pkcs7signeddata.java

这是一个基于java编写的torrent的P2P源码

        //
        // Copy in the certificates and crls used to sign the private key.
        //
        signCert = (X509Certificate)certChain[0];
        for (int i = 0;i < certChain.length;i++)
        {
            certs.add(certChain[i]);
        }

        if (crlList != null)
        {
            for (int i = 0;i < crlList.length;i++)
            {
                crls.add(crlList[i]);
            }
        }

        //
        // Now we have private key, find out what the digestEncryptionAlgorithm is.
        //
        digestEncryptionAlgorithm = privKey.getAlgorithm();
        if (digestEncryptionAlgorithm.equals("RSA"))
        {
            digestEncryptionAlgorithm = ID_RSA;
        }
        else if (digestEncryptionAlgorithm.equals("DSA"))
        {
            digestEncryptionAlgorithm = ID_DSA;
        }
        else
        {
            throw new NoSuchAlgorithmException("Unknown Key Algorithm "+digestEncryptionAlgorithm);
        }

        sig = Signature.getInstance(getDigestAlgorithm(), provider);

        sig.initSign(privKey);
    }

    /**
     * Get the algorithm used to calculate the message digest
     */
    public String getDigestAlgorithm()
    {
        String da = digestAlgorithm;
        String dea = digestEncryptionAlgorithm;

        if (digestAlgorithm.equals(ID_MD5))
        {
            da = "MD5";
        }
	    else if (digestAlgorithm.equals(ID_MD2))
        {
            da = "MD2";
        }
	    else if (digestAlgorithm.equals(ID_SHA1))
        {
            da = "SHA1";
        }

        if (digestEncryptionAlgorithm.equals(ID_RSA))
        {
            dea = "RSA";
        }
	    else if (digestEncryptionAlgorithm.equals(ID_DSA))
        {
            dea = "DSA";
        }

        return da + "with" + dea;
    }

    /**
     * Resets the PKCS7SignedData object to it's initial state, ready
     * to sign or verify a new buffer.
     */
    public void reset()
    {
        try
        {
            if (privKey==null)
            {
                sig.initVerify(signCert.getPublicKey());
            }
            else
            {
                sig.initSign(privKey);
            }
        }
        catch (Exception e)
        {
            throw new RuntimeException(e.toString());
        }
    }

    /**
     * Get the X.509 certificates associated with this PKCS#7 object
     */
    public Certificate[] getCertificates()
    {
        return (X509Certificate[])certs.toArray(new X509Certificate[certs.size()]);
    }

    /**
     * Get the X.509 certificate revocation lists associated with this PKCS#7 object
     */
    public Collection getCRLs()
    {
        return crls;
    }
    
    /**
     * Get the X.509 certificate actually used to sign the digest.
     */
    public X509Certificate getSigningCertificate()
    {
        return signCert;
    }

    /**
     * Get the version of the PKCS#7 object. Always 1
     */
    public int getVersion()
    {
        return version;
    }

    /**
     * Get the version of the PKCS#7 "SignerInfo" object. Always 1
     */
    public int getSigningInfoVersion()
    {
        return signerversion;
    }

    /**
     * Update the digest with the specified byte. This method is used both for signing and verifying
     */
    public void update(byte buf)
        throws SignatureException
    {
        sig.update(buf);
    }

    /**
     * Update the digest with the specified bytes. This method is used both for signing and verifying
     */
    public void update(byte[] buf, int off, int len)
        throws SignatureException
    {
        sig.update(buf, off, len);
    }

    /**
     * Verify the digest
     */
    public boolean verify()
        throws SignatureException
    {
        return sig.verify(digest);
    }

    /**
     * Get the "issuer" from the TBSCertificate bytes that are passed in
     */
    private DERObject getIssuer(byte[] enc)
    {
        try
        {
            DERInputStream in = new DERInputStream(new ByteArrayInputStream(enc));
            ASN1Sequence seq = (ASN1Sequence)in.readObject();
            return (DERObject)seq.getObjectAt(seq.getObjectAt(0) instanceof DERTaggedObject ? 3 : 2);
        }
        catch (IOException e)
        {
            throw new Error("IOException reading from ByteArray: "+e);
	    }
    }

    /**
     * return the bytes for the PKCS7SignedData object.
     */
    public byte[] getEncoded()
    {
        try
        {
        
            digest = sig.sign();

            // Create the set of Hash algorithms. I've assumed this is the
            // set of all hash agorithms used to created the digest in the
            // "signerInfo" structure. I may be wrong.
            //
            ASN1EncodableVector v = new ASN1EncodableVector();
            for (Iterator i = digestalgos.iterator(); i.hasNext();)
            {
                AlgorithmIdentifier a = new AlgorithmIdentifier(
                            new DERObjectIdentifier((String)i.next()),
                            null);
                
                v.add(a);
            }

            DERSet algos = new DERSet(v);

            // Create the contentInfo. Empty, I didn't implement this bit
            //
            DERSequence contentinfo = new DERSequence(
                                        new DERObjectIdentifier(ID_PKCS7_DATA));

            // Get all the certificates
            //
            v = new ASN1EncodableVector();
            for (Iterator i = certs.iterator();i.hasNext();)
            {
                DERInputStream tempstream = new DERInputStream(new ByteArrayInputStream(((X509Certificate)i.next()).getEncoded()));
                v.add(tempstream.readObject());
            }

            DERSet dercertificates = new DERSet(v);

            // Create signerinfo structure.
            //
            ASN1EncodableVector signerinfo = new ASN1EncodableVector();

            // Add the signerInfo version
            //
            signerinfo.add(new DERInteger(signerversion));

            IssuerAndSerialNumber isAnds = new IssuerAndSerialNumber(
                        new X509Name((ASN1Sequence)getIssuer(signCert.getTBSCertificate())),
                        new DERInteger(signCert.getSerialNumber()));
            signerinfo.add(isAnds);

            // Add the digestAlgorithm
            //
            signerinfo.add(new AlgorithmIdentifier(
                                new DERObjectIdentifier(digestAlgorithm),
                                new DERNull()));

            //
            // Add the digestEncryptionAlgorithm
            //
            signerinfo.add(new AlgorithmIdentifier(
                                new DERObjectIdentifier(digestEncryptionAlgorithm),
                                new DERNull()));

            //
            // Add the digest
            //
            signerinfo.add(new DEROctetString(digest));


            //
            // Finally build the body out of all the components above
            //
            ASN1EncodableVector body = new ASN1EncodableVector();
            body.add(new DERInteger(version));
            body.add(algos);
            body.add(contentinfo);
            body.add(new DERTaggedObject(false, 0, dercertificates));

            if (crls.size()>0) {
                v = new ASN1EncodableVector();
                for (Iterator i = crls.iterator();i.hasNext();) {
                    DERInputStream t = new DERInputStream(new ByteArrayInputStream((((X509CRL)i.next()).getEncoded())));
                    v.add(t.readObject());
                }
                DERSet dercrls = new DERSet(v);
                body.add(new DERTaggedObject(false, 1, dercrls));
            }

            // Only allow one signerInfo
            //
            body.add(new DERSet(new DERSequence(signerinfo)));

            // Now we have the body, wrap it in it's PKCS7Signed shell
            // and return it
            //
            ASN1EncodableVector whole = new ASN1EncodableVector();
            whole.add(new DERObjectIdentifier(ID_PKCS7_SIGNED_DATA));
            whole.add(new DERTaggedObject(0, new DERSequence(body)));

            ByteArrayOutputStream   bOut = new ByteArrayOutputStream();

            DEROutputStream dout = new DEROutputStream(bOut);
            dout.writeObject(new DERSequence(whole));
            dout.close();

            return bOut.toByteArray();
        }
        catch (Exception e)
        {
            throw new RuntimeException(e.toString());
        }
    }
}