Java 读取密钥对';是RSA OpenSSH格式的公钥吗?
我通过以下操作在Java中创建了一个Java 读取密钥对';是RSA OpenSSH格式的公钥吗?,java,encryption,cryptography,public-key-encryption,Java,Encryption,Cryptography,Public Key Encryption,我通过以下操作在Java中创建了一个密钥对: KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA"); keyPairGenerator.initialize(1024, new SecureRandom()); KeyPair keyPair = keyPairGenerator.generateKeyPair(); 如何从RSA OpenSSH格式的密钥对中获取公钥,该格式以“----BEGIN”?开头
密钥对
:
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
keyPairGenerator.initialize(1024, new SecureRandom());
KeyPair keyPair = keyPairGenerator.generateKeyPair();
如何从RSA OpenSSH格式的
密钥对中获取公钥
,该格式以“----BEGIN”
?开头。下面是一个我没有测试过的快速破解方法。这需要Java6或更高版本。有关更多信息,请参阅以下RFC:
此代码生成一个新的随机密钥对,它不会从任何地方读取它。的可能副本
import java.io.*;
import java.math.BigInteger;
import java.nio.*;
import java.nio.charset.Charset;
import java.security.*;
import java.security.interfaces.RSAPublicKey;
import javax.xml.bind.DatatypeConverter;
public class SecshPublicKey {
/*
* Taken from RFC 4716, with reference to RFCs 4253 and 4251.
*/
public static void main(String[] args) throws Exception {
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
keyPairGenerator.initialize(1024, new SecureRandom());
KeyPair keyPair = keyPairGenerator.generateKeyPair();
ByteArrayOutputStream binaryOS = new ByteArrayOutputStream();
writeSshString(binaryOS, "ssh-rsa");
RSAPublicKey rsaPub = (RSAPublicKey)keyPair.getPublic();
writeSshMPInt(binaryOS, rsaPub.getPublicExponent());
writeSshMPInt(binaryOS, rsaPub.getModulus());
// Now base64-encode the result.
String b64Encoded = sshBase64Encode(binaryOS.toByteArray());
// Now write out the result
System.out.println("---- BEGIN SSH2 PUBLIC KEY ----");
System.out.println(b64Encoded);
System.out.println("---- END SSH2 PUBLIC KEY ----");
}
private static String sshBase64Encode(byte[] byteArray) {
String b64_prelim = DatatypeConverter.printBase64Binary(byteArray);
// Break into lines of at most 72 characters.
StringBuilder b64_final = new StringBuilder(b64_prelim.length() * 2);
while (b64_prelim.length() > 72) {
b64_final.append(b64_prelim.substring(0, 72));
b64_final.append("\n");
b64_prelim = b64_prelim.substring(72);
}
b64_final.append(b64_prelim);
return b64_final.toString();
}
private static void writeSshMPInt(OutputStream os, BigInteger mpint) throws IOException {
ByteBuffer lengthBuf = ByteBuffer.allocate(4);
lengthBuf.order(ByteOrder.BIG_ENDIAN);
byte [] x;
if (mpint.equals(BigInteger.ZERO)) {
x = new byte[0];
} else {
x = mpint.toByteArray();
}
lengthBuf.putInt(x.length);
os.write(lengthBuf.array());
os.write(x);
}
private static void writeSshString(OutputStream os, String s) throws IOException {
ByteBuffer lengthBuf = ByteBuffer.allocate(4);
lengthBuf.order(ByteOrder.BIG_ENDIAN);
byte [] encoded = s.getBytes(Charset.forName("UTF-8"));
lengthBuf.putInt(encoded.length);
os.write(lengthBuf.array());
os.write(encoded);
}
}