pdfpkcs7.java

iText是一个能够快速产生PDF文件的java类库。iText的java类对于那些要产生包含文本

                }
            }
            if (j == certs.length)
                return new Object[]{cert, "Cannot be verified against the KeyStore or the certificate chain"};
        }
        return new Object[]{null, "Invalid state. Possible circular certificate chain"};
    }

    /**
     * Get the "issuer" from the TBSCertificate bytes that are passed in
     * @param enc a TBSCertificate in a byte array
     * @return a DERObject
     */
    private static DERObject getIssuer(byte[] enc) {
        try {
            ASN1InputStream in = new ASN1InputStream(new ByteArrayInputStream(enc));
            ASN1Sequence seq = (ASN1Sequence)in.readObject();
            return (DERObject)seq.getObjectAt(seq.getObjectAt(0) instanceof DERTaggedObject ? 3 : 2);
        }
        catch (IOException e) {
            throw new ExceptionConverter(e);
        }
    }

    /**
     * Get the "subject" from the TBSCertificate bytes that are passed in
     * @param enc A TBSCertificate in a byte array
     * @return a DERObject
     */
    private static DERObject getSubject(byte[] enc) {
        try {
            ASN1InputStream in = new ASN1InputStream(new ByteArrayInputStream(enc));
            ASN1Sequence seq = (ASN1Sequence)in.readObject();
            return (DERObject)seq.getObjectAt(seq.getObjectAt(0) instanceof DERTaggedObject ? 5 : 4);
        }
        catch (IOException e) {
            throw new ExceptionConverter(e);
        }
    }

    /**
     * Get the issuer fields from an X509 Certificate
     * @param cert an X509Certificate
     * @return an X509Name
     */
    public static X509Name getIssuerFields(X509Certificate cert) {
        try {
            return new X509Name((ASN1Sequence)getIssuer(cert.getTBSCertificate()));
        }
        catch (Exception e) {
            throw new ExceptionConverter(e);
        }
    }

    /**
     * Get the subject fields from an X509 Certificate
     * @param cert an X509Certificate
     * @return an X509Name
     */
    public static X509Name getSubjectFields(X509Certificate cert) {
        try {
            return new X509Name((ASN1Sequence)getSubject(cert.getTBSCertificate()));
        }
        catch (Exception e) {
            throw new ExceptionConverter(e);
        }
    }
    
    /**
     * Gets the bytes for the PKCS#1 object.
     * @return a byte array
     */
    public byte[] getEncodedPKCS1() {
        try {
            if (externalDigest != null)
                digest = externalDigest;
            else
                digest = sig.sign();
            ByteArrayOutputStream   bOut = new ByteArrayOutputStream();
            
            ASN1OutputStream dout = new ASN1OutputStream(bOut);
            dout.writeObject(new DEROctetString(digest));
            dout.close();
            
            return bOut.toByteArray();
        }
        catch (Exception e) {
            throw new ExceptionConverter(e);
        }
    }
    
    /**
     * Sets the digest/signature to an external calculated value.
     * @param digest the digest. This is the actual signature
     * @param RSAdata the extra data that goes into the data tag in PKCS#7
     * @param digestEncryptionAlgorithm the encryption algorithm. It may must be <CODE>null</CODE> if the <CODE>digest</CODE>
     * is also <CODE>null</CODE>. If the <CODE>digest</CODE> is not <CODE>null</CODE>
     * then it may be "RSA" or "DSA"
     */    
    public void setExternalDigest(byte digest[], byte RSAdata[], String digestEncryptionAlgorithm) {
        externalDigest = digest;
        externalRSAdata = RSAdata;
        if (digestEncryptionAlgorithm != null) {
            if (digestEncryptionAlgorithm.equals("RSA")) {
                this.digestEncryptionAlgorithm = ID_RSA;
            }
            else if (digestEncryptionAlgorithm.equals("DSA")) {
                this.digestEncryptionAlgorithm = ID_DSA;
            }
            else
                throw new ExceptionConverter(new NoSuchAlgorithmException("Unknown Key Algorithm "+digestEncryptionAlgorithm));
        }
    }
    
    /**
     * Gets the bytes for the PKCS7SignedData object.
     * @return the bytes for the PKCS7SignedData object
     */
    public byte[] getEncodedPKCS7() {
        return getEncodedPKCS7(null, null);
    }
    
    /**
     * Gets the bytes for the PKCS7SignedData object. Optionally the authenticatedAttributes
     * in the signerInfo can also be set. If either of the parameters is <CODE>null</CODE>, none will be used.
     * @param secondDigest the digest in the authenticatedAttributes
     * @param signingTime the signing time in the authenticatedAttributes
     * @return the bytes for the PKCS7SignedData object
     */
    public byte[] getEncodedPKCS7(byte secondDigest[], Calendar signingTime) {
        try {
            if (externalDigest != null) {
                digest = externalDigest;
                if (RSAdata != null)
                    RSAdata = externalRSAdata;
            }
            else if (externalRSAdata != null && RSAdata != null) {
                RSAdata = externalRSAdata;
                sig.update(RSAdata);
                digest = sig.sign();
            }
            else {
                if (RSAdata != null) {
                    RSAdata = messageDigest.digest();
                    sig.update(RSAdata);
                }
                digest = sig.sign();
            }
            
            // Create the set of Hash algorithms
            DERConstructedSet digestAlgorithms = new DERConstructedSet();
            for(Iterator it = digestalgos.iterator(); it.hasNext();) {
                ASN1EncodableVector algos = new ASN1EncodableVector();
                algos.add(new DERObjectIdentifier((String)it.next()));
                algos.add(new DERNull());
                digestAlgorithms.addObject(new DERSequence(algos));
            }
            
            // Create the contentInfo.
            ASN1EncodableVector v = new ASN1EncodableVector();
            v.add(new DERObjectIdentifier(ID_PKCS7_DATA));
            if (RSAdata != null)
                v.add(new DERTaggedObject(0, new DEROctetString(RSAdata)));
            DERSequence contentinfo = new DERSequence(v);
            
            // Get all the certificates
            //
            v = new ASN1EncodableVector();
            for (Iterator i = certs.iterator(); i.hasNext();) {
                ASN1InputStream tempstream = new ASN1InputStream(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));
            
            v = new ASN1EncodableVector();
            v.add(getIssuer(signCert.getTBSCertificate()));
            v.add(new DERInteger(signCert.getSerialNumber()));
            signerinfo.add(new DERSequence(v));
            
            // Add the digestAlgorithm
            v = new ASN1EncodableVector();
            v.add(new DERObjectIdentifier(digestAlgorithm));
            v.add(new DERNull());
            signerinfo.add(new DERSequence(v));
            
            // add the authenticated attribute if present
            if (secondDigest != null && signingTime != null) {
                ASN1EncodableVector attribute = new ASN1EncodableVector();
                v = new ASN1EncodableVector();
                v.add(new DERObjectIdentifier(ID_CONTENT_TYPE));
                v.add(new DERSet(new DERObjectIdentifier(ID_PKCS7_DATA)));
                attribute.add(new DERSequence(v));
                v = new ASN1EncodableVector();
                v.add(new DERObjectIdentifier(ID_SIGNING_TIME));
                v.add(new DERSet(new DERUTCTime(signingTime.getTime())));
                attribute.add(new DERSequence(v));
                v = new ASN1EncodableVector();
                v.add(new DERObjectIdentifier(ID_MESSAGE_DIGEST));
                v.add(new DERSet(new DEROctetString(secondDigest)));
                attribute.add(new DERSequence(v));
                if (!crls.isEmpty()) {
                    v = new ASN1EncodableVector();
                    v.add(new DERObjectIdentifier(ID_ADBE_REVOCATION));
                    ASN1EncodableVector v2 = new ASN1EncodableVector();
                    for (Iterator i = crls.iterator();i.hasNext();) {
                        ASN1InputStream t = new ASN1InputStream(new ByteArrayInputStream((((X509CRL)i.next()).getEncoded())));
                        v2.add(t.readObject());
                    }
                    v.add(new DERSet(new DERSequence(new DERTaggedObject(true, 0, new DERSequence(v2)))));
                    attribute.add(new DERSequence(v));
                }                
                signerinfo.add(new DERTaggedObject(false, 0, new DERSet(attribute)));
            }
            // Add the digestEncryptionAlgorithm
            v = new ASN1EncodableVector();
            v.add(new DERObjectIdentifier(digestEncryptionAlgorithm));
            v.add(new DERNull());
            signerinfo.add(new DERSequence(v));
            
            // 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(digestAlgorithms);
            body.add(contentinfo);
            body.add(new DERTaggedObject(false, 0, dercertificates));
            
            if (!crls.isEmpty()) {
                v = new ASN1EncodableVector();
                for (Iterator i = crls.iterator();i.hasNext();) {
                    ASN1InputStream t = new ASN1InputStream(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();
            
            ASN1OutputStream dout = new ASN1OutputStream(bOut);
            dout.writeObject(new DERSequence(whole));
            dout.close();
            
            return bOut.toByteArray();
        }
        catch (Exception e) {
            throw new ExceptionConverter(e);
        }
    }
    
    
    /**
     * When using authenticatedAttributes the authentication process is different.
     * The document digest is generated and put inside the attribute. The signing is done over the DER encoded
     * authenticatedAttributes. This method provides that encoding and the parameters must be
     * exactly the same as in {@link #getEncodedPKCS7(byte[],Calendar)}.
     * <p>
     * A simple example:
     * <p>
     * <pre>
     * Calendar cal = Calendar.getInstance();
     * PdfPKCS7 pk7 = new PdfPKCS7(key, chain, null, "SHA1", null, false);
     * MessageDigest messageDigest = MessageDigest.getInstance("SHA1");
     * byte buf[] = new byte[8192];
     * int n;
     * InputStream inp = sap.getRangeStream();
     * while ((n = inp.read(buf)) &gt; 0) {
     *    messageDigest.update(buf, 0, n);
     * }
     * byte hash[] = messageDigest.digest();
     * byte sh[] = pk7.getAuthenticatedAttributeBytes(hash, cal);
     * pk7.update(sh, 0, sh.length);
     * byte sg[] = pk7.getEncodedPKCS7(hash, cal);
     * </pre>
     * @param secondDigest the content digest
     * @param signingTime the signing time
     * @return the byte array representation of the authenticatedAttributes ready to be signed
     */    
    public byte[] getAuthenticatedAttributeBytes(byte secondDigest[], Calendar signingTime) {
        try {
            ASN1EncodableVector attribute = new ASN1EncodableVector();
            ASN1EncodableVector v = new ASN1EncodableVector();
            v.add(new DERObjectIdentifier(ID_CONTENT_TYPE));
            v.add(new DERSet(new DERObjectIdentifier(ID_PKCS7_DATA)));
            attribute.add(new DERSequence(v));
            v = new ASN1EncodableVector();
            v.add(new DERObjectIdentifier(ID_SIGNING_TIME));
            v.add(new DERSet(new DERUTCTime(signingTime.getTime())));
            attribute.add(new DERSequence(v));
            v = new ASN1EncodableVector();
            v.add(new DERObjectIdentifier(ID_MESSAGE_DIGEST));
            v.add(new DERSet(new DEROctetString(secondDigest)));
            attribute.add(new DERSequence(v));
            if (!crls.isEmpty()) {
                v = new ASN1EncodableVector();
                v.add(new DERObjectIdentifier(ID_ADBE_REVOCATION));
                ASN1EncodableVector v2 = new ASN1EncodableVector();
                for (Iterator i = crls.iterator();i.hasNext();) {
                    ASN1InputStream t = new ASN1InputStream(new ByteArrayInputStream((((X509CRL)i.next()).getEncoded())));
                    v2.add(t.readObject());
                }
                v.add(new DERSet(new DERSequence(new DERTaggedObject(true, 0, new DERSequence(v2)))));
                attribute.add(new DERSequence(v));