82 lines
1.9 KiB
Go
82 lines
1.9 KiB
Go
package privacy
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import (
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"context"
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"crypto/aes"
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"crypto/cipher"
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"crypto/rand"
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"fmt"
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"io"
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)
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// Tokenizer handles PII tokenization and encryption
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type Tokenizer struct {
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key []byte
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}
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// NewTokenizer creates a new tokenizer
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func NewTokenizer(key []byte) (*Tokenizer, error) {
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if len(key) != 32 {
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return nil, fmt.Errorf("key must be 32 bytes")
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}
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return &Tokenizer{key: key}, nil
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}
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// Encrypt encrypts sensitive data
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func (t *Tokenizer) Encrypt(ctx context.Context, plaintext []byte) ([]byte, error) {
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block, err := aes.NewCipher(t.key)
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if err != nil {
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return nil, fmt.Errorf("failed to create cipher: %w", 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, fmt.Errorf("failed to create GCM: %w", 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 nil, fmt.Errorf("failed to generate nonce: %w", err)
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}
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ciphertext := gcm.Seal(nonce, nonce, plaintext, nil)
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return ciphertext, nil
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}
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// Decrypt decrypts sensitive data
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func (t *Tokenizer) Decrypt(ctx context.Context, ciphertext []byte) ([]byte, error) {
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block, err := aes.NewCipher(t.key)
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if err != nil {
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return nil, fmt.Errorf("failed to create cipher: %w", 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, fmt.Errorf("failed to create GCM: %w", 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 nil, fmt.Errorf("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 nil, fmt.Errorf("failed to decrypt: %w", err)
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}
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return plaintext, nil
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}
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// Tokenize creates a token for PII
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func (t *Tokenizer) Tokenize(ctx context.Context, pii string) (string, error) {
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encrypted, err := t.Encrypt(ctx, []byte(pii))
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if err != nil {
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return "", err
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}
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// Return base64 encoded token
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return fmt.Sprintf("tok_%x", encrypted), nil
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}
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