1 files changed, 74 insertions, 0 deletions
diff --git a/sys/dev/if_wg/include/crypto/curve25519.h b/sys/dev/if_wg/include/crypto/curve25519.h
new file mode 100644
index 0000000000000..3e90d1b270fe3
--- /dev/null
+++ b/sys/dev/if_wg/include/crypto/curve25519.h
@@ -0,0 +1,74 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2019-2020 Rubicon Communications, LLC (Netgate)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _CURVE25519_H_
+#define _CURVE25519_H_
+
+#include <sys/systm.h>
+
+#define CURVE25519_KEY_SIZE 32
+
+void curve25519_generic(u8 [CURVE25519_KEY_SIZE],
+			const u8 [CURVE25519_KEY_SIZE],
+			const u8 [CURVE25519_KEY_SIZE]);
+
+static inline void curve25519_clamp_secret(u8 secret[CURVE25519_KEY_SIZE])
+{
+	secret[0] &= 248;
+	secret[31] = (secret[31] & 127) | 64;
+}
+
+static const u8 null_point[CURVE25519_KEY_SIZE] = { 0 };
+
+static inline int curve25519(u8 mypublic[CURVE25519_KEY_SIZE],
+		const u8 secret[CURVE25519_KEY_SIZE],
+		const u8 basepoint[CURVE25519_KEY_SIZE])
+{
+	curve25519_generic(mypublic, secret, basepoint);
+	return timingsafe_bcmp(mypublic, null_point, CURVE25519_KEY_SIZE);
+}
+
+static inline int curve25519_generate_public(u8 pub[CURVE25519_KEY_SIZE],
+				const u8 secret[CURVE25519_KEY_SIZE])
+{
+	static const u8 basepoint[CURVE25519_KEY_SIZE] __aligned(32) = { 9 };
+
+	if (timingsafe_bcmp(secret, null_point, CURVE25519_KEY_SIZE) == 0)
+		return 0;
+
+	return curve25519(pub, secret, basepoint);
+}
+
+static inline void curve25519_generate_secret(u8 secret[CURVE25519_KEY_SIZE])
+{
+	arc4random_buf(secret, CURVE25519_KEY_SIZE);
+	curve25519_clamp_secret(secret);
+}
+
+#endif /* _CURVE25519_H_ */