pemreader.java

来自「内容:基于jdk1.4的加密算法的具体实现」· Java 代码 · 共 576 行 · 第 1/2 页

            return (X509Certificate)certFact.generateCertificate(bIn);
        }
        catch (Exception e)
        {
            throw new IOException("problem parsing cert: " + e.toString());
        }
    }

    /**
     * Reads in a PKCS10 certification request.
     *
     * @return the certificate request.
     * @throws IOException if an I/O error occured
     */
    private PKCS10CertificationRequest readCertificateRequest(
        String  endMarker)
        throws IOException
    {
        String          line;
        StringBuffer    buf = new StringBuffer();
  
        while ((line = readLine()) != null)
        {
            if (line.indexOf(endMarker) != -1)
            {
                break;
            }
            buf.append(line.trim());
        }

        if (line == null)
        {
            throw new IOException(endMarker + " not found");
        }

        try
        {
            return new PKCS10CertificationRequest(Base64.decode(buf.toString()));
        }
        catch (Exception e)
        {
            throw new IOException("problem parsing cert: " + e.toString());
        }
    }

    /**
     * Reads in a X509 Attribute Certificate.
     *
     * @return the X509 Attribute Certificate
     * @throws IOException if an I/O error occured
     */
    private X509AttributeCertificate readAttributeCertificate(
        String  endMarker)
        throws IOException
    {
        String          line;
        StringBuffer    buf = new StringBuffer();
  
        while ((line = readLine()) != null)
        {
            if (line.indexOf(endMarker) != -1)
            {
                break;
            }
            buf.append(line.trim());
        }

        if (line == null)
        {
            throw new IOException(endMarker + " not found");
        }

        return new X509V2AttributeCertificate(Base64.decode(buf.toString()));
    }
    
    /**
     * Reads in a PKCS7 object. This returns a ContentInfo object suitable for use with the CMS
     * API.
     *
     * @return the X509Certificate
     * @throws IOException if an I/O error occured
     */
    private ContentInfo readPKCS7(
        String  endMarker)
        throws IOException
    {
        String                                  line;
        StringBuffer                        buf = new StringBuffer();
        ByteArrayOutputStream    bOut = new ByteArrayOutputStream();
  
        while ((line = readLine()) != null)
        {
            if (line.indexOf(endMarker) != -1)
            {
                break;
            }
            
            line = line.trim();
            
            buf.append(line.trim());
            
            Base64.decode(buf.substring(0, (buf.length() / 4) * 4), bOut);

            buf.delete(0, (buf.length() / 4) * 4);
        }

        if (buf.length() != 0)
        {
            throw new RuntimeException("base64 data appears to be truncated");
        }
        
        if (line == null)
        {
            throw new IOException(endMarker + " not found");
        }

        ByteArrayInputStream    bIn = new ByteArrayInputStream(bOut.toByteArray());

        try
        {
            ASN1InputStream aIn = new ASN1InputStream(bIn);

            return ContentInfo.getInstance(aIn.readObject());
        }
        catch (Exception e)
        {
            throw new IOException("problem parsing PKCS7 object: " + e.toString());
        }
    }
    
    /**
     * create the secret key needed for this object, fetching the password
     */
    private SecretKey getKey(
        String  algorithm,
        int     keyLength,
        byte[]  salt)
        throws IOException
    {
        byte[]      key = new byte[keyLength];
        int         offset = 0;
        int         bytesNeeded = keyLength;

        if (pFinder == null)
        {
            throw new IOException("No password finder specified, but a password is required");
        }

        char[]      password = pFinder.getPassword();

        if (password == null)
        {
            throw new IOException("Password is null, but a password is required");
        }
        
        OpenSSLPBEParametersGenerator   pGen = new OpenSSLPBEParametersGenerator();

        pGen.init(PBEParametersGenerator.PKCS5PasswordToBytes(password), salt);

        return new javax.crypto.spec.SecretKeySpec(((KeyParameter)pGen.generateDerivedParameters(keyLength * 8)).getKey(), algorithm);
    }

    /**
     * Read a Key Pair
     */
    private KeyPair readKeyPair(
        String  type,
        String  endMarker)
        throws Exception
    {
        boolean         isEncrypted = false;
        String          line = null;
        String          dekInfo = null;
        StringBuffer    buf = new StringBuffer();

        while ((line = readLine()) != null)
        {
            if (line.startsWith("Proc-Type: 4,ENCRYPTED"))
            {
                isEncrypted = true;
            }
            else if (line.startsWith("DEK-Info:"))
            {
                dekInfo = line.substring(10);
            }
            else if (line.indexOf(endMarker) != -1)
            {
                break;
            }
            else
            {
                buf.append(line.trim());
            }
        }

        //
        // extract the key
        //
        byte[]  keyBytes = null;

        if (isEncrypted)
        {
            StringTokenizer tknz = new StringTokenizer(dekInfo, ",");
            String          encoding = tknz.nextToken();

            if (encoding.equals("DES-EDE3-CBC"))
            {
                String  alg = "DESede";
                byte[]  iv = Hex.decode(tknz.nextToken());
                Key     sKey = getKey(alg, 24, iv);
                Cipher  c = Cipher.getInstance(
                                "DESede/CBC/PKCS5Padding", provider);

                c.init(Cipher.DECRYPT_MODE, sKey, new IvParameterSpec(iv));
                keyBytes = c.doFinal(Base64.decode(buf.toString()));
            }
            else if (encoding.equals("DES-CBC"))
            {
                String  alg = "DES";
                byte[]  iv = Hex.decode(tknz.nextToken());
                Key     sKey = getKey(alg, 8, iv);
                Cipher  c = Cipher.getInstance(
                                "DES/CBC/PKCS5Padding", provider);

                c.init(Cipher.DECRYPT_MODE, sKey, new IvParameterSpec(iv));
                keyBytes = c.doFinal(Base64.decode(buf.toString()));
            }
            else
            {
                throw new IOException("unknown encryption with private key");
            }
        }
        else
        {
            keyBytes = Base64.decode(buf.toString());
        }

        KeySpec                 pubSpec, privSpec;
        ByteArrayInputStream    bIn = new ByteArrayInputStream(keyBytes);
        ASN1InputStream         aIn = new ASN1InputStream(bIn);
        ASN1Sequence            seq = (ASN1Sequence)aIn.readObject();

        if (type.equals("RSA"))
        {
            DERInteger              v = (DERInteger)seq.getObjectAt(0);
            DERInteger              mod = (DERInteger)seq.getObjectAt(1);
            DERInteger              pubExp = (DERInteger)seq.getObjectAt(2);
            DERInteger              privExp = (DERInteger)seq.getObjectAt(3);
            DERInteger              p1 = (DERInteger)seq.getObjectAt(4);
            DERInteger              p2 = (DERInteger)seq.getObjectAt(5);
            DERInteger              exp1 = (DERInteger)seq.getObjectAt(6);
            DERInteger              exp2 = (DERInteger)seq.getObjectAt(7);
            DERInteger              crtCoef = (DERInteger)seq.getObjectAt(8);

            pubSpec = new RSAPublicKeySpec(
                        mod.getValue(), pubExp.getValue());
            privSpec = new RSAPrivateCrtKeySpec(
                    mod.getValue(), pubExp.getValue(), privExp.getValue(),
                    p1.getValue(), p2.getValue(),
                    exp1.getValue(), exp2.getValue(),
                    crtCoef.getValue());
        }
        else    // "DSA"
        {
            DERInteger              v = (DERInteger)seq.getObjectAt(0);
            DERInteger              p = (DERInteger)seq.getObjectAt(1);
            DERInteger              q = (DERInteger)seq.getObjectAt(2);
            DERInteger              g = (DERInteger)seq.getObjectAt(3);
            DERInteger              y = (DERInteger)seq.getObjectAt(4);
            DERInteger              x = (DERInteger)seq.getObjectAt(5);

            privSpec = new DSAPrivateKeySpec(
                        x.getValue(), p.getValue(),
                            q.getValue(), g.getValue());
            pubSpec = new DSAPublicKeySpec(
                        y.getValue(), p.getValue(),
                            q.getValue(), g.getValue());
        }

        KeyFactory          fact = KeyFactory.getInstance(type, provider);

        return new KeyPair(
                    fact.generatePublic(pubSpec),
                    fact.generatePrivate(privSpec));
    }
}