/*
 * Copyright (c) 2024, stelar7  <dudedbz@gmail.com>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <AK/ByteBuffer.h>
#include <LibCrypto/BigInt/UnsignedBigInteger.h>
#include <LibCrypto/Hash/MGF.h>
#include <LibCrypto/Hash/SHA1.h>
#include <LibCrypto/Hash/SHA2.h>
#include <LibCrypto/PK/RSA.h>
#include <LibCrypto/Padding/OAEP.h>
#include <LibTest/TestCase.h>

// https://www.inf.pucrs.br/~calazans/graduate/TPVLSI_I/RSA-oaep_spec.pdf
TEST_CASE(test_oaep)
{
    u8 message_raw[16] {
        0xd4, 0x36, 0xe9, 0x95, 0x69, 0xfd, 0x32, 0xa7, 0xc8, 0xa0, 0x5b, 0xbc, 0x90, 0xd3, 0x2c, 0x49
    };
    auto message = ReadonlyBytes { message_raw, 16 };

    u8 params_raw[0] {};
    auto params = ReadonlyBytes { params_raw, 0 };

    u8 expected_raw[127] {
        0xeb, 0x7a, 0x19, 0xac, 0xe9, 0xe3, 0x00, 0x63,
        0x50, 0xe3, 0x29, 0x50, 0x4b, 0x45, 0xe2, 0xca,
        0x82, 0x31, 0x0b, 0x26, 0xdc, 0xd8, 0x7d, 0x5c,
        0x68, 0xf1, 0xee, 0xa8, 0xf5, 0x52, 0x67, 0xc3,
        0x1b, 0x2e, 0x8b, 0xb4, 0x25, 0x1f, 0x84, 0xd7,
        0xe0, 0xb2, 0xc0, 0x46, 0x26, 0xf5, 0xaf, 0xf9,
        0x3e, 0xdc, 0xfb, 0x25, 0xc9, 0xc2, 0xb3, 0xff,
        0x8a, 0xe1, 0x0e, 0x83, 0x9a, 0x2d, 0xdb, 0x4c,
        0xdc, 0xfe, 0x4f, 0xf4, 0x77, 0x28, 0xb4, 0xa1,
        0xb7, 0xc1, 0x36, 0x2b, 0xaa, 0xd2, 0x9a, 0xb4,
        0x8d, 0x28, 0x69, 0xd5, 0x02, 0x41, 0x21, 0x43,
        0x58, 0x11, 0x59, 0x1b, 0xe3, 0x92, 0xf9, 0x82,
        0xfb, 0x3e, 0x87, 0xd0, 0x95, 0xae, 0xb4, 0x04,
        0x48, 0xdb, 0x97, 0x2f, 0x3a, 0xc1, 0x4f, 0x7b,
        0xc2, 0x75, 0x19, 0x52, 0x81, 0xce, 0x32, 0xd2,
        0xf1, 0xb7, 0x6d, 0x4d, 0x35, 0x3e, 0x2d
    };
    auto expected = ReadonlyBytes { expected_raw, 127 };

    u8 seed_data[20] {
        0xaa, 0xfd, 0x12, 0xf6, 0x59, 0xca, 0xe6, 0x34,
        0x89, 0xb4, 0x79, 0xe5, 0x07, 0x6d, 0xde, 0xc2,
        0xf0, 0x6c, 0xb5, 0x8f
    };

    auto maybe_result = Crypto::Padding::OAEP::encode<Crypto::Hash::SHA1, Crypto::Hash::MGF>(
        message,
        params,
        127,
        [&](auto buffer) {
            memcpy(buffer.data(), seed_data, 20);
        });
    auto result = maybe_result.release_value();

    EXPECT_EQ(expected, result);

    u8 n_bytes[128] {
        0xbb, 0xf8, 0x2f, 0x09, 0x06, 0x82, 0xce, 0x9c, 0x23, 0x38, 0xac, 0x2b, 0x9d, 0xa8, 0x71, 0xf7,
        0x36, 0x8d, 0x07, 0xee, 0xd4, 0x10, 0x43, 0xa4, 0x40, 0xd6, 0xb6, 0xf0, 0x74, 0x54, 0xf5, 0x1f,
        0xb8, 0xdf, 0xba, 0xaf, 0x03, 0x5c, 0x02, 0xab, 0x61, 0xea, 0x48, 0xce, 0xeb, 0x6f, 0xcd, 0x48,
        0x76, 0xed, 0x52, 0x0d, 0x60, 0xe1, 0xec, 0x46, 0x19, 0x71, 0x9d, 0x8a, 0x5b, 0x8b, 0x80, 0x7f,
        0xaf, 0xb8, 0xe0, 0xa3, 0xdf, 0xc7, 0x37, 0x72, 0x3e, 0xe6, 0xb4, 0xb7, 0xd9, 0x3a, 0x25, 0x84,
        0xee, 0x6a, 0x64, 0x9d, 0x06, 0x09, 0x53, 0x74, 0x88, 0x34, 0xb2, 0x45, 0x45, 0x98, 0x39, 0x4e,
        0xe0, 0xaa, 0xb1, 0x2d, 0x7b, 0x61, 0xa5, 0x1f, 0x52, 0x7a, 0x9a, 0x41, 0xf6, 0xc1, 0x68, 0x7f,
        0xe2, 0x53, 0x72, 0x98, 0xca, 0x2a, 0x8f, 0x59, 0x46, 0xf8, 0xe5, 0xfd, 0x09, 0x1d, 0xbd, 0xcb
    };

    u8 e_bytes[1] { 0x11 };

    u8 p_bytes[64] {
        0xee, 0xcf, 0xae, 0x81, 0xb1, 0xb9, 0xb3, 0xc9, 0x08, 0x81, 0x0b, 0x10, 0xa1, 0xb5, 0x60, 0x01,
        0x99, 0xeb, 0x9f, 0x44, 0xae, 0xf4, 0xfd, 0xa4, 0x93, 0xb8, 0x1a, 0x9e, 0x3d, 0x84, 0xf6, 0x32,
        0x12, 0x4e, 0xf0, 0x23, 0x6e, 0x5d, 0x1e, 0x3b, 0x7e, 0x28, 0xfa, 0xe7, 0xaa, 0x04, 0x0a, 0x2d,
        0x5b, 0x25, 0x21, 0x76, 0x45, 0x9d, 0x1f, 0x39, 0x75, 0x41, 0xba, 0x2a, 0x58, 0xfb, 0x65, 0x99
    };

    u8 q_bytes[64] {
        0xc9, 0x7f, 0xb1, 0xf0, 0x27, 0xf4, 0x53, 0xf6, 0x34, 0x12, 0x33, 0xea, 0xaa, 0xd1, 0xd9, 0x35,
        0x3f, 0x6c, 0x42, 0xd0, 0x88, 0x66, 0xb1, 0xd0, 0x5a, 0x0f, 0x20, 0x35, 0x02, 0x8b, 0x9d, 0x86,
        0x98, 0x40, 0xb4, 0x16, 0x66, 0xb4, 0x2e, 0x92, 0xea, 0x0d, 0xa3, 0xb4, 0x32, 0x04, 0xb5, 0xcf,
        0xce, 0x33, 0x52, 0x52, 0x4d, 0x04, 0x16, 0xa5, 0xa4, 0x41, 0xe7, 0x00, 0xaf, 0x46, 0x15, 0x03
    };

    u8 dp_bytes[64] {
        0x54, 0x49, 0x4c, 0xa6, 0x3e, 0xba, 0x03, 0x37, 0xe4, 0xe2, 0x40, 0x23, 0xfc, 0xd6, 0x9a, 0x5a,
        0xeb, 0x07, 0xdd, 0xdc, 0x01, 0x83, 0xa4, 0xd0, 0xac, 0x9b, 0x54, 0xb0, 0x51, 0xf2, 0xb1, 0x3e,
        0xd9, 0x49, 0x09, 0x75, 0xea, 0xb7, 0x74, 0x14, 0xff, 0x59, 0xc1, 0xf7, 0x69, 0x2e, 0x9a, 0x2e,
        0x20, 0x2b, 0x38, 0xfc, 0x91, 0x0a, 0x47, 0x41, 0x74, 0xad, 0xc9, 0x3c, 0x1f, 0x67, 0xc9, 0x81
    };

    u8 dq_bytes[64] {
        0x47, 0x1e, 0x02, 0x90, 0xff, 0x0a, 0xf0, 0x75, 0x03, 0x51, 0xb7, 0xf8, 0x78, 0x86, 0x4c, 0xa9,
        0x61, 0xad, 0xbd, 0x3a, 0x8a, 0x7e, 0x99, 0x1c, 0x5c, 0x05, 0x56, 0xa9, 0x4c, 0x31, 0x46, 0xa7,
        0xf9, 0x80, 0x3f, 0x8f, 0x6f, 0x8a, 0xe3, 0x42, 0xe9, 0x31, 0xfd, 0x8a, 0xe4, 0x7a, 0x22, 0x0d,
        0x1b, 0x99, 0xa4, 0x95, 0x84, 0x98, 0x07, 0xfe, 0x39, 0xf9, 0x24, 0x5a, 0x98, 0x36, 0xda, 0x3d
    };

    u8 qinv_bytes[64] {
        0xb0, 0x6c, 0x4f, 0xda, 0xbb, 0x63, 0x01, 0x19, 0x8d, 0x26, 0x5b, 0xdb, 0xae, 0x94, 0x23, 0xb3,
        0x80, 0xf2, 0x71, 0xf7, 0x34, 0x53, 0x88, 0x50, 0x93, 0x07, 0x7f, 0xcd, 0x39, 0xe2, 0x11, 0x9f,
        0xc9, 0x86, 0x32, 0x15, 0x4f, 0x58, 0x83, 0xb1, 0x67, 0xa9, 0x67, 0xbf, 0x40, 0x2b, 0x4e, 0x9e,
        0x2e, 0x0f, 0x96, 0x56, 0xe6, 0x98, 0xea, 0x36, 0x66, 0xed, 0xfb, 0x25, 0x79, 0x80, 0x39, 0xf7
    };

    u8 expected_rsa_value_bytes[128] {
        0x12, 0x53, 0xe0, 0x4d, 0xc0, 0xa5, 0x39, 0x7b, 0xb4, 0x4a, 0x7a, 0xb8, 0x7e, 0x9b, 0xf2, 0xa0,
        0x39, 0xa3, 0x3d, 0x1e, 0x99, 0x6f, 0xc8, 0x2a, 0x94, 0xcc, 0xd3, 0x00, 0x74, 0xc9, 0x5d, 0xf7,
        0x63, 0x72, 0x20, 0x17, 0x06, 0x9e, 0x52, 0x68, 0xda, 0x5d, 0x1c, 0x0b, 0x4f, 0x87, 0x2c, 0xf6,
        0x53, 0xc1, 0x1d, 0xf8, 0x23, 0x14, 0xa6, 0x79, 0x68, 0xdf, 0xea, 0xe2, 0x8d, 0xef, 0x04, 0xbb,
        0x6d, 0x84, 0xb1, 0xc3, 0x1d, 0x65, 0x4a, 0x19, 0x70, 0xe5, 0x78, 0x3b, 0xd6, 0xeb, 0x96, 0xa0,
        0x24, 0xc2, 0xca, 0x2f, 0x4a, 0x90, 0xfe, 0x9f, 0x2e, 0xf5, 0xc9, 0xc1, 0x40, 0xe5, 0xbb, 0x48,
        0xda, 0x95, 0x36, 0xad, 0x87, 0x00, 0xc8, 0x4f, 0xc9, 0x13, 0x0a, 0xde, 0xa7, 0x4e, 0x55, 0x8d,
        0x51, 0xa7, 0x4d, 0xdf, 0x85, 0xd8, 0xb5, 0x0d, 0xe9, 0x68, 0x38, 0xd6, 0x06, 0x3e, 0x09, 0x55
    };

    auto expected_rsa_value = ReadonlyBytes { expected_rsa_value_bytes, 128 };

    auto n = Crypto::UnsignedBigInteger::import_data(n_bytes, 128);
    auto e = Crypto::UnsignedBigInteger::import_data(e_bytes, 1);
    auto p = Crypto::UnsignedBigInteger::import_data(p_bytes, 64);
    auto q = Crypto::UnsignedBigInteger::import_data(q_bytes, 64);
    auto dp = Crypto::UnsignedBigInteger::import_data(dp_bytes, 64);
    auto dq = Crypto::UnsignedBigInteger::import_data(dq_bytes, 64);
    auto qinv = Crypto::UnsignedBigInteger::import_data(qinv_bytes, 64);
    auto private_key = Crypto::PK::RSAPrivateKey<>::from_crt(n, e, p, q, dp, dq, qinv);
    auto public_key = Crypto::PK::RSAPublicKey(n, e);
    auto rsa = Crypto::PK::RSA(public_key, private_key);

    auto maybe_output_buffer = ByteBuffer::create_uninitialized(128);
    auto output_buffer = maybe_output_buffer.release_value();
    auto output_span = output_buffer.bytes();

    rsa.encrypt(result, output_span);

    EXPECT_EQ(expected_rsa_value, output_span);
}