1 files changed, 208 insertions, 0 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/tls/TlsDHKeyExchange.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/tls/TlsDHKeyExchange.java
new file mode 100644
index 000000000..b4948d9d3
--- /dev/null
+++ b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/tls/TlsDHKeyExchange.java
@@ -0,0 +1,208 @@
+package org.spongycastle.crypto.tls;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.math.BigInteger;
+import java.util.Vector;
+
+import org.spongycastle.asn1.x509.KeyUsage;
+import org.spongycastle.asn1.x509.SubjectPublicKeyInfo;
+import org.spongycastle.crypto.params.AsymmetricKeyParameter;
+import org.spongycastle.crypto.params.DHParameters;
+import org.spongycastle.crypto.params.DHPrivateKeyParameters;
+import org.spongycastle.crypto.params.DHPublicKeyParameters;
+import org.spongycastle.crypto.util.PublicKeyFactory;
+
+/**
+ * TLS 1.0/1.1 DH key exchange.
+ */
+public class TlsDHKeyExchange
+    extends AbstractTlsKeyExchange
+{
+    protected static final BigInteger ONE = BigInteger.valueOf(1);
+    protected static final BigInteger TWO = BigInteger.valueOf(2);
+
+    protected TlsSigner tlsSigner;
+    protected DHParameters dhParameters;
+
+    protected AsymmetricKeyParameter serverPublicKey;
+    protected DHPublicKeyParameters dhAgreeServerPublicKey;
+    protected TlsAgreementCredentials agreementCredentials;
+    protected DHPrivateKeyParameters dhAgreeClientPrivateKey;
+
+    protected DHPrivateKeyParameters dhAgreeServerPrivateKey;
+    protected DHPublicKeyParameters dhAgreeClientPublicKey;
+
+    public TlsDHKeyExchange(int keyExchange, Vector supportedSignatureAlgorithms, DHParameters dhParameters)
+    {
+        super(keyExchange, supportedSignatureAlgorithms);
+
+        switch (keyExchange)
+        {
+        case KeyExchangeAlgorithm.DH_RSA:
+        case KeyExchangeAlgorithm.DH_DSS:
+            this.tlsSigner = null;
+            break;
+        case KeyExchangeAlgorithm.DHE_RSA:
+            this.tlsSigner = new TlsRSASigner();
+            break;
+        case KeyExchangeAlgorithm.DHE_DSS:
+            this.tlsSigner = new TlsDSSSigner();
+            break;
+        default:
+            throw new IllegalArgumentException("unsupported key exchange algorithm");
+        }
+
+        this.dhParameters = dhParameters;
+    }
+
+    public void init(TlsContext context)
+    {
+        super.init(context);
+
+        if (this.tlsSigner != null)
+        {
+            this.tlsSigner.init(context);
+        }
+    }
+
+    public void skipServerCredentials()
+        throws IOException
+    {
+        throw new TlsFatalAlert(AlertDescription.unexpected_message);
+    }
+
+    public void processServerCertificate(Certificate serverCertificate)
+        throws IOException
+    {
+        if (serverCertificate.isEmpty())
+        {
+            throw new TlsFatalAlert(AlertDescription.bad_certificate);
+        }
+
+        org.spongycastle.asn1.x509.Certificate x509Cert = serverCertificate.getCertificateAt(0);
+
+        SubjectPublicKeyInfo keyInfo = x509Cert.getSubjectPublicKeyInfo();
+        try
+        {
+            this.serverPublicKey = PublicKeyFactory.createKey(keyInfo);
+        }
+        catch (RuntimeException e)
+        {
+            throw new TlsFatalAlert(AlertDescription.unsupported_certificate);
+        }
+
+        if (tlsSigner == null)
+        {
+            try
+            {
+                this.dhAgreeServerPublicKey = TlsDHUtils.validateDHPublicKey((DHPublicKeyParameters)this.serverPublicKey);
+            }
+            catch (ClassCastException e)
+            {
+                throw new TlsFatalAlert(AlertDescription.certificate_unknown);
+            }
+
+            TlsUtils.validateKeyUsage(x509Cert, KeyUsage.keyAgreement);
+        }
+        else
+        {
+            if (!tlsSigner.isValidPublicKey(this.serverPublicKey))
+            {
+                throw new TlsFatalAlert(AlertDescription.certificate_unknown);
+            }
+
+            TlsUtils.validateKeyUsage(x509Cert, KeyUsage.digitalSignature);
+        }
+
+        super.processServerCertificate(serverCertificate);
+    }
+
+    public boolean requiresServerKeyExchange()
+    {
+        switch (keyExchange)
+        {
+        case KeyExchangeAlgorithm.DHE_DSS:
+        case KeyExchangeAlgorithm.DHE_RSA:
+        case KeyExchangeAlgorithm.DH_anon:
+            return true;
+        default:
+            return false;
+        }
+    }
+
+    public void validateCertificateRequest(CertificateRequest certificateRequest)
+        throws IOException
+    {
+        short[] types = certificateRequest.getCertificateTypes();
+        for (int i = 0; i < types.length; ++i)
+        {
+            switch (types[i])
+            {
+            case ClientCertificateType.rsa_sign:
+            case ClientCertificateType.dss_sign:
+            case ClientCertificateType.rsa_fixed_dh:
+            case ClientCertificateType.dss_fixed_dh:
+            case ClientCertificateType.ecdsa_sign:
+                break;
+            default:
+                throw new TlsFatalAlert(AlertDescription.illegal_parameter);
+            }
+        }
+    }
+
+    public void processClientCredentials(TlsCredentials clientCredentials)
+        throws IOException
+    {
+        if (clientCredentials instanceof TlsAgreementCredentials)
+        {
+            // TODO Validate client cert has matching parameters (see 'areCompatibleParameters')?
+
+            this.agreementCredentials = (TlsAgreementCredentials)clientCredentials;
+        }
+        else if (clientCredentials instanceof TlsSignerCredentials)
+        {
+            // OK
+        }
+        else
+        {
+            throw new TlsFatalAlert(AlertDescription.internal_error);
+        }
+    }
+
+    public void generateClientKeyExchange(OutputStream output)
+        throws IOException
+    {
+        /*
+         * RFC 2246 7.4.7.2 If the client certificate already contains a suitable Diffie-Hellman
+         * key, then Yc is implicit and does not need to be sent again. In this case, the Client Key
+         * Exchange message will be sent, but will be empty.
+         */
+        if (agreementCredentials == null)
+        {
+            this.dhAgreeClientPrivateKey = TlsDHUtils.generateEphemeralClientKeyExchange(context.getSecureRandom(),
+                dhAgreeServerPublicKey.getParameters(), output);
+        }
+    }
+
+    public byte[] generatePremasterSecret()
+        throws IOException
+    {
+        if (agreementCredentials != null)
+        {
+            return agreementCredentials.generateAgreement(dhAgreeServerPublicKey);
+        }
+
+        if (dhAgreeServerPrivateKey != null)
+        {
+            return TlsDHUtils.calculateDHBasicAgreement(dhAgreeClientPublicKey, dhAgreeServerPrivateKey);
+        }
+
+        if (dhAgreeClientPrivateKey != null)
+        {
+            return TlsDHUtils.calculateDHBasicAgreement(dhAgreeServerPublicKey, dhAgreeClientPrivateKey);
+        }
+
+        throw new TlsFatalAlert(AlertDescription.internal_error);
+    }
+}