如何在Java中生成相当于Python示例的HMAC？(How to generate an HMAC in Java equivalent to a Python example?)

 我正在考虑通过Oauth在Java中实现一个获得Twitter授权的应用程序。 第一步是获取请求令牌 。 这是一个应用程序引擎的Python示例 。 
 
 为了测试我的代码，我运行Python并使用Java检查输出。 以下是生成基于哈希的消息验证码（HMAC）的Python示例： 
 
#!/usr/bin/python

from hashlib import sha1
from hmac import new as hmac

key = "qnscAdgRlkIhAUPY44oiexBKtQbGY0orf7OV1I50"
message = "foo"

print "%s" % hmac(key, message, sha1).digest().encode('base64')[:-1]
 
 输出： 
 
$ ./foo.py
+3h2gpjf4xcynjCGU5lbdMBwGOc=
 
 在Java中如何复制这个例子？ 
 
 我在Java中看到了一个HMAC的例子 ： 
 
try {
    // Generate a key for the HMAC-MD5 keyed-hashing algorithm; see RFC 2104
    // In practice, you would save this key.
    KeyGenerator keyGen = KeyGenerator.getInstance("HmacMD5");
    SecretKey key = keyGen.generateKey();

    // Create a MAC object using HMAC-MD5 and initialize with key
    Mac mac = Mac.getInstance(key.getAlgorithm());
    mac.init(key);

    String str = "This message will be digested";

    // Encode the string into bytes using utf-8 and digest it
    byte[] utf8 = str.getBytes("UTF8");
    byte[] digest = mac.doFinal(utf8);

    // If desired, convert the digest into a string
    String digestB64 = new sun.misc.BASE64Encoder().encode(digest);
} catch (InvalidKeyException e) {
} catch (NoSuchAlgorithmException e) {
} catch (UnsupportedEncodingException e) {
}
 
 它使用javax.crypto.Mac ， 一切都好 。 但是， SecretKey构造函数采用字节和算法。 
 
 Python示例中的算法是什么？ 如何在没有算法的情况下创建Java密钥？ 

I'm looking at implementing an app getting Twitter authorization via Oauth in Java. The first step is getting a request token. Here is a Python example for app engine. 
 
To test my code, I am running Python and checking output with Java. Here is an example of Python generating a Hash-Based Message Authentication Code (HMAC):
 
#!/usr/bin/python

from hashlib import sha1
from hmac import new as hmac

key = "qnscAdgRlkIhAUPY44oiexBKtQbGY0orf7OV1I50"
message = "foo"

print "%s" % hmac(key, message, sha1).digest().encode('base64')[:-1]
 
Output:
 
$ ./foo.py
+3h2gpjf4xcynjCGU5lbdMBwGOc=
 
How does one replicate this example in Java?
 
I've seen an example of HMAC in Java:
 
try {
    // Generate a key for the HMAC-MD5 keyed-hashing algorithm; see RFC 2104
    // In practice, you would save this key.
    KeyGenerator keyGen = KeyGenerator.getInstance("HmacMD5");
    SecretKey key = keyGen.generateKey();

    // Create a MAC object using HMAC-MD5 and initialize with key
    Mac mac = Mac.getInstance(key.getAlgorithm());
    mac.init(key);

    String str = "This message will be digested";

    // Encode the string into bytes using utf-8 and digest it
    byte[] utf8 = str.getBytes("UTF8");
    byte[] digest = mac.doFinal(utf8);

    // If desired, convert the digest into a string
    String digestB64 = new sun.misc.BASE64Encoder().encode(digest);
} catch (InvalidKeyException e) {
} catch (NoSuchAlgorithmException e) {
} catch (UnsupportedEncodingException e) {
}
 
It uses javax.crypto.Mac, all good. However, the SecretKey constructors take bytes and an algorithm. 
 
What's the algorithm in the Python example? How can one create a Java secret key without an algorithm?

原文：https://stackoverflow.com/questions/3208160