mirror of
https://github.com/PurpleI2P/i2pd.git
synced 2025-01-12 18:38:07 +00:00
decrypt and handle Layer 2 of encrypted LeaseSet 2
This commit is contained in:
parent
9b64be07a9
commit
9aaba49a9f
@ -463,9 +463,11 @@ namespace data
|
||||
// handle ciphertext
|
||||
if (verified && identity && lenOuterCiphertext >= 32)
|
||||
{
|
||||
SetIsValid (false); // we must verify it again in Layer 2
|
||||
size_t l = identity->GetFullLen();
|
||||
std::vector<uint8_t> destination (l);
|
||||
l = identity->ToBuffer (destination.data(), l);
|
||||
// outer key
|
||||
uint8_t credential[32], subcredential[36];
|
||||
// credential = H("credential", Destination)
|
||||
H ("credential", { {destination.data(), l} }, credential);
|
||||
@ -475,13 +477,35 @@ namespace data
|
||||
memcpy (subcredential + 32, publishedTimestamp, 4);
|
||||
// outerSalt = outerCiphertext[0:32]
|
||||
// keys = HKDF(outerSalt, outerInput, "ELS2_L1K", 44)
|
||||
uint8_t outerKey[44];
|
||||
HKDF (outerCiphertext, {subcredential, 36}, "ELS2_L1K", outerKey, 44);
|
||||
uint8_t keys[44];
|
||||
HKDF (outerCiphertext, {subcredential, 36}, "ELS2_L1K", keys, 44);
|
||||
// decrypt Layer 1
|
||||
// outerKey = keys[0:31]
|
||||
// outerIV = keys[32:43]
|
||||
std::vector<uint8_t> outerPlainText (lenOuterCiphertext - 32);
|
||||
i2p::crypto::ChaCha20 (outerCiphertext + 32, lenOuterCiphertext - 32, outerKey, outerKey + 32, outerPlainText.data ());
|
||||
size_t lenOuterPlaintext = lenOuterCiphertext - 32;
|
||||
std::vector<uint8_t> outerPlainText (lenOuterPlaintext);
|
||||
i2p::crypto::ChaCha20 (outerCiphertext + 32, lenOuterPlaintext, keys, keys + 32, outerPlainText.data ());
|
||||
// inner key
|
||||
// innerSalt = innerCiphertext[0:32]
|
||||
// keys = HKDF(innerSalt, innerInput, "ELS2_L2K", 44)
|
||||
// skip 1 byte flags
|
||||
HKDF (outerPlainText.data () + 1, {subcredential, 36}, "ELS2_L2K", keys, 44); // no authCookie
|
||||
// decrypt Layer 2
|
||||
// innerKey = keys[0:31]
|
||||
// innerIV = keys[32:43]
|
||||
size_t lenInnerPlaintext = lenOuterPlaintext - 32 - 1;
|
||||
std::vector<uint8_t> innerPlainText (lenInnerPlaintext);
|
||||
i2p::crypto::ChaCha20 (outerPlainText.data () + 32 + 1, 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: unxpected LeaseSet type ", (int)innerPlainText[0], " inside encrypted LeaseSet");
|
||||
}
|
||||
}
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user