use HKDF for NTCP2 key derivation data phase

This commit is contained in:
orignal 2019-12-18 20:45:47 -05:00
parent 19a88300c6
commit 599ec62bb0
4 changed files with 32 additions and 24 deletions

View file

@ -441,23 +441,17 @@ namespace transport
void NTCP2Session::KeyDerivationFunctionDataPhase ()
{
uint8_t tempKey[32]; unsigned int len;
HMAC(EVP_sha256(), m_Establisher->GetCK (), 32, nullptr, 0, tempKey, &len); // temp_key = HMAC-SHA256(ck, zerolen)
static uint8_t one[1] = { 1 };
HMAC(EVP_sha256(), tempKey, 32, one, 1, m_Kab, &len); // k_ab = HMAC-SHA256(temp_key, byte(0x01)).
m_Kab[32] = 2;
HMAC(EVP_sha256(), tempKey, 32, m_Kab, 33, m_Kba, &len); // k_ba = HMAC-SHA256(temp_key, k_ab || byte(0x02))
static uint8_t ask[4] = { 'a', 's', 'k', 1 }, master[32];
HMAC(EVP_sha256(), tempKey, 32, ask, 4, master, &len); // ask_master = HMAC-SHA256(temp_key, "ask" || byte(0x01))
uint8_t k[64];
i2p::crypto::HKDF (m_Establisher->GetCK (), nullptr, 0, "", k); // k_ab, k_ba = HKDF(ck, zerolen)
memcpy (m_Kab, k, 32); memcpy (m_Kba, k + 32, 32);
uint8_t master[32];
i2p::crypto::HKDF (m_Establisher->GetCK (), nullptr, 0, "ask", master, 32); // ask_master = HKDF(ck, zerolen, info="ask")
uint8_t h[39];
memcpy (h, m_Establisher->GetH (), 32);
memcpy (h + 32, "siphash", 7);
HMAC(EVP_sha256(), master, 32, h, 39, tempKey, &len); // temp_key = HMAC-SHA256(ask_master, h || "siphash")
HMAC(EVP_sha256(), tempKey, 32, one, 1, master, &len); // sip_master = HMAC-SHA256(temp_key, byte(0x01))
HMAC(EVP_sha256(), master, 32, nullptr, 0, tempKey, &len); // temp_key = HMAC-SHA256(sip_master, zerolen)
HMAC(EVP_sha256(), tempKey, 32, one, 1, m_Sipkeysab, &len); // sipkeys_ab = HMAC-SHA256(temp_key, byte(0x01)).
m_Sipkeysab[32] = 2;
HMAC(EVP_sha256(), tempKey, 32, m_Sipkeysab, 33, m_Sipkeysba, &len); // sipkeys_ba = HMAC-SHA256(temp_key, sipkeys_ab || byte(0x02))
i2p::crypto::HKDF (master, h, 39, "", master, 32); // sip_master = HKDF(ask_master, h || "siphash")
i2p::crypto::HKDF (master, nullptr, 0, "", k, 64); // sipkeys_ab, sipkeys_ba = HKDF(sip_master, zerolen)
memcpy (m_Sipkeysab, k, 32); memcpy (m_Sipkeysba, k + 32, 32);
}