597fe545b7
Add AES-GCM encryption utilities for payment credentials with key length and ciphertext validation.
71 lines
1.3 KiB
Go
71 lines
1.3 KiB
Go
package payment
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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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var encryptionKey []byte
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func InitEncryptionKey(key string) {
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encryptionKey = []byte(key)
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}
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func Encrypt(plaintext string) (string, error) {
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gcm, err := newGCM()
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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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func Decrypt(encoded string) (string, error) {
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gcm, err := newGCM()
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if err != nil {
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return "", err
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}
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ciphertext, err := base64.StdEncoding.DecodeString(encoded)
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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+gcm.Overhead() {
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return "", fmt.Errorf("ciphertext too short")
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}
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nonce := ciphertext[:nonceSize]
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encrypted := ciphertext[nonceSize:]
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plaintext, err := gcm.Open(nil, nonce, encrypted, 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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func newGCM() (cipher.AEAD, error) {
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if len(encryptionKey) != 32 {
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return nil, fmt.Errorf("invalid encryption key length: got %d, want 32", len(encryptionKey))
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}
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block, err := aes.NewCipher(encryptionKey)
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if err != nil {
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return nil, err
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}
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return cipher.NewGCM(block)
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}
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