From 5034366c72268fe12be64a41120ad260016817f8 Mon Sep 17 00:00:00 2001
From: dan <themighty1@users.noreply.github.com>
Date: Thu, 21 Aug 2025 09:41:59 +0300
Subject: [PATCH] fix(hmac-sha256): compute PHash and AHash concurrently (#969)

---------

Co-authored-by: th4s <th4s@metavoid.xyz>
---
 .../hmac-sha256/src/prf/function/reduced.rs           | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/crates/components/hmac-sha256/src/prf/function/reduced.rs b/crates/components/hmac-sha256/src/prf/function/reduced.rs
index 2120a8293..403d4c529 100644
--- a/crates/components/hmac-sha256/src/prf/function/reduced.rs
+++ b/crates/components/hmac-sha256/src/prf/function/reduced.rs
@@ -40,7 +40,6 @@ enum PrfState {
         inner_partial: [u32; 8],
         a_output: DecodeFutureTyped<BitVec, [u8; 32]>,
     },
-    FinishLastP,
     Done,
 }
 
@@ -137,16 +136,18 @@ impl PrfFunction {
                 assign_inner_local(vm, p.inner_local, *inner_partial, &msg)?;
 
                 if *iter == self.iterations {
-                    self.state = PrfState::FinishLastP;
+                    self.state = PrfState::Done;
                 } else {
                     self.state = PrfState::ComputeA {
                         iter: *iter + 1,
                         inner_partial: *inner_partial,
                         msg: output.to_vec(),
-                    }
-                };
+                    };
+                    // We recurse, so that this PHash and the next AHash could
+                    // be computed in a single VM execute call.
+                    self.flush(vm)?;
+                }
             }
-            PrfState::FinishLastP => self.state = PrfState::Done,
             _ => (),
         }