Method decodePemBody

java/lib/src/main/java/io/github/ccxt/base/Crypto.java:693–701

(String pem, String begin, String end)

    }

    private static byte[] decodePemBody(String pem, String begin, String end) {
        int i = pem.indexOf(begin);
        int j = pem.indexOf(end);
        if (i < 0 || j < 0 || j <= i) {
            throw new IllegalArgumentException("Invalid PEM: missing " + begin + " / " + end);
        }
        String base64 = pem.substring(i + begin.length(), j).replaceAll("\\s+", "");
        return Base64.getMimeDecoder().decode(base64);
    }

    /**
     * Build PKCS#8 PrivateKeyInfo DER for RSA: