package org.bouncycastle.openpgp;
import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.DERInteger;
import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.bcpg.*;
import org.bouncycastle.util.BigIntegers;
import org.bouncycastle.util.Strings;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.security.InvalidKeyException;
import java.security.NoSuchProviderException;
import java.security.Signature;
import java.security.SignatureException;
import java.security.Provider;
import java.util.Date;
/**
*A PGP signature object.
*/
public class PGPSignature
{
public static final int BINARY_DOCUMENT = 0x00;
public static final int CANONICAL_TEXT_DOCUMENT = 0x01;
public static final int STAND_ALONE = 0x02;
public static final int DEFAULT_CERTIFICATION = 0x10;
public static final int NO_CERTIFICATION = 0x11;
public static final int CASUAL_CERTIFICATION = 0x12;
public static final int POSITIVE_CERTIFICATION = 0x13;
public static final int SUBKEY_BINDING = 0x18;
public static final int PRIMARYKEY_BINDING = 0x19;
public static final int DIRECT_KEY = 0x1f;
public static final int KEY_REVOCATION = 0x20;
public static final int SUBKEY_REVOCATION = 0x28;
public static final int CERTIFICATION_REVOCATION = 0x30;
public static final int TIMESTAMP = 0x40;
private SignaturePacket sigPck;
private Signature sig;
private int signatureType;
private TrustPacket trustPck;
private byte lastb;
PGPSignature(
BCPGInputStream pIn)
throws IOException, PGPException
{
this((SignaturePacket)pIn.readPacket());
}
PGPSignature(
SignaturePacket sigPacket)
throws PGPException
{
sigPck = sigPacket;
signatureType = sigPck.getSignatureType();
trustPck = null;
}
PGPSignature(
SignaturePacket sigPacket,
TrustPacket trustPacket)
throws PGPException
{
this(sigPacket);
this.trustPck = trustPacket;
}
private void getSig(
Provider provider)
throws PGPException
{
try
{
this.sig = Signature.getInstance(PGPUtil.getSignatureName(sigPck.getKeyAlgorithm(), sigPck.getHashAlgorithm()), provider);
}
catch (Exception e)
{
throw new PGPException("can't set up signature object.", e);
}
}
/**
* Return the OpenPGP version number for this signature.
*
* @return signature version number.
*/
public int getVersion()
{
return sigPck.getVersion();
}
/**
* Return the key algorithm associated with this signature.
* @return signature key algorithm.
*/
public int getKeyAlgorithm()
{
return sigPck.getKeyAlgorithm();
}
/**
* Return the hash algorithm associated with this signature.
* @return signature hash algorithm.
*/
public int getHashAlgorithm()
{
return sigPck.getHashAlgorithm();
}
public void initVerify(
PGPPublicKey pubKey,
String provider)
throws NoSuchProviderException, PGPException
{
initVerify(pubKey, PGPUtil.getProvider(provider));
}
public void initVerify(
PGPPublicKey pubKey,
Provider provider)
throws PGPException
{
if (sig == null)
{
getSig(provider);
}
try
{
sig.initVerify(pubKey.getKey(provider));
}
catch (InvalidKeyException e)
{
throw new PGPException("invalid key.", e);
}
lastb = 0;
}
public void update(
byte b)
throws SignatureException
{
if (signatureType == PGPSignature.CANONICAL_TEXT_DOCUMENT)
{
if (b == '\r')
{
sig.update((byte)'\r');
sig.update((byte)'\n');
}
else if (b == '\n')
{
if (lastb != '\r')
{
sig.update((byte)'\r');
sig.update((byte)'\n');
}
}
else
{
sig.update(b);
}
lastb = b;
}
else
{
sig.update(b);
}
}
public void update(
byte[] bytes)
throws SignatureException
{
this.update(bytes, 0, bytes.length);
}
public void update(
byte[] bytes,
int off,
int length)
throws SignatureException
{
if (signatureType == PGPSignature.CANONICAL_TEXT_DOCUMENT)
{
int finish = off + length;
for (int i = off; i != finish; i++)
{
this.update(bytes[i]);
}
}
else
{
sig.update(bytes, off, length);
}
}
public boolean verify()
throws PGPException, SignatureException
{
sig.update(this.getSignatureTrailer());
return sig.verify(this.getSignature());
}
private void updateWithIdData(int header, byte[] idBytes)
throws SignatureException
{
this.update((byte)header);
this.update((byte)(idBytes.length >> 24));
this.update((byte)(idBytes.length >> 16));
this.update((byte)(idBytes.length >> 8));
this.update((byte)(idBytes.length));
this.update(idBytes);
}
private void updateWithPublicKey(PGPPublicKey key)
throws PGPException, SignatureException
{
byte[] keyBytes = getEncodedPublicKey(key);
this.update((byte)0x99);
this.update((byte)(keyBytes.length >> 8));
this.update((byte)(keyBytes.length));
this.update(keyBytes);
}
/**
* Verify the signature as certifying the passed in public key as associated
* with the passed in user attributes.
*
* @param userAttributes user attributes the key was stored under
* @param key the key to be verified.
* @return true if the signature matches, false otherwise.
* @throws PGPException
* @throws SignatureException
*/
public boolean verifyCertification(
PGPUserAttributeSubpacketVector userAttributes,
PGPPublicKey key)
throws PGPException, SignatureException
{
updateWithPublicKey(key);
//
// hash in the userAttributes
//
try
{
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
UserAttributeSubpacket[] packets = userAttributes.toSubpacketArray();
for (int i = 0; i != packets.length; i++)
{
packets[i].encode(bOut);
}
updateWithIdData(0xd1, bOut.toByteArray());
}
catch (IOException e)
{
throw new PGPException("cannot encode subpacket array", e);
}
this.update(sigPck.getSignatureTrailer());
return sig.verify(this.getSignature());
}
/**
* Verify the signature as certifying the passed in public key as associated
* with the passed in id.
*
* @param id id the key was stored under
* @param key the key to be verified.
* @return true if the signature matches, false otherwise.
* @throws PGPException
* @throws SignatureException
*/
public boolean verifyCertification(
String id,
PGPPublicKey key)
throws PGPException, SignatureException
{
updateWithPublicKey(key);
//
// hash in the id
//
updateWithIdData(0xb4, Strings.toByteArray(id));
this.update(sigPck.getSignatureTrailer());
return sig.verify(this.getSignature());
}
/**
* Verify a certification for the passed in key against the passed in
* master key.
*
* @param masterKey the key we are verifying against.
* @param pubKey the key we are verifying.
* @return true if the certification is valid, false otherwise.
* @throws SignatureException
* @throws PGPException
*/
public boolean verifyCertification(
PGPPublicKey masterKey,
PGPPublicKey pubKey)
throws SignatureException, PGPException
{
updateWithPublicKey(masterKey);
updateWithPublicKey(pubKey);
this.update(sigPck.getSignatureTrailer());
return sig.verify(this.getSignature());
}
/**
* Verify a key certification, such as a revocation, for the passed in key.
*
* @param pubKey the key we are checking.
* @return true if the certification is valid, false otherwise.
* @throws SignatureException
* @throws PGPException
*/
public boolean verifyCertification(
PGPPublicKey pubKey)
throws SignatureException, PGPException
{
if (this.getSignatureType() != KEY_REVOCATION
&& this.getSignatureType() != SUBKEY_REVOCATION)
{
throw new IllegalStateException("signature is not a key signature");
}
updateWithPublicKey(pubKey);
this.update(sigPck.getSignatureTrailer());
return sig.verify(this.getSignature());
}
public int getSignatureType()
{
return sigPck.getSignatureType();
}
/**
* Return the id of the key that created the signature.
* @return keyID of the signatures corresponding key.
*/
public long getKeyID()
{
return sigPck.getKeyID();
}
/**
* Return the creation time of the signature.
*
* @return the signature creation time.
*/
public Date getCreationTime()
{
return new Date(sigPck.getCreationTime());
}
public byte[] getSignatureTrailer()
{
return sigPck.getSignatureTrailer();
}
/**
* Return true if the signature has either hashed or unhashed subpackets.
*
* @return true if either hashed or unhashed subpackets are present, false otherwise.
*/
public boolean hasSubpackets()
{
return sigPck.getHashedSubPackets() != null || sigPck.getUnhashedSubPackets() != null;
}
public PGPSignatureSubpacketVector getHashedSubPackets()
{
return createSubpacketVector(sigPck.getHashedSubPackets());
}
public PGPSignatureSubpacketVector getUnhashedSubPackets()
{
return createSubpacketVector(sigPck.getUnhashedSubPackets());
}
private PGPSignatureSubpacketVector createSubpacketVector(SignatureSubpacket[] pcks)
{
if (pcks != null)
{
return new PGPSignatureSubpacketVector(pcks);
}
return null;
}
public byte[] getSignature()
throws PGPException
{
MPInteger[] sigValues = sigPck.getSignature();
byte[] signature;
if (sigValues != null)
{
if (sigValues.length == 1) // an RSA signature
{
signature = BigIntegers.asUnsignedByteArray(sigValues[0].getValue());
}
else
{
try
{
ASN1EncodableVector v = new ASN1EncodableVector();
v.add(new DERInteger(sigValues[0].getValue()));
v.add(new DERInteger(sigValues[1].getValue()));
signature = new DERSequence(v).getEncoded();
}
catch (IOException e)
{
throw new PGPException("exception encoding DSA sig.", e);
}
}
}
else
{
signature = sigPck.getSignatureBytes();
}
return signature;
}
public byte[] getEncoded()
throws IOException
{
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
this.encode(bOut);
return bOut.toByteArray();
}
public void encode(
OutputStream outStream)
throws IOException
{
BCPGOutputStream out;
if (outStream instanceof BCPGOutputStream)
{
out = (BCPGOutputStream)outStream;
}
else
{
out = new BCPGOutputStream(outStream);
}
out.writePacket(sigPck);
if (trustPck != null)
{
out.writePacket(trustPck);
}
}
private byte[] getEncodedPublicKey(
PGPPublicKey pubKey)
throws PGPException
{
byte[] keyBytes;
try
{
keyBytes = pubKey.publicPk.getEncodedContents();
}
catch (IOException e)
{
throw new PGPException("exception preparing key.", e);
}
return keyBytes;
}
}