/// <summary>This is SecureData that needs to get to an SA.</summary>
protected void HandleData(MemBlock b, ISender return_path)
{
SecurityDataMessage sdm = new SecurityDataMessage(b);
Dictionary <ISender, SecurityAssociation> sender_to_sa = null;
SecurityAssociation sa = null;
try {
sender_to_sa = _spi[sdm.SPI];
sa = sender_to_sa[return_path];
sa.HandleData(b, return_path, null);
} catch {
if (sender_to_sa == null && !SecurityPolicy.Supports(sdm.SPI))
{
throw new Exception("Invalid SPI: " + sdm.SPI);
}
else if (sa == null)
{
NoSuchSA(sdm.SPI, return_path);
throw new Exception("No SA for: " + return_path);
}
else if (sa.Closed)
{
throw new Exception("SA has been closed.");
}
else
{
throw;
}
}
}
public override bool Equals(object o)
{
SecurityPolicy sp = o as SecurityPolicy;
if (o == null)
{
return(false);
}
return((sp.Index == this.Index) && sp.Encryptor.Equals(this.Encryptor) &&
sp.Authenticator.Equals(this.Authenticator));
}
/// <summary>2a) Receive a CookieResponse that contains a list of CAs, if you have
/// a Certificate that supports one of the CAs send it along with a DHE
/// and a list of your supported CAs in a DHEWithCertificateAndCAs.</summary>
/// <param name="sa">A security association that we wish to perform the
/// specified control operation on.</param>
/// <param name="scm">The received SecurityControlMessage.</param>
/// <param name="scm_reply">A prepared reply message (with headers and such.</param>
/// <param name="return_path">Where to send the result.</param>
/// <param name="low_level_sender">We expect the return_path to not be an edge or
/// some other type of "low level" sender, so this contains the parsed out value.</param>
protected void HandleControlCookieResponse(SecurityAssociation sa,
SecurityControlMessage scm, SecurityControlMessage scm_reply,
ISender return_path, ISender low_level_sender)
{
ProtocolLog.WriteIf(ProtocolLog.Security, GetHashCode() + " Received CookieResponse from: " + low_level_sender);
if (sa == null)
{
throw new Exception("No valid SA!");
}
// This seems like unnecessary code
scm_reply.Type = SecurityControlMessage.MessageType.CookieResponse;
X509Certificate lcert = null;
if (SecurityPolicy.GetPolicy(scm.SPI).PreExchangedKeys)
{
lcert = _ch.DefaultCertificate;
}
else
{
lcert = _ch.FindCertificate(scm.CAs);
}
sa.RemoteCookie.Value = scm.LocalCookie;
sa.LocalCertificate.Value = lcert;
scm_reply.Certificate = lcert.RawData;
scm_reply.DHE = sa.LDHE;
scm_reply.LocalCookie = scm.RemoteCookie;
scm_reply.RemoteCookie = scm.LocalCookie;
scm_reply.Type = SecurityControlMessage.MessageType.DHEWithCertificateAndCAs;
if (SecurityPolicy.GetPolicy(scm.SPI).PreExchangedKeys)
{
scm_reply.CAs = new List <MemBlock>(0);
}
else
{
scm_reply.CAs = _ch.SupportedCAs;
}
HashAlgorithm sha1 = new SHA1CryptoServiceProvider();
lock (_private_key_lock) {
scm_reply.Sign(_private_key, sha1);
}
sa.DHEWithCertificateAndCAsOutHash.Value = sha1.ComputeHash((byte[])scm_reply.Packet);
ICopyable to_send = new CopyList(Security, SecureControl, scm_reply.Packet);
_rrman.SendRequest(return_path, ReqrepManager.ReqrepType.Request,
to_send, this, sa);
ProtocolLog.WriteIf(ProtocolLog.Security, GetHashCode() + " Successful CookieResponse from: " + low_level_sender);
}
/// <summary>2b) Receive a DHEWithCertificateAndCAs, verify the certificate and attempt
/// to find a matching Certificate for the list of CAs, if you find one,
/// finish the DHE handshake and send the certificate via a DHEWithCertificate</summary>
/// <param name="sa">A security association that we wish to perform the
/// specified control operation on.</param>
/// <param name="scm">The received SecurityControlMessage.</param>
/// <param name="scm_reply">A prepared reply message (with headers and such.</param>
/// <param name="return_path">Where to send the result.</param>
/// <param name="low_level_sender">We expect the return_path to not be an edge or
/// some other type of "low level" sender, so this contains the parsed out value.</param>
protected void HandleControlDHEWithCertificateAndCAs(SecurityAssociation sa,
SecurityControlMessage scm, SecurityControlMessage scm_reply,
ISender return_path, ISender low_level_sender)
{
ProtocolLog.WriteIf(ProtocolLog.Security, GetHashCode() + " Received DHEWithCertificateAndCAs from: " + low_level_sender);
if (sa == null)
{
sa = CreateSecurityAssociation(low_level_sender, scm.SPI, false);
}
byte[] cert = new byte[scm.Certificate.Length];
scm.Certificate.CopyTo(cert, 0);
X509Certificate rcert = new X509Certificate(cert);
_ch.Verify(rcert);
HashAlgorithm sha1 = new SHA1CryptoServiceProvider();
scm.Verify((RSACryptoServiceProvider)rcert.RSA, sha1);
X509Certificate lcert = null;
if (SecurityPolicy.GetPolicy(scm.SPI).PreExchangedKeys)
{
lcert = _ch.DefaultCertificate;
}
else
{
lcert = _ch.FindCertificate(scm.CAs);
}
sa.LocalCertificate.Value = lcert;
sa.RemoteCertificate.Value = rcert;
sa.RDHE.Value = scm.DHE;
sa.DHEWithCertificateAndCAsInHash.Value = MemBlock.Reference(sha1.ComputeHash((byte[])scm.Packet));
scm_reply.LocalCookie = scm.RemoteCookie;
scm_reply.RemoteCookie = scm.LocalCookie;
scm_reply.DHE = sa.LDHE;
scm_reply.Certificate = MemBlock.Reference(lcert.RawData);
scm_reply.Type = SecurityControlMessage.MessageType.DHEWithCertificate;
lock (_private_key_lock) {
scm_reply.Sign(_private_key, sha1);
}
sa.DHEWithCertificateHash.Value = MemBlock.Reference(sha1.ComputeHash((byte[])scm_reply.Packet));
ICopyable to_send = new CopyList(SecureControl, scm_reply.Packet);
return_path.Send(to_send);
ProtocolLog.WriteIf(ProtocolLog.Security, GetHashCode() + " Successful DHEWithCertificateAndCAs from: " + low_level_sender);
}
/// <summary>1b) Receive a Cookie which responds with a CookieResponse</summary>
/// <param name="sa">A security association that we wish to perform the
/// specified control operation on.</param>
/// <param name="calc_cookie">Cookie value for the association sender.</param>
/// <param name="scm">The received SecurityControlMessage.</param>
/// <param name="scm_reply">A prepared reply message (with headers and such.</param>
/// <param name="return_path">Where to send the result.</param>
/// <param name="low_level_sender">We expect the return_path to not be an edge or
/// some other type of "low level" sender, so this contains the parsed out value.</param>
protected void HandleControlCookie(SecurityAssociation sa,
MemBlock calc_cookie, SecurityControlMessage scm,
SecurityControlMessage scm_reply, ISender return_path,
ISender low_level_sender)
{
ProtocolLog.WriteIf(ProtocolLog.Security, GetHashCode() + " Received Cookie from: " + low_level_sender);
scm_reply.Type = SecurityControlMessage.MessageType.CookieResponse;
scm_reply.RemoteCookie = scm.LocalCookie;
scm_reply.LocalCookie = calc_cookie;
if (SecurityPolicy.GetPolicy(scm.SPI).PreExchangedKeys)
{
scm_reply.CAs = new List <MemBlock>(0);
}
else
{
scm_reply.CAs = _ch.SupportedCAs;
}
ICopyable to_send = new CopyList(SecureControl, scm_reply.Packet);
return_path.Send(to_send);
ProtocolLog.WriteIf(ProtocolLog.Security, GetHashCode() + " Successful Cookie from: " + low_level_sender);
}
/// <summary>This (idempotently) returns a new SecurityAssociation for the
/// specified sender using the specified SA.</summary>
virtual protected SecurityAssociation CreateSecurityAssociation(ISender Sender, int SPI)
{
if (!SecurityPolicy.Supports(SPI))
{
throw new Exception("Unsupported SPI");
}
SecurityAssociation sa = null;
int count = 0;
lock (_sync) {
Dictionary <ISender, SecurityAssociation> sender_to_sa = null;
if (_spi.ContainsKey(SPI))
{
sender_to_sa = _spi[SPI];
}
else
{
sender_to_sa = new Dictionary <ISender, SecurityAssociation>();
_spi[SPI] = sender_to_sa;
}
if (sender_to_sa.ContainsKey(Sender))
{
sa = sender_to_sa[Sender];
}
else
{
sa = new SecurityAssociation(Sender, SPI);
sa.Subscribe(this, null);
sa.StateChange += SAStateChange;
sa.RequestUpdate += SARequestUpdate;
sender_to_sa[Sender] = sa;
}
}
return(sa);
}
///<summary>Enables the SA if it has been properly setup.</summary>
public void Enable()
{
// If both parties setup simultaneous SAs we could end up calling this
// twice, once as a client and the other as server, this way we only
// go through the whole process once.
lock (_sync) {
if (_called_enable == 1)
{
return;
}
else if (_closed == 1)
{
throw new Exception("Cannot enable a closed SA!");
}
else if (_ldhe == null)
{
throw new Exception("Local DHE not set.");
}
else if (RDHE.Value == null)
{
throw new Exception("Remote DHE not set.");
}
else if (!_hash_verified)
{
throw new Exception("Hash is not verified!");
}
else if (TimedOut)
{
throw new Exception("Timed out on this one!");
}
_called_enable = 1;
// Deriving the DHE exchange and determing the order of keys
// Specifically, we need up to 4 keys for the sender/receiver encryption/
// authentication codes. So to determine the order, we say whomever has
// the smallest gets the first set of keys.
byte[] rdhe = (byte[])RDHE.Value;
RDHE = null;
byte[] key = _dh.DecryptKeyExchange(rdhe);
_dh.Clear();
_dh = null;
int i = 0;
while (i < _ldhe.Length && _ldhe[i] == rdhe[i])
{
i++;
}
bool same = i == _ldhe.Length;
bool first = !same && (_ldhe[i] < rdhe[i]);
_ldhe = null;
// Gathering our security parameter objects
SecurityPolicy sp = SecurityPolicy.GetPolicy(_spi);
SymmetricAlgorithm in_sa = sp.CreateSymmetricAlgorithm();
HashAlgorithm in_ha = sp.CreateHashAlgorithm();
SymmetricAlgorithm out_sa = sp.CreateSymmetricAlgorithm();
HashAlgorithm out_ha = sp.CreateHashAlgorithm();
// Generating the total key length
int key_length = key.Length + 2 + (in_sa.KeySize / 8 + in_sa.BlockSize / 8) * 2;
KeyedHashAlgorithm in_kha = in_ha as KeyedHashAlgorithm;
KeyedHashAlgorithm out_kha = out_ha as KeyedHashAlgorithm;
if (in_kha != null)
{
key_length += (in_kha.HashSize / 8) * 2;
}
// Generating a key by repeatedly hashing the DHE value and the key so far
SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider();
int usable_key_offset = key.Length;
while (key.Length < key_length)
{
byte[] hash = sha1.ComputeHash(key);
byte[] tmp_key = new byte[hash.Length + key.Length];
key.CopyTo(tmp_key, 0);
hash.CopyTo(tmp_key, key.Length);
key = tmp_key;
}
// Like a sub-session ID (see DTLS)
short epoch = (short)((key[usable_key_offset] << 8) + key[usable_key_offset + 1]);
usable_key_offset += 2;
byte[] key0 = new byte[in_sa.KeySize / 8];
Array.Copy(key, usable_key_offset, key0, 0, key0.Length);
usable_key_offset += key0.Length;
byte[] key1 = new byte[in_sa.KeySize / 8];
Array.Copy(key, usable_key_offset, key1, 0, key1.Length);
usable_key_offset += key1.Length;
// Same may occur if we are forming a session with ourselves!
if (same)
{
in_sa.Key = key0;
out_sa.Key = key0;
}
else if (first)
{
in_sa.Key = key0;
out_sa.Key = key1;
}
else
{
out_sa.Key = key0;
in_sa.Key = key1;
}
if (in_kha != null)
{
byte[] hkey0 = new byte[in_kha.HashSize / 8];
Array.Copy(key, usable_key_offset, hkey0, 0, hkey0.Length);
usable_key_offset += hkey0.Length;
byte[] hkey1 = new byte[in_kha.HashSize / 8];
Array.Copy(key, usable_key_offset, hkey1, 0, hkey1.Length);
usable_key_offset += hkey1.Length;
if (same)
{
in_kha.Key = hkey0;
out_kha.Key = hkey0;
}
else if (first)
{
in_kha.Key = hkey0;
out_kha.Key = hkey1;
}
else
{
out_kha.Key = hkey0;
in_kha.Key = hkey1;
}
}
SecurityHandler sh = new SecurityHandler(in_sa, out_sa, in_ha, out_ha, epoch);
sh.Update += UpdateSH;
SecurityHandler to_close = _current_sh;
if (to_close != null)
{
to_close.Close();
}
_current_sh = sh;
_last_epoch = _current_epoch;
_current_epoch = epoch;
}
// All finished set the state (which will probably fire an event)
State = SAState.Active;
}
/// <summary>This is the control state machine. There are three paths in
/// the state machine, iniator, receiver, and bidirectional. The
/// bidirectional case occurs when two remote ISenders that are matched
/// together initiate a handshake at the same time, otherwise the initiator
/// /receiver pattern is followed. The high level overview for the states
/// are:
/// 1a) Send a Cookie
/// 1b) Receive a Cookie which responds with a CookieResponse
/// 2a) Receive a CookieResponse that contains a list of CAs, if you have
/// a Certificate that supports one of the CAs send it along with a DHE
/// and a list of your supported CAs in a DHEWithCertificateAndCAs.
/// 2b) Receive a DHEWithCertificateAndCAs, verify the certificate and attempt
/// to find a matching Certificate for the list of CAs, if you find one,
/// finish the DHE handshake and send the certificate via a DHEWithCertificate
/// 3a) Receive a DHEWithCertificate, verify the certificate and DHE and
/// send a Confirm that you are ready to Verify the stack and start the
/// system.
/// 3b) Receive a Confirm, verify the entire stack and send a Confirm
/// 4a)Receive a Confirm, verify the entire stack and all set to go
/// </summary>
protected void HandleControl(MemBlock b, ISender return_path)
{
ISender low_level_sender = return_path;
if (low_level_sender is ReqrepManager.ReplyState)
{
low_level_sender = ((ReqrepManager.ReplyState)low_level_sender).ReturnPath;
}
SecurityControlMessage scm = new SecurityControlMessage(b);
MemBlock calc_cookie = CalculateCookie(low_level_sender);
if (scm.Version != Version)
{
throw new Exception("Invalid version: " + scm.Version);
}
else if (!SecurityPolicy.Supports(scm.SPI))
{
throw new Exception("No support for SPI: " + scm.SPI);
}
else if (!scm.RemoteCookie.Equals(calc_cookie))
{
if (scm.Type != SecurityControlMessage.MessageType.Cookie &&
scm.Type != SecurityControlMessage.MessageType.NoSuchSA)
{
throw new Exception("Invalid cookie!");
}
}
SecurityControlMessage scm_reply = new SecurityControlMessage();
scm_reply.Version = Version;
scm_reply.SPI = scm.SPI;
SecurityAssociation sa = null;
// This can be in a try statement since this is best effort anyway
try {
Dictionary <ISender, SecurityAssociation> sender_to_sa = _spi[scm.SPI];
sa = sender_to_sa[low_level_sender];
} catch { }
if (sa != null)
{
sa.Reset();
if (sa.Closed)
{
throw new Exception("SA closed!");
}
else if (sa.State == SecurityAssociation.SAState.Active)
{
return;
}
}
try {
switch (scm.Type)
{
case SecurityControlMessage.MessageType.NoSuchSA:
HandleControlNoSuchSA(sa);
break;
case SecurityControlMessage.MessageType.Cookie:
HandleControlCookie(sa, calc_cookie, scm, scm_reply, return_path, low_level_sender);
break;
case SecurityControlMessage.MessageType.CookieResponse:
HandleControlCookieResponse(sa, scm, scm_reply, return_path, low_level_sender);
break;
case SecurityControlMessage.MessageType.DHEWithCertificateAndCAs:
HandleControlDHEWithCertificateAndCAs(sa, scm, scm_reply, return_path, low_level_sender);
break;
case SecurityControlMessage.MessageType.DHEWithCertificate:
HandleControlDHEWithCertificates(sa, scm, scm_reply, return_path, low_level_sender);
break;
case SecurityControlMessage.MessageType.Confirm:
HandleControlConfirm(sa, scm, scm_reply, return_path, low_level_sender);
break;
default:
throw new Exception("Invalid message!");
}
} catch {
if (sa != null && sa.Closed)
{
throw new Exception("SA closed.");
}
else
{
throw;
}
}
}
