Provide a replacement assembly implementation for SHA-256 on amd64.

Replace the perlasm generated SHA-256 assembly implementation with one that
is actually readable. Call the assembly implementation from a C wrapper
that can, in the future, dispatch to alternate implementations. Performance
is similar (or even better) on modern CPUs, while somewhat slower on older
CPUs (this is in part due to the wrapper, the impact of which is more
noticable with small block sizes).

Thanks to gkoehler@ and tb@ for testing.

ok tb@

1 files changed, 26 insertions, 0 deletions

diff --git a/src/lib/libcrypto/sha/sha256_amd64.c b/src/lib/libcrypto/sha/sha256_amd64.c
new file mode 100644
index 0000000000..f7531b340f
--- /dev/null
+++ b/src/lib/libcrypto/sha/sha256_amd64.c
@@ -0,0 +1,26 @@
+/* $OpenBSD: sha256_amd64.c,v 1.1 2024/11/08 15:09:48 jsing Exp $ */
+/*
+ * Copyright (c) 2024 Joel Sing <jsing@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <openssl/sha.h>
+
+void sha256_block_generic(SHA256_CTX *ctx, const void *in, size_t num);
+
+void
+sha256_block_data_order(SHA256_CTX *ctx, const void *in, size_t num)
+{
+        sha256_block_generic(ctx, in, num);
+}