LibCrypto: Refactor Edwards-curves implementation with OpenSSL

Author: https://github.com/devgianlu Commit: 60dcf3e023 Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3671 Reviewed-by: https://github.com/ADKaster Reviewed-by: https://github.com/alimpfard
2025-07-31 21:29:06 +00:00 · 2025-02-16 13:02:13 +01:00 · 2025-02-16 13:02:13 +01:00 · 60dcf3e023 · 2025-02-24 10:12:26 +00:00
commit 60dcf3e023
parent 0fcd7f9aea
16 changed files with 216 additions and 1626 deletions
--- a/Libraries/LibCrypto/Curves/EdwardsCurve.cpp
+++ b/Libraries/LibCrypto/Curves/EdwardsCurve.cpp
@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2025, Altomani Gianluca <altomanigianluca@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/ScopeGuard.h>
+#include <LibCrypto/Curves/EdwardsCurve.h>
+#include <LibCrypto/OpenSSL.h>
+
+#include <openssl/core_names.h>
+#include <openssl/evp.h>
+
+namespace Crypto::Curves {
+
+ErrorOr<ByteBuffer> EdwardsCurve::generate_private_key()
+{
+    auto key = TRY(OpenSSL_PKEY::wrap(EVP_PKEY_Q_keygen(nullptr, nullptr, m_curve_name)));
+
+    size_t key_size = 0;
+    OPENSSL_TRY(EVP_PKEY_get_raw_private_key(key.ptr(), nullptr, &key_size));
+
+    auto buf = TRY(ByteBuffer::create_uninitialized(key_size));
+    OPENSSL_TRY(EVP_PKEY_get_raw_private_key(key.ptr(), buf.data(), &key_size));
+
+    return buf;
+}
+
+ErrorOr<ByteBuffer> EdwardsCurve::generate_public_key(ReadonlyBytes private_key)
+{
+    auto key = TRY(OpenSSL_PKEY::wrap(EVP_PKEY_new_raw_private_key_ex(nullptr, m_curve_name, nullptr, private_key.data(), private_key.size())));
+
+    size_t key_size = 0;
+    OPENSSL_TRY(EVP_PKEY_get_raw_public_key(key.ptr(), nullptr, &key_size));
+
+    auto buf = TRY(ByteBuffer::create_uninitialized(key_size));
+    OPENSSL_TRY(EVP_PKEY_get_raw_public_key(key.ptr(), buf.data(), &key_size));
+
+    return buf;
+}
+
+ErrorOr<ByteBuffer> SignatureEdwardsCurve::sign(ReadonlyBytes private_key, ReadonlyBytes message, ReadonlyBytes context)
+{
+    auto key = TRY(OpenSSL_PKEY::wrap(EVP_PKEY_new_raw_private_key_ex(nullptr, m_curve_name, nullptr, private_key.data(), private_key.size())));
+
+    auto ctx = TRY(OpenSSL_MD_CTX::create());
+
+    OSSL_PARAM params[2] = {
+        OSSL_PARAM_END,
+        OSSL_PARAM_END
+    };
+
+    if (!context.is_null()) {
+        params[0] = OSSL_PARAM_octet_string(OSSL_SIGNATURE_PARAM_CONTEXT_STRING, const_cast<u8*>(context.data()), context.size());
+    }
+
+    OPENSSL_TRY(EVP_DigestSignInit_ex(ctx.ptr(), nullptr, nullptr, nullptr, nullptr, key.ptr(), params));
+
+    size_t sig_len = 0;
+    OPENSSL_TRY(EVP_DigestSign(ctx.ptr(), nullptr, &sig_len, message.data(), message.size()));
+
+    auto sig = TRY(ByteBuffer::create_uninitialized(sig_len));
+    OPENSSL_TRY(EVP_DigestSign(ctx.ptr(), sig.data(), &sig_len, message.data(), message.size()));
+
+    return sig;
+}
+
+ErrorOr<bool> SignatureEdwardsCurve::verify(ReadonlyBytes public_key, ReadonlyBytes signature, ReadonlyBytes message, ReadonlyBytes context)
+{
+    auto key = TRY(OpenSSL_PKEY::wrap(EVP_PKEY_new_raw_public_key_ex(nullptr, m_curve_name, nullptr, public_key.data(), public_key.size())));
+
+    auto ctx = TRY(OpenSSL_MD_CTX::create());
+
+    OSSL_PARAM params[2] = {
+        OSSL_PARAM_END,
+        OSSL_PARAM_END
+    };
+
+    if (!context.is_null()) {
+        params[0] = OSSL_PARAM_octet_string(OSSL_SIGNATURE_PARAM_CONTEXT_STRING, const_cast<u8*>(context.data()), context.size());
+    }
+
+    OPENSSL_TRY(EVP_DigestVerifyInit_ex(ctx.ptr(), nullptr, nullptr, nullptr, nullptr, key.ptr(), params));
+
+    auto res = EVP_DigestVerify(ctx.ptr(), signature.data(), signature.size(), message.data(), message.size());
+    if (res == 1)
+        return true;
+    if (res == 0)
+        return false;
+    OPENSSL_TRY(res);
+    VERIFY_NOT_REACHED();
+}
+
+ErrorOr<ByteBuffer> ExchangeEdwardsCurve::compute_coordinate(ReadonlyBytes private_key, ReadonlyBytes public_key)
+{
+    auto key = TRY(OpenSSL_PKEY::wrap(EVP_PKEY_new_raw_private_key_ex(nullptr, m_curve_name, nullptr, private_key.data(), private_key.size())));
+    auto peerkey = TRY(OpenSSL_PKEY::wrap(EVP_PKEY_new_raw_public_key_ex(nullptr, m_curve_name, nullptr, public_key.data(), public_key.size())));
+
+    auto ctx = TRY(OpenSSL_PKEY_CTX::wrap(EVP_PKEY_CTX_new(key.ptr(), nullptr)));
+
+    OPENSSL_TRY(EVP_PKEY_derive_init(ctx.ptr()));
+    OPENSSL_TRY(EVP_PKEY_derive_set_peer(ctx.ptr(), peerkey.ptr()));
+
+    size_t key_size = 0;
+    OPENSSL_TRY(EVP_PKEY_derive(ctx.ptr(), nullptr, &key_size));
+
+    auto buf = TRY(ByteBuffer::create_uninitialized(key_size));
+    OPENSSL_TRY(EVP_PKEY_derive(ctx.ptr(), buf.data(), &key_size));
+
+    return buf;
+}
+
+}