Monthly Archives: 2月 2015

22
2月

Google Authenticator 샘플

import java.nio.ByteBuffer;
import java.security.SecureRandom;
import java.util.ArrayList;
import java.util.List;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

/**
 * https://tools.ietf.org/html/rfc6238
 * https://weblogs.java.net/blog/evanx/archive/2012/11/07/google-authenticator-thus-enabled
 */
public class TOTP {

	static String encodedKey;

	public static String getQRBarcodeURL(String user, String host, String secret) {
		String format = "https://www.google.com/chart?chs=200x200&chld=M%%7C0&cht=qr&chl=otpauth://totp/%s@%s%%3Fsecret%%3D%s";
		return String.format(format, user, host, secret);
	}

	public static void main(String[] args) throws Exception {
		byte[] secretKey = new byte[10];
		new SecureRandom().nextBytes(secretKey);

		encodedKey = Base32.encodeRfc(secretKey);
		System.out.println("secret => " + encodedKey);
		System.out.println(getQRBarcodeURL("jo.27", "acekorea.info", encodedKey));

		long X = 30;
		long T0 = 0;
		long t = (System.currentTimeMillis() - T0) / 1000 / X;
		System.out.println(getCode(encodedKey, t));
		System.out.println(getCodeList(encodedKey, t, 5));
	}

	public static boolean verifyCode(String secret, int code, long timeIndex,
			int variance) throws Exception {
		byte[] secretBytes = Base32.decodeRfc(secret);
		for (int i = -variance; i <= variance; i++) {
			if (getCode(secretBytes, timeIndex + i) == code) {
				return true;
			}
		}
		return false;
	}

	private static long getCode(byte[] secret, long timeIndex) throws Exception {
		SecretKeySpec signKey = new SecretKeySpec(secret, "HmacSHA1");
		ByteBuffer buffer = ByteBuffer.allocate(8);
		buffer.putLong(timeIndex);
		byte[] timeBytes = buffer.array();
		Mac mac = Mac.getInstance("HmacSHA1");
		mac.init(signKey);
		byte[] hash = mac.doFinal(timeBytes);
		int offset = hash[19] & 0xf;
		long truncatedHash = hash[offset] & 0x7f;
		for (int i = 1; i < 4; i++) {
			truncatedHash <<= 8;
			truncatedHash |= hash[offset + i] & 0xff;
		}
		return (truncatedHash %= 1000000);
	}

	static long getCode(String secret, long timeIndex) throws Exception {
		return getCode(Base32.decodeRfc(secret), timeIndex);
	}

	static List getCodeList(String secret, long timeIndex, int variance) throws Exception {
		List list = new ArrayList();
		for (int i = -variance; i <= variance; i++) {
			list.add(getCode(secret, timeIndex + i));
		}
		return list;
	}
}

import java.nio.ByteBuffer;

import java.security.SecureRandom;

import java.util.ArrayList;

import java.util.List;

import javax.crypto.Mac;

import javax.crypto.spec.SecretKeySpec;

/**

* https://tools.ietf.org/html/rfc6238

* https://weblogs.java.net/blog/evanx/archive/2012/11/07/google-authenticator-thus-enabled

public class TOTP {

static String encodedKey;

public static String getQRBarcodeURL(String user, String host, String secret) {

String format = "https://www.google.com/chart?chs=200x200&chld=M%%7C0&cht=qr&chl=otpauth://totp/%s@%s%%3Fsecret%%3D%s";

return String.format(format, user, host, secret);

}

public static void main(String[] args) throws Exception {

byte[] secretKey = new byte[10];

new SecureRandom().nextBytes(secretKey);

encodedKey = Base32.encodeRfc(secretKey);

System.out.println("secret => " + encodedKey);

System.out.println(getQRBarcodeURL("jo.27", "acekorea.info", encodedKey));

long X = 30;

long T0 = 0;

long t = (System.currentTimeMillis() - T0) / 1000 / X;

System.out.println(getCode(encodedKey, t));

System.out.println(getCodeList(encodedKey, t, 5));

}

public static boolean verifyCode(String secret, int code, long timeIndex,

int variance) throws Exception {

byte[] secretBytes = Base32.decodeRfc(secret);

for (int i = -variance; i <= variance; i++) {

if (getCode(secretBytes, timeIndex + i) == code) {

return true;

}

return false;

}

private static long getCode(byte[] secret, long timeIndex) throws Exception {

SecretKeySpec signKey = new SecretKeySpec(secret, "HmacSHA1");

ByteBuffer buffer = ByteBuffer.allocate(8);

buffer.putLong(timeIndex);

byte[] timeBytes = buffer.array();

Mac mac = Mac.getInstance("HmacSHA1");

mac.init(signKey);

byte[] hash = mac.doFinal(timeBytes);

int offset = hash[19] & 0xf;

long truncatedHash = hash[offset] & 0x7f;

for (int i = 1; i < 4; i++) {

truncatedHash <<= 8;

truncatedHash |= hash[offset + i] & 0xff;

}

return (truncatedHash %= 1000000);

}

static long getCode(String secret, long timeIndex) throws Exception {

return getCode(Base32.decodeRfc(secret), timeIndex);

}

static List getCodeList(String secret, long timeIndex, int variance) throws Exception {

List list = new ArrayList();

for (int i = -variance; i <= variance; i++) {

list.add(getCode(secret, timeIndex + i));

}

return list;

}

Posted in Java | コメントは受け付けていません。

2
2月

linux시간변경이 안될때

date -s “2015-02-02 00:00:00&#8243 … Continue reading →

Posted in Linux | コメントは受け付けていません。

Monthly Archives: 2月 2015

Google Authenticator 샘플

linux시간변경이 안될때

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