无法在Java中输出正确的哈希值。怎么了？ [英] Cannot output correct hash in Java. What is wrong?

问题描述

在我的Android应用程序中，我有一个SHA256哈希，我必须使用RIPEMD160消息摘要算法进一步哈希。

In my Android app I have a SHA256 hash which I must further hash with the RIPEMD160 message digest algorithm.

我可以输出任何正确的sha256和ripemd160哈希值字符串，但是当我尝试使用ripemd160散列sha256哈希时，我得到一个不正确的哈希。

I can output the correct sha256 and ripemd160 hash of any string, but when I try to hash the sha256 hash with ripemd160 I get a hash which is incorrect.

根据在线哈希计算器，字符串'test的SHA256值'（全部小写）是：

According to online hash calculators, the SHA256 value of the string 'test'(all lowercase) is:

9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08

字符串'test'的RIPEMD160值为：

And the RIPEMD160 value of the string 'test' is:

5e52fee47e6b070565f74372468cdc699de89107

根据在线计算，使用ripemd160散列生成的sha256哈希的值是：

The value from hashing the resulting sha256 hash with ripemd160 according to online calcs is:

4efc1c36d3349189fb3486d2914f56e05d3e66f8

一个我的应用程序给我的是：

And the one my app gives me is:

cebaa98c19807134434d107b0d3e5692a516ea66

这显然是错误的。

这是我的代码：

public static String toRIPEMD160(String in)
{
    byte[] addr = in.getBytes();
    byte[] out = new byte[20];
    RIPEMD160Digest digest = new RIPEMD160Digest();
    byte[] sha256 = sha256(addr);
    digest.update(sha256,0,sha256.length);
    digest.doFinal(out,0);
    return getHexString(out);
}

public static byte[] sha256(byte[] data)
{
    byte[] sha256 = new byte[32];
    try
    {
        sha256 = MessageDigest.getInstance("SHA-256").digest(data);
    }
    catch(NoSuchAlgorithmException e)
    {}

    return sha256;
}

对于ripemd160算法，sha256需要bouncycastle和java.security.MessageDigest 。

For the ripemd160 algorithm, you need bouncycastle and java.security.MessageDigest for sha256.

推荐答案

你的哈希工作正常。问题是你正在使用的在线计算器正在处理你的输入：

Your hash is working fine. The problem is that the online calculators that you're using are treating your input:

9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08

作为字符串而不是字节数组。换句话说，它将每个字符视为一个字节，而不是将字符对解析为十六进制的字节。如果我把它作为一个字符串给在线计算器，我确实得到你所得到的：

as a string instead of an array of bytes. In other words, it's treating each character as a byte instead of parsing character pairs as bytes in hexadecimal. If I give this as a string to online calculators, I indeed get exactly what you got:

4efc1c36d3349189fb3486d2914f56e05d3e66f8

但是，您将输出视为字节数组而不是字符串，这会给你不同的结果。您应该将原始SHA256哈希编码为字符串，然后将编码的字符串传递给哈希函数。我看到你有一个 getHexString 方法，所以我们只是使用它。

However, you're treating the output as an array of bytes instead of a String and that's giving you different results. You should encode your raw SHA256 hash as a string, then pass the encoded string to the hash function. I see you have a getHexString method, so we'll just use that.

public static String toRIPEMD160(String in) {
    try {
        byte[] addr = in.getBytes();
        byte[] out = new byte[20];
        RIPEMD160Digest digest = new RIPEMD160Digest();

        // These are the lines that changed
        byte[] rawSha256 = sha256(addr);
        String encodedSha256 = getHexString(rawSha256);
        byte[] strBytes = encodedSha256.getBytes("UTF-8");
        digest.update(strBytes, 0, strBytes.length);

        digest.doFinal(out, 0);
        return getHexString(out);
    } catch (UnsupportedEncodingException ex) {
        // Never happens, everything supports UTF-8
        return null;
    }
}

如果你想知道它的工作原理，请选择价值 encodedSha256 并将其放入在线哈希计算器中。只要计算器使用UTF-8编码将字符串转换为字节数组，它就会匹配您的输出。

If you want to know it's working, take the value of encodedSha256 and put that into an online hash calculator. As long as the calculator uses UTF-8 encoding to turn the string into a byte array, it will match your output.

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