aliceywang@google.com> Fri Dec 01 08:33:12 2023 +0000
committer Alice Wang <aliceywang@google.com> Thu Dec 07 14:35:55 2023 +0000
tree e54d43fe6efa567e0508d1a3ae18d79ecbc5c976
parent 46211912331c2f31500663e1207770e9270582cd

[dm][refactoring] Use hex crate to encode/decode hex string

Bug: 239413416
Test: atest MicrodroidTests
Change-Id: I259cc08fc264b41df3228d01f7b89ad55c530259

apkdmverity/Android.bp

diff --git a/apkdmverity/Android.bp b/apkdmverity/Android.bp
index c4c90cd..0cb8ca1 100644
--- a/apkdmverity/Android.bp
+++ b/apkdmverity/Android.bp
@@ -15,6 +15,7 @@
         "libbitflags",
         "libclap",
         "libdm_rust",
+        "libhex",
         "libitertools",
         "liblibc",
         "libnix",

apkdmverity/src/main.rs

diff --git a/apkdmverity/src/main.rs b/apkdmverity/src/main.rs
index 2901304..0ecb0ea 100644
--- a/apkdmverity/src/main.rs
+++ b/apkdmverity/src/main.rs
@@ -46,7 +46,7 @@
 
     for (apk, idsig, name, roothash) in apks.tuples() {
         let roothash = if roothash != "none" {
-            Some(util::parse_hexstring(roothash).expect("failed to parse roothash"))
+            Some(hex::decode(roothash).expect("failed to parse roothash"))
         } else {
             None
         };

libs/devicemapper/src/util.rs

diff --git a/libs/devicemapper/src/util.rs b/libs/devicemapper/src/util.rs
index e8df424..cc071e4 100644
--- a/libs/devicemapper/src/util.rs
+++ b/libs/devicemapper/src/util.rs
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-use anyhow::{anyhow, bail, Result};
+use anyhow::{bail, Result};
 use nix::sys::stat::FileStat;
 use std::fs::File;
 use std::os::unix::fs::FileTypeExt;
@@ -52,24 +52,6 @@
     Ok(())
 }
 
-/// Returns hexadecimal reprentation of a given byte array.
-pub fn hexstring_from(s: &[u8]) -> String {
-    s.iter().map(|byte| format!("{:02x}", byte)).reduce(|i, j| i + &j).unwrap_or_default()
-}
-
-/// Parses a hexadecimal string into a byte array
-pub fn parse_hexstring(s: &str) -> Result<Vec<u8>> {
-    let len = s.len();
-    if len % 2 != 0 {
-        bail!("length {} is not even", len)
-    } else {
-        (0..len)
-            .step_by(2)
-            .map(|i| u8::from_str_radix(&s[i..i + 2], 16).map_err(|e| anyhow!(e)))
-            .collect()
-    }
-}
-
 /// fstat that accepts a path rather than FD
 pub fn fstat(p: &Path) -> Result<FileStat> {
     let f = File::open(p)?;

libs/devicemapper/src/verity.rs

diff --git a/libs/devicemapper/src/verity.rs b/libs/devicemapper/src/verity.rs
index 24584f8..bbd9d38 100644
--- a/libs/devicemapper/src/verity.rs
+++ b/libs/devicemapper/src/verity.rs
@@ -151,7 +151,7 @@
         };
 
         let root_digest = if let Some(root_digest) = self.root_digest {
-            hexstring_from(root_digest)
+            hex::encode(root_digest)
         } else {
             bail!("root digest is not set")
         };
@@ -159,7 +159,7 @@
         let salt = if self.salt.is_none() || self.salt.unwrap().is_empty() {
             "-".to_string() // Note. It's not an empty string!
         } else {
-            hexstring_from(self.salt.unwrap())
+            hex::encode(self.salt.unwrap())
         };
 
         // Step2: serialize the information according to the spec, which is ...