pbecrypt.java

一个java开发的非常全面的关于证书发放

     **/
    public static void encryptFile(String file
                                   , String newfile
                                   , StringBuffer passphrase
                                   , byte[] seed
                                   , String algorithm) throws CryptoException, IOException {

        FileInputStream fis = null;
        FileOutputStream fos = null;
        DataOutputStream dao = null;

        try {
            fis = new FileInputStream(file);

            fos = new FileOutputStream(newfile);
            dao = new DataOutputStream(fos);

            // encrypt file
            encrypt(fis, dao, seed, passphrase, algorithm, BUFFERSIZE_FILE);

        } catch (IOException ioe) {
            ioe.printStackTrace();
            throw new IOException(ioe.getMessage());
        } finally {
            if (dao != null) {
                // close outputstream
                try {
                    dao.close();
                } catch (IOException e) {
                    ;
                }
            }
            if (fis != null) {
                // close outputstream
                try {
                    fis.close();
                } catch (IOException e) {
                    ;
                }
            }
        }
    }

    /**
     * Decrypts a ciphertext with PBE
     *
     * @param text the ciphertext
     * @param passphrase password or passphrase
     * @param algorithm encryption algorithm (e.g. "PBEWithSHAAndIDEA-CBC")
     * @return the decrypted plaintext
     * @throws net.sourceforge.jcetaglib.exceptions.CryptoException for all encryption errors
     */
    public static StringBuffer decrypt(StringBuffer text
                                       , StringBuffer passphrase
                                       , String algorithm) throws CryptoException {

        ByteArrayOutputStream bao = null;
        DataOutputStream dao = null;

        try {
            bao = new ByteArrayOutputStream();
            dao = new DataOutputStream(bao);

            // decrypt
            decrypt(new ByteArrayInputStream(Base64.decode(text.toString())), dao, passphrase, algorithm, BUFFERSIZE_TEXT);

            return new StringBuffer(new String(bao.toByteArray()));

        } catch (IOException ioe) {
            ioe.printStackTrace();
            throw new CryptoException(ioe.getMessage());
        } finally {
            if (dao != null) {
                // close outputstream
                try {
                    dao.close();
                } catch (IOException e) {
                    ;
                }
            }
        }
    }

    /**
     * Decrypts any inputstream with PBE
     *
     * @param is the ciphered inputstream
     * @param daos deciphered outputstream
     * @param passphrase password or passphrase
     * @param algorithm encryption algorithm (e.g. "PBEWithSHAAndIDEA-CBC")
     * @param bufferlength buffer length in bytes
     * @throws net.sourceforge.jcetaglib.exceptions.CryptoException encryption errors
     * @throws IOException I/O errors
     */
    public static void decrypt(InputStream is
                               , DataOutputStream daos
                               , StringBuffer passphrase
                               , String algorithm
                               , int bufferlength)
            throws CryptoException, IOException {

        CipherInputStream ciStr = null;
        PBEKeySpec pbeKeySpec;
        PBEParameterSpec pbeParamSpec;
        SecretKeyFactory keyFac;
        SecretKey pbeKey;
        Cipher pbeCipher;

        try {
            // Add Bouncy Castle provider
            Security.addProvider(new BouncyCastleProvider());

            // read the salt
            byte[] randomsalt = new byte[8];
            is.read(randomsalt);

            // Create PBE parameter set
            pbeParamSpec = new PBEParameterSpec(randomsalt, PBE_COUNT);

            pbeKeySpec = new PBEKeySpec(passphrase.toString().toCharArray());
            keyFac = SecretKeyFactory.getInstance(algorithm);
            pbeKey = keyFac.generateSecret(pbeKeySpec);

            // Create PBE Cipher
            pbeCipher = Cipher.getInstance(algorithm);

            // Initialize PBE Cipher with key and parameters
            pbeCipher.init(Cipher.DECRYPT_MODE, pbeKey, pbeParamSpec);

            // Initialize cipher inputstream
            ciStr = new CipherInputStream(is, pbeCipher);

            // Read bytes and run them through cipher
            byte[] buffer = new byte[bufferlength];
            int length = 0;
            while ((length = ciStr.read(buffer)) != -1) {
                daos.write(buffer, 0, length);
            }
        } catch (IOException ioe) {
            ioe.printStackTrace();
            throw new IOException(ioe.getMessage());
        } catch (Exception ex) {
            ex.printStackTrace();
            throw new CryptoException(ex.getMessage());
        } finally {
            if (ciStr != null) {
                try {
                    ciStr.close();
                } catch (IOException ioe) {
                    ;
                }
            }
        }
    }

    /**
     * Decrypts a ciphered file with PBE
     *
     * @param file the file to decrypt
     * @param file the deciphered file
     * @param passphrase the password or passphrase
     * @param algorithm encryption algorithm (e.g. "PBEWithSHAAndIDEA-CBC")
     * @exception net.sourceforge.jcetaglib.exceptions.CryptoException for all encryption errors
     * @exception IOException I/O errors
     **/
    public static void decryptFile(String file
                                   , String newfile
                                   , StringBuffer passphrase
                                   , String algorithm) throws CryptoException, IOException {

        FileInputStream fis = null;
        FileOutputStream fos = null;
        DataOutputStream dao = null;

        try {
            fis = new FileInputStream(file);

            fos = new FileOutputStream(newfile);
            dao = new DataOutputStream(fos);

            // decrypt file
            decrypt(fis, dao, passphrase, algorithm, BUFFERSIZE_FILE);

        } catch (IOException ioe) {
            ioe.printStackTrace();
            throw new IOException(ioe.getMessage());
        } finally {
            if (dao != null) {
                // close outputstream
                try {
                    dao.close();
                } catch (IOException e) {
                    ;
                }
            }
            if (fis != null) {
                // close inputstream
                try {
                    fis.close();
                } catch (IOException e) {
                    ;
                }
            }
        }
    }
}