生成RSA密鑰對並將私鑰編碼爲字符串

Question

我想生成512位RSA密鑰對，然後將我的公鑰作爲字符串進行編碼。我怎樣才能做到這一點？

Answer 1

對於爲十六進制字符串

import java.security.*; 
public class Test { 
    public static void main(String[] args) throws NoSuchAlgorithmException, NoSuchProviderException { 
     KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA"); 
     keyGen.initialize(512); 
     byte[] publicKey = keyGen.genKeyPair().getPublic().getEncoded(); 
     StringBuffer retString = new StringBuffer(); 
     for (int i = 0; i < publicKey.length; ++i) { 
      retString.append(Integer.toHexString(0x0100 + (publicKey[i] & 0x00FF)).substring(1)); 
     } 
     System.out.println(retString); 
    } 
} 

輸出作爲字節輸出值

import java.security.*; 
import java.security.*; 
public class Test { 
    public static void main(String[] args) throws NoSuchAlgorithmException, NoSuchProviderException { 
     KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA"); 
     keyGen.initialize(512); 
     byte[] publicKey = keyGen.genKeyPair().getPublic().getEncoded(); 
     StringBuffer retString = new StringBuffer(); 
     retString.append("["); 
     for (int i = 0; i < publicKey.length; ++i) { 
      retString.append(publicKey[i]); 
      retString.append(", "); 
     } 
     retString = retString.delete(retString.length()-2,retString.length()); 
     retString.append("]"); 
     System.out.println(retString); //e.g. [48, 92, 48, .... , 0, 1] 
    } 
}