Question

public static void main(String[] args) throws SignatureException {
    String data = "GET"+"\n"+"webservices.amazon.com"+"\n"+"/onca/xml"+"\n"+"AWSAccessKeyId=AKIAIOSFODNN7EXAMPLE&ItemId=0679722769&Operation=ItemLookup&ResponeGroup=ItemAttributes%2COffers%2CImages%2CReviews&Service=AWSECommerceService&Timestamp=2009-01-01T12%3A00%3A00Z&Version=2009-01-06";
    String key = "1234567890";
    String result = calculateRFC2104HMAC(data, key);
    System.out.println(result);

}

private static final String HMAC_SHA_ALGORITHM = "HmacSHA256";


public static String calculateRFC2104HMAC(String data, String key)throws java.security.SignatureException{
    String result;
    try {

    // get an hmac_sha256 key from the raw key bytes
    SecretKeySpec signingKey = new SecretKeySpec(key.getBytes("UTF-8"), HMAC_SHA_ALGORITHM);

    // get an hmac_sha256 Mac instance and initialize with the signing key
    Mac mac = Mac.getInstance(HMAC_SHA_ALGORITHM);
    mac.init(signingKey);

    // compute the hmac256 on input data bytes
    byte[] rawHmac = mac.doFinal(data.getBytes("UTF-8"));

    // base64-encode the hmac256
    result = Base64.encodeBase64String(rawHmac);

    } catch (Exception e) {
        throw new SignatureException("Failed to generate HMAC : " + e.getMessage());
    }
    return result;
    }

所以我试图用sha256为AWS计算这个hmac，但是我没有得到令人满意的结果，即使这个例子来自官方的AWS文档：http://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/AuthJavaSampleHMACSignature.html唯一改变的是算法，这没有打破程序，所以它应该工作，但事实并非如此。

我得到的结果：k1T / qvVoXgEvmdFhTEh71vLDznqEVCyKcslA5RRSB6s = 我期待的结果：M / y0 + EAFFGaUAp4bWv / WEuXYah99pVsxvqtAuC8YN7I =

有没有人知道出了什么问题？

Answer 1

它可能与解释换行符的方式有关。 \ n可以是cr，lf或cr-lf，具体取决于您的操作系统。

Answer 2

AWS使用两个不同的HMAC函数，第一个返回字符串表示，另一个返回二进制表示。这是来自我使用OpenSSL的C ++实现，希望它有所帮助：

string hmacHex(string key, string msg)
{
    unsigned char hash[32];

    HMAC_CTX hmac;
    HMAC_CTX_init(&hmac);
    HMAC_Init_ex(&hmac, &key[0], key.length(), EVP_sha256(), NULL);
    HMAC_Update(&hmac, (unsigned char*)&msg[0], msg.length());
    unsigned int len = 32;
    HMAC_Final(&hmac, hash, &len);
    HMAC_CTX_cleanup(&hmac);

    std::stringstream ss;
    ss << std::hex << std::setfill('0');
    for (int i = 0; i < len; i++)
    {   
        ss << std::hex << std::setw(2)  << (unsigned int)hash[i];
    }

    return (ss.str());
}

字符串实现

string hmac(string key, string msg)
{
    unsigned char hash[32];

    HMAC_CTX hmac;
    HMAC_CTX_init(&hmac);
    HMAC_Init_ex(&hmac, &key[0], key.length(), EVP_sha256(), NULL);
    HMAC_Update(&hmac, ( unsigned char* )&msg[0], msg.length());
    unsigned int len = 32;
    HMAC_Final(&hmac, hash, &len);
    HMAC_CTX_cleanup(&hmac);

    std::stringstream ss;
    ss << std::setfill('0');
    for (int i = 0; i < len; i++)
    {
        ss  << hash[i];
    }

    return (ss.str());
}

如果您使用的是Java，我建议您使用相应的SDK。我的经验是，API往往会很快发生变化。

Hmac Sha256结果值不正确AWS-Java

2 个答案: