如何在Go中向函数发送切片？

Question

I'm rewriting some C code in Go. And in my C code I have stuff like this:

static void sharedb(unsigned char *sharedkey, unsigned char *send,
                    const unsigned char *received) {
    unsigned char krq[96]; 
    unsigned char buf[64];
    // rest removed for brevity

    indcpa_enc(send, buf, received, krq + 32);
}

Where indcpa_enc function is defined like this:

static void indcpa_enc(unsigned char *c,
                       const unsigned char *m,
                       const unsigned char *pk,
                       const unsigned char *coins)

So, in my Go code instead of using char arrays I used byte arrays. Where I have something like this:

func SharedB(sharedKey, send, received []byte) {
    var krq [96]byte
    var buf [64]byte

    // rest removed for brevity

    INDCPAEnc(send[:], buf[:SharedKeyBytes], received[:], krq[32:32+CoinBytes])
}

Where INDCPAEnc function is defined like this:

func INDCPAEnc(c []byte, m [SharedKeyBytes]byte, pk []byte, coins [CoinBytes]byte) 

Though, this function call in Go gives me an array, regarding type mismatch. How can I convert a C code like above to a proper Go code? Also, should I use the pointer notation * for my Go function parameters as in C?

Answer 1

The parameters that specify a length (e.g. [SharedKeyBytes]byte) are arrays, not slices; therefor, you cannot pass a slice, hence the type mismatch error. You can either:

• Change the parameter type to slice ([]byte)
• Copy the slice to an appropriately-sized array prior to calling the function, then pass the array to the function instead of the slice (playground example)