tải RSA khóa công khai từ file

Question

tôi đã tạo ra một chìa khóa riêng với:

openssl genrsa [-out file] –des3 

Sau này, tôi đã tạo ra một khóa công khai với:

openssl rsa –pubout -in private.key [-out file] 

Tôi muốn đăng ký một số thông báo với khóa cá nhân của tôi và xác minh một số tin nhắn khác bằng khóa công khai của tôi, sử dụng mã như sau:

public String sign(String message) throws SignatureException{ 
    try { 
     Signature sign = Signature.getInstance("SHA1withRSA"); 
     sign.initSign(privateKey); 
     sign.update(message.getBytes("UTF-8")); 
     return new String(Base64.encodeBase64(sign.sign()),"UTF-8"); 
    } catch (Exception ex) { 
     throw new SignatureException(ex); 
    } 
} 

public boolean verify(String message, String signature) throws SignatureException{ 
    try { 
     Signature sign = Signature.getInstance("SHA1withRSA"); 
     sign.initVerify(publicKey); 
     sign.update(message.getBytes("UTF-8")); 
     return sign.verify(Base64.decodeBase64(signature.getBytes("UTF-8"))); 
    } catch (Exception ex) { 
     throw new SignatureException(ex); 
    } 
} 

Tôi tìm thấy giải pháp để chuyển đổi riêng tư của mình để định dạng PKCS8 và tải nó. Nó hoạt động với một số mã như thế này:

public PrivateKey getPrivateKey(String filename) throws Exception { 

    File f = new File(filename); 
    FileInputStream fis = new FileInputStream(f); 
    DataInputStream dis = new DataInputStream(fis); 
    byte[] keyBytes = new byte[(int) f.length()]; 
    dis.readFully(keyBytes); 
    dis.close(); 
    PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(keyBytes); 
    KeyFactory kf = 
      KeyFactory.getInstance("RSA"); 
    return kf.generatePrivate(spec); 
} 

Và cuối cùng câu hỏi của tôi là: Làm thế nào để tải Public Key RSA của tôi từ một tập tin?

Tôi nghĩ có lẽ tôi cần chuyển đổi tệp khóa công khai của mình thành định dạng x509 và sử dụng X509EncodedKeySpec. Nhưng làm thế nào tôi có thể làm điều này?

Answer 1

Dưới đây là thông tin có liên quan từ the link được cung cấp zaki.

Tạo một 2048-bit RSA tin chính

$ openssl genrsa -out private_key.pem 2048

Chuyển đổi chính riêng để định dạng PKCS # 8 (vì vậy Java có thể đọc nó)

$ openssl pkcs8 -topk8 -inform PEM -outform DER -in private_key.pem -out private_key.der -nocrypt

Output khóa công khai phần ở định dạng DER (vì vậy Java có thể đọc được)

$ openssl rsa -in private_key.pem -pubout -outform DER -out public_key.der

Private key

import java.io.*; 
import java.nio.*; 
import java.security.*; 
import java.security.spec.*; 

public class PrivateKeyReader { 

    public static PrivateKey get(String filename) 
    throws Exception { 

    byte[] keyBytes = Files.readAllBytes(Paths.get(filename)); 

    PKCS8EncodedKeySpec spec = 
     new PKCS8EncodedKeySpec(keyBytes); 
    KeyFactory kf = KeyFactory.getInstance("RSA"); 
    return kf.generatePrivate(spec); 
    } 
} 

Công chìa khóa

import java.io.*; 
import java.nio.*; 
import java.security.*; 
import java.security.spec.*; 

public class PublicKeyReader { 

    public static PublicKey get(String filename) 
    throws Exception { 

    byte[] keyBytes = Files.readAllBytes(Paths.get(filename)); 

    X509EncodedKeySpec spec = 
     new X509EncodedKeySpec(keyBytes); 
    KeyFactory kf = KeyFactory.getInstance("RSA"); 
    return kf.generatePublic(spec); 
    } 
} 

Answer 2

Chương trình này được thực hiện gần như tất cả mọi thứ với các phím công cộng và tư nhân. Có thể lấy định dạng der nhưng lưu dữ liệu thô (không mã hóa base64). Tôi hy vọng điều này sẽ giúp các lập trình viên.

import java.io.ByteArrayOutputStream; 
import java.io.DataInputStream; 
import java.io.DataOutputStream; 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.PrintStream; 
import java.security.InvalidKeyException; 
import java.security.KeyFactory; 
import java.security.KeyPair; 
import java.security.KeyPairGenerator; 
import java.security.NoSuchAlgorithmException; 
import java.security.PrivateKey; 
import java.security.PublicKey; 
import java.security.Signature; 
import java.security.SignatureException; 

import sun.misc.BASE64Decoder; 
import sun.misc.BASE64Encoder; 
import sun.security.pkcs.PKCS8Key; 
import sun.security.pkcs10.PKCS10; 
import sun.security.x509.X500Name; 

import java.security.spec.PKCS8EncodedKeySpec; 
import java.security.spec.X509EncodedKeySpec; 



/** 
* @author Desphilboy 
* DorOd bar shomA barobach 
* 
*/ 
public class csrgenerator { 

    private static PublicKey publickey= null; 
    private static PrivateKey privateKey=null; 
    //private static PKCS8Key privateKey=null; 
    private static KeyPairGenerator kpg= null; 
    private static ByteArrayOutputStream bs =null; 
    private static csrgenerator thisinstance; 
    private KeyPair keypair; 
    private static PKCS10 pkcs10; 
    private String signaturealgorithm= "MD5WithRSA"; 

    public String getSignaturealgorithm() { 
     return signaturealgorithm; 
    } 



    public void setSignaturealgorithm(String signaturealgorithm) { 
     this.signaturealgorithm = signaturealgorithm; 
    } 



    private csrgenerator() { 
     try { 
      kpg = KeyPairGenerator.getInstance("RSA"); 
     } catch (NoSuchAlgorithmException e) { 
      e.printStackTrace(); 
      System.out.print("No such algorithm RSA in constructor csrgenerator\n"); 
     } 
     kpg.initialize(2048); 
     keypair = kpg.generateKeyPair(); 
     publickey = keypair.getPublic(); 
     privateKey = keypair.getPrivate(); 
    } 



    /** Generates a new key pair 
    * 
    * @param int bits 
    * this is the number of bits in modulus must be 512, 1024, 2048 or so on 
    */ 
    public KeyPair generateRSAkys(int bits) 
    { 
      kpg.initialize(bits); 
      keypair = kpg.generateKeyPair(); 
      publickey = keypair.getPublic(); 
      privateKey = keypair.getPrivate(); 
      KeyPair dup= keypair; 
    return dup; 
    } 

    public static csrgenerator getInstance() { 
      if (thisinstance == null) 
       thisinstance = new csrgenerator(); 
      return thisinstance; 
     } 


    /** 
     * Returns a CSR as string 
     * @param cn Common Name 
     * @param OU Organizational Unit 
     * @param Org Organization 
     * @param LocName Location name 
     * @param Statename State/Territory/Province/Region 
     * @param Country Country 
     * @return  returns csr as string. 
     * @throws Exception 
     */ 
    public String getCSR(String commonname, String organizationunit, String organization,String localname, String statename, String country) throws Exception { 
      byte[] csr = generatePKCS10(commonname, organizationunit, organization, localname, statename, country,signaturealgorithm); 
      return new String(csr); 
     } 

    /** This function generates a new Certificate 
     * Signing Request. 
    * 
    * @param CN 
    *   Common Name, is X.509 speak for the name that distinguishes 
    *   the Certificate best, and ties it to your Organization 
    * @param OU 
    *   Organizational unit 
    * @param O 
    *   Organization NAME 
    * @param L 
    *   Location 
    * @param S 
    *   State 
    * @param C 
    *   Country 
    * @return byte stream of generated request 
    * @throws Exception 
    */ 
    private static byte[] generatePKCS10(String CN, String OU, String O,String L, String S, String C,String sigAlg) throws Exception { 
     // generate PKCS10 certificate request 

     pkcs10 = new PKCS10(publickey); 
     Signature signature = Signature.getInstance(sigAlg); 
     signature.initSign(privateKey); 
     // common, orgUnit, org, locality, state, country 
     //X500Name(String commonName, String organizationUnit,String organizationName,Local,State, String country) 
     X500Name x500Name = new X500Name(CN, OU, O, L, S, C); 
     pkcs10.encodeAndSign(x500Name,signature); 
     bs = new ByteArrayOutputStream(); 
     PrintStream ps = new PrintStream(bs); 
     pkcs10.print(ps); 
     byte[] c = bs.toByteArray(); 
     try { 
      if (ps != null) 
       ps.close(); 
      if (bs != null) 
       bs.close(); 
     } catch (Throwable th) { 
     } 
     return c; 
    } 

    public PublicKey getPublicKey() { 
     return publickey; 
    } 




    /** 
    * @return 
    */ 
    public PrivateKey getPrivateKey() { 
     return privateKey; 
    } 

    /** 
    * saves private key to a file 
    * @param filename 
    */ 
    public void SavePrivateKey(String filename) 
    { 
     PKCS8EncodedKeySpec pemcontents=null; 
     pemcontents= new PKCS8EncodedKeySpec(privateKey.getEncoded()); 
     PKCS8Key pemprivatekey= new PKCS8Key(); 
     try { 
      pemprivatekey.decode(pemcontents.getEncoded()); 
     } catch (InvalidKeyException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
     File file=new File(filename); 
     try { 

      file.createNewFile(); 
      FileOutputStream fos=new FileOutputStream(file); 
      fos.write(pemprivatekey.getEncoded()); 
      fos.flush(); 
      fos.close(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 



    } 



    /** 
    * Saves Certificate Signing Request to a file; 
    * @param filename is a String containing full path to the file which will be created containing the CSR. 
    */ 
    public void SaveCSR(String filename) 
    { 
     FileOutputStream fos=null; 
     PrintStream ps=null; 
     File file; 
     try { 

      file = new File(filename); 
      file.createNewFile(); 
      fos = new FileOutputStream(file); 
      ps= new PrintStream(fos); 
     }catch (IOException e) 
     { 
      System.out.print("\n could not open the file "+ filename); 
     } 

     try { 
      try { 
       pkcs10.print(ps); 
      } catch (SignatureException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      ps.flush(); 
      ps.close(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      System.out.print("\n cannot write to the file "+ filename); 
      e.printStackTrace(); 

     } 

     } 


    /** 
    * Saves both public key and private key to file names specified 
    * @param fnpub file name of public key 
    * @param fnpri file name of private key 
    * @throws IOException 
    */ 
    public static void SaveKeyPair(String fnpub,String fnpri) throws IOException { 

// Store Public Key. 
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(
publickey.getEncoded()); 
FileOutputStream fos = new FileOutputStream(fnpub); 
fos.write(x509EncodedKeySpec.getEncoded()); 
fos.close(); 

// Store Private Key. 
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(privateKey.getEncoded()); 
fos = new FileOutputStream(fnpri); 
fos.write(pkcs8EncodedKeySpec.getEncoded()); 
fos.close(); 
} 


    /** 
    * Reads a Private Key from a pem base64 encoded file. 
    * @param filename name of the file to read. 
    * @param algorithm Algorithm is usually "RSA" 
    * @return returns the privatekey which is read from the file; 
    * @throws Exception 
    */ 
    public PrivateKey getPemPrivateKey(String filename, String algorithm) throws Exception { 
      File f = new File(filename); 
      FileInputStream fis = new FileInputStream(f); 
      DataInputStream dis = new DataInputStream(fis); 
      byte[] keyBytes = new byte[(int) f.length()]; 
      dis.readFully(keyBytes); 
      dis.close(); 

      String temp = new String(keyBytes); 
      String privKeyPEM = temp.replace("-----BEGIN PRIVATE KEY-----", ""); 
      privKeyPEM = privKeyPEM.replace("-----END PRIVATE KEY-----", ""); 
      //System.out.println("Private key\n"+privKeyPEM); 

      BASE64Decoder b64=new BASE64Decoder(); 
      byte[] decoded = b64.decodeBuffer(privKeyPEM); 

      PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(decoded); 
      KeyFactory kf = KeyFactory.getInstance(algorithm); 
      return kf.generatePrivate(spec); 
      } 



    /** 
    * Saves the private key to a pem file. 
    * @param filename name of the file to write the key into 
    * @param key the Private key to save. 
    * @return String representation of the pkcs8 object. 
    * @throws Exception 
    */ 
    public String SavePemPrivateKey(String filename) throws Exception { 
     PrivateKey key=this.privateKey; 
      File f = new File(filename); 
      FileOutputStream fos = new FileOutputStream(f); 
      DataOutputStream dos = new DataOutputStream(fos); 


      byte[] keyBytes = key.getEncoded(); 
      PKCS8Key pkcs8= new PKCS8Key(); 
      pkcs8.decode(keyBytes); 
      byte[] b=pkcs8.encode(); 

      BASE64Encoder b64=new BASE64Encoder(); 
      String encoded = b64.encodeBuffer(b); 

      encoded= "-----BEGIN PRIVATE KEY-----\r\n" + encoded + "-----END PRIVATE KEY-----"; 

     dos.writeBytes(encoded); 
     dos.flush(); 
     dos.close(); 

      //System.out.println("Private key\n"+privKeyPEM); 
     return pkcs8.toString(); 

      } 


    /** 
    * Saves a public key to a base64 encoded pem file 
    * @param filename name of the file 
    * @param key public key to be saved 
    * @return string representation of the pkcs8 object. 
    * @throws Exception 
    */ 
    public String SavePemPublicKey(String filename) throws Exception { 
     PublicKey key=this.publickey; 
     File f = new File(filename); 
      FileOutputStream fos = new FileOutputStream(f); 
      DataOutputStream dos = new DataOutputStream(fos); 


      byte[] keyBytes = key.getEncoded(); 
      BASE64Encoder b64=new BASE64Encoder(); 
      String encoded = b64.encodeBuffer(keyBytes); 

      encoded= "-----BEGIN PUBLIC KEY-----\r\n" + encoded + "-----END PUBLIC KEY-----"; 

     dos.writeBytes(encoded); 
     dos.flush(); 
     dos.close(); 

      //System.out.println("Private key\n"+privKeyPEM); 
     return encoded.toString(); 

      } 





     /** 
    * reads a public key from a file 
    * @param filename name of the file to read 
    * @param algorithm is usually RSA 
    * @return the read public key 
    * @throws Exception 
    */ 
    public PublicKey getPemPublicKey(String filename, String algorithm) throws Exception { 
      File f = new File(filename); 
      FileInputStream fis = new FileInputStream(f); 
      DataInputStream dis = new DataInputStream(fis); 
      byte[] keyBytes = new byte[(int) f.length()]; 
      dis.readFully(keyBytes); 
      dis.close(); 

      String temp = new String(keyBytes); 
      String publicKeyPEM = temp.replace("-----BEGIN PUBLIC KEY-----\n", ""); 
      publicKeyPEM = publicKeyPEM.replace("-----END PUBLIC KEY-----", ""); 


      BASE64Decoder b64=new BASE64Decoder(); 
      byte[] decoded = b64.decodeBuffer(publicKeyPEM); 

      X509EncodedKeySpec spec = 
       new X509EncodedKeySpec(decoded); 
      KeyFactory kf = KeyFactory.getInstance(algorithm); 
      return kf.generatePublic(spec); 
      } 




    public static void main(String[] args) throws Exception { 
     csrgenerator gcsr = csrgenerator.getInstance(); 
     gcsr.setSignaturealgorithm("SHA512WithRSA"); 
     System.out.println("Public Key:\n"+gcsr.getPublicKey().toString()); 

     System.out.println("Private Key:\nAlgorithm: "+gcsr.getPrivateKey().getAlgorithm().toString()); 
     System.out.println("Format:"+gcsr.getPrivateKey().getFormat().toString()); 
     System.out.println("To String :"+gcsr.getPrivateKey().toString()); 
     System.out.println("GetEncoded :"+gcsr.getPrivateKey().getEncoded().toString()); 
     BASE64Encoder encoder= new BASE64Encoder(); 
     String s=encoder.encodeBuffer(gcsr.getPrivateKey().getEncoded()); 
     System.out.println("Base64:"+s+"\n"); 

     String csr = gcsr.getCSR("desphilboy@yahoo.com","baxshi az xodam", "Xodam","PointCook","VIC" ,"AU"); 
     System.out.println("CSR Request Generated!!"); 
     System.out.println(csr); 
     gcsr.SaveCSR("c:\\testdir\\javacsr.csr"); 
     String p=gcsr.SavePemPrivateKey("c:\\testdir\\java_private.pem"); 
     System.out.print(p); 
     p=gcsr.SavePemPublicKey("c:\\testdir\\java_public.pem"); 
     privateKey= gcsr.getPemPrivateKey("c:\\testdir\\java_private.pem", "RSA"); 
     BASE64Encoder encoder1= new BASE64Encoder(); 
     String s1=encoder1.encodeBuffer(gcsr.getPrivateKey().getEncoded()); 
     System.out.println("Private Key in Base64:"+s1+"\n"); 
     System.out.print(p); 


    } 

    } 

Answer 3

Một khi bạn đã chìa khóa của bạn được lưu trữ trong một tập tin PEM, bạn có thể đọc nó lại dễ dàng sử dụng PemObject và PemReader lớp được cung cấp bởi BouncyCastle, như thể hiện trong this tutorial này.

Tạo một lớp PemFile rằng gói gọn xử lý file:

import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.IOException; 
import java.io.InputStreamReader; 

import org.bouncycastle.util.io.pem.PemObject; 
import org.bouncycastle.util.io.pem.PemReader; 

public class PemFile { 

    private PemObject pemObject; 

    public PemFile(String filename) throws FileNotFoundException, IOException { 
     PemReader pemReader = new PemReader(new InputStreamReader(
       new FileInputStream(filename))); 
     try { 
      this.pemObject = pemReader.readPemObject(); 
     } finally { 
      pemReader.close(); 
     } 
    } 

    public PemObject getPemObject() { 
     return pemObject; 
    } 
} 

Sau đó nhanh chóng phím tư nhân và công cộng như bình thường:

import java.io.FileNotFoundException; 
import java.io.IOException; 
import java.security.KeyFactory; 
import java.security.NoSuchAlgorithmException; 
import java.security.NoSuchProviderException; 
import java.security.PrivateKey; 
import java.security.PublicKey; 
import java.security.Security; 
import java.security.spec.InvalidKeySpecException; 
import java.security.spec.PKCS8EncodedKeySpec; 
import java.security.spec.X509EncodedKeySpec; 

import org.apache.log4j.Logger; 
import org.bouncycastle.jce.provider.BouncyCastleProvider; 

public class Main { 

    protected final static Logger LOGGER = Logger.getLogger(Main.class); 

    public final static String RESOURCES_DIR = "src/main/resources/rsa-sample/"; 

    public static void main(String[] args) throws FileNotFoundException, 
      IOException, NoSuchAlgorithmException, NoSuchProviderException { 
     Security.addProvider(new BouncyCastleProvider()); 
     LOGGER.info("BouncyCastle provider added."); 

     KeyFactory factory = KeyFactory.getInstance("RSA", "BC"); 
     try { 
      PrivateKey priv = generatePrivateKey(factory, RESOURCES_DIR 
        + "id_rsa"); 
      LOGGER.info(String.format("Instantiated private key: %s", priv)); 

      PublicKey pub = generatePublicKey(factory, RESOURCES_DIR 
        + "id_rsa.pub"); 
      LOGGER.info(String.format("Instantiated public key: %s", pub)); 
     } catch (InvalidKeySpecException e) { 
      e.printStackTrace(); 
     } 
    } 

    private static PrivateKey generatePrivateKey(KeyFactory factory, 
      String filename) throws InvalidKeySpecException, 
      FileNotFoundException, IOException { 
     PemFile pemFile = new PemFile(filename); 
     byte[] content = pemFile.getPemObject().getContent(); 
     PKCS8EncodedKeySpec privKeySpec = new PKCS8EncodedKeySpec(content); 
     return factory.generatePrivate(privKeySpec); 
    } 

    private static PublicKey generatePublicKey(KeyFactory factory, 
      String filename) throws InvalidKeySpecException, 
      FileNotFoundException, IOException { 
     PemFile pemFile = new PemFile(filename); 
     byte[] content = pemFile.getPemObject().getContent(); 
     X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(content); 
     return factory.generatePublic(pubKeySpec); 
    } 
} 

Hope this helps.

Answer 4

Mã dưới đây hoạt động hoàn toàn tốt với tôi và hoạt động. Mã này sẽ đọc khóa riêng và khóa công khai RSA mặc dù mã java. Bạn có thể tham khảo http://snipplr.com/view/18368/

import java.io.DataInputStream; 
    import java.io.File; 
    import java.io.FileInputStream; 
    import java.io.IOException; 
    import java.security.KeyFactory; 
    import java.security.NoSuchAlgorithmException; 
    import java.security.interfaces.RSAPrivateKey; 
    import java.security.interfaces.RSAPublicKey; 
    import java.security.spec.InvalidKeySpecException; 
    import java.security.spec.PKCS8EncodedKeySpec; 
    import java.security.spec.X509EncodedKeySpec; 

    public class Demo { 

     public static final String PRIVATE_KEY="/home/user/private.der"; 
     public static final String PUBLIC_KEY="/home/user/public.der"; 

     public static void main(String[] args) throws IOException, NoSuchAlgorithmException, InvalidKeySpecException { 
      //get the private key 
      File file = new File(PRIVATE_KEY); 
      FileInputStream fis = new FileInputStream(file); 
      DataInputStream dis = new DataInputStream(fis); 

      byte[] keyBytes = new byte[(int) file.length()]; 
      dis.readFully(keyBytes); 
      dis.close(); 

      PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(keyBytes); 
      KeyFactory kf = KeyFactory.getInstance("RSA"); 
      RSAPrivateKey privKey = (RSAPrivateKey) kf.generatePrivate(spec); 
      System.out.println("Exponent :" + privKey.getPrivateExponent()); 
      System.out.println("Modulus" + privKey.getModulus()); 

      //get the public key 
      File file1 = new File(PUBLIC_KEY); 
      FileInputStream fis1 = new FileInputStream(file1); 
      DataInputStream dis1 = new DataInputStream(fis1); 
      byte[] keyBytes1 = new byte[(int) file1.length()]; 
      dis1.readFully(keyBytes1); 
      dis1.close(); 

      X509EncodedKeySpec spec1 = new X509EncodedKeySpec(keyBytes1); 
      KeyFactory kf1 = KeyFactory.getInstance("RSA"); 
      RSAPublicKey pubKey = (RSAPublicKey) kf1.generatePublic(spec1); 

      System.out.println("Exponent :" + pubKey.getPublicExponent()); 
      System.out.println("Modulus" + pubKey.getModulus()); 
     } 
    }