69 lines
1.3 KiB
Go
69 lines
1.3 KiB
Go
package services
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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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"fmt"
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"io"
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)
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type CryptoService struct {
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gcm cipher.AEAD
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}
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func NewCryptoService(rawKey string) (*CryptoService, error) {
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key := []byte(rawKey)
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if len(key) < 32 {
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padded := make([]byte, 32)
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copy(padded, key)
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key = padded
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}
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if len(key) > 32 {
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key = key[:32]
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}
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, 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 nil, err
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}
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return &CryptoService{gcm: gcm}, nil
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}
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func (c *CryptoService) Encrypt(plain string) (string, error) {
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nonce := make([]byte, c.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 := c.gcm.Seal(nonce, nonce, []byte(plain), nil)
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return base64.StdEncoding.EncodeToString(ciphertext), nil
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}
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func (c *CryptoService) Decrypt(token string) (string, error) {
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raw, err := base64.StdEncoding.DecodeString(token)
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if err != nil {
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return "", err
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}
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nonceSize := c.gcm.NonceSize()
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if len(raw) < nonceSize {
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return "", fmt.Errorf("ciphertext too short")
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}
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nonce, ciphertext := raw[:nonceSize], raw[nonceSize:]
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plain, err := c.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(plain), nil
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}
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