1 files changed, 83 insertions, 0 deletions
diff --git a/src/crypto/zinc/curve25519/curve25519.c b/src/crypto/zinc/curve25519/curve25519.c
new file mode 100644
index 0000000..183eeb5
--- /dev/null
+++ b/src/crypto/zinc/curve25519/curve25519.c
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ * This is an implementation of the Curve25519 ECDH algorithm, using either
+ * a 32-bit implementation or a 64-bit implementation with 128-bit integers,
+ * depending on what is supported by the target compiler.
+ *
+ * Information: https://cr.yp.to/ecdh.html
+ */
+
+#include <zinc/curve25519.h>
+
+#include <asm/unaligned.h>
+#include <linux/version.h>
+#include <linux/string.h>
+#include <linux/random.h>
+#include <crypto/algapi.h>
+
+#ifndef HAVE_CURVE25519_ARCH_IMPLEMENTATION
+void __init curve25519_fpu_init(void)
+{
+}
+static inline bool curve25519_arch(u8 mypublic[CURVE25519_POINT_SIZE],
+				   const u8 secret[CURVE25519_POINT_SIZE],
+				   const u8 basepoint[CURVE25519_POINT_SIZE])
+{
+	return false;
+}
+static inline bool curve25519_base_arch(u8 pub[CURVE25519_POINT_SIZE],
+					const u8 secret[CURVE25519_POINT_SIZE])
+{
+	return false;
+}
+#endif
+
+static __always_inline void normalize_secret(u8 secret[CURVE25519_POINT_SIZE])
+{
+	secret[0] &= 248;
+	secret[31] &= 127;
+	secret[31] |= 64;
+}
+
+#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
+#include "curve25519-hacl64.h"
+#else
+#include "curve25519-fiat32.h"
+#endif
+
+static const u8 null_point[CURVE25519_POINT_SIZE] = { 0 };
+
+bool curve25519(u8 mypublic[CURVE25519_POINT_SIZE],
+		const u8 secret[CURVE25519_POINT_SIZE],
+		const u8 basepoint[CURVE25519_POINT_SIZE])
+{
+	if (!curve25519_arch(mypublic, secret, basepoint))
+		curve25519_generic(mypublic, secret, basepoint);
+	return crypto_memneq(mypublic, null_point, CURVE25519_POINT_SIZE);
+}
+EXPORT_SYMBOL(curve25519);
+
+bool curve25519_generate_public(u8 pub[CURVE25519_POINT_SIZE],
+				const u8 secret[CURVE25519_POINT_SIZE])
+{
+	static const u8 basepoint[CURVE25519_POINT_SIZE] __aligned(32) = { 9 };
+
+	if (unlikely(!crypto_memneq(secret, null_point, CURVE25519_POINT_SIZE)))
+		return false;
+
+	if (curve25519_base_arch(pub, secret))
+		return crypto_memneq(pub, null_point, CURVE25519_POINT_SIZE);
+	return curve25519(pub, secret, basepoint);
+}
+EXPORT_SYMBOL(curve25519_generate_public);
+
+void curve25519_generate_secret(u8 secret[CURVE25519_POINT_SIZE])
+{
+	get_random_bytes_wait(secret, CURVE25519_POINT_SIZE);
+	normalize_secret(secret);
+}
+EXPORT_SYMBOL(curve25519_generate_secret);
+
+#include "../selftest/curve25519.h"