65 lines
1.7 KiB
Go
65 lines
1.7 KiB
Go
package encryption_decryption
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import (
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"bytes"
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"crypto/aes"
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"crypto/cipher"
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"encoding/base64"
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"fmt"
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"math/rand"
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)
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// 必须16字节
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var key = "fusen20230405145"
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// 加密(key必须16字节),前端加解密需要先把base64转字符串再取前16字节作为iv
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func CBCEncrypt(data string) (string, error) {
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defer func() {
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if err := recover(); err != nil {
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fmt.Println("cbc decrypt err:", err)
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}
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}()
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block, err := aes.NewCipher([]byte(key))
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if err != nil {
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return "", err
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}
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blockSize := len(key)
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padding := blockSize - len(data)%blockSize // 填充字节
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if padding == 0 {
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padding = blockSize
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}
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// 填充 padding 个 byte(padding) 到 data
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data += string(bytes.Repeat([]byte{byte(padding)}, padding))
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ciphertext := make([]byte, aes.BlockSize+len(data))
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iv := ciphertext[:aes.BlockSize]
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if _, err = rand.Read(iv); err != nil { // 将同时写到 ciphertext 的开头
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return "", err
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}
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mode := cipher.NewCBCEncrypter(block, iv)
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mode.CryptBlocks(ciphertext[aes.BlockSize:], []byte(data))
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return base64.StdEncoding.EncodeToString(ciphertext), nil
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}
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// 解密(key必须16字节)
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func CBCDecrypt(src string) (string, error) {
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defer func() {
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if err := recover(); err != nil {
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fmt.Println("cbc decrypt err:", err)
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}
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}()
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block, err := aes.NewCipher([]byte(key))
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if err != nil {
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return "", err
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}
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ciphercode, err := base64.StdEncoding.DecodeString(src)
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if err != nil {
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return "", err
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}
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iv := ciphercode[:aes.BlockSize] // 密文的前 16 个字节为 iv
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ciphercode = ciphercode[aes.BlockSize:] // 正式密文
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mode := cipher.NewCBCDecrypter(block, iv)
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mode.CryptBlocks(ciphercode, ciphercode)
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plaintext := string(ciphercode) // ↓ 减去 padding
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return plaintext[:len(plaintext)-int(plaintext[len(plaintext)-1])], nil
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}
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