From d2c0a99bf5bdcaa9e29e68b403200abb564fc2fe Mon Sep 17 00:00:00 2001
From: Max Kellermann <mk@cm4all.com>
Date: Sat, 21 Oct 2023 13:43:42 +0200
Subject: [PATCH] lib/sodium: add C++ wrappers for crypto_stream_chacha20 and
 crypto_onetimeauth_poly1305

---
 src/lib/sodium/OnetimeauthPoly1305.hxx | 31 +++++++++++++++++++++++
 src/lib/sodium/StreamChaCha20.hxx      | 34 ++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 src/lib/sodium/OnetimeauthPoly1305.hxx
 create mode 100644 src/lib/sodium/StreamChaCha20.hxx

diff --git a/src/lib/sodium/OnetimeauthPoly1305.hxx b/src/lib/sodium/OnetimeauthPoly1305.hxx
new file mode 100644
index 000000000..4de6637e7
--- /dev/null
+++ b/src/lib/sodium/OnetimeauthPoly1305.hxx
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright CM4all GmbH
+// author: Max Kellermann <mk@cm4all.com>
+
+#pragma once
+
+#include <sodium/crypto_onetimeauth_poly1305.h>
+
+#include <cstddef>
+#include <span>
+
+static void
+crypto_onetimeauth_poly1305(std::span<std::byte, crypto_onetimeauth_poly1305_BYTES> out,
+			    std::span<const std::byte> in,
+			    std::span<const std::byte, crypto_onetimeauth_poly1305_KEYBYTES> k) noexcept
+{
+	crypto_onetimeauth_poly1305(reinterpret_cast<unsigned char *>(out.data()),
+				    reinterpret_cast<const unsigned char *>(in.data()), in.size(),
+				    reinterpret_cast<const unsigned char *>(k.data()));
+}
+
+[[nodiscard]] [[gnu::pure]]
+static bool
+crypto_onetimeauth_poly1305_verify(std::span<const std::byte, crypto_onetimeauth_poly1305_BYTES> h,
+				   std::span<const std::byte> in,
+				   std::span<const std::byte, crypto_onetimeauth_poly1305_KEYBYTES> k) noexcept
+{
+	return crypto_onetimeauth_poly1305_verify(reinterpret_cast<const unsigned char *>(h.data()),
+						  reinterpret_cast<const unsigned char *>(in.data()), in.size(),
+						  reinterpret_cast<const unsigned char *>(k.data())) == 0;
+}
diff --git a/src/lib/sodium/StreamChaCha20.hxx b/src/lib/sodium/StreamChaCha20.hxx
new file mode 100644
index 000000000..7e360371a
--- /dev/null
+++ b/src/lib/sodium/StreamChaCha20.hxx
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: BSD-2-Clause
+// Copyright CM4all GmbH
+// author: Max Kellermann <mk@cm4all.com>
+
+#pragma once
+
+#include <sodium/crypto_stream_chacha20.h>
+
+#include <cstddef>
+#include <span>
+
+static void
+crypto_stream_chacha20_xor(std::byte *c, std::span<const std::byte> m,
+			   std::span<const std::byte, crypto_stream_chacha20_NONCEBYTES> n,
+			   std::span<const std::byte, crypto_stream_chacha20_KEYBYTES> k) noexcept
+{
+	crypto_stream_chacha20_xor(reinterpret_cast<unsigned char *>(c),
+				   reinterpret_cast<const unsigned char *>(m.data()), m.size(),
+				   reinterpret_cast<const unsigned char *>(n.data()),
+				   reinterpret_cast<const unsigned char *>(k.data()));
+}
+
+static void
+crypto_stream_chacha20_xor_ic(std::byte *c, std::span<const std::byte> m,
+			      std::span<const std::byte, crypto_stream_chacha20_NONCEBYTES> n,
+			      uint64_t ic,
+			      std::span<const std::byte, crypto_stream_chacha20_KEYBYTES> k) noexcept
+{
+	crypto_stream_chacha20_xor_ic(reinterpret_cast<unsigned char *>(c),
+				      reinterpret_cast<const unsigned char *>(m.data()), m.size(),
+				      reinterpret_cast<const unsigned char *>(n.data()),
+				      ic,
+				      reinterpret_cast<const unsigned char *>(k.data()));
+}