加密:

package main

import (
        "crypto/aes"
        "crypto/cipher"
        "crypto/rand"
        "fmt"
        "io"
)

func main() {
        // The key argument should be the AES key, either 16 or 32 bytes
        // to select AES-128 or AES-256.
        key := []byte("0123456789ABCDEF")
        plaintext := []byte("Apple")

        block, err := aes.NewCipher(key)
        if err != nil {
                panic(err.Error())
        }

        nonce := make([]byte, 12)
        if false {
                if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
                        panic(err.Error())
                }
        }

        fmt.Printf("nonce: %x\n", nonce)

        aesgcm, err := cipher.NewGCM(block)
        if err != nil {
                panic(err.Error())
        }

        ciphertext := aesgcm.Seal(nil, nonce, plaintext, nil)
        fmt.Printf("cipher:%x\n", ciphertext)
}

解密:

package main

import (
        "crypto/aes"
        "crypto/cipher"
        "fmt"
    "encoding/hex"
)


func main (){

    key := []byte("0123456789ABCDEF")

        ciphertext, _ := hex.DecodeString("08f24c28f0fc9aef5812a35ce66235bc2488d6c29b")  //加密生成的结果

        nonce, _ := hex.DecodeString("000000000000000000000000") //加密用的nonce

        block, err := aes.NewCipher(key)
        if err != nil {
                panic(err.Error())
        }

        aesgcm, err := cipher.NewGCM(block)
        if err != nil {
                panic(err.Error())
        }

        plaintext, err := aesgcm.Open(nil, nonce, ciphertext, nil)
        if err != nil {
                panic(err.Error())
        }
    fmt.Println(string(plaintext))
}

跟踪 tls(https) 代码里面, server 和client 走的 就是 aes GCM。
nonce 应该就是随机数(random)