mirrors/i2pd
2
0
Fork 0
mirror of https://github.com/PurpleI2P/i2pd synced 2024-11-10 00:00:29 +03:00
Code Issues Packages Projects Releases Wiki Activity

decrypt payload section

Browse Source
This commit is contained in:
orignal 2019-12-18 14:44:02 -05:00
parent b5d55e1ffb
commit 19a88300c6
2 changed files with 77 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

68
libi2pd/Garlic.cpp
View File

@ -832,7 +832,7 @@ namespace garlic
void GarlicDestination::HandleECIESx25519 (const uint8_t * buf, size_t len)
{
// KDF
// KDF1
// TODO : use precalculated hashes
static const char protocolName[41] = "Noise_IKelg2+hs2_25519_ChaChaPoly_SHA256"; // 40 bytes
uint8_t h[64], ck[32];
@ -849,7 +849,7 @@ namespace garlic
LogPrint (eLogError, "Garlic: Can't decode elligator");
return;
}
buf += 32;
buf += 32; len -= 32;
memcpy (h + 32, aepk, 32);
SHA256 (h, 64, h); // h = SHA256(h || aepk)
@ -866,7 +866,69 @@ namespace garlic
LogPrint (eLogWarning, "Garlic: Flags/static section AEAD verification failed ");
return;
}
buf += 48; // 32 data + 16 poly
memcpy (h + 32, buf, 32);
SHA256 (h, 64, h); // h = SHA256(h || ciphertext)
buf += 48; len -= 48; // 32 data + 16 poly
// decrypt payload
std::vector<uint8_t> payload (len + 32); uint8_t h1[32];
// KDF2 for payload
bool isStatic = !i2p::data::Tag<32> (fs).IsZero ();
if (isStatic)
{
// static key, fs is apk
Decrypt (fs, sharedSecret, m_Ctx); // DH(bsk, apk)
i2p::crypto::HKDF (ck, sharedSecret, 32, "", keyData); // keydata = HKDF(chainKey, sharedSecret, "", 64)
memcpy (ck, keyData, 32); // chainKey = keydata[0:31]
memcpy (payload.data (), h, 32);
memcpy (payload.data () + 32, buf, len); // h || ciphertext
SHA256 (payload.data (), len + 32, h1);
}
else // all zeros flags
htole64buf (nonce + 4, 1); // n = 1
if (!i2p::crypto::AEADChaCha20Poly1305 (buf, len - 16, h, 32, keyData + 32, nonce, payload.data () + 32, len - 16, false)) // decrypt
{
LogPrint (eLogWarning, "Garlic: Payload section AEAD verification failed");
return;
}
if (isStatic) memcpy (h, h1, 32); // h = SHA256(h || ciphertext)
HandleECIESx25519Payload (payload.data () + 32, len - 16);
}
void GarlicDestination::HandleECIESx25519Payload (const uint8_t * buf, size_t len)
{
size_t offset = 0;
while (offset < len)
{
uint8_t blk = buf[offset];
offset++;
auto size = bufbe16toh (buf + offset);
offset += 2;
LogPrint (eLogDebug, "Garlic: Block type ", (int)blk, " of size ", size);
if (size > len)
{
LogPrint (eLogError, "Garlic: Unexpected block length ", size);
break;
}
switch (blk)
{
case eECIESx25519BlkGalicClove:
// TODO:
break;
case eECIESx25519BlkDateTime:
LogPrint (eLogDebug, "Garlic: datetime");
break;
case eECIESx25519BlkOptions:
LogPrint (eLogDebug, "Garlic: options");
break;
case eECIESx25519BlkPadding:
LogPrint (eLogDebug, "NTCP2: padding");
break;
default:
LogPrint (eLogWarning, "Garlic: Unknown block type ", (int)blk);
}
offset += size;
}
}
}
}

12
libi2pd/Garlic.h
View File

@ -165,6 +165,17 @@ namespace garlic
//using GarlicRoutingSessionPtr = std::shared_ptr<GarlicRoutingSession>;
typedef std::shared_ptr<GarlicRoutingSession> GarlicRoutingSessionPtr; // TODO: replace to using after switch to 4.8
enum ECIESx25519BlockType
{
eECIESx25519BlkDateTime = 0,
eECIESx25519BlkSessionID = 1,
eECIESx25519BlkTermination = 4,
eECIESx25519BlkOptions = 5,
eECIESx25519BlkNextSessionKey = 7,
eECIESx25519BlkGalicClove = 11,
eECIESx25519BlkPadding = 254
};
class GarlicDestination: public i2p::data::LocalDestination
{
public:
@ -208,6 +219,7 @@ namespace garlic
// ECIES-X25519-AEAD-Ratchet
void HandleECIESx25519 (const uint8_t * buf, size_t len);
void HandleECIESx25519Payload (const uint8_t * buf, size_t len);
private: