SonatypeNexus:Apt

  private PGPSecretKey readSecretKey() throws IOException, PGPException {
    PGPSecretKeyRingCollection pgpSec = new PGPSecretKeyRingCollection(
        PGPUtil.getDecoderStream(new ByteArrayInputStream(config.keypair.getBytes())),
        new JcaKeyFingerprintCalculator());

    Iterator<PGPSecretKeyRing> keyRings = pgpSec.getKeyRings();
    while (keyRings.hasNext()) {
      PGPSecretKeyRing keyRing = (PGPSecretKeyRing) keyRings.next();

      Iterator<PGPSecretKey> keys = keyRing.getSecretKeys();
      while (keys.hasNext()) {
        PGPSecretKey key = (PGPSecretKey) keys.next();

        if (key.isSigningKey()) {
          return key;
        }
      }
    }

    throw new IllegalStateException("Can't find signing key in key ring.");
  }

    /**
     * Obtains a stream that can be used to read PGP data from the provided stream.
     * <p>
     * If the initial bytes of the underlying stream are binary PGP encodings, then the stream will
     * be returned directly, otherwise an {@link ArmoredInputStream} is used to wrap the provided
     * stream and remove ASCII-Armored encoding.
     * </p>
     *
     * @param in the stream to be checked and possibly wrapped.
     * @return a stream that will return PGP binary encoded data.
     * @throws IOException if an error occurs reading the stream, or initialising the
     * {@link ArmoredInputStream}.
     */
    public static InputStream getDecoderStream(
        InputStream in)
        throws IOException
    {
        if (!in.markSupported())
        {
            in = new BufferedInputStreamExt(in);
        }

        in.mark(READ_AHEAD);

        int ch = in.read();


        if ((ch & 0x80) != 0)
        {
            in.reset();

            return in;
        }
        else
        {
            if (!isPossiblyBase64(ch))
            {
                in.reset();

                return new ArmoredInputStream(in);
            }

            byte[] buf = new byte[READ_AHEAD];
            int count = 1;
            int index = 1;

            buf[0] = (byte)ch;
            while (count != READ_AHEAD && (ch = in.read()) >= 0)
            {
                if (!isPossiblyBase64(ch))
                {
                    in.reset();

                    return new ArmoredInputStream(in);
                }

                if (ch != '\n' && ch != '\r')
                {
                    buf[index++] = (byte)ch;
                }

                count++;
            }

            in.reset();

            //
            // nothing but new lines, little else, assume regular armoring
            //
            if (count < 4)
            {
                return new ArmoredInputStream(in);
            }

            //
            // test our non-blank data
            //
            byte[] firstBlock = new byte[8];

            System.arraycopy(buf, 0, firstBlock, 0, firstBlock.length);

            try
            {
                byte[] decoded = Base64.decode(firstBlock);

                //
                // it's a base64 PGP block.
                //
                if ((decoded[0] & 0x80) != 0)
                {
                    return new ArmoredInputStream(in, false);
                }

                return new ArmoredInputStream(in);
            }
            catch (DecoderException e)
            {
                throw new IOException(e.getMessage());
            }
        }
    }