Nix/src/libstore/path-info.cc

#include <nlohmann/json.hpp>

#include "path-info.hh"
#include "store-api.hh"
#include "json-utils.hh"

namespace nix {

GENERATE_CMP_EXT(
    ,
    UnkeyedValidPathInfo,
    me->deriver,
    me->narHash,
    me->references,
    me->registrationTime,
    me->narSize,
    //me->id,
    me->ultimate,
    me->sigs,
    me->ca);

GENERATE_CMP_EXT(
    ,
    ValidPathInfo,
    me->path,
    static_cast<const UnkeyedValidPathInfo &>(*me));

std::string ValidPathInfo::fingerprint(const Store & store) const
{
    if (narSize == 0)
        throw Error("cannot calculate fingerprint of path '%s' because its size is not known",
            store.printStorePath(path));
    return
            "1;" + store.printStorePath(path) + ";"
            + narHash.to_string(HashFormat::Nix32, true) + ";"
            + std::to_string(narSize) + ";"
        + concatStringsSep(",", store.printStorePathSet(references));
}


void ValidPathInfo::sign(const Store & store, const Signer & signer)
{
    sigs.insert(signer.signDetached(fingerprint(store)));
}

std::optional<ContentAddressWithReferences> ValidPathInfo::contentAddressWithReferences() const
{
    if (! ca)
        return std::nullopt;

    return std::visit(overloaded {
        [&](const TextIngestionMethod &) -> ContentAddressWithReferences {
            assert(references.count(path) == 0);
            return TextInfo {
                .hash = ca->hash,
                .references = references,
            };
        },
        [&](const FileIngestionMethod & m2) -> ContentAddressWithReferences {
            auto refs = references;
            bool hasSelfReference = false;
            if (refs.count(path)) {
                hasSelfReference = true;
                refs.erase(path);
            }
            return FixedOutputInfo {
                .method = m2,
                .hash = ca->hash,
                .references = {
                    .others = std::move(refs),
                    .self = hasSelfReference,
                },
            };
        },
    }, ca->method.raw);
}

bool ValidPathInfo::isContentAddressed(const Store & store) const
{
    auto fullCaOpt = contentAddressWithReferences();

    if (! fullCaOpt)
        return false;

    auto caPath = store.makeFixedOutputPathFromCA(path.name(), *fullCaOpt);

    bool res = caPath == path;

    if (!res)
        printError("warning: path '%s' claims to be content-addressed but isn't", store.printStorePath(path));

    return res;
}


size_t ValidPathInfo::checkSignatures(const Store & store, const PublicKeys & publicKeys) const
{
    if (isContentAddressed(store)) return maxSigs;

    size_t good = 0;
    for (auto & sig : sigs)
        if (checkSignature(store, publicKeys, sig))
            good++;
    return good;
}


bool ValidPathInfo::checkSignature(const Store & store, const PublicKeys & publicKeys, const std::string & sig) const
{
    return verifyDetached(fingerprint(store), sig, publicKeys);
}


Strings ValidPathInfo::shortRefs() const
{
    Strings refs;
    for (auto & r : references)
        refs.push_back(std::string(r.to_string()));
    return refs;
}

ValidPathInfo::ValidPathInfo(
    const Store & store,
    std::string_view name,
    ContentAddressWithReferences && ca,
    Hash narHash)
      : UnkeyedValidPathInfo(narHash)
      , path(store.makeFixedOutputPathFromCA(name, ca))
{
    std::visit(overloaded {
        [this](TextInfo && ti) {
            this->references = std::move(ti.references);
            this->ca = ContentAddress {
                .method = TextIngestionMethod {},
                .hash = std::move(ti.hash),
            };
        },
        [this](FixedOutputInfo && foi) {
            this->references = std::move(foi.references.others);
            if (foi.references.self)
                this->references.insert(path);
            this->ca = ContentAddress {
                .method = std::move(foi.method),
                .hash = std::move(foi.hash),
            };
        },
    }, std::move(ca).raw);
}


nlohmann::json UnkeyedValidPathInfo::toJSON(
    const Store & store,
    bool includeImpureInfo,
    HashFormat hashFormat) const
{
    using nlohmann::json;

    auto jsonObject = json::object();

    jsonObject["narHash"] = narHash.to_string(hashFormat, true);
    jsonObject["narSize"] = narSize;

    {
        auto& jsonRefs = (jsonObject["references"] = json::array());
        for (auto & ref : references)
            jsonRefs.emplace_back(store.printStorePath(ref));
    }

    if (ca)
        jsonObject["ca"] = renderContentAddress(ca);

    if (includeImpureInfo) {
        if (deriver)
            jsonObject["deriver"] = store.printStorePath(*deriver);

        if (registrationTime)
            jsonObject["registrationTime"] = registrationTime;

        if (ultimate)
            jsonObject["ultimate"] = ultimate;

        if (!sigs.empty()) {
            for (auto & sig : sigs)
                jsonObject["signatures"].push_back(sig);
        }
    }

    return jsonObject;
}

UnkeyedValidPathInfo UnkeyedValidPathInfo::fromJSON(
    const Store & store,
    const nlohmann::json & json)
{
    using nlohmann::detail::value_t;

    UnkeyedValidPathInfo res {
        Hash(Hash::dummy),
    };

    ensureType(json, value_t::object);
    res.narHash = Hash::parseAny(
        static_cast<const std::string &>(
            ensureType(valueAt(json, "narHash"), value_t::string)),
        std::nullopt);
    res.narSize = ensureType(valueAt(json, "narSize"), value_t::number_integer);

    try {
        auto & references = ensureType(valueAt(json, "references"), value_t::array);
        for (auto & input : references)
            res.references.insert(store.parseStorePath(static_cast<const std::string &>
(input)));
    } catch (Error & e) {
        e.addTrace({}, "while reading key 'references'");
        throw;
    }

    if (json.contains("ca"))
        res.ca = ContentAddress::parse(
            static_cast<const std::string &>(
                ensureType(valueAt(json, "ca"), value_t::string)));

    if (json.contains("deriver"))
        res.deriver = store.parseStorePath(
            static_cast<const std::string &>(
                ensureType(valueAt(json, "deriver"), value_t::string)));

    if (json.contains("registrationTime"))
        res.registrationTime = ensureType(valueAt(json, "registrationTime"), value_t::number_integer);

    if (json.contains("ultimate"))
        res.ultimate = ensureType(valueAt(json, "ultimate"), value_t::boolean);

    if (json.contains("signatures"))
        res.sigs = valueAt(json, "signatures");

    return res;
}

}