最近项目老大又交给我一个模块，设计一个licence，其功能是这样的：
我们发布系统，通过licence机制来保证用户可以在一定时间内可以使用，同时也保证只有一定数量的用户可以用。
我觉得应该注意这么几点，
1. 时间机制，保证获取licence后只能在一定时间段内使用。
2. 要保证其时效性，也就是说不能让该licence重复使用或者转手给其他人使用。
3. 要用验证机制，保证该licence得合法性。
4. 保密性。
有哪位兄弟做过类似的，请给些建议吧，谢谢！
自己先写个程序，加密的，打包成jar。
可以参考下JIRA的licence,这里不能上传项目jira_kengen.rar
[code="java"]import com.atlassian.license.LicensePair;
import java.io.*;
import java.security.KeyFactory;
import java.security.Signature;
import java.security.spec.PKCS8EncodedKeySpec;
public class keygen
{
public keygen()
{
}
public static void main(String args[])
throws IOException
{
try
{
long l = 267L;
long l1 = System.currentTimeMillis();
long l2 = System.currentTimeMillis();
String s = "";
System.out.println("Keygen for JIRA Enterprise Edition.");
System.out.print("created by mydaj[ROR].");
do
{
System.out.print("\nEnter your organization name: ");
for(int i = System.in.read(); i != 10 && i != 13; i = System.in.read())
s = s + (char)i;
} while(s == "");
try
{
PKCS8EncodedKeySpec pkcs8encodedkeyspec = new PKCS8EncodedKeySpec(EncodedPrvKey);
KeyFactory keyfactory = KeyFactory.getInstance("DSA", "SUN");
java.security.PrivateKey privatekey = keyfactory.generatePrivate(pkcs8encodedkeyspec);
String s1 = Long.toString(l, 10);
s1 = s1 + "^^";
s1 = s1 + Long.toString(l1, 10);
s1 = s1 + "^^";
s1 = s1 + Long.toString(l2, 10);
s1 = s1 + "^^";
s1 = s1 + s;
byte abyte0[] = s1.getBytes();
Signature signature = Signature.getInstance("SHA1withDSA");
signature.initSign(privatekey);
signature.update(abyte0);
byte abyte1[] = signature.sign();
LicensePair licensepair = null;
try
{
licensepair = new LicensePair(abyte0, abyte1);
}
catch(Exception exception1)
{
exception1.printStackTrace();
}
System.out.println(s1);
System.out.println("Your license key is: ");
System.out.println(licensepair.toString());
}
catch(Exception exception)
{
exception.printStackTrace();
}
}
catch(IOException ioexception) { }
}
static byte EncodedPrvKey[] = {
48, -126, 1, 75, 2, 1, 0, 48, -126, 1,
44, 6, 7, 42, -122, 72, -50, 56, 4, 1,
48, -126, 1, 31, 2, -127, -127, 0, -3, 127,
83, -127, 29, 117, 18, 41, 82, -33, 74, -100,
46, -20, -28, -25, -10, 17, -73, 82, 60, -17,
68, 0, -61, 30, 63, -128, -74, 81, 38, 105,
69, 93, 64, 34, 81, -5, 89, 61, -115, 88,
-6, -65, -59, -11, -70, 48, -10, -53, -101, 85,
108, -41, -127, 59, -128, 29, 52, 111, -14, 102,
96, -73, 107, -103, 80, -91, -92, -97, -97, -24,
4, 123, 16, 34, -62, 79, -69, -87, -41, -2,
-73, -58, 27, -8, 59, 87, -25, -58, -88, -90,
21, 15, 4, -5, -125, -10, -45, -59, 30, -61,
2, 53, 84, 19, 90, 22, -111, 50, -10, 117,
-13, -82, 43, 97, -41, 42, -17, -14, 34, 3,
25, -99, -47, 72, 1, -57, 2, 21, 0, -105,
96, 80, -113, 21, 35, 11, -52, -78, -110, -71,
-126, -94, -21, -124, 11, -16, 88, 28, -11, 2,
-127, -127, 0, -9, -31, -96, -123, -42, -101, 61,
-34, -53, -68, -85, 92, 54, -72, 87, -71, 121,
-108, -81, -69, -6, 58, -22, -126, -7, 87, 76,
11, 61, 7, -126, 103, 81, 89, 87, -114, -70,
-44, 89, 79, -26, 113, 7, 16, -127, -128, -76,
73, 22, 113, 35, -24, 76, 40, 22, 19, -73,
-49, 9, 50, -116, -56, -90, -31, 60, 22, 122,
-117, 84, 124, -115, 40, -32, -93, -82, 30, 43,
-77, -90, 117, -111, 110, -93, 127, 11, -6, 33,
53, 98, -15, -5, 98, 122, 1, 36, 59, -52,
-92, -15, -66, -88, 81, -112, -119, -88, -125, -33,
-31, 90, -27, -97, 6, -110, -117, 102, 94, -128,
123, 85, 37, 100, 1, 76, 59, -2, -49, 73,
42, 4, 22, 2, 20, 42, 50, -88, 30, 125,
-37, 118, -50, 20, -82, -63, 0, 8, -36, 106,
-9, -110, 124, 107, 68
};
}
[/code]
如果产品是面向企业用户，以下方法就足够了：MAC地址绑定，启用、禁用时间绑定，再找一种可逆算法加加密。
如果是面向公众的共享软件，那没法，java不适合。
我们的实现方法和楼上差不多，但是如果要实现绑定机器，如果是指服务器，就要在服务器运行一个东西，算出一个识别码，然后配置到你的license里，再做摘要，加密得处理。如果是WEB客户客户端的可能就得搞一个activex或者applet来绑定机器了。