LibCrypto: Remove unused MGF class

Author: https://github.com/devgianlu
Commit: 8ae01f81c9
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3606

Libraries/LibCrypto/Hash/MGF.h

@@ -1,57 +0,0 @@
-/*
- * Copyright (c) 2024, stelar7 <dudedbz@gmail.com>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#pragma once
-
-#include <AK/ByteBuffer.h>
-#include <AK/ByteReader.h>
-#include <AK/Endian.h>
-
-namespace Crypto::Hash {
-
-class MGF {
-public:
-    // https://datatracker.ietf.org/doc/html/rfc2437#section-10.2.1
-    template<typename HashFunction>
-    static ErrorOr<ByteBuffer> mgf1(ReadonlyBytes seed, size_t length)
-    requires requires { HashFunction::digest_size(); }
-    {
-        auto hash = HashFunction::create();
-
-        size_t h_len = hash->digest_size();
-
-        // 1. If length > 2^32(hLen), output "mask too long" and stop.
-        if constexpr (sizeof(size_t) > 32) {
-            if (length > (h_len << 32))
-                return Error::from_string_literal("mask too long");
-        }
-
-        // 2. Let T be the empty octet string.
-        auto t = TRY(ByteBuffer::create_uninitialized(0));
-
-        // 3. For counter from 0 to ceil(length / hLen) - 1, do the following:
-        auto counter = 0u;
-        auto iterations = AK::ceil_div(length, h_len) - 1;
-
-        auto c = TRY(ByteBuffer::create_uninitialized(4));
-        for (; counter <= iterations; ++counter) {
-            // a. Convert counter to an octet string C of length 4 with the primitive I2OSP: C = I2OSP(counter, 4)
-            ByteReader::store(static_cast<u8*>(c.data()), AK::convert_between_host_and_big_endian(static_cast<u32>(counter)));
-
-            // b. Concatenate the hash of the seed Z and C to the octet string T: T = T || Hash (Z || C)
-            hash->update(seed);
-            hash->update(c);
-            auto digest = hash->digest();
-
-            TRY(t.try_append(digest.bytes()));
-        }
-
-        // 4. Output the leading l octets of T as the octet string mask.
-        return t.slice(0, length);
-    }
-};
-
-}