From 265336a702d6a4a117889f2fe281e8f2bbb7e0ef Mon Sep 17 00:00:00 2001
From: Darren Tucker <dtucker@dtucker.net>
Date: Mon, 3 Aug 2026 22:15:07 +1000
Subject: [PATCH] Don't enable Brainpool on AWS-LC or BoringSSL.

These fail at runtime, so disable until we figure out why.
---
 configure.ac | 42 ++++++++++++++++++++++++++++++++++--------
 kex-names.c  |  4 ++--
 2 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/configure.ac b/configure.ac
index d495d012c..cb1711f6b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3113,8 +3113,9 @@ if test "x$openssl" = "xyes" ; then
 			100*|10100*) # 1.0.x, 1.1.0x
 				AC_MSG_ERROR([OpenSSL >= 1.1.1 required (have "$ssl_showver")])
 				;;
-			101*)   ;; # 1.1.x
-			200*)   # LibreSSL
+			101*)   openssl_impl="openssl" # 1.1.x
+				;;
+			200*)   openssl_impl="libressl"
 				lver=`echo "$sslver" | sed 's/.*libressl-//'`
 				case "$lver" in
 				2*|300*) # 2.x, 3.0.0
@@ -3123,7 +3124,7 @@ if test "x$openssl" = "xyes" ; then
 				*) ;;	# Assume all other versions are good.
 				esac
 				;;
-			30*|40*)
+			30*|40*) openssl_impl="openssl"
 				# OpenSSL 3 & 4; we use the 1.1x API
 				# https://openssl.org/policies/general/versioning-policy.html
 				CPPFLAGS="$CPPFLAGS -DOPENSSL_API_COMPAT=0x10100000L"
@@ -3211,6 +3212,18 @@ if test "x$openssl" = "xyes" ; then
 		]
 	)
 
+	AC_CHECK_DECL([OPENSSL_IS_AWSLC],
+	    [openssl_impl="aws-lc"], [],
+	    [#include <openssl/base.h>]
+	)
+	AC_CHECK_DECL([OPENSSL_IS_BORINGSSL],
+	    [openssl_impl="boringssl"], [],
+	    [#include <openssl/base.h>]
+	)
+
+	AC_MSG_CHECKING([OpenSSL implementation])
+	AC_MSG_RESULT([$openssl_impl])
+
 	AC_CHECK_FUNCS([ \
 		BN_is_prime_ex \
 		DES_crypt \
@@ -3337,17 +3350,30 @@ if test "x$openssl" = "xyes" ; then
 			AC_MSG_RESULT([no])
 		]
 	)
+
+	case "$openssl_impl" in
+	aws-lc|boringssl)
+		# Brainpool does not work with AWC-LS or BoringSSL.
+		unsupported_algorithms="$unsupported_algorithms mlkem768brainpoolp256r1-sha256"
+		;;
+	*)
+		AC_CHECK_DECL([NID_brainpoolP256r1],
+		    [AC_DEFINE([USE_BRAINPOOLP256R1], [1], [Enable brainpool])],
+		    [],
+		    [[#include <openssl/evp.h>]]
+		)
+		;;
+	esac
+
 fi
 
 # PKCS11/U2F depend on OpenSSL and dlopen().
 enable_pkcs11=yes
 enable_sk=yes
 
-AC_CHECK_DECL([OPENSSL_IS_AWSLC],
-	[enable_pkcs11="disabled; PKCS#11 not supported with AWS-LC"],
-	[],
-	[#include <openssl/base.h>]
-)
+if test "x$openssl_impl" = "xaws-lc"; then
+	enable_pkcs11="disabled; PKCS#11 not supported with AWS-LC"
+fi
 if test "x$ac_cv_func_dlopen" != "xyes" ; then
 	enable_pkcs11="disabled; missing dlopen(3)"
 	enable_sk="disabled; missing dlopen(3)"
diff --git a/kex-names.c b/kex-names.c
index 7660c2edc..225efb0dc 100644
--- a/kex-names.c
+++ b/kex-names.c
@@ -69,10 +69,10 @@ static const struct kexalg kexalgs[] = {
 	    SSH_DIGEST_SHA512, KEX_NOT_PQ },
 	{ KEX_MLKEM768NISTP256_SHA256, KEX_KEM_MLKEM768ECDH_SHA256,
 	    NID_X9_62_prime256v1, SSH_DIGEST_SHA256, KEX_IS_PQ },
-# ifdef NID_brainpoolP256r1
+# ifdef USE_BRAINPOOLP256R1
 	{ KEX_MLKEM768BRAINPOOLP256R1_SHA256, KEX_KEM_MLKEM768ECDH_SHA256,
 	    NID_brainpoolP256r1, SSH_DIGEST_SHA256, KEX_IS_PQ },
-# endif /* NID_brainpoolP256r1 */
+# endif /* USE_BRAINPOOLP256R1 */
 #endif /* WITH_OPENSSL */
 #if defined(HAVE_EVP_SHA256) || !defined(WITH_OPENSSL)
 	{ KEX_CURVE25519_SHA256, KEX_C25519_SHA256, 0, SSH_DIGEST_SHA256, KEX_NOT_PQ },
-- 
2.47.3