SignatureAlgorithmConverter Class — netty Architecture

Source Code

handler/src/main/java/io/netty/handler/ssl/SignatureAlgorithmConverter.java lines 27–74

final class SignatureAlgorithmConverter {

    private SignatureAlgorithmConverter() { }

    // OpenSSL has 3 different formats it uses at the moment we will match against all of these.
    // For example:
    //              ecdsa-with-SHA384
    //              hmacWithSHA384
    //              dsa_with_SHA224
    //
    // For more details see https://github.com/openssl/openssl/blob/OpenSSL_1_0_2p/crypto/objects/obj_dat.h
    //
    // BoringSSL uses a different format:
    // https://github.com/google/boringssl/blob/8525ff3/ssl/ssl_privkey.cc#L436
    //
    private static final Pattern PATTERN = Pattern.compile(
            // group 1 - 2
            "(?:(^[a-zA-Z].+)With(.+)Encryption$)|" +
            // group 3 - 4
            "(?:(^[a-zA-Z].+)(?:_with_|-with-|_pkcs1_|_pss_rsae_)(.+$))|" +
            // group 5 - 6
            "(?:(^[a-zA-Z].+)_(.+$))");

    /**
     * Converts an OpenSSL algorithm name to a Java algorithm name and return it,
     * or return {@code null} if the conversation failed because the format is not known.
     */
    static String toJavaName(String opensslName) {
        if (opensslName == null) {
            return null;
        }
        Matcher matcher = PATTERN.matcher(opensslName);
        if (matcher.matches()) {
            String group1 = matcher.group(1);
            if (group1 != null) {
                return group1.toUpperCase(Locale.ROOT) + "with" + matcher.group(2).toUpperCase(Locale.ROOT);
            }
            if (matcher.group(3) != null) {
                return matcher.group(4).toUpperCase(Locale.ROOT) + "with" + matcher.group(3).toUpperCase(Locale.ROOT);
            }

            if (matcher.group(5) != null) {
                return matcher.group(6).toUpperCase(Locale.ROOT) + "with" + matcher.group(5).toUpperCase(Locale.ROOT);
            }
        }
        return null;
    }
}