//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2012, 2013 Ripple Labs Inc.

    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.

    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

#include <ripple/app/misc/Manifest.h>
#include <ripple/basics/Log.h>
#include <ripple/basics/StringUtilities.h>
#include <ripple/basics/base64.h>
#include <ripple/basics/contract.h>
#include <ripple/core/DatabaseCon.h>
#include <ripple/json/json_reader.h>
#include <ripple/protocol/PublicKey.h>
#include <ripple/protocol/Sign.h>
#include <boost/algorithm/clamp.hpp>
#include <boost/algorithm/string/trim.hpp>
#include <boost/regex.hpp>
#include <numeric>
#include <stdexcept>

namespace ripple {

std::string
to_string(Manifest const& m)
{
    auto const mk = toBase58(TokenType::NodePublic, m.masterKey);

    if (m.revoked())
        return "Revocation Manifest " + mk;

    return "Manifest " + mk + " (" + std::to_string(m.sequence) + ": " +
        toBase58(TokenType::NodePublic, m.signingKey) + ")";
}

std::optional<Manifest>
deserializeManifest(Slice s)
{
    if (s.empty())
        return std::nullopt;

    static SOTemplate const manifestFormat{
        // A manifest must include:
        // - the master public key
        {sfPublicKey, soeREQUIRED},

        // - a signature with that public key
        {sfMasterSignature, soeREQUIRED},

        // - a sequence number
        {sfSequence, soeREQUIRED},

        // It may, optionally, contain:
        // - a version number which defaults to 0
        {sfVersion, soeDEFAULT},

        // - a domain name
        {sfDomain, soeOPTIONAL},

        // - an ephemeral signing key that can be changed as necessary
        {sfSigningPubKey, soeOPTIONAL},

        // - a signature using the ephemeral signing key, if it is present
        {sfSignature, soeOPTIONAL},
    };

    try
    {
        SerialIter sit{s};
        STObject st{sit, sfGeneric};

        st.applyTemplate(manifestFormat);

        // We only understand "version 0" manifests at this time:
        if (st.isFieldPresent(sfVersion) && st.getFieldU16(sfVersion) != 0)
            return std::nullopt;

        auto const pk = st.getFieldVL(sfPublicKey);

        if (!publicKeyType(makeSlice(pk)))
            return std::nullopt;

        Manifest m;
        m.serialized.assign(reinterpret_cast<char const*>(s.data()), s.size());
        m.masterKey = PublicKey(makeSlice(pk));
        m.sequence = st.getFieldU32(sfSequence);

        if (st.isFieldPresent(sfDomain))
        {
            auto const d = st.getFieldVL(sfDomain);

            m.domain.assign(reinterpret_cast<char const*>(d.data()), d.size());

            if (!isProperlyFormedTomlDomain(m.domain))
                return std::nullopt;
        }

        bool const hasEphemeralKey = st.isFieldPresent(sfSigningPubKey);
        bool const hasEphemeralSig = st.isFieldPresent(sfSignature);

        if (m.revoked())
        {
            // Revocation manifests should not specify a new signing key
            // or a signing key signature.
            if (hasEphemeralKey)
                return std::nullopt;

            if (hasEphemeralSig)
                return std::nullopt;
        }
        else
        {
            // Regular manifests should contain a signing key and an
            // associated signature.
            if (!hasEphemeralKey)
                return std::nullopt;

            if (!hasEphemeralSig)
                return std::nullopt;

            auto const spk = st.getFieldVL(sfSigningPubKey);

            if (!publicKeyType(makeSlice(spk)))
                return std::nullopt;

            m.signingKey = PublicKey(makeSlice(spk));

            // The signing and master keys can't be the same
            if (m.signingKey == m.masterKey)
                return std::nullopt;
        }

        return m;
    }
    catch (std::exception const&)
    {
        return std::nullopt;
    }
}

template <class Stream>
Stream&
logMftAct(
    Stream& s,
    std::string const& action,
    PublicKey const& pk,
    std::uint32_t seq)
{
    s << "Manifest: " << action
      << ";Pk: " << toBase58(TokenType::NodePublic, pk) << ";Seq: " << seq
      << ";";
    return s;
}

template <class Stream>
Stream&
logMftAct(
    Stream& s,
    std::string const& action,
    PublicKey const& pk,
    std::uint32_t seq,
    std::uint32_t oldSeq)
{
    s << "Manifest: " << action
      << ";Pk: " << toBase58(TokenType::NodePublic, pk) << ";Seq: " << seq
      << ";OldSeq: " << oldSeq << ";";
    return s;
}

bool
Manifest::verify() const
{
    STObject st(sfGeneric);
    SerialIter sit(serialized.data(), serialized.size());
    st.set(sit);

    // Signing key and signature are not required for
    // master key revocations
    if (!revoked() && !ripple::verify(st, HashPrefix::manifest, signingKey))
        return false;

    return ripple::verify(
        st, HashPrefix::manifest, masterKey, sfMasterSignature);
}

uint256
Manifest::hash() const
{
    STObject st(sfGeneric);
    SerialIter sit(serialized.data(), serialized.size());
    st.set(sit);
    return st.getHash(HashPrefix::manifest);
}

bool
Manifest::revoked() const
{
    /*
        The maximum possible sequence number means that the master key
        has been revoked.
    */
    return sequence == std::numeric_limits<std::uint32_t>::max();
}

std::optional<Blob>
Manifest::getSignature() const
{
    STObject st(sfGeneric);
    SerialIter sit(serialized.data(), serialized.size());
    st.set(sit);
    if (!get(st, sfSignature))
        return std::nullopt;
    return st.getFieldVL(sfSignature);
}

Blob
Manifest::getMasterSignature() const
{
    STObject st(sfGeneric);
    SerialIter sit(serialized.data(), serialized.size());
    st.set(sit);
    return st.getFieldVL(sfMasterSignature);
}

std::optional<ValidatorToken>
loadValidatorToken(std::vector<std::string> const& blob)
{
    try
    {
        std::string tokenStr;

        tokenStr.reserve(std::accumulate(
            blob.cbegin(),
            blob.cend(),
            std::size_t(0),
            [](std::size_t init, std::string const& s) {
                return init + s.size();
            }));

        for (auto const& line : blob)
            tokenStr += boost::algorithm::trim_copy(line);

        tokenStr = base64_decode(tokenStr);

        Json::Reader r;
        Json::Value token;

        if (r.parse(tokenStr, token))
        {
            auto const m = token.get("manifest", Json::Value{});
            auto const k = token.get("validation_secret_key", Json::Value{});

            if (m.isString() && k.isString())
            {
                auto const key = strUnHex(k.asString());

                if (key && key->size() == 32)
                    return ValidatorToken{m.asString(), makeSlice(*key)};
            }
        }

        return std::nullopt;
    }
    catch (std::exception const&)
    {
        return std::nullopt;
    }
}

PublicKey
ManifestCache::getSigningKey(PublicKey const& pk) const
{
    std::lock_guard lock{read_mutex_};
    auto const iter = map_.find(pk);

    if (iter != map_.end() && !iter->second.revoked())
        return iter->second.signingKey;

    return pk;
}

PublicKey
ManifestCache::getMasterKey(PublicKey const& pk) const
{
    std::lock_guard lock{read_mutex_};

    if (auto const iter = signingToMasterKeys_.find(pk);
        iter != signingToMasterKeys_.end())
        return iter->second;

    return pk;
}

std::optional<std::uint32_t>
ManifestCache::getSequence(PublicKey const& pk) const
{
    std::lock_guard lock{read_mutex_};
    auto const iter = map_.find(pk);

    if (iter != map_.end() && !iter->second.revoked())
        return iter->second.sequence;

    return std::nullopt;
}

std::optional<std::string>
ManifestCache::getDomain(PublicKey const& pk) const
{
    std::lock_guard lock{read_mutex_};
    auto const iter = map_.find(pk);

    if (iter != map_.end() && !iter->second.revoked())
        return iter->second.domain;

    return std::nullopt;
}

std::optional<std::string>
ManifestCache::getManifest(PublicKey const& pk) const
{
    std::lock_guard lock{read_mutex_};
    auto const iter = map_.find(pk);

    if (iter != map_.end() && !iter->second.revoked())
        return iter->second.serialized;

    return std::nullopt;
}

bool
ManifestCache::revoked(PublicKey const& pk) const
{
    std::lock_guard lock{read_mutex_};
    auto const iter = map_.find(pk);

    if (iter != map_.end())
        return iter->second.revoked();

    return false;
}

ManifestDisposition
ManifestCache::applyManifest(Manifest m)
{
    std::lock_guard applyLock{apply_mutex_};

    // Before we spend time checking the signature, make sure the
    // sequence number is newer than any we have.
    auto const iter = map_.find(m.masterKey);

    if (iter != map_.end() && m.sequence <= iter->second.sequence)
    {
        // We received a manifest whose sequence number is not strictly greater
        // than the one we already know about. This can happen in several cases
        // including when we receive manifests from a peer who doesn't have the
        // latest data.
        if (auto stream = j_.debug())
            logMftAct(
                stream,
                "Stale",
                m.masterKey,
                m.sequence,
                iter->second.sequence);
        return ManifestDisposition::stale;
    }

    // Now check the signature
    if (!m.verify())
    {
        if (auto stream = j_.warn())
            logMftAct(stream, "Invalid", m.masterKey, m.sequence);
        return ManifestDisposition::invalid;
    }

    // If the master key associated with a manifest is or might be compromised
    // and is, therefore, no longer trustworthy.
    //
    // A manifest revocation essentially marks a manifest as compromised. By
    // setting the sequence number to the highest value possible, the manifest
    // is effectively neutered and cannot be superseded by a forged one.
    bool const revoked = m.revoked();

    if (auto stream = j_.warn(); stream && revoked)
        logMftAct(stream, "Revoked", m.masterKey, m.sequence);

    std::lock_guard readLock{read_mutex_};

    // Sanity check: the master key of this manifest should not be used as
    // the ephemeral key of another manifest:
    if (auto const x = signingToMasterKeys_.find(m.masterKey);
        x != signingToMasterKeys_.end())
    {
        JLOG(j_.warn()) << to_string(m)
                        << ": Master key already used as ephemeral key for "
                        << toBase58(TokenType::NodePublic, x->second);

        return ManifestDisposition::badMasterKey;
    }

    if (!revoked)
    {
        // Sanity check: the ephemeral key of this manifest should not be used
        // as the master or ephemeral key of another manifest:
        if (auto const x = signingToMasterKeys_.find(m.signingKey);
            x != signingToMasterKeys_.end())
        {
            JLOG(j_.warn())
                << to_string(m)
                << ": Ephemeral key already used as ephemeral key for "
                << toBase58(TokenType::NodePublic, x->second);

            return ManifestDisposition::badEphemeralKey;
        }

        if (auto const x = map_.find(m.signingKey); x != map_.end())
        {
            JLOG(j_.warn())
                << to_string(m) << ": Ephemeral key used as master key for "
                << to_string(x->second);

            return ManifestDisposition::badEphemeralKey;
        }
    }

    // This is the first manifest we are seeing for a master key. This should
    // only ever happen once per validator run.
    if (iter == map_.end())
    {
        if (auto stream = j_.info())
            logMftAct(stream, "AcceptedNew", m.masterKey, m.sequence);

        if (!revoked)
            signingToMasterKeys_[m.signingKey] = m.masterKey;

        auto masterKey = m.masterKey;
        map_.emplace(std::move(masterKey), std::move(m));
        return ManifestDisposition::accepted;
    }

    // An ephemeral key was revoked and superseded by a new key. This is
    // expected, but should happen infrequently.
    if (auto stream = j_.info())
        logMftAct(
            stream,
            "AcceptedUpdate",
            m.masterKey,
            m.sequence,
            iter->second.sequence);

    signingToMasterKeys_.erase(iter->second.signingKey);

    if (!revoked)
        signingToMasterKeys_[m.signingKey] = m.masterKey;

    iter->second = std::move(m);

    // Something has changed. Keep track of it.
    seq_++;

    return ManifestDisposition::accepted;
}

void
ManifestCache::load(DatabaseCon& dbCon, std::string const& dbTable)
{
    // Load manifests stored in database
    std::string const sql = "SELECT RawData FROM " + dbTable + ";";
    auto db = dbCon.checkoutDb();
    soci::blob sociRawData(*db);
    soci::statement st = (db->prepare << sql, soci::into(sociRawData));
    st.execute();
    while (st.fetch())
    {
        std::string serialized;
        convert(sociRawData, serialized);
        if (auto mo = deserializeManifest(serialized))
        {
            if (!mo->verify())
            {
                JLOG(j_.warn()) << "Unverifiable manifest in db";
                continue;
            }

            applyManifest(std::move(*mo));
        }
        else
        {
            JLOG(j_.warn()) << "Malformed manifest in database";
        }
    }
}

bool
ManifestCache::load(
    DatabaseCon& dbCon,
    std::string const& dbTable,
    std::string const& configManifest,
    std::vector<std::string> const& configRevocation)
{
    load(dbCon, dbTable);

    if (!configManifest.empty())
    {
        auto mo = deserializeManifest(base64_decode(configManifest));
        if (!mo)
        {
            JLOG(j_.error()) << "Malformed validator_token in config";
            return false;
        }

        if (mo->revoked())
        {
            JLOG(j_.warn()) << "Configured manifest revokes public key";
        }

        if (applyManifest(std::move(*mo)) == ManifestDisposition::invalid)
        {
            JLOG(j_.error()) << "Manifest in config was rejected";
            return false;
        }
    }

    if (!configRevocation.empty())
    {
        std::string revocationStr;
        revocationStr.reserve(std::accumulate(
            configRevocation.cbegin(),
            configRevocation.cend(),
            std::size_t(0),
            [](std::size_t init, std::string const& s) {
                return init + s.size();
            }));

        for (auto const& line : configRevocation)
            revocationStr += boost::algorithm::trim_copy(line);

        auto mo = deserializeManifest(base64_decode(revocationStr));

        if (!mo || !mo->revoked() ||
            applyManifest(std::move(*mo)) == ManifestDisposition::invalid)
        {
            JLOG(j_.error()) << "Invalid validator key revocation in config";
            return false;
        }
    }

    return true;
}

void
ManifestCache::save(
    DatabaseCon& dbCon,
    std::string const& dbTable,
    std::function<bool(PublicKey const&)> isTrusted)
{
    std::lock_guard lock{apply_mutex_};

    auto db = dbCon.checkoutDb();

    soci::transaction tr(*db);
    *db << "DELETE FROM " << dbTable;
    std::string const sql =
        "INSERT INTO " + dbTable + " (RawData) VALUES (:rawData);";
    for (auto const& v : map_)
    {
        // Save all revocation manifests,
        // but only save trusted non-revocation manifests.
        if (!v.second.revoked() && !isTrusted(v.second.masterKey))
        {
            JLOG(j_.info()) << "Untrusted manifest in cache not saved to db";
            continue;
        }

        // soci does not support bulk insertion of blob data
        // Do not reuse blob because manifest ecdsa signatures vary in length
        // but blob write length is expected to be >= the last write
        soci::blob rawData(*db);
        convert(v.second.serialized, rawData);
        *db << sql, soci::use(rawData);
    }
    tr.commit();
}
}  // namespace ripple