// Copyright (c) 2014 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <random.h>
#include <utilstrencodings.h>
#include <test/test_bitcoin.h>
#include <wallet/crypter.h>

#include <vector>

#include <boost/test/unit_test.hpp>
#include <openssl/aes.h>
#include <openssl/evp.h>

BOOST_FIXTURE_TEST_SUITE(wallet_crypto, BasicTestingSetup)

bool OldSetKeyFromPassphrase(const SecureString& strKeyData, const std::vector<unsigned char>& chSalt, const unsigned int nRounds, const unsigned int nDerivationMethod, unsigned char* chKey, unsigned char* chIV)
{
    if (nRounds < 1 || chSalt.size() != WALLET_CRYPTO_SALT_SIZE)
        return false;

    int i = 0;
    if (nDerivationMethod == 0)
        i = EVP_BytesToKey(EVP_aes_256_cbc(), EVP_sha512(), &chSalt[0],
                          (unsigned char *)&strKeyData[0], strKeyData.size(), nRounds, chKey, chIV);

    if (i != (int)WALLET_CRYPTO_KEY_SIZE)
    {
        memory_cleanse(chKey, sizeof(chKey));
        memory_cleanse(chIV, sizeof(chIV));
        return false;
    }
    return true;
}

bool OldEncrypt(const CKeyingMaterial& vchPlaintext, std::vector<unsigned char> &vchCiphertext, const unsigned char chKey[32], const unsigned char chIV[16])
{
    // max ciphertext len for a n bytes of plaintext is
    // n + AES_BLOCK_SIZE - 1 bytes
    int nLen = vchPlaintext.size();
    int nCLen = nLen + AES_BLOCK_SIZE, nFLen = 0;
    vchCiphertext = std::vector<unsigned char> (nCLen);

    EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();

    if (!ctx) return false;

    bool fOk = true;

    EVP_CIPHER_CTX_init(ctx);
    if (fOk) fOk = EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, chKey, chIV) != 0;
    if (fOk) fOk = EVP_EncryptUpdate(ctx, &vchCiphertext[0], &nCLen, &vchPlaintext[0], nLen) != 0;
    if (fOk) fOk = EVP_EncryptFinal_ex(ctx, (&vchCiphertext[0]) + nCLen, &nFLen) != 0;
    EVP_CIPHER_CTX_cleanup(ctx);

    EVP_CIPHER_CTX_free(ctx);

    if (!fOk) return false;

    vchCiphertext.resize(nCLen + nFLen);
    return true;
}

bool OldDecrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext, const unsigned char chKey[32], const unsigned char chIV[16])
{
    // plaintext will always be equal to or lesser than length of ciphertext
    int nLen = vchCiphertext.size();
    int nPLen = nLen, nFLen = 0;

    vchPlaintext = CKeyingMaterial(nPLen);

    EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();

    if (!ctx) return false;

    bool fOk = true;

    EVP_CIPHER_CTX_init(ctx);
    if (fOk) fOk = EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, chKey, chIV) != 0;
    if (fOk) fOk = EVP_DecryptUpdate(ctx, &vchPlaintext[0], &nPLen, &vchCiphertext[0], nLen) != 0;
    if (fOk) fOk = EVP_DecryptFinal_ex(ctx, (&vchPlaintext[0]) + nPLen, &nFLen) != 0;
    EVP_CIPHER_CTX_cleanup(ctx);

    EVP_CIPHER_CTX_free(ctx);

    if (!fOk) return false;

    vchPlaintext.resize(nPLen + nFLen);
    return true;
}

class TestCrypter
{
public:
static void TestPassphraseSingle(const std::vector<unsigned char>& vchSalt, const SecureString& passphrase, uint32_t rounds,
                 const std::vector<unsigned char>& correctKey = std::vector<unsigned char>(),
                 const std::vector<unsigned char>& correctIV=std::vector<unsigned char>())
{
    unsigned char chKey[WALLET_CRYPTO_KEY_SIZE];
    unsigned char chIV[WALLET_CRYPTO_IV_SIZE];

    CCrypter crypt;
    crypt.SetKeyFromPassphrase(passphrase, vchSalt, rounds, 0);

    OldSetKeyFromPassphrase(passphrase, vchSalt, rounds, 0, chKey, chIV);

    BOOST_CHECK_MESSAGE(memcmp(chKey, crypt.chKey, sizeof(chKey)) == 0, \
        HexStr(chKey, chKey+sizeof(chKey)) + std::string(" != ") + HexStr(crypt.chKey, crypt.chKey + (sizeof crypt.chKey)));
    BOOST_CHECK_MESSAGE(memcmp(chIV, crypt.chIV, sizeof(chIV)) == 0, \
        HexStr(chIV, chIV+sizeof(chIV)) + std::string(" != ") + HexStr(crypt.chIV, crypt.chIV + (sizeof crypt.chIV)));

    if(!correctKey.empty())
        BOOST_CHECK_MESSAGE(memcmp(chKey, &correctKey[0], sizeof(chKey)) == 0, \
            HexStr(chKey, chKey+sizeof(chKey)) + std::string(" != ") + HexStr(correctKey.begin(), correctKey.end()));
    if(!correctIV.empty())
        BOOST_CHECK_MESSAGE(memcmp(chIV, &correctIV[0], sizeof(chIV)) == 0,
            HexStr(chIV, chIV+sizeof(chIV)) + std::string(" != ") + HexStr(correctIV.begin(), correctIV.end()));
}

static void TestPassphrase(const std::vector<unsigned char>& vchSalt, const SecureString& passphrase, uint32_t rounds,
                 const std::vector<unsigned char>& correctKey = std::vector<unsigned char>(),
                 const std::vector<unsigned char>& correctIV=std::vector<unsigned char>())
{
    TestPassphraseSingle(vchSalt, passphrase, rounds, correctKey, correctIV);
    for(SecureString::const_iterator i(passphrase.begin()); i != passphrase.end(); ++i)
        TestPassphraseSingle(vchSalt, SecureString(i, passphrase.end()), rounds);
}


static void TestDecrypt(const CCrypter& crypt, const std::vector<unsigned char>& vchCiphertext, \
                        const std::vector<unsigned char>& vchPlaintext = std::vector<unsigned char>())
{
    CKeyingMaterial vchDecrypted1;
    CKeyingMaterial vchDecrypted2;
    int result1, result2;
    result1 = crypt.Decrypt(vchCiphertext, vchDecrypted1);
    result2 = OldDecrypt(vchCiphertext, vchDecrypted2, crypt.chKey, crypt.chIV);
    BOOST_CHECK(result1 == result2);

    // These two should be equal. However, OpenSSL 1.0.1j introduced a change
    // that would zero all padding except for the last byte for failed decrypts.
    // This behavior was reverted for 1.0.1k.
    if (vchDecrypted1 != vchDecrypted2 && vchDecrypted1.size() >= AES_BLOCK_SIZE && SSLeay() == 0x100010afL)
    {
        for(CKeyingMaterial::iterator it = vchDecrypted1.end() - AES_BLOCK_SIZE; it != vchDecrypted1.end() - 1; it++)
            *it = 0;
    }

    BOOST_CHECK_MESSAGE(vchDecrypted1 == vchDecrypted2, HexStr(vchDecrypted1.begin(), vchDecrypted1.end()) + " != " + HexStr(vchDecrypted2.begin(), vchDecrypted2.end()));

    if (vchPlaintext.size())
        BOOST_CHECK(CKeyingMaterial(vchPlaintext.begin(), vchPlaintext.end()) == vchDecrypted2);
}

static void TestEncryptSingle(const CCrypter& crypt, const CKeyingMaterial& vchPlaintext,
                       const std::vector<unsigned char>& vchCiphertextCorrect = std::vector<unsigned char>())
{
    std::vector<unsigned char> vchCiphertext1;
    std::vector<unsigned char> vchCiphertext2;
    int result1 = crypt.Encrypt(vchPlaintext, vchCiphertext1);

    int result2 = OldEncrypt(vchPlaintext, vchCiphertext2, crypt.chKey, crypt.chIV);
    BOOST_CHECK(result1 == result2);
    BOOST_CHECK(vchCiphertext1 == vchCiphertext2);

    if (!vchCiphertextCorrect.empty())
        BOOST_CHECK(vchCiphertext2 == vchCiphertextCorrect);

    const std::vector<unsigned char> vchPlaintext2(vchPlaintext.begin(), vchPlaintext.end());

    if(vchCiphertext1 == vchCiphertext2)
        TestDecrypt(crypt, vchCiphertext1, vchPlaintext2);
}

static void TestEncrypt(const CCrypter& crypt, const std::vector<unsigned char>& vchPlaintextIn, \
                       const std::vector<unsigned char>& vchCiphertextCorrect = std::vector<unsigned char>())
{
    TestEncryptSingle(crypt, CKeyingMaterial(vchPlaintextIn.begin(), vchPlaintextIn.end()), vchCiphertextCorrect);
    for(std::vector<unsigned char>::const_iterator i(vchPlaintextIn.begin()); i != vchPlaintextIn.end(); ++i)
        TestEncryptSingle(crypt, CKeyingMaterial(i, vchPlaintextIn.end()));
}

};

BOOST_AUTO_TEST_CASE(passphrase) {
    // These are expensive.

    TestCrypter::TestPassphrase(ParseHex("0000deadbeef0000"), "test", 25000, \
                                ParseHex("fc7aba077ad5f4c3a0988d8daa4810d0d4a0e3bcb53af662998898f33df0556a"), \
                                ParseHex("cf2f2691526dd1aa220896fb8bf7c369"));

    std::string hash(GetRandHash().ToString());
    std::vector<unsigned char> vchSalt(8);
    GetRandBytes(&vchSalt[0], vchSalt.size());
    uint32_t rounds = insecure_rand();
    if (rounds > 30000)
        rounds = 30000;
    TestCrypter::TestPassphrase(vchSalt, SecureString(hash.begin(), hash.end()), rounds);
}

BOOST_AUTO_TEST_CASE(encrypt) {
    std::vector<unsigned char> vchSalt = ParseHex("0000deadbeef0000");
    BOOST_CHECK(vchSalt.size() == WALLET_CRYPTO_SALT_SIZE);
    CCrypter crypt;
    crypt.SetKeyFromPassphrase("passphrase", vchSalt, 25000, 0);
    TestCrypter::TestEncrypt(crypt, ParseHex("22bcade09ac03ff6386914359cfe885cfeb5f77ff0d670f102f619687453b29d"));

    for (int i = 0; i != 100; i++)
    {
        uint256 hash(GetRandHash());
        TestCrypter::TestEncrypt(crypt, std::vector<unsigned char>(hash.begin(), hash.end()));
    }

}

BOOST_AUTO_TEST_CASE(decrypt) {
    std::vector<unsigned char> vchSalt = ParseHex("0000deadbeef0000");
    BOOST_CHECK(vchSalt.size() == WALLET_CRYPTO_SALT_SIZE);
    CCrypter crypt;
    crypt.SetKeyFromPassphrase("passphrase", vchSalt, 25000, 0);

    // Some corner cases the came up while testing
    TestCrypter::TestDecrypt(crypt,ParseHex("795643ce39d736088367822cdc50535ec6f103715e3e48f4f3b1a60a08ef59ca"));
    TestCrypter::TestDecrypt(crypt,ParseHex("de096f4a8f9bd97db012aa9d90d74de8cdea779c3ee8bc7633d8b5d6da703486"));
    TestCrypter::TestDecrypt(crypt,ParseHex("32d0a8974e3afd9c6c3ebf4d66aa4e6419f8c173de25947f98cf8b7ace49449c"));
    TestCrypter::TestDecrypt(crypt,ParseHex("e7c055cca2faa78cb9ac22c9357a90b4778ded9b2cc220a14cea49f931e596ea"));
    TestCrypter::TestDecrypt(crypt,ParseHex("b88efddd668a6801d19516d6830da4ae9811988ccbaf40df8fbb72f3f4d335fd"));
    TestCrypter::TestDecrypt(crypt,ParseHex("8cae76aa6a43694e961ebcb28c8ca8f8540b84153d72865e8561ddd93fa7bfa9"));

    for (int i = 0; i != 100; i++)
    {
        uint256 hash(GetRandHash());
        TestCrypter::TestDecrypt(crypt, std::vector<unsigned char>(hash.begin(), hash.end()));
    }
}

BOOST_AUTO_TEST_SUITE_END()
