public virtual int GetSelectedCipherSuite()
{
/*
* TODO RFC 5246 7.4.3. In order to negotiate correctly, the server MUST check any candidate
* cipher suites against the "signature_algorithms" extension before selecting them. This is
* somewhat inelegant but is a compromise designed to minimize changes to the original
* cipher suite design.
*/
/*
* RFC 4429 5.1. A server that receives a ClientHello containing one or both of these
* extensions MUST use the client's enumerated capabilities to guide its selection of an
* appropriate cipher suite. One of the proposed ECC cipher suites must be negotiated only
* if the server can successfully complete the handshake while using the curves and point
* formats supported by the client [...].
*/
bool eccCipherSuitesEnabled = SupportsClientEccCapabilities(this.mNamedCurves, this.mClientECPointFormats);
int[] cipherSuites = GetCipherSuites();
for (int i = 0; i < cipherSuites.Length; ++i)
{
int cipherSuite = cipherSuites[i];
if (Arrays.Contains(this.mOfferedCipherSuites, cipherSuite) &&
(eccCipherSuitesEnabled || !TlsEccUtilities.IsEccCipherSuite(cipherSuite)) &&
TlsUtilities.IsValidCipherSuiteForVersion(cipherSuite, mServerVersion))
{
return(this.mSelectedCipherSuite = cipherSuite);
}
}
throw new TlsFatalAlert(AlertDescription.handshake_failure);
}
protected virtual byte[] GenerateOtherSecret(int pskLength)
{
if (this.mKeyExchange == KeyExchangeAlgorithm.DHE_PSK)
{
if (mDHAgreePrivateKey != null)
{
return(TlsDHUtilities.CalculateDHBasicAgreement(mDHAgreePublicKey, mDHAgreePrivateKey));
}
throw new TlsFatalAlert(AlertDescription.internal_error);
}
if (this.mKeyExchange == KeyExchangeAlgorithm.ECDHE_PSK)
{
if (mECAgreePrivateKey != null)
{
return(TlsEccUtilities.CalculateECDHBasicAgreement(mECAgreePublicKey, mECAgreePrivateKey));
}
throw new TlsFatalAlert(AlertDescription.internal_error);
}
if (this.mKeyExchange == KeyExchangeAlgorithm.RSA_PSK)
{
return(this.mPremasterSecret);
}
return(new byte[pskLength]);
}
protected virtual bool SupportsClientEccCapabilities(int[] namedCurves, byte[] ecPointFormats)
{
// NOTE: BC supports all the current set of point formats so we don't check them here
if (namedCurves == null)
{
/*
* RFC 4492 4. A client that proposes ECC cipher suites may choose not to include these
* extensions. In this case, the server is free to choose any one of the elliptic curves
* or point formats [...].
*/
return(TlsEccUtilities.HasAnySupportedNamedCurves());
}
for (int i = 0; i < namedCurves.Length; ++i)
{
int namedCurve = namedCurves[i];
if (NamedCurve.IsValid(namedCurve) &&
(!NamedCurve.RefersToASpecificNamedCurve(namedCurve) || TlsEccUtilities.IsSupportedNamedCurve(namedCurve)))
{
return(true);
}
}
return(false);
}
public override byte[] GenerateServerKeyExchange()
{
DigestInputBuffer buf = new DigestInputBuffer();
this.mECAgreePrivateKey = TlsEccUtilities.GenerateEphemeralServerKeyExchange(mContext.SecureRandom, mNamedCurves,
mClientECPointFormats, buf);
/*
* RFC 5246 4.7. digitally-signed element needs SignatureAndHashAlgorithm from TLS 1.2
*/
SignatureAndHashAlgorithm signatureAndHashAlgorithm = TlsUtilities.GetSignatureAndHashAlgorithm(
mContext, mServerCredentials);
IDigest d = TlsUtilities.CreateHash(signatureAndHashAlgorithm);
SecurityParameters securityParameters = mContext.SecurityParameters;
d.BlockUpdate(securityParameters.clientRandom, 0, securityParameters.clientRandom.Length);
d.BlockUpdate(securityParameters.serverRandom, 0, securityParameters.serverRandom.Length);
buf.UpdateDigest(d);
byte[] hash = DigestUtilities.DoFinal(d);
byte[] signature = mServerCredentials.GenerateCertificateSignature(hash);
DigitallySigned signed_params = new DigitallySigned(signatureAndHashAlgorithm, signature);
signed_params.Encode(buf);
return(buf.ToArray());
}
public virtual void ProcessServerExtensions(IDictionary serverExtensions)
{
/*
* TlsProtocol implementation validates that any server extensions received correspond to
* client extensions sent. By default, we don't send any, and this method is not called.
*/
if (serverExtensions != null)
{
/*
* RFC 5246 7.4.1.4.1. Servers MUST NOT send this extension.
*/
CheckForUnexpectedServerExtension(serverExtensions, ExtensionType.signature_algorithms);
CheckForUnexpectedServerExtension(serverExtensions, ExtensionType.elliptic_curves);
if (TlsEccUtilities.IsEccCipherSuite(this.mSelectedCipherSuite))
{
this.mServerECPointFormats = TlsEccUtilities.GetSupportedPointFormatsExtension(serverExtensions);
}
else
{
CheckForUnexpectedServerExtension(serverExtensions, ExtensionType.ec_point_formats);
}
}
}
public override void GenerateClientKeyExchange(Stream output)
{
if (mAgreementCredentials == null)
{
this.mECAgreePrivateKey = TlsEccUtilities.GenerateEphemeralClientKeyExchange(mContext.SecureRandom,
mServerECPointFormats, mECAgreePublicKey.Parameters, output);
}
}
public override byte[] GeneratePremasterSecret()
{
if (mAgreementCredentials != null)
{
return(mAgreementCredentials.GenerateAgreement(mECAgreePublicKey));
}
if (mECAgreePrivateKey != null)
{
return(TlsEccUtilities.CalculateECDHBasicAgreement(mECAgreePublicKey, mECAgreePrivateKey));
}
throw new TlsFatalAlert(AlertDescription.internal_error);
}
public override void ProcessClientKeyExchange(Stream input)
{
if (mECAgreePublicKey != null)
{
// For ecdsa_fixed_ecdh and rsa_fixed_ecdh, the key arrived in the client certificate
return;
}
byte[] point = TlsUtilities.ReadOpaque8(input);
ECDomainParameters curve_params = this.mECAgreePrivateKey.Parameters;
this.mECAgreePublicKey = TlsEccUtilities.ValidateECPublicKey(TlsEccUtilities.DeserializeECPublicKey(
mServerECPointFormats, curve_params, point));
}
protected virtual bool AllowUnexpectedServerExtension(int extensionType, byte[] extensionData)
{
switch (extensionType)
{
case ExtensionType.elliptic_curves:
/*
* Exception added based on field reports that some servers do send this, although the
* Supported Elliptic Curves Extension is clearly intended to be client-only. If
* present, we still require that it is a valid EllipticCurveList.
*/
TlsEccUtilities.ReadSupportedEllipticCurvesExtension(extensionData);
return(true);
default:
return(false);
}
}
public virtual IDictionary GetClientExtensions()
{
IDictionary clientExtensions = null;
ProtocolVersion clientVersion = mContext.ClientVersion;
/*
* RFC 5246 7.4.1.4.1. Note: this extension is not meaningful for TLS versions prior to 1.2.
* Clients MUST NOT offer it if they are offering prior versions.
*/
if (TlsUtilities.IsSignatureAlgorithmsExtensionAllowed(clientVersion))
{
// TODO Provide a way for the user to specify the acceptable hash/signature algorithms.
this.mSupportedSignatureAlgorithms = TlsUtilities.GetDefaultSupportedSignatureAlgorithms();
clientExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(clientExtensions);
TlsUtilities.AddSignatureAlgorithmsExtension(clientExtensions, mSupportedSignatureAlgorithms);
}
if (TlsEccUtilities.ContainsEccCipherSuites(GetCipherSuites()))
{
/*
* RFC 4492 5.1. A client that proposes ECC cipher suites in its ClientHello message
* appends these extensions (along with any others), enumerating the curves it supports
* and the point formats it can parse. Clients SHOULD send both the Supported Elliptic
* Curves Extension and the Supported Point Formats Extension.
*/
/*
* TODO Could just add all the curves since we support them all, but users may not want
* to use unnecessarily large fields. Need configuration options.
*/
this.mNamedCurves = new int[] { NamedCurve.secp256r1, NamedCurve.secp384r1 };
this.mClientECPointFormats = new byte[] { ECPointFormat.uncompressed,
ECPointFormat.ansiX962_compressed_prime, ECPointFormat.ansiX962_compressed_char2, };
clientExtensions = TlsExtensionsUtilities.EnsureExtensionsInitialised(clientExtensions);
TlsEccUtilities.AddSupportedEllipticCurvesExtension(clientExtensions, mNamedCurves);
TlsEccUtilities.AddSupportedPointFormatsExtension(clientExtensions, mClientECPointFormats);
}
return(clientExtensions);
}
public override void ProcessServerCertificate(Certificate serverCertificate)
{
if (serverCertificate.IsEmpty)
{
throw new TlsFatalAlert(AlertDescription.bad_certificate);
}
X509CertificateStructure x509Cert = serverCertificate.GetCertificateAt(0);
SubjectPublicKeyInfo keyInfo = x509Cert.SubjectPublicKeyInfo;
try
{
this.mServerPublicKey = PublicKeyFactory.CreateKey(keyInfo);
}
catch (Exception e)
{
throw new TlsFatalAlert(AlertDescription.unsupported_certificate, e);
}
if (mTlsSigner == null)
{
try
{
this.mECAgreePublicKey = TlsEccUtilities.ValidateECPublicKey((ECPublicKeyParameters)this.mServerPublicKey);
}
catch (InvalidCastException e)
{
throw new TlsFatalAlert(AlertDescription.certificate_unknown, e);
}
TlsUtilities.ValidateKeyUsage(x509Cert, KeyUsage.KeyAgreement);
}
else
{
if (!mTlsSigner.IsValidPublicKey(this.mServerPublicKey))
{
throw new TlsFatalAlert(AlertDescription.certificate_unknown);
}
TlsUtilities.ValidateKeyUsage(x509Cert, KeyUsage.DigitalSignature);
}
base.ProcessServerCertificate(serverCertificate);
}
public virtual void ProcessClientExtensions(IDictionary clientExtensions)
{
this.mClientExtensions = clientExtensions;
if (clientExtensions != null)
{
this.mEncryptThenMacOffered = TlsExtensionsUtilities.HasEncryptThenMacExtension(clientExtensions);
this.mMaxFragmentLengthOffered = TlsExtensionsUtilities.GetMaxFragmentLengthExtension(clientExtensions);
if (mMaxFragmentLengthOffered >= 0 && !MaxFragmentLength.IsValid((byte)mMaxFragmentLengthOffered))
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
this.mTruncatedHMacOffered = TlsExtensionsUtilities.HasTruncatedHMacExtension(clientExtensions);
this.mSupportedSignatureAlgorithms = TlsUtilities.GetSignatureAlgorithmsExtension(clientExtensions);
if (this.mSupportedSignatureAlgorithms != null)
{
/*
* RFC 5246 7.4.1.4.1. Note: this extension is not meaningful for TLS versions prior
* to 1.2. Clients MUST NOT offer it if they are offering prior versions.
*/
if (!TlsUtilities.IsSignatureAlgorithmsExtensionAllowed(mClientVersion))
{
throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
}
this.mNamedCurves = TlsEccUtilities.GetSupportedEllipticCurvesExtension(clientExtensions);
this.mClientECPointFormats = TlsEccUtilities.GetSupportedPointFormatsExtension(clientExtensions);
}
/*
* RFC 4429 4. The client MUST NOT include these extensions in the ClientHello message if it
* does not propose any ECC cipher suites.
*
* NOTE: This was overly strict as there may be ECC cipher suites that we don't recognize.
* Also, draft-ietf-tls-negotiated-ff-dhe will be overloading the 'elliptic_curves'
* extension to explicitly allow FFDHE (i.e. non-ECC) groups.
*/
//if (!this.mEccCipherSuitesOffered && (this.mNamedCurves != null || this.mClientECPointFormats != null))
// throw new TlsFatalAlert(AlertDescription.illegal_parameter);
}
// IDictionary is (Int32 -> byte[])
public virtual IDictionary GetServerExtensions()
{
if (this.mEncryptThenMacOffered && AllowEncryptThenMac)
{
/*
* RFC 7366 3. If a server receives an encrypt-then-MAC request extension from a client
* and then selects a stream or Authenticated Encryption with Associated Data (AEAD)
* ciphersuite, it MUST NOT send an encrypt-then-MAC response extension back to the
* client.
*/
if (TlsUtilities.IsBlockCipherSuite(this.mSelectedCipherSuite))
{
TlsExtensionsUtilities.AddEncryptThenMacExtension(CheckServerExtensions());
}
}
if (this.mMaxFragmentLengthOffered >= 0 &&
TlsUtilities.IsValidUint8(mMaxFragmentLengthOffered) &&
MaxFragmentLength.IsValid((byte)mMaxFragmentLengthOffered))
{
TlsExtensionsUtilities.AddMaxFragmentLengthExtension(CheckServerExtensions(), (byte)mMaxFragmentLengthOffered);
}
if (this.mTruncatedHMacOffered && AllowTruncatedHMac)
{
TlsExtensionsUtilities.AddTruncatedHMacExtension(CheckServerExtensions());
}
if (this.mClientECPointFormats != null && TlsEccUtilities.IsEccCipherSuite(this.mSelectedCipherSuite))
{
/*
* RFC 4492 5.2. A server that selects an ECC cipher suite in response to a ClientHello
* message including a Supported Point Formats Extension appends this extension (along
* with others) to its ServerHello message, enumerating the point formats it can parse.
*/
this.mServerECPointFormats = new byte[] { ECPointFormat.uncompressed,
ECPointFormat.ansiX962_compressed_prime, ECPointFormat.ansiX962_compressed_char2, };
TlsEccUtilities.AddSupportedPointFormatsExtension(CheckServerExtensions(), mServerECPointFormats);
}
return(mServerExtensions);
}
public override void GenerateClientKeyExchange(Stream output)
{
if (mPskIdentityHint == null)
{
mPskIdentity.SkipIdentityHint();
}
else
{
mPskIdentity.NotifyIdentityHint(mPskIdentityHint);
}
byte[] psk_identity = mPskIdentity.GetPskIdentity();
if (psk_identity == null)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
this.mPsk = mPskIdentity.GetPsk();
if (mPsk == null)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
TlsUtilities.WriteOpaque16(psk_identity, output);
mContext.SecurityParameters.pskIdentity = psk_identity;
if (this.mKeyExchange == KeyExchangeAlgorithm.DHE_PSK)
{
this.mDHAgreePrivateKey = TlsDHUtilities.GenerateEphemeralClientKeyExchange(mContext.SecureRandom,
mDHParameters, output);
}
else if (this.mKeyExchange == KeyExchangeAlgorithm.ECDHE_PSK)
{
this.mECAgreePrivateKey = TlsEccUtilities.GenerateEphemeralClientKeyExchange(mContext.SecureRandom,
mServerECPointFormats, mECAgreePublicKey.Parameters, output);
}
else if (this.mKeyExchange == KeyExchangeAlgorithm.RSA_PSK)
{
this.mPremasterSecret = TlsRsaUtilities.GenerateEncryptedPreMasterSecret(mContext,
this.mRsaServerPublicKey, output);
}
}
public override void ProcessClientKeyExchange(Stream input)
{
byte[] psk_identity = TlsUtilities.ReadOpaque16(input);
this.mPsk = mPskIdentityManager.GetPsk(psk_identity);
if (mPsk == null)
{
throw new TlsFatalAlert(AlertDescription.unknown_psk_identity);
}
mContext.SecurityParameters.pskIdentity = psk_identity;
if (this.mKeyExchange == KeyExchangeAlgorithm.DHE_PSK)
{
BigInteger Yc = TlsDHUtilities.ReadDHParameter(input);
this.mDHAgreePublicKey = TlsDHUtilities.ValidateDHPublicKey(new DHPublicKeyParameters(Yc, mDHParameters));
}
else if (this.mKeyExchange == KeyExchangeAlgorithm.ECDHE_PSK)
{
byte[] point = TlsUtilities.ReadOpaque8(input);
ECDomainParameters curve_params = this.mECAgreePrivateKey.Parameters;
this.mECAgreePublicKey = TlsEccUtilities.ValidateECPublicKey(TlsEccUtilities.DeserializeECPublicKey(
mServerECPointFormats, curve_params, point));
}
else if (this.mKeyExchange == KeyExchangeAlgorithm.RSA_PSK)
{
byte[] encryptedPreMasterSecret;
if (TlsUtilities.IsSsl(mContext))
{
// TODO Do any SSLv3 clients actually include the length?
encryptedPreMasterSecret = Streams.ReadAll(input);
}
else
{
encryptedPreMasterSecret = TlsUtilities.ReadOpaque16(input);
}
this.mPremasterSecret = mServerCredentials.DecryptPreMasterSecret(encryptedPreMasterSecret);
}
}
public override void ProcessServerKeyExchange(Stream input)
{
this.mPskIdentityHint = TlsUtilities.ReadOpaque16(input);
if (this.mKeyExchange == KeyExchangeAlgorithm.DHE_PSK)
{
ServerDHParams serverDHParams = ServerDHParams.Parse(input);
this.mDHAgreePublicKey = TlsDHUtilities.ValidateDHPublicKey(serverDHParams.PublicKey);
this.mDHParameters = mDHAgreePublicKey.Parameters;
}
else if (this.mKeyExchange == KeyExchangeAlgorithm.ECDHE_PSK)
{
ECDomainParameters ecParams = TlsEccUtilities.ReadECParameters(mNamedCurves, mClientECPointFormats, input);
byte[] point = TlsUtilities.ReadOpaque8(input);
this.mECAgreePublicKey = TlsEccUtilities.ValidateECPublicKey(TlsEccUtilities.DeserializeECPublicKey(
mClientECPointFormats, ecParams, point));
}
}
public override byte[] GenerateServerKeyExchange()
{
this.mPskIdentityHint = mPskIdentityManager.GetHint();
if (this.mPskIdentityHint == null && !RequiresServerKeyExchange)
{
return(null);
}
MemoryStream buf = new MemoryStream();
if (this.mPskIdentityHint == null)
{
TlsUtilities.WriteOpaque16(TlsUtilities.EmptyBytes, buf);
}
else
{
TlsUtilities.WriteOpaque16(this.mPskIdentityHint, buf);
}
if (this.mKeyExchange == KeyExchangeAlgorithm.DHE_PSK)
{
if (this.mDHParameters == null)
{
throw new TlsFatalAlert(AlertDescription.internal_error);
}
this.mDHAgreePrivateKey = TlsDHUtilities.GenerateEphemeralServerKeyExchange(mContext.SecureRandom,
this.mDHParameters, buf);
}
else if (this.mKeyExchange == KeyExchangeAlgorithm.ECDHE_PSK)
{
this.mECAgreePrivateKey = TlsEccUtilities.GenerateEphemeralServerKeyExchange(mContext.SecureRandom,
mNamedCurves, mClientECPointFormats, buf);
}
return(buf.ToArray());
}
public override void ProcessServerKeyExchange(Stream input)
{
SecurityParameters securityParameters = mContext.SecurityParameters;
SignerInputBuffer buf = new SignerInputBuffer();
Stream teeIn = new TeeInputStream(input, buf);
ECDomainParameters curve_params = TlsEccUtilities.ReadECParameters(mNamedCurves, mClientECPointFormats, teeIn);
byte[] point = TlsUtilities.ReadOpaque8(teeIn);
DigitallySigned signed_params = ParseSignature(input);
ISigner signer = InitVerifyer(mTlsSigner, signed_params.Algorithm, securityParameters);
buf.UpdateSigner(signer);
if (!signer.VerifySignature(signed_params.Signature))
{
throw new TlsFatalAlert(AlertDescription.decrypt_error);
}
this.mECAgreePublicKey = TlsEccUtilities.ValidateECPublicKey(TlsEccUtilities.DeserializeECPublicKey(
mClientECPointFormats, curve_params, point));
}
public virtual void NotifyOfferedCipherSuites(int[] offeredCipherSuites)
{
this.mOfferedCipherSuites = offeredCipherSuites;
this.mEccCipherSuitesOffered = TlsEccUtilities.ContainsEccCipherSuites(this.mOfferedCipherSuites);
}