PemReader Class — netty Architecture

Source Code

handler/src/main/java/io/netty/handler/ssl/PemReader.java lines 40–165

final class PemReader {

    private static final Pattern CERT_HEADER = Pattern.compile(
            "-+BEGIN\\s[^-\\r\\n]*CERTIFICATE[^-\\r\\n]*-+(?:\\s|\\r|\\n)+");
    private static final Pattern CERT_FOOTER = Pattern.compile(
            "-+END\\s[^-\\r\\n]*CERTIFICATE[^-\\r\\n]*-+(?:\\s|\\r|\\n)*");
    private static final Pattern KEY_HEADER = Pattern.compile(
            "-+BEGIN\\s[^-\\r\\n]*PRIVATE\\s+KEY[^-\\r\\n]*-+(?:\\s|\\r|\\n)+");
    private static final Pattern KEY_FOOTER = Pattern.compile(
            "-+END\\s[^-\\r\\n]*PRIVATE\\s+KEY[^-\\r\\n]*-+(?:\\s|\\r|\\n)*");
    private static final Pattern BODY = Pattern.compile("[a-z0-9+/=][a-z0-9+/=\\r\\n]*", Pattern.CASE_INSENSITIVE);

    static ByteBuf[] readCertificates(File file) throws CertificateException {
        try (InputStream in = new FileInputStream(file)) {
            return readCertificates(in);
        } catch (IOException e) {
            throw new CertificateException("could not find certificate file: " + file);
        }
    }

    static ByteBuf[] readCertificates(InputStream in) throws CertificateException {
        String content;
        try {
            content = readContent(in);
        } catch (IOException e) {
            throw new CertificateException("failed to read certificate input stream", e);
        }

        List<ByteBuf> certs = new ArrayList<ByteBuf>();
        Matcher m = CERT_HEADER.matcher(content);
        int start = 0;
        for (;;) {
            if (!m.find(start)) {
                break;
            }

            // Here and below it's necessary to save the position as it is reset
            // after calling usePattern() on Android due to a bug.
            //
            // See https://issuetracker.google.com/issues/293206296
            start = m.end();
            m.usePattern(BODY);
            if (!m.find(start)) {
                break;
            }

            ByteBuf base64 = Unpooled.copiedBuffer(m.group(0), CharsetUtil.US_ASCII);
            start = m.end();
            m.usePattern(CERT_FOOTER);
            if (!m.find(start)) {
                // Certificate is incomplete.
                break;
            }
            ByteBuf der = Base64.decode(base64);
            base64.release();
            certs.add(der);

            start = m.end();
            m.usePattern(CERT_HEADER);
        }

        if (certs.isEmpty()) {
            throw new CertificateException("found no certificates in input stream");
        }

        return certs.toArray(new ByteBuf[0]);
    }

    static ByteBuf readPrivateKey(File file) throws KeyException {
        try (InputStream in = new FileInputStream(file)) {
            return readPrivateKey(in);
        } catch (IOException e) {
            throw new KeyException("could not find key file: " + file);
        }
    }

    static ByteBuf readPrivateKey(InputStream in) throws KeyException {
        String content;
        try {
            content = readContent(in);
        } catch (IOException e) {