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check packet number for SessionConfirmed

pull/1907/head
orignal 2 years ago
parent
commit
f41563a700
  1. 20
      libi2pd/SSU2Session.cpp

20
libi2pd/SSU2Session.cpp

@ -608,7 +608,7 @@ namespace transport @@ -608,7 +608,7 @@ namespace transport
* payload = m_SentHandshakePacket->payload;
// fill packet
header.h.connID = m_DestConnID; // dest id
header.h.packetNum = 0;
RAND_bytes (header.buf + 8, 4); // random packet num
header.h.type = eSSU2SessionRequest;
header.h.flags[0] = 2; // ver
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID
@ -636,7 +636,7 @@ namespace transport @@ -636,7 +636,7 @@ namespace transport
m_EphemeralKeys->Agree (m_Address->s, sharedSecret);
m_NoiseState->MixKey (sharedSecret);
// encrypt
const uint8_t nonce[12] = {0};
const uint8_t nonce[12] = {0}; // always 0
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, m_NoiseState->m_H, 32, m_NoiseState->m_CK + 32, nonce, payload, payloadSize + 16, true);
payloadSize += 16;
header.ll[0] ^= CreateHeaderMask (m_Address->i, payload + (payloadSize - 24));
@ -721,7 +721,7 @@ namespace transport @@ -721,7 +721,7 @@ namespace transport
uint8_t * headerX = m_SentHandshakePacket->headerX,
* payload = m_SentHandshakePacket->payload;
header.h.connID = m_DestConnID; // dest id
header.h.packetNum = 0;
RAND_bytes (header.buf + 8, 4); // random packet num
header.h.type = eSSU2SessionCreated;
header.h.flags[0] = 2; // ver
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID
@ -760,7 +760,7 @@ namespace transport @@ -760,7 +760,7 @@ namespace transport
m_EphemeralKeys->Agree (X, sharedSecret);
m_NoiseState->MixKey (sharedSecret);
// encrypt
const uint8_t nonce[12] = {0};
const uint8_t nonce[12] = {0}; // always zero
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, m_NoiseState->m_H, 32, m_NoiseState->m_CK + 32, nonce, payload, payloadSize + 16, true);
payloadSize += 16;
m_NoiseState->MixHash (payload, payloadSize); // h = SHA256(h || encrypted Noise payload from Session Created)
@ -832,7 +832,7 @@ namespace transport @@ -832,7 +832,7 @@ namespace transport
// fill packet
Header& header = m_SentHandshakePacket->header;
header.h.connID = m_DestConnID; // dest id
header.h.packetNum = 0;
header.h.packetNum = 0; // always zero
header.h.type = eSSU2SessionConfirmed;
memset (header.h.flags, 0, 3);
header.h.flags[0] = 1; // frag, total fragments always 1
@ -855,7 +855,7 @@ namespace transport @@ -855,7 +855,7 @@ namespace transport
// Encrypt part 1
uint8_t * part1 = m_SentHandshakePacket->headerX;
uint8_t nonce[12];
CreateNonce (1, nonce);
CreateNonce (1, nonce); // always one
i2p::crypto::AEADChaCha20Poly1305 (i2p::context.GetSSU2StaticPublicKey (), 32, m_NoiseState->m_H, 32, m_NoiseState->m_CK + 32, nonce, part1, 48, true);
m_NoiseState->MixHash (part1, 48); // h = SHA256(h || ciphertext);
// KDF for Session Confirmed part 2
@ -863,7 +863,7 @@ namespace transport @@ -863,7 +863,7 @@ namespace transport
i2p::context.GetSSU2StaticKeys ().Agree (Y, sharedSecret);
m_NoiseState->MixKey (sharedSecret);
// Encrypt part2
memset (nonce, 0, 12);
memset (nonce, 0, 12); // always zero
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, m_NoiseState->m_H, 32, m_NoiseState->m_CK + 32, nonce, payload, payloadSize + 16, true);
payloadSize += 16;
m_NoiseState->MixHash (payload, payloadSize); // h = SHA256(h || ciphertext);
@ -920,6 +920,12 @@ namespace transport @@ -920,6 +920,12 @@ namespace transport
// TODO: queue up
return true;
}
// packet num must be aways zero
if (header.h.packetNum)
{
LogPrint (eLogError, "SSU2: Non zero packet number in SessionConfirmed");
return false;
}
// check if fragmented
uint8_t numFragments = header.h.flags[0] & 0x0F;
if (numFragments > 1)

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