From 4d26e5b33ac62350a4ab53f79e89ad5ebae7c1c0 Mon Sep 17 00:00:00 2001
From: Emanuele Cesena <ecesena@jumptrading.com>
Date: Fri, 15 Mar 2024 14:33:42 +0000
Subject: [PATCH] ed25519: fix fd_r43x6_ge_decode2 produces non-canonical
 results #fuzz

---
 ...fuzz_ed25519_sigverify-highend-5677237600780288 | Bin 0 -> 32 bytes
 src/ballet/ed25519/avx512/fd_r43x6_ge.c            |   2 ++
 2 files changed, 2 insertions(+)
 create mode 100644 corpus/fuzz_ed25519_sigverify/clusterfuzz-testcase-minimized-fuzz_ed25519_sigverify-highend-5677237600780288

diff --git a/corpus/fuzz_ed25519_sigverify/clusterfuzz-testcase-minimized-fuzz_ed25519_sigverify-highend-5677237600780288 b/corpus/fuzz_ed25519_sigverify/clusterfuzz-testcase-minimized-fuzz_ed25519_sigverify-highend-5677237600780288
new file mode 100644
index 0000000000000000000000000000000000000000..9f3c58620f839283be21e5600869e4b264720793
GIT binary patch
literal 32
kcmY#mWB>vKAijL*Qtton|A8z<U0q!UhU#0(eX`a70Eu-97XSbN

literal 0
HcmV?d00001

diff --git a/src/ballet/ed25519/avx512/fd_r43x6_ge.c b/src/ballet/ed25519/avx512/fd_r43x6_ge.c
index e6ff1806d5..953530e8ff 100644
--- a/src/ballet/ed25519/avx512/fd_r43x6_ge.c
+++ b/src/ballet/ed25519/avx512/fd_r43x6_ge.c
@@ -150,6 +150,7 @@ fd_r43x6_ge_decode( wwl_t * _P03, wwl_t * _P14, wwl_t * _P25,
     y,                      /* Reduced */
     one,                    /* Reduced */
     fd_r43x6_mul( x, y ) ); /* in u44 */
+  FD_R43X6_QUAD_FOLD_UNSIGNED( *_P, *_P );
   return 0;
 
 fail:
@@ -234,6 +235,7 @@ fd_r43x6_ge_decode2( wwl_t * _Pa03, wwl_t * _Pa14, wwl_t * _Pa25,
   fd_r43x6_t xya,  xyb;  FD_R43X6_MUL2_INL      ( xya,  xa,ya,     xyb,  xb,yb    );
 
   FD_R43X6_QUAD_PACK( *_Pa, xa,ya,one,xya );                       FD_R43X6_QUAD_PACK( *_Pb, xb,yb,one,xyb );
+  FD_R43X6_QUAD_FOLD_UNSIGNED( *_Pa, *_Pa );                       FD_R43X6_QUAD_FOLD_UNSIGNED( *_Pb, *_Pb );
   return 0;
 
 faila: