60 lines
1.2 KiB
Go
60 lines
1.2 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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"fmt"
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"io"
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)
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type Encryptor struct {
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key []byte
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}
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func New(key []byte) *Encryptor {
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return &Encryptor{key: key}
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}
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func (e *Encryptor) Encrypt(plaintext string) (string, error) {
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block, err := aes.NewCipher(e.key)
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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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func (e *Encryptor) Decrypt(encoded string) (string, error) {
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data, 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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block, err := aes.NewCipher(e.key)
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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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if len(data) < gcm.NonceSize() {
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return "", fmt.Errorf("ciphertext too short")
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}
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nonce, ciphertext := data[:gcm.NonceSize()], data[gcm.NonceSize():]
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plain, 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(plain), nil
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}
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