LibCrypto: Refactor HMAC implementations with OpenSSL

Author: https://github.com/devgianlu
Commit: 80fe259dab
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3749
Reviewed-by: https://github.com/konradekk

Libraries/LibCrypto/Authentication/HMAC.cpp

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2025, Altomani Gianluca <altomanigianluca@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibCrypto/Authentication/HMAC.h>
+
+#include <openssl/core_names.h>
+#include <openssl/evp.h>
+
+namespace Crypto::Authentication {
+
+HMAC::HMAC(Hash::HashKind hash_kind, ReadonlyBytes key)
+    : m_hash_kind(hash_kind)
+    , m_key(key)
+    , m_mac(EVP_MAC_fetch(nullptr, "HMAC", nullptr))
+{
+    reset();
+}
+
+HMAC::~HMAC()
+{
+    EVP_MAC_free(m_mac);
+    EVP_MAC_CTX_free(m_ctx);
+}
+
+size_t HMAC::digest_size() const
+{
+    return EVP_MAC_CTX_get_mac_size(m_ctx);
+}
+
+void HMAC::update(u8 const* message, size_t length)
+{
+    if (EVP_MAC_update(m_ctx, message, length) != 1) {
+        VERIFY_NOT_REACHED();
+    }
+}
+
+ByteBuffer HMAC::digest()
+{
+    auto buf = MUST(ByteBuffer::create_uninitialized(digest_size()));
+
+    auto size = digest_size();
+    if (EVP_MAC_final(m_ctx, buf.data(), &size, size) != 1) {
+        VERIFY_NOT_REACHED();
+    }
+
+    return MUST(buf.slice(0, size));
+}
+
+void HMAC::reset()
+{
+    EVP_MAC_CTX_free(m_ctx);
+    m_ctx = EVP_MAC_CTX_new(m_mac);
+
+    auto hash_name = MUST(hash_kind_to_openssl_digest_name(m_hash_kind));
+
+    OSSL_PARAM params[] = {
+        OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_DIGEST, const_cast<char*>(hash_name.characters_without_null_termination()), hash_name.length()),
+        OSSL_PARAM_END
+    };
+
+    if (EVP_MAC_init(m_ctx, m_key.data(), m_key.size(), params) != 1) {
+        VERIFY_NOT_REACHED();
+    }
+}
+
+}