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tunnels through ECIES routers

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orignal 2020-10-23 15:53:22 -04:00
parent 57d6c7a3b3
commit c93ee0d65d
6 changed files with 137 additions and 39 deletions
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88
libi2pd/TunnelConfig.cpp
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@ -9,6 +9,9 @@
#include <memory>
#include <openssl/rand.h>
#include <openssl/sha.h>
#include "Crypto.h"
#include "Log.h"
#include "Transports.h"
#include "Timestamp.h"
#include "I2PEndian.h"
@ -76,39 +79,86 @@ namespace tunnel
}
}
void TunnelHopConfig::CreateBuildRequestRecord (uint8_t * record, uint32_t replyMsgID, BN_CTX * ctx) const
void TunnelHopConfig::CreateBuildRequestRecord (uint8_t * record, uint32_t replyMsgID, BN_CTX * ctx)
{
uint8_t clearText[BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE];
htobe32buf (clearText + BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET, tunnelID);
memcpy (clearText + BUILD_REQUEST_RECORD_OUR_IDENT_OFFSET, ident->GetIdentHash (), 32);
htobe32buf (clearText + BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET, nextTunnelID);
memcpy (clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, nextIdent, 32);
memcpy (clearText + BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET, layerKey, 32);
memcpy (clearText + BUILD_REQUEST_RECORD_IV_KEY_OFFSET, ivKey, 32);
memcpy (clearText + BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET, replyKey, 32);
memcpy (clearText + BUILD_REQUEST_RECORD_REPLY_IV_OFFSET, replyIV, 16);
uint8_t flag = 0;
if (isGateway) flag |= 0x80;
if (isEndpoint) flag |= 0x40;
clearText[BUILD_REQUEST_RECORD_FLAG_OFFSET] = flag;
htobe32buf (clearText + BUILD_REQUEST_RECORD_REQUEST_TIME_OFFSET, i2p::util::GetHoursSinceEpoch ());
htobe32buf (clearText + BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET, replyMsgID);
RAND_bytes (clearText + BUILD_REQUEST_RECORD_PADDING_OFFSET, BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE - BUILD_REQUEST_RECORD_PADDING_OFFSET);
auto encryptor = ident->CreateEncryptor (nullptr);
if (encryptor)
if (IsECIES ())
{
if (ident->GetCryptoKeyType () == i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD_RATCHET)
uint8_t clearText[ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE];
htobe32buf (clearText + ECIES_BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET, tunnelID);
htobe32buf (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET, nextTunnelID);
memcpy (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, nextIdent, 32);
memcpy (clearText + ECIES_BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET, layerKey, 32);
memcpy (clearText + ECIES_BUILD_REQUEST_RECORD_IV_KEY_OFFSET, ivKey, 32);
memcpy (clearText + ECIES_BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET, replyKey, 32);
memcpy (clearText + ECIES_BUILD_REQUEST_RECORD_REPLY_IV_OFFSET, replyIV, 16);
clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] = flag;
memset (clearText + ECIES_BUILD_REQUEST_RECORD_MORE_FLAGS_OFFSET, 0, 3); // set to 0 for compatibility
htobe32buf (clearText + ECIES_BUILD_REQUEST_RECORD_REQUEST_TIME_OFFSET, i2p::util::GetMinutesSinceEpoch ());
htobe32buf (clearText + ECIES_BUILD_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET, i2p::util::GetSecondsSinceEpoch () + 600); // 10 minutes
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);
if (encryptor)
EncryptECIES (encryptor, clearText, record + BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET, ctx);
else
}
else
{
uint8_t clearText[BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE];
htobe32buf (clearText + BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET, tunnelID);
memcpy (clearText + BUILD_REQUEST_RECORD_OUR_IDENT_OFFSET, ident->GetIdentHash (), 32);
htobe32buf (clearText + BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET, nextTunnelID);
memcpy (clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, nextIdent, 32);
memcpy (clearText + BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET, layerKey, 32);
memcpy (clearText + BUILD_REQUEST_RECORD_IV_KEY_OFFSET, ivKey, 32);
memcpy (clearText + BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET, replyKey, 32);
memcpy (clearText + BUILD_REQUEST_RECORD_REPLY_IV_OFFSET, replyIV, 16);
clearText[BUILD_REQUEST_RECORD_FLAG_OFFSET] = flag;
htobe32buf (clearText + BUILD_REQUEST_RECORD_REQUEST_TIME_OFFSET, i2p::util::GetHoursSinceEpoch ());
htobe32buf (clearText + BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET, replyMsgID);
RAND_bytes (clearText + BUILD_REQUEST_RECORD_PADDING_OFFSET, BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE - BUILD_REQUEST_RECORD_PADDING_OFFSET);
if (encryptor)
encryptor->Encrypt (clearText, record + BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET, ctx, false);
}
memcpy (record + BUILD_REQUEST_RECORD_TO_PEER_OFFSET, (const uint8_t *)ident->GetIdentHash (), 16);
}
void TunnelHopConfig::EncryptECIES (std::shared_ptr<i2p::crypto::CryptoKeyEncryptor>& encryptor,
const uint8_t * clearText, uint8_t * encrypted, BN_CTX * ctx) const
const uint8_t * plainText, uint8_t * encrypted, BN_CTX * ctx)
{
memset (encrypted, 0, 512); // TODO: implement
static const char protocolName[] = "Noise_N_25519_ChaChaPoly_SHA256"; // 31 chars
memcpy (ck, protocolName, 32); // ck = h = protocol_name || 0
SHA256 (ck, 32, h); // h = SHA256(h);
uint8_t hepk[32];
encryptor->Encrypt (nullptr, hepk, nullptr, false);
MixHash (hepk, 32);
auto ephemeralKeys = i2p::transport::transports.GetNextX25519KeysPair ();
memcpy (encrypted, ephemeralKeys->GetPublicKey (), 32); encrypted += 32;
uint8_t sharedSecret[32];
ephemeralKeys->Agree (hepk, sharedSecret); // x25519(sesk, hepk)
uint8_t keydata[64];
i2p::crypto::HKDF (ck, sharedSecret, 32, "", keydata);
memcpy (ck, keydata, 32);
uint8_t nonce[12];
memset (nonce, 0, 12);
if (!i2p::crypto::AEADChaCha20Poly1305 (plainText, ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE, h, 32,
keydata + 32, nonce, encrypted, ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE + 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)
}
void TunnelHopConfig::MixHash (const uint8_t * buf, size_t len)
{
SHA256_CTX ctx;
SHA256_Init (&ctx);
SHA256_Update (&ctx, h, 32);
SHA256_Update (&ctx, buf, len);
SHA256_Final (h, &ctx);
}
}
}