去郎SHA3-256提供无效的输出？ [关闭]

Question

I am facing strange results fo go SHA3-256 function: here is source code

import (
    "golang.org/x/crypto/sha3"
    "encoding/hex"
)

func main() {
    pub, _ := hex.DecodeString("c342dbf7cdd3096c4c3910c511a57049e62847dd5030c7e644bc855acc1fd626")
    h := sha3.Sum256(pub[:])
    fmt.Printf("SHA3 %x
", h)
    // expected: b32562e67d3ea44ba1367ce134caac49fd305b24cde6716ad3857ac682576379
    // received: 8a3ccc097f854811f4c49346da9c3bd1745d087ed539fa7817960f3e0ed8a44f
}

I verified result on couple of online converters, they all give same result, different from mine.

Answer 1

You are assuming that the online converters that you've tested perform hexadecimal decoding. They don't; they just take the ASCII/UTF-8/whatever value of the string and use that, i.e. they hash the text.

This can be easily observed by inputting your c342... string and then inputting hello. Both will work, while hello obviously doesn't contain hexadecimals. Another way is to start with an uppercase C instead of c, which will also return a different result, while the hexadecimal decoding should return an identical byte array and thus hash.

And a small Java application does indeed confirm your value of:

8a3ccc097f854811f4c49346da9c3bd1745d087ed539fa7817960f3e0ed8a44f

Note that most if not all online tools are basically hobby projects by amateur cryptographers. Expect all kind of encoding / decoding issues, errors and uncertainties in the implementation. If you want to test your implementation, use the official NIST test vectors.