etalon
f2c534f636
- mongo-driver v2 connection with bounded startup retry + /readyz gate - idempotent creation of all §4.9 indexes - UpdateVersioned: version-filtered updates, conflict vs not-found errors - AES-256-GCM Seal/Open for ticketing credentials, base64(nonce|ct) - GridFS file store: MIME sniffing, MAX_UPLOAD_MB cap, sha256 metadata - HMAC-signed short-lived file URL tokens (§5.1, 1h TTL) - integration tests against compose Mongo via docker-compose.test.yml overlay Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
65 lines
1.6 KiB
Go
65 lines
1.6 KiB
Go
// Package crypto provides AES-256-GCM sealing for customer ticketing
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// credentials stored in Mongo (§4.2): ciphertext format base64(nonce|sealed).
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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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"fmt"
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)
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const keyLen = 32
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// Seal encrypts plaintext with AES-256-GCM and returns
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// base64(nonce|ciphertext) for storage.
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func Seal(key, plaintext []byte) (string, error) {
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gcm, err := newGCM(key)
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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 := rand.Read(nonce); err != nil {
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return "", fmt.Errorf("nonce: %w", err)
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}
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sealed := gcm.Seal(nonce, nonce, plaintext, nil)
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return base64.StdEncoding.EncodeToString(sealed), nil
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}
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// Open decrypts a value produced by Seal.
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func Open(key []byte, encoded string) ([]byte, error) {
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gcm, err := newGCM(key)
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if err != nil {
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return nil, err
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}
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raw, err := base64.StdEncoding.DecodeString(encoded)
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if err != nil {
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return nil, fmt.Errorf("decode ciphertext: %w", err)
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}
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if len(raw) < gcm.NonceSize() {
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return nil, errors.New("ciphertext shorter than nonce")
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}
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plaintext, err := gcm.Open(nil, raw[:gcm.NonceSize()], raw[gcm.NonceSize():], nil)
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if err != nil {
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return nil, fmt.Errorf("decrypt: %w", err)
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}
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return plaintext, nil
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}
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func newGCM(key []byte) (cipher.AEAD, error) {
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if len(key) != keyLen {
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return nil, fmt.Errorf("key must be %d bytes, got %d", keyLen, len(key))
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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, fmt.Errorf("aes: %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("gcm: %w", err)
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}
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return gcm, nil
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}
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