lokinet/llarp/router_contact.cpp
Jason Rhinelander 9f10e8003e
Remove useless iterator assignments
A back_inserter doesn't change when you insert onto it.
2022-10-26 17:18:47 -03:00

603 lines
14 KiB
C++

#include "router_contact.hpp"
#include "constants/version.hpp"
#include "crypto/crypto.hpp"
#include "net/net.hpp"
#include "util/bencode.hpp"
#include "util/buffer.hpp"
#include "util/logging.hpp"
#include "util/mem.hpp"
#include "util/time.hpp"
#include <oxenc/bt_serialize.h>
#include "util/file.hpp"
namespace llarp
{
static auto logcat = log::Cat("RC");
NetID&
NetID::DefaultValue()
{
static NetID defaultID(reinterpret_cast<const byte_t*>(llarp::DEFAULT_NETID));
return defaultID;
}
bool RouterContact::BlockBogons = true;
/// 1 day rc lifespan
constexpr auto rc_lifetime = 24h;
/// an RC inserted long enough ago (4 hrs) is considered stale and is removed
constexpr auto rc_stale_age = 4h;
/// window of time in which a router wil try to update their RC before it is marked stale
constexpr auto rc_update_window = 5min;
/// update RCs shortly before they are about to expire
constexpr auto rc_update_interval = rc_stale_age - rc_update_window;
llarp_time_t RouterContact::Lifetime = rc_lifetime;
llarp_time_t RouterContact::StaleInsertionAge = rc_stale_age;
llarp_time_t RouterContact::UpdateInterval = rc_update_interval;
/// how many rc lifetime intervals should we wait until purging an rc
constexpr auto expiration_lifetime_generations = 10;
/// the max age of an rc before we want to expire it
constexpr auto rc_expire_age = rc_lifetime * expiration_lifetime_generations;
NetID::NetID(const byte_t* val)
{
const size_t len = strnlen(reinterpret_cast<const char*>(val), size());
std::copy(val, val + len, begin());
}
NetID::NetID() : NetID(DefaultValue().data())
{}
bool
NetID::operator==(const NetID& other) const
{
return ToString() == other.ToString();
}
std::string
NetID::ToString() const
{
return {begin(), std::find(begin(), end(), '\0')};
}
bool
NetID::BDecode(llarp_buffer_t* buf)
{
Zero();
llarp_buffer_t strbuf;
if (!bencode_read_string(buf, &strbuf))
return false;
if (strbuf.sz > size())
return false;
std::copy(strbuf.base, strbuf.base + strbuf.sz, begin());
return true;
}
bool
NetID::BEncode(llarp_buffer_t* buf) const
{
auto term = std::find(begin(), end(), '\0');
return bencode_write_bytestring(buf, data(), std::distance(begin(), term));
}
bool
RouterContact::BEncode(llarp_buffer_t* buf) const
{
if (version == 0)
return BEncodeSignedSection(buf);
else if (version == 1)
{
// TODO: heapless serialization for this in lokimq's bt serialization.
if (not buf->writef("li1e%zu:", signature.size()))
return false;
if (not buf->write(signature.begin(), signature.end()))
return false;
if (not buf->write(signed_bt_dict.begin(), signed_bt_dict.end()))
return false;
if (not buf->writef("e"))
return false;
return true;
}
return false;
}
std::string
RouterContact::ToTXTRecord() const
{
std::string result;
auto out = std::back_inserter(result);
for (const auto& addr : addrs)
fmt::format_to(out, "ai_addr={}; ai_pk={}; ", addr.toIpAddress(), addr.pubkey);
fmt::format_to(out, "updated={}; onion_pk={}; ", last_updated.count(), enckey.ToHex());
if (routerVersion.has_value())
fmt::format_to(out, "router_version={}; ", *routerVersion);
return result;
}
bool
RouterContact::FromOurNetwork() const
{
return netID == NetID::DefaultValue();
}
bool
RouterContact::BEncodeSignedSection(llarp_buffer_t* buf) const
{
/* write dict begin */
if (!bencode_start_dict(buf))
return false;
/* write ai if they exist */
if (!bencode_write_bytestring(buf, "a", 1))
return false;
if (!BEncodeWriteList(addrs.begin(), addrs.end(), buf))
return false;
/* write netid */
if (!bencode_write_bytestring(buf, "i", 1))
return false;
if (!netID.BEncode(buf))
return false;
/* write signing pubkey */
if (!bencode_write_bytestring(buf, "k", 1))
return false;
if (!pubkey.BEncode(buf))
return false;
std::string nick = Nick();
if (!nick.empty())
{
/* write nickname */
if (!bencode_write_bytestring(buf, "n", 1))
{
return false;
}
if (!bencode_write_bytestring(buf, nick.c_str(), nick.size()))
{
return false;
}
}
/* write encryption pubkey */
if (!bencode_write_bytestring(buf, "p", 1))
return false;
if (!enckey.BEncode(buf))
return false;
// write router version if present
if (routerVersion)
{
if (not BEncodeWriteDictEntry("r", *routerVersion, buf))
return false;
}
if (version > 0)
{
// srv records if present
if (not BEncodeWriteDictList("s", srvRecords, buf))
return false;
}
/* write last updated */
if (!bencode_write_bytestring(buf, "u", 1))
return false;
if (!bencode_write_uint64(buf, last_updated.count()))
return false;
/* write versions */
if (!bencode_write_uint64_entry(buf, "v", 1, version))
return false;
if (serializeExit)
{
/* write xi if they exist */
if (!bencode_write_bytestring(buf, "x", 1))
return false;
/* no exits anymore in RCs */
const std::vector<AlignedBuffer<8>> exits{};
if (!BEncodeWriteList(exits.begin(), exits.end(), buf))
return false;
}
if (version == 0)
{
/* write signature */
if (!bencode_write_bytestring(buf, "z", 1))
return false;
if (!signature.BEncode(buf))
return false;
}
return bencode_end(buf);
}
void
RouterContact::Clear()
{
addrs.clear();
signature.Zero();
nickname.Zero();
enckey.Zero();
pubkey.Zero();
routerVersion = std::optional<RouterVersion>{};
last_updated = 0s;
srvRecords.clear();
version = llarp::constants::proto_version;
}
util::StatusObject
RouterContact::ExtractStatus() const
{
util::StatusObject obj{
{"lastUpdated", last_updated.count()},
{"publicRouter", IsPublicRouter()},
{"identity", pubkey.ToString()},
{"addresses", addrs}};
if (HasNick())
{
obj["nickname"] = Nick();
}
if (routerVersion)
{
obj["routerVersion"] = routerVersion->ToString();
}
std::vector<util::StatusObject> srv;
for (const auto& record : srvRecords)
{
srv.emplace_back(record.ExtractStatus());
}
obj["srvRecords"] = srv;
return obj;
}
bool
RouterContact::BDecode(llarp_buffer_t* buf)
{
Clear();
if (*buf->cur == 'd') // old format
{
return DecodeVersion_0(buf);
}
else if (*buf->cur != 'l') // if not dict, should be new format and start with list
{
return false;
}
try
{
std::string_view buf_view(reinterpret_cast<char*>(buf->cur), buf->size_left());
oxenc::bt_list_consumer btlist(buf_view);
uint64_t outer_version = btlist.consume_integer<uint64_t>();
if (outer_version == 1)
{
bool decode_result = DecodeVersion_1(btlist);
// advance the llarp_buffer_t since lokimq serialization is unaware of it.
buf->cur += btlist.current_buffer().data() - buf_view.data() + 1;
return decode_result;
}
else
{
log::warning(logcat, "Received RouterContact with unkown version ({})", outer_version);
return false;
}
}
catch (const std::exception& e)
{
log::debug(logcat, "RouterContact::BDecode failed: {}", e.what());
}
return false;
}
bool
RouterContact::DecodeVersion_0(llarp_buffer_t* buf)
{
return bencode_decode_dict(*this, buf);
}
bool
RouterContact::DecodeVersion_1(oxenc::bt_list_consumer& btlist)
{
auto signature_string = btlist.consume_string_view();
signed_bt_dict = btlist.consume_dict_data();
if (not btlist.is_finished())
{
log::debug(logcat, "RouterContact serialized list too long for specified version.");
return false;
}
llarp_buffer_t sigbuf(signature_string.data(), signature_string.size());
if (not signature.FromBytestring(&sigbuf))
{
log::debug(logcat, "RouterContact serialized signature had invalid length.");
return false;
}
llarp_buffer_t data_dict_buf(signed_bt_dict.data(), signed_bt_dict.size());
return bencode_decode_dict(*this, &data_dict_buf);
}
bool
RouterContact::DecodeKey(const llarp_buffer_t& key, llarp_buffer_t* buf)
{
bool read = false;
if (!BEncodeMaybeReadDictList("a", addrs, read, key, buf))
return false;
if (!BEncodeMaybeReadDictEntry("i", netID, read, key, buf))
return false;
if (!BEncodeMaybeReadDictEntry("k", pubkey, read, key, buf))
return false;
if (key.startswith("r"))
{
RouterVersion r;
if (not r.BDecode(buf))
return false;
routerVersion = r;
return true;
}
if (key.startswith("n"))
{
llarp_buffer_t strbuf;
if (!bencode_read_string(buf, &strbuf))
{
return false;
}
if (strbuf.sz > llarp::AlignedBuffer<(32)>::size())
{
return false;
}
nickname.Zero();
std::copy(strbuf.base, strbuf.base + strbuf.sz, nickname.begin());
return true;
}
if (not BEncodeMaybeReadDictList("s", srvRecords, read, key, buf))
return false;
if (!BEncodeMaybeReadDictEntry("p", enckey, read, key, buf))
return false;
if (!BEncodeMaybeReadDictInt("u", last_updated, read, key, buf))
return false;
if (!BEncodeMaybeReadDictInt("v", version, read, key, buf))
return false;
if (key.startswith("x") and serializeExit)
{
return bencode_discard(buf);
}
if (!BEncodeMaybeReadDictEntry("z", signature, read, key, buf))
return false;
return read or bencode_discard(buf);
}
bool
RouterContact::IsPublicRouter() const
{
if (not routerVersion)
return false;
return !addrs.empty();
}
bool
RouterContact::HasNick() const
{
return nickname[0] != 0;
}
void
RouterContact::SetNick(std::string_view nick)
{
nickname.Zero();
std::copy(
nick.begin(), nick.begin() + std::min(nick.size(), nickname.size()), nickname.begin());
}
bool
RouterContact::IsExpired(llarp_time_t now) const
{
return Age(now) >= rc_expire_age;
}
llarp_time_t
RouterContact::TimeUntilExpires(llarp_time_t now) const
{
const auto expiresAt = last_updated + Lifetime;
return now < expiresAt ? expiresAt - now : 0s;
}
llarp_time_t
RouterContact::Age(llarp_time_t now) const
{
return now > last_updated ? now - last_updated : 0s;
}
bool
RouterContact::ExpiresSoon(llarp_time_t now, llarp_time_t dlt) const
{
return TimeUntilExpires(now) <= dlt;
}
std::string
RouterContact::Nick() const
{
auto term = std::find(nickname.begin(), nickname.end(), '\0');
return std::string(nickname.begin(), term);
}
bool
RouterContact::Sign(const SecretKey& secretkey)
{
pubkey = llarp::seckey_topublic(secretkey);
std::array<byte_t, MAX_RC_SIZE> tmp;
llarp_buffer_t buf(tmp);
signature.Zero();
last_updated = time_now_ms();
if (!BEncodeSignedSection(&buf))
{
return false;
}
buf.sz = buf.cur - buf.base;
buf.cur = buf.base;
signed_bt_dict = std::string(reinterpret_cast<char*>(buf.base), buf.sz);
if (version == 0 or version == 1)
{
return CryptoManager::instance()->sign(signature, secretkey, buf);
}
return false;
}
bool
RouterContact::Verify(llarp_time_t now, bool allowExpired) const
{
if (netID != NetID::DefaultValue())
{
log::error(
logcat, "netid mismatch: '{}' (theirs) != '{}' (ours)", netID, NetID::DefaultValue());
return false;
}
if (IsExpired(now) and not allowExpired)
return false;
// TODO: make net* overridable
const auto* net = net::Platform::Default_ptr();
for (const auto& a : addrs)
{
if (net->IsBogon(a.ip) && BlockBogons)
{
log::error(logcat, "invalid address info: {}", a);
return false;
}
}
if (!VerifySignature())
{
log::error(logcat, "invalid signature: {}", *this);
return false;
}
return true;
}
bool
RouterContact::VerifySignature() const
{
if (version == 0)
{
RouterContact copy;
copy = *this;
copy.signature.Zero();
std::array<byte_t, MAX_RC_SIZE> tmp;
llarp_buffer_t buf(tmp);
if (!copy.BEncode(&buf))
{
log::error(logcat, "bencode failed");
return false;
}
buf.sz = buf.cur - buf.base;
buf.cur = buf.base;
return CryptoManager::instance()->verify(pubkey, buf, signature);
}
/* else */
if (version == 1)
{
llarp_buffer_t buf{signed_bt_dict};
return CryptoManager::instance()->verify(pubkey, buf, signature);
}
return false;
}
static constexpr std::array obsolete_bootstraps = {
"7a16ac0b85290bcf69b2f3b52456d7e989ac8913b4afbb980614e249a3723218"sv};
bool
RouterContact::IsObsoleteBootstrap() const
{
for (const auto& k : obsolete_bootstraps)
{
if (pubkey.ToHex() == k)
return true;
}
return false;
}
bool
RouterContact::Write(const fs::path& fname) const
{
std::array<byte_t, MAX_RC_SIZE> tmp;
llarp_buffer_t buf(tmp);
if (!BEncode(&buf))
{
return false;
}
try
{
util::dump_file(fname, tmp.data(), buf.cur - buf.base);
}
catch (const std::exception& e)
{
log::error(logcat, "Failed to write RC to {}: {}", fname, e.what());
return false;
}
return true;
}
bool
RouterContact::Read(const fs::path& fname)
{
std::array<byte_t, MAX_RC_SIZE> tmp;
llarp_buffer_t buf(tmp);
try
{
util::slurp_file(fname, tmp.data(), tmp.size());
}
catch (const std::exception& e)
{
log::error(logcat, "Failed to read RC from {}: {}", fname, e.what());
return false;
}
return BDecode(&buf);
}
std::string
RouterContact::ToString() const
{
return fmt::format(
"[RC k={} updated={} netid={} v={} ai={{{}}} e={} z={}]",
pubkey,
last_updated.count(),
netID,
version,
fmt::format("{}", fmt::join(addrs, ",")),
enckey,
signature);
}
} // namespace llarp