From ba5882c2b9835d9662986ec63e39912d7a2e60c2 Mon Sep 17 00:00:00 2001
From: Fabio Valentini <decathorpe@gmail.com>
Date: Tue, 18 Jan 2022 20:10:23 +0100
Subject: [PATCH] revert commit 17cd68f

---
 src/packet/container.rs | 41 +++++++++++++++++++++++++++--------------
 src/parse.rs            |  4 +---
 2 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/src/packet/container.rs b/src/packet/container.rs
index dfbb624..3a4bb26 100644
--- a/src/packet/container.rs
+++ b/src/packet/container.rs
@@ -8,11 +8,11 @@ use std::hash::{Hash, Hasher};
 use std::slice;
 use std::vec;
 
-use xxhash_rust::xxh3::Xxh3;
-
 use crate::{
     Packet,
+    crypto::hash,
     packet::Iter,
+    types::HashAlgorithm,
 };
 
 /// A packet's body holds either unprocessed bytes, processed bytes,
@@ -126,7 +126,7 @@ pub struct Container {
     body: Body,
 
     /// We compute a digest over the body to implement comparison.
-    body_digest: u64,
+    body_digest: Vec<u8>,
 }
 
 assert_send_and_sync!(Container);
@@ -138,6 +138,14 @@ impl std::ops::Deref for Container {
     }
 }
 
+// Pick the fastest hash function from the SHA2 family for the
+// architectures word size.  On 64-bit architectures, SHA512 is almost
+// twice as fast, but on 32-bit ones, SHA256 is faster.
+#[cfg(target_pointer_width = "64")]
+const CONTAINER_BODY_HASH: HashAlgorithm = HashAlgorithm::SHA512;
+#[cfg(not(target_pointer_width = "64"))]
+const CONTAINER_BODY_HASH: HashAlgorithm = HashAlgorithm::SHA256;
+
 impl PartialEq for Container {
     fn eq(&self, other: &Container) -> bool {
         use Body::*;
@@ -169,7 +177,7 @@ impl Default for Container {
     fn default() -> Self {
         Self {
             body: Body::Structured(Vec::with_capacity(0)),
-            body_digest: 0,
+            body_digest: Vec::with_capacity(0),
         }
     }
 }
@@ -178,7 +186,7 @@ impl From<Vec<Packet>> for Container {
     fn from(packets: Vec<Packet>) -> Self {
         Self {
             body: Body::Structured(packets),
-            body_digest: 0,
+            body_digest: Vec::with_capacity(0),
         }
     }
 }
@@ -296,31 +304,36 @@ impl Container {
     }
 
     /// Returns the hash for the empty body.
-    fn empty_body_digest() -> u64 {
+    fn empty_body_digest() -> Vec<u8> {
         lazy_static::lazy_static!{
-            static ref DIGEST: u64 = {
-                Container::make_body_hash().digest()
+            static ref DIGEST: Vec<u8> = {
+                let mut h = Container::make_body_hash();
+                let mut d = vec![0; h.digest_size()];
+                let _ = h.digest(&mut d);
+                d
             };
         }
 
-        *DIGEST
+        DIGEST.clone()
     }
 
     /// Creates a hash context for hashing the body.
     pub(crate) // For parse.rs
-    fn make_body_hash() -> Box<Xxh3> {
-        Box::new(Xxh3::new())
+    fn make_body_hash() -> Box<dyn hash::Digest> {
+        CONTAINER_BODY_HASH.context()
+            .expect("CONTAINER_BODY_HASH must be implemented")
     }
 
     /// Hashes content that has been streamed.
     pub(crate) // For parse.rs
-    fn set_body_hash(&mut self, h: Box<Xxh3>) {
-        self.body_digest = h.digest();
+    fn set_body_hash(&mut self, mut h: Box<dyn hash::Digest>) {
+        self.body_digest.resize(h.digest_size(), 0);
+        let _ = h.digest(&mut self.body_digest);
     }
 
     pub(crate)
     fn body_digest(&self) -> String {
-        format!("{:08X}", self.body_digest)
+        crate::fmt::hex::encode(&self.body_digest)
     }
 
     // Converts an indentation level to whitespace.
diff --git a/src/parse.rs b/src/parse.rs
index 1fe8899..23084af 100644
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -183,8 +183,6 @@ use std::fmt;
 use std::path::Path;
 use std::result::Result as StdResult;
 
-use xxhash_rust::xxh3::Xxh3;
-
 use ::buffered_reader::*;
 
 use crate::{
@@ -3306,7 +3304,7 @@ pub struct PacketParser<'a> {
 
     /// We compute a hashsum over the body to implement comparison on
     /// containers that have been streamed.
-    body_hash: Option<Box<Xxh3>>,
+    body_hash: Option<Box<dyn crate::crypto::hash::Digest>>,
 
     state: PacketParserState,
 }
-- 
2.34.1