public Scp03Session(Session session, ushort key_id, Session auth_session, ushort auth_key_id)
{
var host_chal = auth_session.SendCmd(new GetChallengeReq {
key_id = auth_key_id
});
if (host_chal[0] != 38)
{
throw new IOException($"Unknown host challenge algorithm: {host_chal[0]}");
}
var create_req = new CreateSessionReq
{
key_id = key_id,
host_chal = host_chal.Slice(1).ToArray()
};
var create_resp = session.SendCmd(create_req);
session_id = create_resp[0];
var card_chal = create_resp.Slice(1, 8);
var card_crypto = create_resp.Slice(1 + 8, 8);
var client_auth = new ClientAuthReq
{
key_id = auth_key_id,
host_chal = host_chal.Slice(1).ToArray(),
card_chal = card_chal.ToArray(),
card_crypto = card_crypto.ToArray()
};
var auth_resp = auth_session.SendCmd(client_auth).ToArray();
key_enc = new KeyParameter(auth_resp, 0, 16);
var key_mac = new KeyParameter(auth_resp, 16, 16);
var key_rmac = new KeyParameter(auth_resp, 32, 16);
var host_crypto = auth_resp.AsMemory(48, 8);
this.session = new Scp03CMacSession(cmac, session, key_mac, key_rmac, new byte[16]);
var auth_req = new AuthenticateSessionReq
{
session_id = session_id,
host_crypto = host_crypto
};
this.session.SendCmd(auth_req);
}
public Scp03Session(Session session, ushort key_id, KeyParameter enc_key, KeyParameter mac_key, ReadOnlyMemory <byte> host_chal)
{
var create_req = new CreateSessionReq
{
key_id = key_id,
host_chal = host_chal
};
var create_resp = session.SendCmd(create_req);
session_id = create_resp[0];
var card_chal = create_resp.Slice(1, 8);
var card_crypto = create_resp.Slice(1 + 8, 8);
var context = new byte[host_chal.Length + card_chal.Length];
host_chal.CopyTo(context);
card_chal.CopyTo(context.AsSpan(host_chal.Length));
key_enc = ComputeCryptogram(enc_key, 4, context, 0x80);
var key_mac = ComputeCryptogram(mac_key, 6, context, 0x80);
var key_rmac = ComputeCryptogram(mac_key, 7, context, 0x80);
var card_crypto_host = ComputeCryptogram(key_mac, 0, context, 0x40).GetKey();
var host_crypto = ComputeCryptogram(key_mac, 1, context, 0x40).GetKey();
if (!card_crypto.SequenceEqual(card_crypto_host))
{
throw new IOException("The card cryptogram was invalid");
}
this.session = new Scp03CMacSession(cmac, session, key_mac, key_rmac, new byte[16]);
var auth_req = new AuthenticateSessionReq
{
session_id = session_id,
host_crypto = host_crypto
};
this.session.SendCmd(auth_req);
}
