阅读KeyPair的公钥RSA OpenSSH格式? [英] Read KeyPair's publickey in RSA OpenSSH format?
本文介绍了阅读KeyPair的公钥RSA OpenSSH格式?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我在Java中通过执行以下操作创建了 KeyPair
:
I’ve created a KeyPair
in Java by doing the following:
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
keyPairGenerator.initialize(1024, new SecureRandom());
KeyPair keyPair = keyPairGenerator.generateKeyPair();
如何获取 publicKey
以----- BEGIN
?
推荐答案
这是一个我没有测试的快速黑客。这需要Java 6或更高版本。有关详情,请参阅以下RFC:
Here is a quick hack which I haven't tested. This requires Java 6 or greater. For more information see the following RFCs:
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);
}
}
这篇关于阅读KeyPair的公钥RSA OpenSSH格式?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文