[crypto] Remove redundant ECDHE algorithm

Remove the now-unused implementation of ECDHE that requires an
underlying elliptic curve abstraction, since we now use a standalone
key exchange algorithm abstraction instead.

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

src/crypto/ecdhe.c

@@ -1,75 +0,0 @@
-/*
- * 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 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 );
-FILE_SECBOOT ( PERMITTED );
-
-/** @file
- *
- * Elliptic Curve Ephemeral Diffie-Hellman (ECDHE) key exchange
- *
- */
-
-#include <string.h>
-#include <errno.h>
-#include <ipxe/ecdhe.h>
-
-/**
- * Calculate ECDHE key
- *
- * @v curve		Elliptic curve
- * @v partner		Partner public curve point
- * @v private		Private key
- * @v public		Public curve point to fill in (may overlap partner key)
- * @v shared		Shared secret curve point to fill in
- * @ret rc		Return status code
- */
-int ecdhe_key ( struct elliptic_curve *curve, const void *partner,
-		const void *private, void *public, void *shared ) {
-	int rc;
-
-	/* Construct shared key */
-	if ( ( rc = elliptic_multiply ( curve, partner, private,
-					shared ) ) != 0 ) {
-		DBGC ( curve, "CURVE %s could not generate shared key: %s\n",
-		       curve->name, strerror ( rc ) );
-		return rc;
-	}
-
-	/* Construct public key */
-	if ( ( rc = elliptic_multiply ( curve, curve->base, private,
-					public ) ) != 0 ) {
-		DBGC ( curve, "CURVE %s could not generate public key: %s\n",
-		       curve->name, strerror ( rc ) );
-		return rc;
-	}
-
-	/* Check that partner and shared keys are not the point at infinity */
-	if ( elliptic_is_infinity ( curve, shared ) ) {
-		DBGC ( curve, "CURVE %s constructed point at infinity\n",
-		       curve->name );
-		return -EPERM;
-	}
-
-	return 0;
-}

src/include/ipxe/ecdhe.h

@@ -1,18 +0,0 @@
-#ifndef _IPXE_ECDHE_H
-#define _IPXE_ECDHE_H
-
-/** @file
- *
- * Elliptic Curve Ephemeral Diffie-Hellman (ECDHE) key exchange
- *
- */
-
-FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
-FILE_SECBOOT ( PERMITTED );
-
-#include <ipxe/crypto.h>
-
-extern int ecdhe_key ( struct elliptic_curve *curve, const void *partner,
-		       const void *private, void *public, void *shared );
-
-#endif /* _IPXE_ECDHE_H */

src/net/tls.c

@@ -51,7 +51,6 @@ FILE_SECBOOT ( PERMITTED );
 #include <ipxe/validator.h>
 #include <ipxe/job.h>
 #include <ipxe/dhe.h>
-#include <ipxe/ecdhe.h>
 #include <ipxe/tls.h>
 #include <config/crypto.h>