Publickey von bouncycastle RSAKeyParameters

Question

Ich habe den folgenden Code, der eine CSR aus einer Zeichenfolge liest und den öffentlichen Schlüssel in einem PEM-Format ausgibt. Ich muss auch den öffentlichen Schlüssel als Java RSAPublickey bekommen, aber ich kann nicht herausfinden, wie das geht.

import org.bouncycastle.crypto.params.RSAKeyParameters; 
import org.bouncycastle.crypto.util.PublicKeyFactory; 
import org.bouncycastle.pkcs.PKCS10CertificationRequest; 
import org.bouncycastle.util.io.pem.PemObject; 
import org.bouncycastle.util.io.pem.PemReader; 
import org.bouncycastle.util.io.pem.PemWriter; 

import java.io.*; 
import java.security.KeyFactory; 
import java.security.NoSuchAlgorithmException; 
import java.security.PublicKey; 
import java.security.spec.InvalidKeySpecException; 
import java.security.spec.RSAPublicKeySpec; 


    public class parseCSRfromString { 


     String csrPEM = "-----BEGIN CERTIFICATE REQUEST-----\n" + 
       "MIICwjCCAaoCAQAwfTELMAkGA1UEBhMCVVMxEDAOBgNVBAgTB0Zsb3JpZGExEzAR\n" + 
       "BgNVBAcTCkJvY2EgUmF0b24xGzAZBgNVBAoTEkxvb25leSBUb29ucywgSW5jLjEU\n" + 
       "MBIGA1UECxMLRGV2ZWxvcG1lbnQxFDASBgNVBAMTC2V4YW1wbGUuY29tMIIBIjAN\n" + 
       "BgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAiJCj31d1Rp+aKz/GTkedaiS/VSCc\n" + 
       "PRARYgXukobjgBHx46HjldAcfg/DoANn5lEQaFxaIZJLbZ/AdLUyw/hUbU0CjWXv\n" + 
       "pN3Ep3o9XgRTPkIFoI22VOI/O2ZLjBq/E4DWyVmv+vG6BK0LRh7hykzPCw6KIRR9\n" + 
       "NCmUMJMQX5d5P/r1lR5H399pnLcLsrHoWDwBSEDgkGWyxnvEB0+/bIz42T3qnlFt\n" + 
       "7avarxlHG2p5DoRTf8GJ+6imY88ZeBW/Nk18aDINsAHWLv383JICIAsZ3VuMk8m/\n" + 
       "Z/Z5b21zIuZECDJjZjvAAjr/shVLB+Pck5+HJy6tqj79MJOQu+jKIrK8VwIDAQAB\n" + 
       "oAAwDQYJKoZIhvcNAQEFBQADggEBAGtuAAHG4OC9jSRjGWSqfMXTDMz9tgekDREA\n" + 
       "SYv5QIrOXsMzwbgDw8LxRJZEskl4JJOnjwEvUXWUF1M6XmG2h358nOnrkOlsumHw\n" + 
       "Tx5gGSr6S6aJO/HG46erctE8aWpnFZYMfuEkul4ApsIufL7Bxqs3NHZWcrWBlLIP\n" + 
       "aVCKx1FPRMC36Tj3EslbuUB/iTRt90Nfq1IxHMIKiwCiSNJSqfRVLANhI8MUbOjB\n" + 
       "CBly1wcH68WWNkyvHVvbcF/B9AfYG9AqWjZjygKpyf81VZWctXhDc8UtomqrblXN\n" + 
       "mvz4RKpIhZQLuuxlBrdzJkPm2sOdtdZghebCRRVWdjsig4sylgQ=\n" + 
       "-----END CERTIFICATE REQUEST-----"; 


     StringReader csrstring = new StringReader(csrPEM); 
     PemReader pemReader = new PemReader(csrstring); 

     public String readCSR() { 
      String theKey = new String(); 


      try { 
       PKCS10CertificationRequest csr = new PKCS10CertificationRequest(pemReader.readPemObject().getContent()); 
       pemReader.close(); 


       // Write the Public Key as a PEM-File 
       StringWriter output = new StringWriter(); 
       PemWriter pemWriter = new PemWriter(output); 

       PemObject pkPemObject = new PemObject("PUBLIC KEY", 
         csr.getSubjectPublicKeyInfo().getEncoded()); 

       pemWriter.writeObject(pkPemObject); 
       pemWriter.close(); 

       // System.out.println(output.getBuffer()); 
       theKey = output.getBuffer().toString(); 

       RSAKeyParameters pubkey = (RSAKeyParameters) PublicKeyFactory.createKey(csr.getSubjectPublicKeyInfo()); 

      } catch (IOException e) { 
       e.printStackTrace(); 
      } 
      return theKey; 
     } 


    } 

Answer 1

Bauen Sie den öffentlichen Schlüssel Modul mit und Exponenten von RSAKeyParameters

RSAKeyParameters pubkey =... 

RSAPublicKeySpec spec = new RSAPublicKeySpec(pubkey.getModulus(), pubkey.getExponent()); 
KeyFactory factory = KeyFactory.getInstance("RSA"); 
PublicKey pub = factory.generatePublic(spec);