Go语言中可以使用标准库中的crypto包进行加解密操作。具体实现方法如下：

1. 导入crypto包和相关子包：

import (
    "crypto/aes"
    "crypto/cipher"
    "crypto/rand"
    "encoding/hex"
    "io"
)

1. 定义用于加解密的key和iv（初始化向量）：

var key = []byte("0123456789ABCDEF") // 16位或32位的key
var iv = []byte("ABCDEF0123456789") // 16位iv

1. 定义加密函数encrypt：

func encrypt(plaintext string) (string, error) {
    plaintextBytes := []byte(plaintext)

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

    ciphertext := make([]byte, aes.BlockSize+len(plaintextBytes))
    iv := ciphertext[:aes.BlockSize]
    if _, err := io.ReadFull(rand.Reader, iv); err != nil {
        return "", err
    }

    stream := cipher.NewCFBEncrypter(block, iv)
    stream.XORKeyStream(ciphertext[aes.BlockSize:], plaintextBytes)

    return hex.EncodeToString(ciphertext), nil
}

1. 定义解密函数decrypt：

func decrypt(ciphertext string) (string, error) {
    ciphertextBytes, err := hex.DecodeString(ciphertext)
    if err != nil {
        return "", err
    }

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

    if len(ciphertextBytes) < aes.BlockSize {
        return "", errors.New("ciphertext too short")
    }

    iv := ciphertextBytes[:aes.BlockSize]
    ciphertextBytes = ciphertextBytes[aes.BlockSize:]

    stream := cipher.NewCFBDecrypter(block, iv)
    stream.XORKeyStream(ciphertextBytes, ciphertextBytes)

    return string(ciphertextBytes), nil
}

1. 测试加解密函数：

func main() {
    plaintext := "Hello World!"
    
    ciphertext, err := encrypt(plaintext)
    if err != nil {
        fmt.Println(err)
        return
    }
    fmt.Println("ciphertext:", ciphertext)

    decryptedText, err := decrypt(ciphertext)
    if err != nil {
        fmt.Println(err)
        return
    }
    fmt.Println("decrypted text:", decryptedText)
}

完整的示例代码如下：

package main

import (
    "crypto/aes"
    "crypto/cipher"
    "crypto/rand"
    "encoding/hex"
    "errors"
    "fmt"
    "io"
)

var key = []byte("0123456789ABCDEF") // 16位或32位的key
var iv = []byte("ABCDEF0123456789") // 16位iv

func encrypt(plaintext string) (string, error) {
    plaintextBytes := []byte(plaintext)

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

    ciphertext := make([]byte, aes.BlockSize+len(plaintextBytes))
    iv := ciphertext[:aes.BlockSize]
    if _, err := io.ReadFull(rand.Reader, iv); err != nil {
        return "", err
    }

    stream := cipher.NewCFBEncrypter(block, iv)
    stream.XORKeyStream(ciphertext[aes.BlockSize:], plaintextBytes)

    return hex.EncodeToString(ciphertext), nil
}

func decrypt(ciphertext string) (string, error) {
    ciphertextBytes, err := hex.DecodeString(ciphertext)
    if err != nil {
        return "", err
    }

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

    if len(ciphertextBytes) < aes.BlockSize {
        return "", errors.New("ciphertext too short")
    }

    iv := ciphertextBytes[:aes.BlockSize]
    ciphertextBytes = ciphertextBytes[aes.BlockSize:]

    stream := cipher.NewCFBDecrypter(block, iv)
    stream.XORKeyStream(ciphertextBytes, ciphertextBytes)

    return string(ciphertextBytes), nil
}

func main() {
    plaintext := "Hello World!"
    
    ciphertext, err := encrypt(plaintext)
    if err != nil {
        fmt.Println(err)
        return
    }
    fmt.Println("ciphertext:", ciphertext)

    decryptedText, err := decrypt(ciphertext)
    if err != nil {
        fmt.Println(err)
        return
    }
    fmt.Println("decrypted text:", decryptedText)
}