#include #include "I2PEndian.h" #include "Crypto.h" #include "Log.h" #include "Timestamp.h" #include "NetDb.hpp" #include "Tunnel.h" #include "LeaseSet.h" namespace i2p { namespace data { LeaseSet::LeaseSet (bool storeLeases): m_IsValid (false), m_StoreLeases (storeLeases), m_ExpirationTime (0), m_EncryptionKey (nullptr), m_Buffer (nullptr), m_BufferLen (0) { } LeaseSet::LeaseSet (const uint8_t * buf, size_t len, bool storeLeases): m_IsValid (true), m_StoreLeases (storeLeases), m_ExpirationTime (0), m_EncryptionKey (nullptr) { m_Buffer = new uint8_t[len]; memcpy (m_Buffer, buf, len); m_BufferLen = len; ReadFromBuffer (); } void LeaseSet::Update (const uint8_t * buf, size_t len, bool verifySignature) { if (len > m_BufferLen) { auto oldBuffer = m_Buffer; m_Buffer = new uint8_t[len]; delete[] oldBuffer; } memcpy (m_Buffer, buf, len); m_BufferLen = len; ReadFromBuffer (false, verifySignature); } void LeaseSet::PopulateLeases () { m_StoreLeases = true; ReadFromBuffer (false); } void LeaseSet::ReadFromBuffer (bool readIdentity, bool verifySignature) { if (readIdentity || !m_Identity) m_Identity = std::make_shared(m_Buffer, m_BufferLen); size_t size = m_Identity->GetFullLen (); if (size > m_BufferLen) { LogPrint (eLogError, "LeaseSet: identity length ", size, " exceeds buffer size ", m_BufferLen); m_IsValid = false; return; } if (m_StoreLeases) { if (!m_EncryptionKey) m_EncryptionKey = new uint8_t[256]; memcpy (m_EncryptionKey, m_Buffer + size, 256); } size += 256; // encryption key size += m_Identity->GetSigningPublicKeyLen (); // unused signing key uint8_t num = m_Buffer[size]; size++; // num LogPrint (eLogDebug, "LeaseSet: read num=", (int)num); if (!num || num > MAX_NUM_LEASES) { LogPrint (eLogError, "LeaseSet: incorrect number of leases", (int)num); m_IsValid = false; return; } UpdateLeasesBegin (); // process leases m_ExpirationTime = 0; auto ts = i2p::util::GetMillisecondsSinceEpoch (); const uint8_t * leases = m_Buffer + size; for (int i = 0; i < num; i++) { Lease lease; lease.tunnelGateway = leases; leases += 32; // gateway lease.tunnelID = bufbe32toh (leases); leases += 4; // tunnel ID lease.endDate = bufbe64toh (leases); leases += 8; // end date UpdateLease (lease, ts); } if (!m_ExpirationTime) { LogPrint (eLogWarning, "LeaseSet: all leases are expired. Dropped"); m_IsValid = false; return; } m_ExpirationTime += LEASE_ENDDATE_THRESHOLD; UpdateLeasesEnd (); // verify if (verifySignature && !m_Identity->Verify (m_Buffer, leases - m_Buffer, leases)) { LogPrint (eLogWarning, "LeaseSet: verification failed"); m_IsValid = false; } } void LeaseSet::UpdateLeasesBegin () { // reset existing leases if (m_StoreLeases) for (auto& it: m_Leases) it->isUpdated = false; else m_Leases.clear (); } void LeaseSet::UpdateLeasesEnd () { // delete old leases if (m_StoreLeases) { for (auto it = m_Leases.begin (); it != m_Leases.end ();) { if (!(*it)->isUpdated) { (*it)->endDate = 0; // somebody might still hold it m_Leases.erase (it++); } else ++it; } } } void LeaseSet::UpdateLease (const Lease& lease, uint64_t ts) { if (ts < lease.endDate + LEASE_ENDDATE_THRESHOLD) { if (lease.endDate > m_ExpirationTime) m_ExpirationTime = lease.endDate; if (m_StoreLeases) { auto ret = m_Leases.insert (std::make_shared(lease)); if (!ret.second) (*ret.first)->endDate = lease.endDate; // update existing (*ret.first)->isUpdated = true; // check if lease's gateway is in our netDb if (!netdb.FindRouter (lease.tunnelGateway)) { // if not found request it LogPrint (eLogInfo, "LeaseSet: Lease's tunnel gateway not found, requesting"); netdb.RequestDestination (lease.tunnelGateway); } } } else LogPrint (eLogWarning, "LeaseSet: Lease is expired already "); } uint64_t LeaseSet::ExtractTimestamp (const uint8_t * buf, size_t len) const { if (!m_Identity) return 0; size_t size = m_Identity->GetFullLen (); if (size > len) return 0; size += 256; // encryption key size += m_Identity->GetSigningPublicKeyLen (); // unused signing key if (size > len) return 0; uint8_t num = buf[size]; size++; // num if (size + num*LEASE_SIZE > len) return 0; uint64_t timestamp= 0 ; for (int i = 0; i < num; i++) { size += 36; // gateway (32) + tunnelId(4) auto endDate = bufbe64toh (buf + size); size += 8; // end date if (!timestamp || endDate < timestamp) timestamp = endDate; } return timestamp; } bool LeaseSet::IsNewer (const uint8_t * buf, size_t len) const { return ExtractTimestamp (buf, len) > ExtractTimestamp (m_Buffer, m_BufferLen); } bool LeaseSet::ExpiresSoon(const uint64_t dlt, const uint64_t fudge) const { auto now = i2p::util::GetMillisecondsSinceEpoch (); if (fudge) now += rand() % fudge; if (now >= m_ExpirationTime) return true; return m_ExpirationTime - now <= dlt; } const std::vector > LeaseSet::GetNonExpiredLeases (bool withThreshold) const { return GetNonExpiredLeasesExcluding( [] (const Lease & l) -> bool { return false; }, withThreshold); } const std::vector > LeaseSet::GetNonExpiredLeasesExcluding (LeaseInspectFunc exclude, bool withThreshold) const { auto ts = i2p::util::GetMillisecondsSinceEpoch (); std::vector > leases; for (const auto& it: m_Leases) { auto endDate = it->endDate; if (withThreshold) endDate += LEASE_ENDDATE_THRESHOLD; else endDate -= LEASE_ENDDATE_THRESHOLD; if (ts < endDate && !exclude(*it)) leases.push_back (it); } return leases; } bool LeaseSet::HasExpiredLeases () const { auto ts = i2p::util::GetMillisecondsSinceEpoch (); for (const auto& it: m_Leases) if (ts >= it->endDate) return true; return false; } bool LeaseSet::IsExpired () const { if (m_StoreLeases && IsEmpty ()) return true; auto ts = i2p::util::GetMillisecondsSinceEpoch (); return ts > m_ExpirationTime; } void LeaseSet::Encrypt (const uint8_t * data, uint8_t * encrypted, BN_CTX * ctx) const { if (!m_EncryptionKey) return; auto encryptor = m_Identity->CreateEncryptor (m_EncryptionKey); if (encryptor) encryptor->Encrypt (data, encrypted, ctx, true); } void LeaseSet::SetBuffer (const uint8_t * buf, size_t len) { if (m_Buffer) delete[] m_Buffer; m_Buffer = new uint8_t[len]; m_BufferLen = len; memcpy (m_Buffer, buf, len); } LeaseSet2::LeaseSet2 (uint8_t storeType, const uint8_t * buf, size_t len, bool storeLeases): LeaseSet (storeLeases), m_StoreType (storeType) { SetBuffer (buf, len); if (storeType == NETDB_STORE_TYPE_ENCRYPTED_LEASESET2) ReadFromBufferEncrypted (buf, len); else ReadFromBuffer (buf, len); } void LeaseSet2::Update (const uint8_t * buf, size_t len, bool verifySignature) { SetBuffer (buf, len); if (GetStoreType () != NETDB_STORE_TYPE_ENCRYPTED_LEASESET2) ReadFromBuffer (buf, len, false, verifySignature); // TODO: implement encrypted } void LeaseSet2::ReadFromBuffer (const uint8_t * buf, size_t len, bool readIdentity, bool verifySignature) { // standard LS2 header std::shared_ptr identity; if (readIdentity) { identity = std::make_shared(buf, len); SetIdentity (identity); } else identity = GetIdentity (); size_t offset = identity->GetFullLen (); if (offset + 8 >= len) return; uint32_t timestamp = bufbe32toh (buf + offset); offset += 4; // published timestamp (seconds) uint16_t expires = bufbe16toh (buf + offset); offset += 2; // expires (seconds) SetExpirationTime ((timestamp + expires)*1000LL); // in milliseconds uint16_t flags = bufbe16toh (buf + offset); offset += 2; // flags if (flags & 0x0001) { // transient key m_TransientVerifier = ProcessOfflineSignature (identity, buf, len, offset); if (!m_TransientVerifier) { LogPrint (eLogError, "LeaseSet2: offline signature failed"); return; } } // type specific part size_t s = 0; switch (m_StoreType) { case NETDB_STORE_TYPE_STANDARD_LEASESET2: s = ReadStandardLS2TypeSpecificPart (buf + offset, len - offset); break; case NETDB_STORE_TYPE_META_LEASESET2: s = ReadMetaLS2TypeSpecificPart (buf + offset, len - offset); break; default: LogPrint (eLogWarning, "LeaseSet2: Unexpected store type ", (int)m_StoreType); } if (!s) return; offset += s; if (verifySignature || m_TransientVerifier) { // verify signature bool verified = m_TransientVerifier ? VerifySignature (m_TransientVerifier, buf, len, offset) : VerifySignature (identity, buf, len, offset); SetIsValid (verified); } } template bool LeaseSet2::VerifySignature (Verifier& verifier, const uint8_t * buf, size_t len, size_t signatureOffset) { if (signatureOffset + verifier->GetSignatureLen () > len) return false; // we assume buf inside DatabaseStore message, so buf[-1] is valid memory // change it for signature verification, and restore back uint8_t c = buf[-1]; const_cast(buf)[-1] = m_StoreType; bool verified = verifier->Verify (buf - 1, signatureOffset + 1, buf + signatureOffset); const_cast(buf)[-1] = c; if (!verified) LogPrint (eLogWarning, "LeaseSet2: verification failed"); return verified; } size_t LeaseSet2::ReadStandardLS2TypeSpecificPart (const uint8_t * buf, size_t len) { size_t offset = 0; // properties uint16_t propertiesLen = bufbe16toh (buf + offset); offset += 2; offset += propertiesLen; // skip for now. TODO: implement properties if (offset + 1 >= len) return 0; // key sections uint16_t currentKeyType = 0; int numKeySections = buf[offset]; offset++; for (int i = 0; i < numKeySections; i++) { uint16_t keyType = bufbe16toh (buf + offset); offset += 2; // encryption key type if (offset + 2 >= len) return 0; uint16_t encryptionKeyLen = bufbe16toh (buf + offset); offset += 2; if (offset + encryptionKeyLen >= len) return 0; if (IsStoreLeases ()) // create encryptor with leases only { // we pick first valid key, higher key type has higher priority 4-1-0 // if two keys with of the same type, pick first auto encryptor = i2p::data::IdentityEx::CreateEncryptor (keyType, buf + offset); if (encryptor && (!m_Encryptor || keyType > currentKeyType)) { m_Encryptor = encryptor; // TODO: atomic currentKeyType = keyType; } } offset += encryptionKeyLen; } // leases if (offset + 1 >= len) return 0; int numLeases = buf[offset]; offset++; auto ts = i2p::util::GetMillisecondsSinceEpoch (); if (IsStoreLeases ()) { UpdateLeasesBegin (); for (int i = 0; i < numLeases; i++) { if (offset + LEASE2_SIZE > len) return 0; Lease lease; lease.tunnelGateway = buf + offset; offset += 32; // gateway lease.tunnelID = bufbe32toh (buf + offset); offset += 4; // tunnel ID lease.endDate = bufbe32toh (buf + offset)*1000LL; offset += 4; // end date UpdateLease (lease, ts); } UpdateLeasesEnd (); } else offset += numLeases*LEASE2_SIZE; // 40 bytes per lease return offset; } size_t LeaseSet2::ReadMetaLS2TypeSpecificPart (const uint8_t * buf, size_t len) { size_t offset = 0; // properties uint16_t propertiesLen = bufbe16toh (buf + offset); offset += 2; offset += propertiesLen; // skip for now. TODO: implement properties // entries if (offset + 1 >= len) return 0; int numEntries = buf[offset]; offset++; for (int i = 0; i < numEntries; i++) { if (offset + 40 >= len) return 0; offset += 32; // hash offset += 3; // flags offset += 1; // cost offset += 4; // expires } // revocations if (offset + 1 >= len) return 0; int numRevocations = buf[offset]; offset++; for (int i = 0; i < numRevocations; i++) { if (offset + 32 > len) return 0; offset += 32; // hash } return offset; } void LeaseSet2::ReadFromBufferEncrypted (const uint8_t * buf, size_t len) { size_t offset = 0; // blinded key if (len < 2) return; uint16_t blindedKeyType = bufbe16toh (buf + offset); offset += 2; std::unique_ptr blindedVerifier (i2p::data::IdentityEx::CreateVerifier (blindedKeyType)); if (!blindedVerifier) return; auto blindedKeyLen = blindedVerifier->GetPublicKeyLen (); if (offset + blindedKeyLen >= len) return; blindedVerifier->SetPublicKey (buf + offset); offset += blindedKeyLen; // expiration if (offset + 8 >= len) return; uint32_t timestamp = bufbe32toh (buf + offset); offset += 4; // published timestamp (seconds) uint16_t expires = bufbe16toh (buf + offset); offset += 2; // expires (seconds) SetExpirationTime ((timestamp + expires)*1000LL); // in milliseconds uint16_t flags = bufbe16toh (buf + offset); offset += 2; // flags if (flags & 0x0001) { // transient key m_TransientVerifier = ProcessOfflineSignature (blindedVerifier, buf, len, offset); if (!m_TransientVerifier) { LogPrint (eLogError, "LeaseSet2: offline signature failed"); return; } } // outer ciphertext if (offset + 2 > len) return; uint16_t lenOuterCiphertext = bufbe16toh (buf + offset); offset += 2 + lenOuterCiphertext; // verify signature bool verified = m_TransientVerifier ? VerifySignature (m_TransientVerifier, buf, len, offset) : VerifySignature (blindedVerifier, buf, len, offset); SetIsValid (verified); } void LeaseSet2::Encrypt (const uint8_t * data, uint8_t * encrypted, BN_CTX * ctx) const { auto encryptor = m_Encryptor; // TODO: atomic if (encryptor) encryptor->Encrypt (data, encrypted, ctx, true); } uint64_t LeaseSet2::ExtractTimestamp (const uint8_t * buf, size_t len) const { if (len < 8) return 0; if (m_StoreType == NETDB_STORE_TYPE_ENCRYPTED_LEASESET2) { // encrypted LS2 size_t offset = 0; uint16_t blindedKeyType = bufbe16toh (buf + offset); offset += 2; std::unique_ptr blindedVerifier (i2p::data::IdentityEx::CreateVerifier (blindedKeyType)); if (!blindedVerifier) return 0 ; auto blindedKeyLen = blindedVerifier->GetPublicKeyLen (); if (offset + blindedKeyLen + 6 >= len) return 0; offset += blindedKeyLen; uint32_t timestamp = bufbe32toh (buf + offset); offset += 4; uint16_t expires = bufbe16toh (buf + offset); offset += 2; return (timestamp + expires)* 1000LL; } else { auto identity = GetIdentity (); if (!identity) return 0; size_t offset = identity->GetFullLen (); if (offset + 6 >= len) return 0; uint32_t timestamp = bufbe32toh (buf + offset); offset += 4; uint16_t expires = bufbe16toh (buf + offset); offset += 2; return (timestamp + expires)* 1000LL; } } LocalLeaseSet::LocalLeaseSet (std::shared_ptr identity, const uint8_t * encryptionPublicKey, std::vector > tunnels): m_ExpirationTime (0), m_Identity (identity) { int num = tunnels.size (); if (num > MAX_NUM_LEASES) num = MAX_NUM_LEASES; // identity auto signingKeyLen = m_Identity->GetSigningPublicKeyLen (); m_BufferLen = m_Identity->GetFullLen () + 256 + signingKeyLen + 1 + num*LEASE_SIZE + m_Identity->GetSignatureLen (); m_Buffer = new uint8_t[m_BufferLen]; auto offset = m_Identity->ToBuffer (m_Buffer, m_BufferLen); memcpy (m_Buffer + offset, encryptionPublicKey, 256); offset += 256; memset (m_Buffer + offset, 0, signingKeyLen); offset += signingKeyLen; // num leases m_Buffer[offset] = num; offset++; // leases m_Leases = m_Buffer + offset; auto currentTime = i2p::util::GetMillisecondsSinceEpoch (); for (int i = 0; i < num; i++) { memcpy (m_Buffer + offset, tunnels[i]->GetNextIdentHash (), 32); offset += 32; // gateway id htobe32buf (m_Buffer + offset, tunnels[i]->GetNextTunnelID ()); offset += 4; // tunnel id uint64_t ts = tunnels[i]->GetCreationTime () + i2p::tunnel::TUNNEL_EXPIRATION_TIMEOUT - i2p::tunnel::TUNNEL_EXPIRATION_THRESHOLD; // 1 minute before expiration ts *= 1000; // in milliseconds if (ts > m_ExpirationTime) m_ExpirationTime = ts; // make sure leaseset is newer than previous, but adding some time to expiration date ts += (currentTime - tunnels[i]->GetCreationTime ()*1000LL)*2/i2p::tunnel::TUNNEL_EXPIRATION_TIMEOUT; // up to 2 secs htobe64buf (m_Buffer + offset, ts); offset += 8; // end date } // we don't sign it yet. must be signed later on } LocalLeaseSet::LocalLeaseSet (std::shared_ptr identity, const uint8_t * buf, size_t len): m_ExpirationTime (0), m_Identity (identity) { if (buf) { m_BufferLen = len; m_Buffer = new uint8_t[m_BufferLen]; memcpy (m_Buffer, buf, len); } else { m_Buffer = nullptr; m_BufferLen = 0; } } bool LocalLeaseSet::IsExpired () const { auto ts = i2p::util::GetMillisecondsSinceEpoch (); return ts > m_ExpirationTime; } bool LeaseSetBufferValidate(const uint8_t * ptr, size_t sz, uint64_t & expires) { IdentityEx ident(ptr, sz); size_t size = ident.GetFullLen (); if (size > sz) { LogPrint (eLogError, "LeaseSet: identity length ", size, " exceeds buffer size ", sz); return false; } // encryption key size += 256; // signing key (unused) size += ident.GetSigningPublicKeyLen (); uint8_t numLeases = ptr[size]; ++size; if (!numLeases || numLeases > MAX_NUM_LEASES) { LogPrint (eLogError, "LeaseSet: incorrect number of leases", (int)numLeases); return false; } const uint8_t * leases = ptr + size; expires = 0; /** find lease with the max expiration timestamp */ for (int i = 0; i < numLeases; i++) { leases += 36; // gateway + tunnel ID uint64_t endDate = bufbe64toh (leases); leases += 8; // end date if(endDate > expires) expires = endDate; } return ident.Verify(ptr, leases - ptr, leases); } LocalLeaseSet2::LocalLeaseSet2 (uint8_t storeType, std::shared_ptr identity, uint16_t keyType, uint16_t keyLen, const uint8_t * encryptionPublicKey, std::vector > tunnels): LocalLeaseSet (identity, nullptr, 0) { // assume standard LS2 int num = tunnels.size (); if (num > MAX_NUM_LEASES) num = MAX_NUM_LEASES; m_BufferLen = identity->GetFullLen () + 4/*published*/ + 2/*expires*/ + 2/*flag*/ + 2/*properties len*/ + 1/*num keys*/ + 2/*key type*/ + 2/*key len*/ + keyLen/*key*/ + 1/*num leases*/ + num*LEASE2_SIZE + identity->GetSignatureLen (); m_Buffer = new uint8_t[m_BufferLen + 1]; m_Buffer[0] = storeType; // LS2 header auto offset = identity->ToBuffer (m_Buffer + 1, m_BufferLen) + 1; auto timestamp = i2p::util::GetSecondsSinceEpoch (); htobe32buf (m_Buffer + offset, timestamp); offset += 4; // published timestamp (seconds) uint8_t * expiresBuf = m_Buffer + offset; offset += 2; // expires, fill later htobe16buf (m_Buffer + offset, 0); offset += 2; // flags htobe16buf (m_Buffer + offset, 0); offset += 2; // properties len // keys m_Buffer[offset] = 1; offset++; // 1 key htobe16buf (m_Buffer + offset, keyType); offset += 2; // key type htobe16buf (m_Buffer + offset, keyLen); offset += 2; // key len memcpy (m_Buffer + offset, encryptionPublicKey, keyLen); offset += keyLen; // key // leases uint32_t expirationTime = 0; // in seconds m_Buffer[offset] = num; offset++; // num leases for (int i = 0; i < num; i++) { memcpy (m_Buffer + offset, tunnels[i]->GetNextIdentHash (), 32); offset += 32; // gateway id htobe32buf (m_Buffer + offset, tunnels[i]->GetNextTunnelID ()); offset += 4; // tunnel id auto ts = tunnels[i]->GetCreationTime () + i2p::tunnel::TUNNEL_EXPIRATION_TIMEOUT - i2p::tunnel::TUNNEL_EXPIRATION_THRESHOLD; // in seconds, 1 minute before expiration if (ts > expirationTime) expirationTime = ts; htobe32buf (m_Buffer + offset, ts); offset += 4; // end date } // update expiration SetExpirationTime (expirationTime*1000LL); auto expires = expirationTime - timestamp; htobe16buf (expiresBuf, expires > 0 ? expires : 0); // we don't sign it yet. must be signed later on } LocalLeaseSet2::LocalLeaseSet2 (uint8_t storeType, std::shared_ptr identity, const uint8_t * buf, size_t len): LocalLeaseSet (identity, nullptr, 0) { m_BufferLen = len; m_Buffer = new uint8_t[m_BufferLen + 1]; memcpy (m_Buffer + 1, buf, len); m_Buffer[0] = storeType; } } }