mirror of https://github.com/PurpleI2P/i2pd.git
I2P: End-to-End encrypted and anonymous Internet
https://i2pd.website/
1039 lines
37 KiB
1039 lines
37 KiB
/* |
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* Copyright (c) 2013-2023, The PurpleI2P Project |
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* |
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* This file is part of Purple i2pd project and licensed under BSD3 |
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* |
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* See full license text in LICENSE file at top of project tree |
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*/ |
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#include <string.h> |
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#include "I2PEndian.h" |
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#include "Crypto.h" |
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#include "Log.h" |
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#include "Tag.h" |
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#include "Timestamp.h" |
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#include "NetDb.hpp" |
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#include "Tunnel.h" |
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#include "LeaseSet.h" |
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namespace i2p |
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{ |
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namespace data |
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{ |
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LeaseSet::LeaseSet (bool storeLeases): |
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m_IsValid (false), m_StoreLeases (storeLeases), m_ExpirationTime (0), m_EncryptionKey (nullptr), |
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m_Buffer (nullptr), m_BufferLen (0) |
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{ |
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} |
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LeaseSet::LeaseSet (const uint8_t * buf, size_t len, bool storeLeases): |
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m_IsValid (true), m_StoreLeases (storeLeases), m_ExpirationTime (0), m_EncryptionKey (nullptr) |
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{ |
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m_Buffer = new uint8_t[len]; |
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memcpy (m_Buffer, buf, len); |
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m_BufferLen = len; |
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ReadFromBuffer (); |
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} |
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void LeaseSet::Update (const uint8_t * buf, size_t len, bool verifySignature) |
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{ |
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SetBuffer (buf, len); |
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ReadFromBuffer (false, verifySignature); |
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} |
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void LeaseSet::PopulateLeases () |
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{ |
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m_StoreLeases = true; |
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ReadFromBuffer (false); |
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} |
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void LeaseSet::ReadFromBuffer (bool readIdentity, bool verifySignature) |
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{ |
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if (readIdentity || !m_Identity) |
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m_Identity = netdb.NewIdentity (m_Buffer, m_BufferLen); |
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size_t size = m_Identity->GetFullLen (); |
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if (size + 256 > m_BufferLen) |
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{ |
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LogPrint (eLogError, "LeaseSet: Identity length ", int(size), " exceeds buffer size ", int(m_BufferLen)); |
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m_IsValid = false; |
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return; |
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} |
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if (m_StoreLeases) |
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{ |
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if (!m_EncryptionKey) m_EncryptionKey = new uint8_t[256]; |
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memcpy (m_EncryptionKey, m_Buffer + size, 256); |
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} |
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size += 256; // encryption key |
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size += m_Identity->GetSigningPublicKeyLen (); // unused signing key |
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if (size + 1 > m_BufferLen) |
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{ |
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LogPrint (eLogError, "LeaseSet: ", int(size), " exceeds buffer size ", int(m_BufferLen)); |
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m_IsValid = false; |
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return; |
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} |
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uint8_t num = m_Buffer[size]; |
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size++; // num |
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LogPrint (eLogDebug, "LeaseSet: Read num=", (int)num); |
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if (!num || num > MAX_NUM_LEASES) |
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{ |
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LogPrint (eLogError, "LeaseSet: Incorrect number of leases", (int)num); |
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m_IsValid = false; |
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return; |
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} |
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if (size + num*LEASE_SIZE > m_BufferLen) |
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{ |
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LogPrint (eLogError, "LeaseSet: ", int(size), " exceeds buffer size ", int(m_BufferLen)); |
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m_IsValid = false; |
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return; |
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} |
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UpdateLeasesBegin (); |
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// process leases |
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m_ExpirationTime = 0; |
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auto ts = i2p::util::GetMillisecondsSinceEpoch (); |
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const uint8_t * leases = m_Buffer + size; |
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for (int i = 0; i < num; i++) |
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{ |
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Lease lease; |
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lease.tunnelGateway = leases; |
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leases += 32; // gateway |
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lease.tunnelID = bufbe32toh (leases); |
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leases += 4; // tunnel ID |
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lease.endDate = bufbe64toh (leases); |
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leases += 8; // end date |
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UpdateLease (lease, ts); |
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} |
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if (!m_ExpirationTime) |
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{ |
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LogPrint (eLogWarning, "LeaseSet: All leases are expired. Dropped"); |
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m_IsValid = false; |
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return; |
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} |
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m_ExpirationTime += LEASE_ENDDATE_THRESHOLD; |
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UpdateLeasesEnd (); |
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// verify |
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if (verifySignature) |
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{ |
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auto signedSize = leases - m_Buffer; |
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if (signedSize + m_Identity->GetSignatureLen () > m_BufferLen) |
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{ |
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LogPrint (eLogError, "LeaseSet: Signature exceeds buffer size ", int(m_BufferLen)); |
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m_IsValid = false; |
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} |
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else if (!m_Identity->Verify (m_Buffer, signedSize, leases)) |
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{ |
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LogPrint (eLogWarning, "LeaseSet: Verification failed"); |
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m_IsValid = false; |
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} |
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} |
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} |
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void LeaseSet::UpdateLeasesBegin () |
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{ |
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// reset existing leases |
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if (m_StoreLeases) |
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for (auto& it: m_Leases) |
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it->isUpdated = false; |
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else |
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m_Leases.clear (); |
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} |
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void LeaseSet::UpdateLeasesEnd () |
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{ |
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// delete old leases |
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if (m_StoreLeases) |
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{ |
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for (auto it = m_Leases.begin (); it != m_Leases.end ();) |
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{ |
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if (!(*it)->isUpdated) |
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{ |
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(*it)->endDate = 0; // somebody might still hold it |
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m_Leases.erase (it++); |
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} |
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else |
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++it; |
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} |
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} |
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} |
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void LeaseSet::UpdateLease (const Lease& lease, uint64_t ts) |
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{ |
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if (ts < lease.endDate + LEASE_ENDDATE_THRESHOLD) |
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{ |
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if (lease.endDate > m_ExpirationTime) |
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m_ExpirationTime = lease.endDate; |
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if (m_StoreLeases) |
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{ |
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auto ret = m_Leases.insert (i2p::data::netdb.NewLease (lease)); |
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if (!ret.second) (*ret.first)->endDate = lease.endDate; // update existing |
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(*ret.first)->isUpdated = true; |
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} |
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} |
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else |
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LogPrint (eLogWarning, "LeaseSet: Lease is expired already"); |
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} |
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uint64_t LeaseSet::ExtractExpirationTimestamp (const uint8_t * buf, size_t len) const |
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{ |
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if (!m_Identity) return 0; |
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size_t size = m_Identity->GetFullLen (); |
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if (size > len) return 0; |
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size += 256; // encryption key |
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size += m_Identity->GetSigningPublicKeyLen (); // unused signing key |
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if (size > len) return 0; |
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uint8_t num = buf[size]; |
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size++; // num |
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if (size + num*LEASE_SIZE > len) return 0; |
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uint64_t timestamp= 0 ; |
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for (int i = 0; i < num; i++) |
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{ |
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size += 36; // gateway (32) + tunnelId(4) |
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auto endDate = bufbe64toh (buf + size); |
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size += 8; // end date |
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if (!timestamp || endDate < timestamp) |
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timestamp = endDate; |
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} |
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return timestamp; |
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} |
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bool LeaseSet::IsNewer (const uint8_t * buf, size_t len) const |
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{ |
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return ExtractExpirationTimestamp (buf, len) > ExtractExpirationTimestamp (m_Buffer, m_BufferLen); |
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} |
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bool LeaseSet::ExpiresSoon(const uint64_t dlt, const uint64_t fudge) const |
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{ |
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auto now = i2p::util::GetMillisecondsSinceEpoch (); |
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if (fudge) now += rand() % fudge; |
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if (now >= m_ExpirationTime) return true; |
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return m_ExpirationTime - now <= dlt; |
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} |
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const std::vector<std::shared_ptr<const Lease> > LeaseSet::GetNonExpiredLeases (bool withThreshold) const |
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{ |
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return GetNonExpiredLeasesExcluding( [] (const Lease & l) -> bool { return false; }, withThreshold); |
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} |
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const std::vector<std::shared_ptr<const Lease> > LeaseSet::GetNonExpiredLeasesExcluding (LeaseInspectFunc exclude, bool withThreshold) const |
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{ |
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auto ts = i2p::util::GetMillisecondsSinceEpoch (); |
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std::vector<std::shared_ptr<const Lease> > leases; |
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for (const auto& it: m_Leases) |
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{ |
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auto endDate = it->endDate; |
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if (withThreshold) |
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endDate += LEASE_ENDDATE_THRESHOLD; |
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else |
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endDate -= LEASE_ENDDATE_THRESHOLD; |
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if (ts < endDate && !exclude(*it)) |
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leases.push_back (it); |
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} |
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return leases; |
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} |
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bool LeaseSet::HasExpiredLeases () const |
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{ |
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auto ts = i2p::util::GetMillisecondsSinceEpoch (); |
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for (const auto& it: m_Leases) |
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if (ts >= it->endDate) return true; |
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return false; |
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} |
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bool LeaseSet::IsExpired () const |
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{ |
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if (m_StoreLeases && IsEmpty ()) return true; |
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auto ts = i2p::util::GetMillisecondsSinceEpoch (); |
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return ts > m_ExpirationTime; |
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} |
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void LeaseSet::Encrypt (const uint8_t * data, uint8_t * encrypted) const |
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{ |
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if (!m_EncryptionKey) return; |
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auto encryptor = m_Identity->CreateEncryptor (m_EncryptionKey); |
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if (encryptor) |
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encryptor->Encrypt (data, encrypted); |
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} |
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void LeaseSet::SetBuffer (const uint8_t * buf, size_t len) |
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{ |
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if (len > MAX_LS_BUFFER_SIZE) |
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{ |
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LogPrint (eLogError, "LeaseSet: Buffer is too long ", len); |
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len = MAX_LS_BUFFER_SIZE; |
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} |
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if (m_Buffer && len > m_BufferLen) |
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{ |
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delete[] m_Buffer; |
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m_Buffer = nullptr; |
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} |
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if (!m_Buffer) |
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m_Buffer = new uint8_t[len]; |
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m_BufferLen = len; |
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memcpy (m_Buffer, buf, len); |
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} |
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void LeaseSet::SetBufferLen (size_t len) |
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{ |
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if (len <= m_BufferLen) m_BufferLen = len; |
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else |
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LogPrint (eLogError, "LeaseSet2: Actual buffer size ", int(len) , " exceeds full buffer size ", int(m_BufferLen)); |
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} |
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LeaseSet2::LeaseSet2 (uint8_t storeType, const uint8_t * buf, size_t len, bool storeLeases, CryptoKeyType preferredCrypto): |
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LeaseSet (storeLeases), m_StoreType (storeType), m_EncryptionType (preferredCrypto) |
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{ |
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SetBuffer (buf, len); |
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if (storeType == NETDB_STORE_TYPE_ENCRYPTED_LEASESET2) |
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ReadFromBufferEncrypted (buf, len, nullptr, nullptr); |
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else |
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ReadFromBuffer (buf, len); |
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} |
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LeaseSet2::LeaseSet2 (const uint8_t * buf, size_t len, std::shared_ptr<const BlindedPublicKey> key, |
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const uint8_t * secret, CryptoKeyType preferredCrypto): |
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LeaseSet (true), m_StoreType (NETDB_STORE_TYPE_ENCRYPTED_LEASESET2), m_EncryptionType (preferredCrypto) |
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{ |
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ReadFromBufferEncrypted (buf, len, key, secret); |
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} |
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void LeaseSet2::Update (const uint8_t * buf, size_t len, bool verifySignature) |
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{ |
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SetBuffer (buf, len); |
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if (GetStoreType () != NETDB_STORE_TYPE_ENCRYPTED_LEASESET2) |
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ReadFromBuffer (buf, len, false, verifySignature); |
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// TODO: implement encrypted |
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} |
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bool LeaseSet2::IsNewer (const uint8_t * buf, size_t len) const |
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{ |
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uint64_t expiration; |
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return ExtractPublishedTimestamp (buf, len, expiration) > m_PublishedTimestamp; |
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} |
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void LeaseSet2::ReadFromBuffer (const uint8_t * buf, size_t len, bool readIdentity, bool verifySignature) |
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{ |
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// standard LS2 header |
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std::shared_ptr<const IdentityEx> identity; |
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if (readIdentity || !GetIdentity ()) |
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{ |
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identity = netdb.NewIdentity (buf, len); |
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SetIdentity (identity); |
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} |
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else |
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identity = GetIdentity (); |
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size_t offset = identity->GetFullLen (); |
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if (offset + 8 > len) return; |
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m_PublishedTimestamp = bufbe32toh (buf + offset); offset += 4; // published timestamp (seconds) |
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uint16_t expires = bufbe16toh (buf + offset); offset += 2; // expires (seconds) |
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SetExpirationTime ((m_PublishedTimestamp + expires)*1000LL); // in milliseconds |
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uint16_t flags = bufbe16toh (buf + offset); offset += 2; // flags |
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if (flags & LEASESET2_FLAG_OFFLINE_KEYS) |
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{ |
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// transient key |
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m_TransientVerifier = ProcessOfflineSignature (identity, buf, len, offset); |
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if (!m_TransientVerifier) |
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{ |
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LogPrint (eLogError, "LeaseSet2: Offline signature failed"); |
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return; |
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} |
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} |
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if (flags & LEASESET2_FLAG_UNPUBLISHED_LEASESET) m_IsPublic = false; |
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if (flags & LEASESET2_FLAG_PUBLISHED_ENCRYPTED) |
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{ |
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m_IsPublishedEncrypted = true; |
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m_IsPublic = true; |
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} |
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// type specific part |
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size_t s = 0; |
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switch (m_StoreType) |
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{ |
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case NETDB_STORE_TYPE_STANDARD_LEASESET2: |
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s = ReadStandardLS2TypeSpecificPart (buf + offset, len - offset); |
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break; |
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case NETDB_STORE_TYPE_META_LEASESET2: |
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s = ReadMetaLS2TypeSpecificPart (buf + offset, len - offset); |
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break; |
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default: |
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LogPrint (eLogWarning, "LeaseSet2: Unexpected store type ", (int)m_StoreType); |
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} |
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if (!s) return; |
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offset += s; |
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if (verifySignature || m_TransientVerifier) |
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{ |
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// verify signature |
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bool verified = m_TransientVerifier ? VerifySignature (m_TransientVerifier, buf, len, offset) : |
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VerifySignature (identity, buf, len, offset); |
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SetIsValid (verified); |
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} |
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else |
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SetIsValid (true); |
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offset += m_TransientVerifier ? m_TransientVerifier->GetSignatureLen () : identity->GetSignatureLen (); |
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if (offset > len) { |
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LogPrint (eLogWarning, "LeaseSet2: short buffer: wanted ", int(offset), "bytes, have ", int(len)); |
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return; |
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} |
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SetBufferLen (offset); |
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} |
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template<typename Verifier> |
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bool LeaseSet2::VerifySignature (Verifier& verifier, const uint8_t * buf, size_t len, size_t signatureOffset) |
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{ |
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if (signatureOffset + verifier->GetSignatureLen () > len) return false; |
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// we assume buf inside DatabaseStore message, so buf[-1] is valid memory |
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// change it for signature verification, and restore back |
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uint8_t c = buf[-1]; |
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const_cast<uint8_t *>(buf)[-1] = m_StoreType; |
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bool verified = verifier->Verify (buf - 1, signatureOffset + 1, buf + signatureOffset); |
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const_cast<uint8_t *>(buf)[-1] = c; |
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if (!verified) |
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LogPrint (eLogWarning, "LeaseSet2: Verification failed"); |
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return verified; |
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} |
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size_t LeaseSet2::ReadStandardLS2TypeSpecificPart (const uint8_t * buf, size_t len) |
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{ |
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size_t offset = 0; |
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// properties |
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uint16_t propertiesLen = bufbe16toh (buf + offset); offset += 2; |
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offset += propertiesLen; // skip for now. TODO: implement properties |
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// key sections |
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CryptoKeyType preferredKeyType = m_EncryptionType; |
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bool preferredKeyFound = false; |
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if (offset + 1 > len) return 0; |
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int numKeySections = buf[offset]; offset++; |
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for (int i = 0; i < numKeySections; i++) |
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{ |
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if (offset + 4 > len) return 0; |
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uint16_t keyType = bufbe16toh (buf + offset); offset += 2; // encryption key type |
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uint16_t encryptionKeyLen = bufbe16toh (buf + offset); offset += 2; |
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if (offset + encryptionKeyLen > len) return 0; |
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if (IsStoreLeases () && !preferredKeyFound) // create encryptor with leases only |
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{ |
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// we pick first valid key if preferred not found |
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auto encryptor = i2p::data::IdentityEx::CreateEncryptor (keyType, buf + offset); |
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if (encryptor && (!m_Encryptor || keyType == preferredKeyType)) |
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{ |
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m_Encryptor = encryptor; // TODO: atomic |
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m_EncryptionType = keyType; |
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if (keyType == preferredKeyType) preferredKeyFound = true; |
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} |
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} |
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offset += encryptionKeyLen; |
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} |
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// leases |
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if (offset + 1 > len) return 0; |
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int numLeases = buf[offset]; offset++; |
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auto ts = i2p::util::GetMillisecondsSinceEpoch (); |
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if (IsStoreLeases ()) |
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{ |
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UpdateLeasesBegin (); |
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for (int i = 0; i < numLeases; i++) |
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{ |
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if (offset + LEASE2_SIZE > len) return 0; |
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Lease lease; |
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lease.tunnelGateway = buf + offset; offset += 32; // gateway |
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lease.tunnelID = bufbe32toh (buf + offset); offset += 4; // tunnel ID |
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lease.endDate = bufbe32toh (buf + offset)*1000LL; offset += 4; // end date |
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UpdateLease (lease, ts); |
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} |
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UpdateLeasesEnd (); |
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} |
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else |
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offset += numLeases*LEASE2_SIZE; // 40 bytes per lease |
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return (offset > len ? 0 : offset); |
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} |
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size_t LeaseSet2::ReadMetaLS2TypeSpecificPart (const uint8_t * buf, size_t len) |
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{ |
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size_t offset = 0; |
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// properties |
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uint16_t propertiesLen = bufbe16toh (buf + offset); offset += 2; |
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offset += propertiesLen; // skip for now. TODO: implement properties |
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// entries |
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if (offset + 1 > len) return 0; |
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int numEntries = buf[offset]; offset++; |
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for (int i = 0; i < numEntries; i++) |
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{ |
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if (offset + LEASE2_SIZE > len) return 0; |
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offset += 32; // hash |
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offset += 3; // flags |
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offset += 1; // cost |
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offset += 4; // expires |
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} |
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// revocations |
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if (offset + 1 > len) return 0; |
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int numRevocations = buf[offset]; offset++; |
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for (int i = 0; i < numRevocations; i++) |
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{ |
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if (offset + 32 > len) return 0; |
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offset += 32; // hash |
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} |
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return offset; |
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} |
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void LeaseSet2::ReadFromBufferEncrypted (const uint8_t * buf, size_t len, std::shared_ptr<const BlindedPublicKey> key, const uint8_t * secret) |
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{ |
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size_t offset = 0; |
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// blinded key |
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if (len < 2) return; |
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const uint8_t * stA1 = buf + offset; // stA1 = blinded signature type, 2 bytes big endian |
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uint16_t blindedKeyType = bufbe16toh (stA1); offset += 2; |
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std::unique_ptr<i2p::crypto::Verifier> blindedVerifier (i2p::data::IdentityEx::CreateVerifier (blindedKeyType)); |
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if (!blindedVerifier) return; |
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auto blindedKeyLen = blindedVerifier->GetPublicKeyLen (); |
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if (offset + blindedKeyLen >= len) return; |
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const uint8_t * blindedPublicKey = buf + offset; |
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blindedVerifier->SetPublicKey (blindedPublicKey); offset += blindedKeyLen; |
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// expiration |
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if (offset + 8 >= len) return; |
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const uint8_t * publishedTimestamp = buf + offset; |
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m_PublishedTimestamp = bufbe32toh (publishedTimestamp); offset += 4; // published timestamp (seconds) |
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uint16_t expires = bufbe16toh (buf + offset); offset += 2; // expires (seconds) |
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SetExpirationTime ((m_PublishedTimestamp + expires)*1000LL); // in milliseconds |
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uint16_t flags = bufbe16toh (buf + offset); offset += 2; // flags |
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if (flags & LEASESET2_FLAG_OFFLINE_KEYS) |
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{ |
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// transient key |
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m_TransientVerifier = ProcessOfflineSignature (blindedVerifier, buf, len, offset); |
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if (!m_TransientVerifier) |
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{ |
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LogPrint (eLogError, "LeaseSet2: Offline signature failed"); |
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return; |
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} |
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} |
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// outer ciphertext |
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if (offset + 2 > len) return; |
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uint16_t lenOuterCiphertext = bufbe16toh (buf + offset); offset += 2; |
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const uint8_t * outerCiphertext = buf + offset; |
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offset += lenOuterCiphertext; |
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// verify signature |
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bool verified = m_TransientVerifier ? VerifySignature (m_TransientVerifier, buf, len, offset) : |
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VerifySignature (blindedVerifier, buf, len, offset); |
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SetIsValid (verified); |
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// handle ciphertext |
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if (verified && key && lenOuterCiphertext >= 32) |
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{ |
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SetIsValid (false); // we must verify it again in Layer 2 |
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if (blindedKeyType == key->GetBlindedSigType ()) |
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{ |
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// verify blinding |
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char date[9]; |
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i2p::util::GetDateString (m_PublishedTimestamp, date); |
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std::vector<uint8_t> blinded (blindedKeyLen); |
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key->GetBlindedKey (date, blinded.data ()); |
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if (memcmp (blindedPublicKey, blinded.data (), blindedKeyLen)) |
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{ |
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LogPrint (eLogError, "LeaseSet2: Blinded public key doesn't match"); |
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return; |
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} |
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} |
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else |
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{ |
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LogPrint (eLogError, "LeaseSet2: Unexpected blinded key type ", blindedKeyType, " instead ", key->GetBlindedSigType ()); |
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return; |
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} |
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// outer key |
|
// outerInput = subcredential || publishedTimestamp |
|
uint8_t subcredential[36]; |
|
key->GetSubcredential (blindedPublicKey, blindedKeyLen, subcredential); |
|
memcpy (subcredential + 32, publishedTimestamp, 4); |
|
// outerSalt = outerCiphertext[0:32] |
|
// keys = HKDF(outerSalt, outerInput, "ELS2_L1K", 44) |
|
uint8_t keys[64]; // 44 bytes actual data |
|
i2p::crypto::HKDF (outerCiphertext, subcredential, 36, "ELS2_L1K", keys); |
|
// decrypt Layer 1 |
|
// outerKey = keys[0:31] |
|
// outerIV = keys[32:43] |
|
size_t lenOuterPlaintext = lenOuterCiphertext - 32; |
|
std::vector<uint8_t> outerPlainText (lenOuterPlaintext); |
|
i2p::crypto::ChaCha20 (outerCiphertext + 32, lenOuterPlaintext, keys, keys + 32, outerPlainText.data ()); |
|
// inner key |
|
// innerInput = authCookie || subcredential || publishedTimestamp |
|
// innerSalt = innerCiphertext[0:32] |
|
// keys = HKDF(innerSalt, innerInput, "ELS2_L2K", 44) |
|
uint8_t innerInput[68]; |
|
size_t authDataLen = ExtractClientAuthData (outerPlainText.data (), lenOuterPlaintext, secret, subcredential, innerInput); |
|
if (authDataLen > 0) |
|
{ |
|
memcpy (innerInput + 32, subcredential, 36); |
|
i2p::crypto::HKDF (outerPlainText.data () + 1 + authDataLen, innerInput, 68, "ELS2_L2K", keys); |
|
} |
|
else |
|
// no authData presented, innerInput = subcredential || publishedTimestamp |
|
// skip 1 byte flags |
|
i2p::crypto::HKDF (outerPlainText.data () + 1, subcredential, 36, "ELS2_L2K", keys); // no authCookie |
|
// decrypt Layer 2 |
|
// innerKey = keys[0:31] |
|
// innerIV = keys[32:43] |
|
size_t lenInnerPlaintext = lenOuterPlaintext - 32 - 1 - authDataLen; |
|
std::vector<uint8_t> innerPlainText (lenInnerPlaintext); |
|
i2p::crypto::ChaCha20 (outerPlainText.data () + 32 + 1 + authDataLen, lenInnerPlaintext, keys, keys + 32, innerPlainText.data ()); |
|
if (innerPlainText[0] == NETDB_STORE_TYPE_STANDARD_LEASESET2 || innerPlainText[0] == NETDB_STORE_TYPE_META_LEASESET2) |
|
{ |
|
// override store type and buffer |
|
m_StoreType = innerPlainText[0]; |
|
SetBuffer (innerPlainText.data () + 1, lenInnerPlaintext - 1); |
|
// parse and verify Layer 2 |
|
ReadFromBuffer (innerPlainText.data () + 1, lenInnerPlaintext - 1); |
|
} |
|
else |
|
LogPrint (eLogError, "LeaseSet2: Unexpected LeaseSet type ", (int)innerPlainText[0], " inside encrypted LeaseSet"); |
|
} |
|
else |
|
{ |
|
// we set actual length of encrypted buffer |
|
offset += m_TransientVerifier ? m_TransientVerifier->GetSignatureLen () : blindedVerifier->GetSignatureLen (); |
|
SetBufferLen (offset); |
|
} |
|
} |
|
|
|
// helper for ExtractClientAuthData |
|
static inline bool GetAuthCookie (const uint8_t * authClients, int numClients, const uint8_t * okm, uint8_t * authCookie) |
|
{ |
|
// try to find clientCookie_i for clientID_i = okm[44:51] |
|
for (int i = 0; i < numClients; i++) |
|
{ |
|
if (!memcmp (okm + 44, authClients + i*40, 8)) // clientID_i |
|
{ |
|
// clientKey_i = okm[0:31] |
|
// clientIV_i = okm[32:43] |
|
i2p::crypto::ChaCha20 (authClients + i*40 + 8, 32, okm, okm + 32, authCookie); // clientCookie_i |
|
return true; |
|
} |
|
} |
|
return false; |
|
} |
|
|
|
size_t LeaseSet2::ExtractClientAuthData (const uint8_t * buf, size_t len, const uint8_t * secret, const uint8_t * subcredential, uint8_t * authCookie) const |
|
{ |
|
size_t offset = 0; |
|
uint8_t flag = buf[offset]; offset++; // flag |
|
if (flag & 0x01) // client auth |
|
{ |
|
if (!(flag & 0x0E)) // DH, bit 1-3 all zeroes |
|
{ |
|
const uint8_t * ephemeralPublicKey = buf + offset; offset += 32; // ephemeralPublicKey |
|
uint16_t numClients = bufbe16toh (buf + offset); offset += 2; // clients |
|
const uint8_t * authClients = buf + offset; offset += numClients*40; // authClients |
|
if (offset > len) |
|
{ |
|
LogPrint (eLogError, "LeaseSet2: Too many clients ", numClients, " in DH auth data"); |
|
return 0; |
|
} |
|
// calculate authCookie |
|
if (secret) |
|
{ |
|
i2p::crypto::X25519Keys ck (secret, nullptr); // derive cpk_i from csk_i |
|
uint8_t authInput[100]; |
|
ck.Agree (ephemeralPublicKey, authInput); // sharedSecret is first 32 bytes of authInput |
|
memcpy (authInput + 32, ck.GetPublicKey (), 32); // cpk_i |
|
memcpy (authInput + 64, subcredential, 36); |
|
uint8_t okm[64]; // 52 actual data |
|
i2p::crypto::HKDF (ephemeralPublicKey, authInput, 100, "ELS2_XCA", okm); |
|
if (!GetAuthCookie (authClients, numClients, okm, authCookie)) |
|
LogPrint (eLogError, "LeaseSet2: Client cookie DH not found"); |
|
} |
|
else |
|
LogPrint (eLogError, "LeaseSet2: Can't calculate authCookie: csk_i is not provided"); |
|
} |
|
else if (flag & 0x02) // PSK, bit 1 is set to 1 |
|
{ |
|
const uint8_t * authSalt = buf + offset; offset += 32; // authSalt |
|
uint16_t numClients = bufbe16toh (buf + offset); offset += 2; // clients |
|
const uint8_t * authClients = buf + offset; offset += numClients*40; // authClients |
|
if (offset > len) |
|
{ |
|
LogPrint (eLogError, "LeaseSet2: Too many clients ", numClients, " in PSK auth data"); |
|
return 0; |
|
} |
|
// calculate authCookie |
|
if (secret) |
|
{ |
|
uint8_t authInput[68]; |
|
memcpy (authInput, secret, 32); |
|
memcpy (authInput + 32, subcredential, 36); |
|
uint8_t okm[64]; // 52 actual data |
|
i2p::crypto::HKDF (authSalt, authInput, 68, "ELS2PSKA", okm); |
|
if (!GetAuthCookie (authClients, numClients, okm, authCookie)) |
|
LogPrint (eLogError, "LeaseSet2: Client cookie PSK not found"); |
|
} |
|
else |
|
LogPrint (eLogError, "LeaseSet2: Can't calculate authCookie: psk_i is not provided"); |
|
} |
|
else |
|
LogPrint (eLogError, "LeaseSet2: Unknown client auth type ", (int)flag); |
|
} |
|
return offset - 1; |
|
} |
|
|
|
void LeaseSet2::Encrypt (const uint8_t * data, uint8_t * encrypted) const |
|
{ |
|
auto encryptor = m_Encryptor; // TODO: atomic |
|
if (encryptor) |
|
encryptor->Encrypt (data, encrypted); |
|
} |
|
|
|
uint64_t LeaseSet2::ExtractExpirationTimestamp (const uint8_t * buf, size_t len) const |
|
{ |
|
uint64_t expiration = 0; |
|
ExtractPublishedTimestamp (buf, len, expiration); |
|
return expiration; |
|
} |
|
|
|
uint64_t LeaseSet2::ExtractPublishedTimestamp (const uint8_t * buf, size_t len, uint64_t& expiration) 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<i2p::crypto::Verifier> 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; |
|
expiration = (timestamp + expires)* 1000LL; |
|
return timestamp; |
|
} |
|
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; |
|
expiration = (timestamp + expires)* 1000LL; |
|
return timestamp; |
|
} |
|
} |
|
|
|
LocalLeaseSet::LocalLeaseSet (std::shared_ptr<const IdentityEx> identity, const uint8_t * encryptionPublicKey, std::vector<std::shared_ptr<i2p::tunnel::InboundTunnel> > 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<const IdentityEx> 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, const i2p::data::PrivateKeys& keys, |
|
const KeySections& encryptionKeys, const std::vector<std::shared_ptr<i2p::tunnel::InboundTunnel> >& tunnels, |
|
bool isPublic, bool isPublishedEncrypted): |
|
LocalLeaseSet (keys.GetPublic (), nullptr, 0) |
|
{ |
|
auto identity = keys.GetPublic (); |
|
// assume standard LS2 |
|
int num = tunnels.size (); |
|
if (num > MAX_NUM_LEASES) num = MAX_NUM_LEASES; |
|
size_t keySectionsLen = 0; |
|
for (const auto& it: encryptionKeys) |
|
keySectionsLen += 2/*key type*/ + 2/*key len*/ + it.keyLen/*key*/; |
|
m_BufferLen = identity->GetFullLen () + 4/*published*/ + 2/*expires*/ + 2/*flag*/ + 2/*properties len*/ + |
|
1/*num keys*/ + keySectionsLen + 1/*num leases*/ + num*LEASE2_SIZE + keys.GetSignatureLen (); |
|
uint16_t flags = 0; |
|
if (keys.IsOfflineSignature ()) |
|
{ |
|
flags |= LEASESET2_FLAG_OFFLINE_KEYS; |
|
m_BufferLen += keys.GetOfflineSignature ().size (); |
|
} |
|
if (isPublishedEncrypted) |
|
{ |
|
flags |= LEASESET2_FLAG_PUBLISHED_ENCRYPTED; |
|
isPublic = true; |
|
} |
|
if (!isPublic) flags |= LEASESET2_FLAG_UNPUBLISHED_LEASESET; |
|
|
|
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, flags); offset += 2; // flags |
|
if (keys.IsOfflineSignature ()) |
|
{ |
|
// offline signature |
|
const auto& offlineSignature = keys.GetOfflineSignature (); |
|
memcpy (m_Buffer + offset, offlineSignature.data (), offlineSignature.size ()); |
|
offset += offlineSignature.size (); |
|
} |
|
htobe16buf (m_Buffer + offset, 0); offset += 2; // properties len |
|
// keys |
|
m_Buffer[offset] = encryptionKeys.size (); offset++; // 1 key |
|
for (const auto& it: encryptionKeys) |
|
{ |
|
htobe16buf (m_Buffer + offset, it.keyType); offset += 2; // key type |
|
htobe16buf (m_Buffer + offset, it.keyLen); offset += 2; // key len |
|
memcpy (m_Buffer + offset, it.encryptionPublicKey, it.keyLen); offset += it.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 |
|
if (expirationTime) |
|
{ |
|
SetExpirationTime (expirationTime*1000LL); |
|
auto expires = (int)expirationTime - timestamp; |
|
htobe16buf (expiresBuf, expires > 0 ? expires : 0); |
|
} |
|
else |
|
{ |
|
// no tunnels or withdraw |
|
SetExpirationTime (timestamp*1000LL); |
|
memset (expiresBuf, 0, 2); // expires immeditely |
|
} |
|
// sign |
|
keys.Sign (m_Buffer, offset, m_Buffer + offset); // LS + leading store type |
|
} |
|
|
|
LocalLeaseSet2::LocalLeaseSet2 (uint8_t storeType, std::shared_ptr<const IdentityEx> 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; |
|
} |
|
|
|
LocalEncryptedLeaseSet2::LocalEncryptedLeaseSet2 (std::shared_ptr<const LocalLeaseSet2> ls, const i2p::data::PrivateKeys& keys, |
|
int authType, std::shared_ptr<std::vector<AuthPublicKey> > authKeys): |
|
LocalLeaseSet2 (ls->GetIdentity ()), m_InnerLeaseSet (ls) |
|
{ |
|
size_t lenInnerPlaintext = ls->GetBufferLen () + 1, lenOuterPlaintext = lenInnerPlaintext + 32 + 1; |
|
uint8_t layer1Flags = 0; |
|
if (authKeys) |
|
{ |
|
if (authType == ENCRYPTED_LEASESET_AUTH_TYPE_DH) layer1Flags |= 0x01; // DH, authentication scheme 0, auth bit 1 |
|
else if (authType == ENCRYPTED_LEASESET_AUTH_TYPE_PSK) layer1Flags |= 0x03; // PSK, authentication scheme 1, auth bit 1 |
|
if (layer1Flags) |
|
lenOuterPlaintext += 32 + 2 + authKeys->size ()*40; // auth data len |
|
} |
|
size_t lenOuterCiphertext = lenOuterPlaintext + 32; |
|
|
|
m_BufferLen = 2/*blinded sig type*/ + 32/*blinded pub key*/ + 4/*published*/ + 2/*expires*/ + 2/*flags*/ + 2/*lenOuterCiphertext*/ + lenOuterCiphertext + 64/*signature*/; |
|
m_Buffer = new uint8_t[m_BufferLen + 1]; |
|
m_Buffer[0] = NETDB_STORE_TYPE_ENCRYPTED_LEASESET2; |
|
BlindedPublicKey blindedKey (ls->GetIdentity ()); |
|
auto timestamp = i2p::util::GetSecondsSinceEpoch (); |
|
char date[9]; |
|
i2p::util::GetDateString (timestamp, date); |
|
uint8_t blindedPriv[64], blindedPub[128]; // 64 and 128 max |
|
size_t publicKeyLen = blindedKey.BlindPrivateKey (keys.GetSigningPrivateKey (), date, blindedPriv, blindedPub); |
|
std::unique_ptr<i2p::crypto::Signer> blindedSigner (i2p::data::PrivateKeys::CreateSigner (blindedKey.GetBlindedSigType (), blindedPriv)); |
|
if (!blindedSigner) |
|
{ |
|
LogPrint (eLogError, "LeaseSet2: Can't create blinded signer for signature type ", blindedKey.GetSigType ()); |
|
return; |
|
} |
|
auto offset = 1; |
|
htobe16buf (m_Buffer + offset, blindedKey.GetBlindedSigType ()); offset += 2; // Blinded Public Key Sig Type |
|
memcpy (m_Buffer + offset, blindedPub, publicKeyLen); offset += publicKeyLen; // Blinded Public Key |
|
htobe32buf (m_Buffer + offset, timestamp); offset += 4; // published timestamp (seconds) |
|
auto nextMidnight = (timestamp/86400LL + 1)*86400LL; // 86400 = 24*3600 seconds |
|
auto expirationTime = ls->GetExpirationTime ()/1000LL; |
|
if (expirationTime > nextMidnight) expirationTime = nextMidnight; |
|
SetExpirationTime (expirationTime*1000LL); |
|
htobe16buf (m_Buffer + offset, expirationTime > timestamp ? expirationTime - timestamp : 0); offset += 2; // expires |
|
uint16_t flags = 0; |
|
htobe16buf (m_Buffer + offset, flags); offset += 2; // flags |
|
htobe16buf (m_Buffer + offset, lenOuterCiphertext); offset += 2; // lenOuterCiphertext |
|
// outerChipherText |
|
// Layer 1 |
|
uint8_t subcredential[36]; |
|
blindedKey.GetSubcredential (blindedPub, 32, subcredential); |
|
htobe32buf (subcredential + 32, timestamp); // outerInput = subcredential || publishedTimestamp |
|
// keys = HKDF(outerSalt, outerInput, "ELS2_L1K", 44) |
|
uint8_t keys1[64]; // 44 bytes actual data |
|
RAND_bytes (m_Buffer + offset, 32); // outerSalt = CSRNG(32) |
|
i2p::crypto::HKDF (m_Buffer + offset, subcredential, 36, "ELS2_L1K", keys1); |
|
offset += 32; // outerSalt |
|
uint8_t * outerPlainText = m_Buffer + offset; |
|
m_Buffer[offset] = layer1Flags; offset++; // layer 1 flags |
|
// auth data |
|
uint8_t innerInput[68]; // authCookie || subcredential || publishedTimestamp |
|
if (layer1Flags) |
|
{ |
|
RAND_bytes (innerInput, 32); // authCookie |
|
CreateClientAuthData (subcredential, authType, authKeys, innerInput, m_Buffer + offset); |
|
offset += 32 + 2 + authKeys->size ()*40; // auth clients |
|
} |
|
// Layer 2 |
|
// keys = HKDF(outerSalt, outerInput, "ELS2_L2K", 44) |
|
uint8_t keys2[64]; // 44 bytes actual data |
|
RAND_bytes (m_Buffer + offset, 32); // innerSalt = CSRNG(32) |
|
if (layer1Flags) |
|
{ |
|
memcpy (innerInput + 32, subcredential, 36); // + subcredential || publishedTimestamp |
|
i2p::crypto::HKDF (m_Buffer + offset, innerInput, 68, "ELS2_L2K", keys2); |
|
} |
|
else |
|
i2p::crypto::HKDF (m_Buffer + offset, subcredential, 36, "ELS2_L2K", keys2); // no authCookie |
|
offset += 32; // innerSalt |
|
m_Buffer[offset] = ls->GetStoreType (); |
|
memcpy (m_Buffer + offset + 1, ls->GetBuffer (), ls->GetBufferLen ()); |
|
i2p::crypto::ChaCha20 (m_Buffer + offset, lenInnerPlaintext, keys2, keys2 + 32, m_Buffer + offset); // encrypt Layer 2 |
|
offset += lenInnerPlaintext; |
|
i2p::crypto::ChaCha20 (outerPlainText, lenOuterPlaintext, keys1, keys1 + 32, outerPlainText); // encrypt Layer 1 |
|
// signature |
|
blindedSigner->Sign (m_Buffer, offset, m_Buffer + offset); |
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// store hash |
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m_StoreHash = blindedKey.GetStoreHash (date); |
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} |
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|
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LocalEncryptedLeaseSet2::LocalEncryptedLeaseSet2 (std::shared_ptr<const IdentityEx> identity, const uint8_t * buf, size_t len): |
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LocalLeaseSet2 (NETDB_STORE_TYPE_ENCRYPTED_LEASESET2, identity, buf, len) |
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{ |
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// fill inner LeaseSet2 |
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auto blindedKey = std::make_shared<BlindedPublicKey>(identity); |
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i2p::data::LeaseSet2 ls (buf, len, blindedKey); // inner layer |
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if (ls.IsValid ()) |
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{ |
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m_InnerLeaseSet = std::make_shared<LocalLeaseSet2>(ls.GetStoreType (), identity, ls.GetBuffer (), ls.GetBufferLen ()); |
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m_StoreHash = blindedKey->GetStoreHash (); |
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} |
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else |
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LogPrint (eLogError, "LeaseSet2: Couldn't extract inner layer"); |
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} |
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|
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void LocalEncryptedLeaseSet2::CreateClientAuthData (const uint8_t * subcredential, int authType, std::shared_ptr<std::vector<AuthPublicKey> > authKeys, const uint8_t * authCookie, uint8_t * authData) const |
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{ |
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if (authType == ENCRYPTED_LEASESET_AUTH_TYPE_DH) |
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{ |
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i2p::crypto::X25519Keys ek; |
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ek.GenerateKeys (); // esk and epk |
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memcpy (authData, ek.GetPublicKey (), 32); authData += 32; // epk |
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htobe16buf (authData, authKeys->size ()); authData += 2; // num clients |
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uint8_t authInput[100]; // sharedSecret || cpk_i || subcredential || publishedTimestamp |
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memcpy (authInput + 64, subcredential, 36); |
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for (auto& it: *authKeys) |
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{ |
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ek.Agree (it, authInput); // sharedSecret = DH(esk, cpk_i) |
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memcpy (authInput + 32, it, 32); |
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uint8_t okm[64]; // 52 actual data |
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i2p::crypto::HKDF (ek.GetPublicKey (), authInput, 100, "ELS2_XCA", okm); |
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memcpy (authData, okm + 44, 8); authData += 8; // clientID_i |
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i2p::crypto::ChaCha20 (authCookie, 32, okm, okm + 32, authData); authData += 32; // clientCookie_i |
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} |
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} |
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else // assume PSK |
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{ |
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uint8_t authSalt[32]; |
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RAND_bytes (authSalt, 32); |
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memcpy (authData, authSalt, 32); authData += 32; // authSalt |
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htobe16buf (authData, authKeys->size ()); authData += 2; // num clients |
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uint8_t authInput[68]; // authInput = psk_i || subcredential || publishedTimestamp |
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memcpy (authInput + 32, subcredential, 36); |
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for (auto& it: *authKeys) |
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{ |
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memcpy (authInput, it, 32); |
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uint8_t okm[64]; // 52 actual data |
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i2p::crypto::HKDF (authSalt, authInput, 68, "ELS2PSKA", okm); |
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memcpy (authData, okm + 44, 8); authData += 8; // clientID_i |
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i2p::crypto::ChaCha20 (authCookie, 32, okm, okm + 32, authData); authData += 32; // clientCookie_i |
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} |
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} |
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} |
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} |
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}
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