Mirrors/i2pd
2
0
Fork 0
mirror of https://github.com/PurpleI2P/i2pd.git synced 2025-04-28 11:47:48 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

create new ECIESX25519AEADRatchet session if not found

Browse source
This commit is contained in:
orignal 2020-01-16 19:33:00 -05:00
parent 00cb15d9b4
commit 451c3945f0
3 changed files with 35 additions and 24 deletions
Download patch file Download diff file Expand all files Collapse all files

44
libi2pd/ECIESX25519AEADRatchetSession.cpp
View file

@ -35,7 +35,7 @@ namespace garlic
SHA256_Update (&ctx, buf, len);
SHA256_Final (m_H, &ctx);
}
bool ECIESX25519AEADRatchetSession::NewIncomingSession (const uint8_t * buf, size_t len, CloveHandler handleClove)
{
if (!GetOwner ()) return false;
@ -52,15 +52,14 @@ namespace garlic
buf += 32; len -= 32;
MixHash (aepk, 32); // h = SHA256(h || aepk)
uint8_t sharedSecret[32], keyData[64];
uint8_t sharedSecret[32];
GetOwner ()->Decrypt (aepk, sharedSecret, nullptr); // x25519(bsk, aepk)
i2p::crypto::HKDF (m_CK, sharedSecret, 32, "", keyData); // keydata = HKDF(chainKey, sharedSecret, "", 64)
memcpy (m_CK, keyData, 32); // chainKey = keydata[0:31]
i2p::crypto::HKDF (m_CK, sharedSecret, 32, "", m_CK); // [chainKey, key] = HKDF(chainKey, sharedSecret, "", 64)
// decrypt flags/static
uint8_t nonce[12], fs[32];
memset (nonce, 0, 12); // n = 0
if (!i2p::crypto::AEADChaCha20Poly1305 (buf, 32, m_H, 32, keyData + 32, nonce, fs, 32, false)) // decrypt
if (!i2p::crypto::AEADChaCha20Poly1305 (buf, 32, m_H, 32, m_CK + 32, nonce, fs, 32, false)) // decrypt
{
LogPrint (eLogWarning, "Garlic: Flags/static section AEAD verification failed ");
return false;
@ -75,14 +74,13 @@ namespace garlic
if (isStatic)
{
// static key, fs is apk
memcpy (m_StaticKey, fs, 32);
memcpy (m_RemoteStaticKey, fs, 32);
GetOwner ()->Decrypt (fs, sharedSecret, nullptr); // x25519(bsk, apk)
i2p::crypto::HKDF (m_CK, sharedSecret, 32, "", keyData); // keydata = HKDF(chainKey, sharedSecret, "", 64)
memcpy (m_CK, keyData, 32); // chainKey = keydata[0:31]
i2p::crypto::HKDF (m_CK, sharedSecret, 32, "", m_CK); // [chainKey, key] = HKDF(chainKey, sharedSecret, "", 64)
}
else // all zeros flags
htole64buf (nonce + 4, 1); // n = 1
if (!i2p::crypto::AEADChaCha20Poly1305 (buf, len - 16, m_H, 32, keyData + 32, nonce, payload.data (), len - 16, false)) // decrypt
if (!i2p::crypto::AEADChaCha20Poly1305 (buf, len - 16, m_H, 32, m_CK + 32, nonce, payload.data (), len - 16, false)) // decrypt
{
LogPrint (eLogWarning, "Garlic: Payload section AEAD verification failed");
return false;
@ -132,7 +130,7 @@ namespace garlic
bool ECIESX25519AEADRatchetSession::NewOutgoingSessionMessage (const uint8_t * payload, size_t len, uint8_t * out, size_t outLen)
{
// we are Alice, bpk is m_StaticKey
// we are Alice, bpk is m_RemoteStaticKey
size_t offset = 0;
if (!i2p::crypto::GetElligator ()->Encode (m_EphemeralKeys.GetPublicKey (), out + offset))
{
@ -142,26 +140,32 @@ namespace garlic
offset += 32;
// KDF1
MixHash (m_StaticKey, 32); // h = SHA256(h || bpk)
MixHash (m_RemoteStaticKey, 32); // h = SHA256(h || bpk)
MixHash (m_EphemeralKeys.GetPublicKey (), 32); // h = SHA256(h || aepk)
uint8_t sharedSecret[32], keyData[64];
m_EphemeralKeys.Agree (m_StaticKey, nullptr); // x25519(aesk, bpk)
i2p::crypto::HKDF (m_CK, sharedSecret, 32, "", keyData); // keydata = HKDF(chainKey, sharedSecret, "", 64)
memcpy (m_CK, keyData, 32); // chainKey = keydata[0:31]
uint8_t sharedSecret[32];
m_EphemeralKeys.Agree (m_RemoteStaticKey, nullptr); // x25519(aesk, bpk)
i2p::crypto::HKDF (m_CK, sharedSecret, 32, "", m_CK); // [chainKey, key] = HKDF(chainKey, sharedSecret, "", 64)
// encrypt static key section
uint8_t nonce[12];
memset (nonce, 0, 12); // n = 0
if (!i2p::crypto::AEADChaCha20Poly1305 (GetOwner ()->GetEncryptionPublicKey (), 32, m_H, 32, keyData + 32, nonce, out + offset, 48, true)) // encrypt
if (!i2p::crypto::AEADChaCha20Poly1305 (GetOwner ()->GetEncryptionPublicKey (), 32, m_H, 32, m_CK + 32, nonce, out + offset, 48, true)) // encrypt
{
LogPrint (eLogWarning, "Garlic: Static section AEAD encryption failed ");
return false;
}
MixHash (out + offset, 48); // h = SHA256(h || ciphertext)
offset += 48;
// KDF2
// TODO: // x25519 (ask, bpk)
GetOwner ()->Decrypt (m_RemoteStaticKey, sharedSecret, nullptr); // x25519 (ask, bpk)
i2p::crypto::HKDF (m_CK, sharedSecret, 32, "", m_CK); // [chainKey, key] = HKDF(chainKey, sharedSecret, "", 64)
// encrypt payload
if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len, m_H, 32, m_CK + 32, nonce, out + offset, len + 16, true)) // encrypt
{
LogPrint (eLogWarning, "Garlic: Payload section AEAD encryption failed");
return false;
}
MixHash (out + offset, len + 16); // h = SHA256(h || ciphertext)
return true;
}