[crypto] Add definitions and tests for the NIST P-256 elliptic curve

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/crypto/mishmash/oid_p256.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2025 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <byteswap.h>
+#include <ipxe/p256.h>
+#include <ipxe/asn1.h>
+#include <ipxe/tls.h>
+
+/** "prime256v1" object identifier */
+static uint8_t oid_prime256v1[] = { ASN1_OID_PRIME256V1 };
+
+/** "prime256v1" OID-identified algorithm */
+struct asn1_algorithm prime256v1_algorithm __asn1_algorithm = {
+	.name = "prime256v1",
+	.curve = &p256_curve,
+	.oid = ASN1_CURSOR ( oid_prime256v1 ),
+};
+
+/** P-256 named curve */
+struct tls_named_curve tls_secp256r1_named_curve __tls_named_curve ( 01 ) = {
+	.curve = &p256_curve,
+	.code = htons ( TLS_NAMED_CURVE_SECP256R1 ),
+	.format = TLS_POINT_FORMAT_UNCOMPRESSED,
+	.pre_master_secret_len = P256_LEN,
+};