From aace644815dbf170b3e9e8e720b2116922de0f8a Mon Sep 17 00:00:00 2001 From: orignal Date: Fri, 2 Jul 2021 22:06:24 -0400 Subject: [PATCH] added ShortECIESTunnelHopConfig --- libi2pd/I2NPProtocol.h | 1 + libi2pd/TunnelConfig.cpp | 59 ++++++++++++++++++++++++++++++++-------- libi2pd/TunnelConfig.h | 12 ++++++-- 3 files changed, 58 insertions(+), 14 deletions(-) diff --git a/libi2pd/I2NPProtocol.h b/libi2pd/I2NPProtocol.h index 69d6bb04..8cb68856 100644 --- a/libi2pd/I2NPProtocol.h +++ b/libi2pd/I2NPProtocol.h @@ -113,6 +113,7 @@ namespace i2p const size_t SHORT_REQUEST_RECORD_REQUEST_TIME_OFFSET = SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE + 1; const size_t SHORT_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET = SHORT_REQUEST_RECORD_REQUEST_TIME_OFFSET + 4; const size_t SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET = SHORT_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET + 4; + const size_t SHORT_REQUEST_RECORD_PADDING_OFFSET = SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET + 4; const size_t SHORT_REQUEST_RECORD_CLEAR_TEXT_SIZE = 154; enum I2NPMessageType diff --git a/libi2pd/TunnelConfig.cpp b/libi2pd/TunnelConfig.cpp index 6a314ec3..505f66cc 100644 --- a/libi2pd/TunnelConfig.cpp +++ b/libi2pd/TunnelConfig.cpp @@ -113,9 +113,10 @@ namespace tunnel return true; } - void ECIESTunnelHopConfig::EncryptECIES (std::shared_ptr& encryptor, - const uint8_t * plainText, uint8_t * encrypted, BN_CTX * ctx) + void ECIESTunnelHopConfig::EncryptECIES (const uint8_t * plainText, size_t len, uint8_t * encrypted) { + auto encryptor = ident->CreateEncryptor (nullptr); + if (!encryptor) return; uint8_t hepk[32]; encryptor->Encrypt (nullptr, hepk, nullptr, false); i2p::crypto::InitNoiseNState (*this, hepk); @@ -128,13 +129,19 @@ namespace tunnel MixKey (sharedSecret); uint8_t nonce[12]; memset (nonce, 0, 12); - if (!i2p::crypto::AEADChaCha20Poly1305 (plainText, ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE, m_H, 32, - m_CK + 32, nonce, encrypted, ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE + 16, true)) // encrypt + if (!i2p::crypto::AEADChaCha20Poly1305 (plainText, len, m_H, 32, m_CK + 32, nonce, encrypted, len + 16, true)) // encrypt { LogPrint (eLogWarning, "Tunnel: Plaintext AEAD encryption failed"); return; } - MixHash (encrypted, ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE + 16); // h = SHA256(h || ciphertext) + MixHash (encrypted, len + 16); // h = SHA256(h || ciphertext) + } + + bool ECIESTunnelHopConfig::DecryptECIES (const uint8_t * encrypted, size_t len, uint8_t * clearText) + { + uint8_t nonce[12]; + memset (nonce, 0, 12); + return i2p::crypto::AEADChaCha20Poly1305 (encrypted, len - 16, m_H, 32, m_CK, nonce, clearText, len - 16, false); // decrypt } void LongECIESTunnelHopConfig::CreateBuildRequestRecord (uint8_t * record, uint32_t replyMsgID, BN_CTX * ctx) @@ -158,18 +165,46 @@ namespace tunnel htobe32buf (clearText + ECIES_BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET, replyMsgID); memset (clearText + ECIES_BUILD_REQUEST_RECORD_PADDING_OFFSET, 0, ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE - ECIES_BUILD_REQUEST_RECORD_PADDING_OFFSET); // encrypt - auto encryptor = ident->CreateEncryptor (nullptr); - if (encryptor) - EncryptECIES (encryptor, clearText, record + BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET, ctx); + EncryptECIES (clearText, ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE, record + BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET); memcpy (record + BUILD_REQUEST_RECORD_TO_PEER_OFFSET, (const uint8_t *)ident->GetIdentHash (), 16); } bool LongECIESTunnelHopConfig::DecryptBuildResponseRecord (const uint8_t * encrypted, uint8_t * clearText) { - uint8_t nonce[12]; - memset (nonce, 0, 12); - if (!i2p::crypto::AEADChaCha20Poly1305 (encrypted, TUNNEL_BUILD_RECORD_SIZE - 16, - m_H, 32, m_CK, nonce, clearText, TUNNEL_BUILD_RECORD_SIZE - 16, false)) // decrypt + if (!DecryptECIES (encrypted, TUNNEL_BUILD_RECORD_SIZE, clearText)) + { + LogPrint (eLogWarning, "Tunnel: Response AEAD decryption failed"); + return false; + } + return true; + } + + void ShortECIESTunnelHopConfig::CreateBuildRequestRecord (uint8_t * record, uint32_t replyMsgID, BN_CTX * ctx) + { + // fill clear text + uint8_t flag = 0; + if (isGateway) flag |= TUNNEL_BUILD_RECORD_GATEWAY_FLAG; + if (isEndpoint) flag |= TUNNEL_BUILD_RECORD_ENDPOINT_FLAG; + uint8_t clearText[SHORT_REQUEST_RECORD_CLEAR_TEXT_SIZE ]; + htobe32buf (clearText + SHORT_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET, tunnelID); + htobe32buf (clearText + SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET, nextTunnelID); + memcpy (clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, nextIdent, 32); + clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] = flag; + memset (clearText + SHORT_REQUEST_RECORD_MORE_FLAGS_OFFSET, 0, 2); + clearText[SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE] = 0; // AES + htobe32buf (clearText + SHORT_REQUEST_RECORD_REQUEST_TIME_OFFSET, i2p::util::GetMinutesSinceEpoch ()); + htobe32buf (clearText + SHORT_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET , 600); // +10 minutes + htobe32buf (clearText + SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET, replyMsgID); + memset (clearText + SHORT_REQUEST_RECORD_PADDING_OFFSET, 0, SHORT_REQUEST_RECORD_CLEAR_TEXT_SIZE - SHORT_REQUEST_RECORD_PADDING_OFFSET); + // TODO: derive layer and reply keys + // encrypt + EncryptECIES (clearText, SHORT_REQUEST_RECORD_CLEAR_TEXT_SIZE, record + SHORT_REQUEST_RECORD_ENCRYPTED_OFFSET); + memcpy (record + BUILD_REQUEST_RECORD_TO_PEER_OFFSET, (const uint8_t *)ident->GetIdentHash (), 16); + } + + bool ShortECIESTunnelHopConfig::DecryptBuildResponseRecord (const uint8_t * encrypted, uint8_t * clearText) + { + if (!DecryptECIES (encrypted, SHORT_TUNNEL_BUILD_RECORD_SIZE, clearText)) { LogPrint (eLogWarning, "Tunnel: Response AEAD decryption failed"); return false; diff --git a/libi2pd/TunnelConfig.h b/libi2pd/TunnelConfig.h index f64db0b0..7d6456fd 100644 --- a/libi2pd/TunnelConfig.h +++ b/libi2pd/TunnelConfig.h @@ -58,8 +58,8 @@ namespace tunnel ECIESTunnelHopConfig (std::shared_ptr r): TunnelHopConfig (r) {}; bool IsECIES () const { return true; }; - void EncryptECIES (std::shared_ptr& encryptor, - const uint8_t * clearText, uint8_t * encrypted, BN_CTX * ctx); + void EncryptECIES (const uint8_t * clearText, size_t len, uint8_t * encrypted); + bool DecryptECIES (const uint8_t * encrypted, size_t len, uint8_t * clearText); }; struct LongECIESTunnelHopConfig: public ECIESTunnelHopConfig @@ -69,6 +69,14 @@ namespace tunnel void CreateBuildRequestRecord (uint8_t * record, uint32_t replyMsgID, BN_CTX * ctx); bool DecryptBuildResponseRecord (const uint8_t * encrypted, uint8_t * clearText); }; + + struct ShortECIESTunnelHopConfig: public ECIESTunnelHopConfig + { + ShortECIESTunnelHopConfig (std::shared_ptr r): + ECIESTunnelHopConfig (r) {}; + void CreateBuildRequestRecord (uint8_t * record, uint32_t replyMsgID, BN_CTX * ctx); + bool DecryptBuildResponseRecord (const uint8_t * encrypted, uint8_t * clearText); + }; class TunnelConfig {