73 lines
1.5 KiB
Go
73 lines
1.5 KiB
Go
package crypto
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import (
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"crypto/aes"
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"crypto/cipher"
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"crypto/rand"
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"encoding/base64"
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"errors"
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"io"
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)
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// Encrypt 使用 AES-256-GCM 加密明文，返回 base64 编码的密文
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func Encrypt(plaintext, key string) (string, error) {
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keyBytes := []byte(key)
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if len(keyBytes) != 32 {
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return "", errors.New("encrypt key must be 32 bytes")
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}
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block, err := aes.NewCipher(keyBytes)
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if err != nil {
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return "", err
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}
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gcm, err := cipher.NewGCM(block)
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if err != nil {
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return "", err
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}
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nonce := make([]byte, gcm.NonceSize())
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if _, err = io.ReadFull(rand.Reader, nonce); err != nil {
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return "", err
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}
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ciphertext := gcm.Seal(nonce, nonce, []byte(plaintext), nil)
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return base64.StdEncoding.EncodeToString(ciphertext), nil
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}
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// Decrypt 使用 AES-256-GCM 解密
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func Decrypt(ciphertextB64, key string) (string, error) {
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keyBytes := []byte(key)
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if len(keyBytes) != 32 {
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return "", errors.New("decrypt key must be 32 bytes")
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}
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ciphertext, err := base64.StdEncoding.DecodeString(ciphertextB64)
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if err != nil {
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return "", err
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}
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block, err := aes.NewCipher(keyBytes)
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if err != nil {
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return "", err
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}
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gcm, err := cipher.NewGCM(block)
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if err != nil {
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return "", err
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}
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nonceSize := gcm.NonceSize()
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if len(ciphertext) < nonceSize {
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return "", errors.New("ciphertext too short")
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}
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nonce, ciphertext := ciphertext[:nonceSize], ciphertext[nonceSize:]
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plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)
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if err != nil {
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return "", err
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}
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return string(plaintext), nil
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}
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