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| 1 | +// SPDX-License-Identifier: AGPL-3.0-or-later |
| 2 | + |
| 3 | +package webhook |
| 4 | + |
| 5 | +import ( |
| 6 | + "crypto/rand" |
| 7 | + "encoding/hex" |
| 8 | + "errors" |
| 9 | + |
| 10 | + "github.com/tenseleyFlow/shithub/internal/auth/secretbox" |
| 11 | +) |
| 12 | + |
| 13 | +// SecretLength is the byte length of a freshly minted webhook secret. |
| 14 | +// 32 bytes ≈ 256 bits — well above HMAC-SHA256's effective security. |
| 15 | +const SecretLength = 32 |
| 16 | + |
| 17 | +// GenerateSecret returns a hex-encoded random secret suitable for |
| 18 | +// dropping into the webhook config form. The hex shape keeps it easy |
| 19 | +// to paste into receiver code. |
| 20 | +func GenerateSecret() (string, error) { |
| 21 | + b := make([]byte, SecretLength) |
| 22 | + if _, err := rand.Read(b); err != nil { |
| 23 | + return "", err |
| 24 | + } |
| 25 | + return hex.EncodeToString(b), nil |
| 26 | +} |
| 27 | + |
| 28 | +// SealSecret AEAD-wraps secret under the supplied box. Returns |
| 29 | +// (ciphertext, nonce) for storage in webhooks.secret_ciphertext + |
| 30 | +// webhooks.secret_nonce. |
| 31 | +func SealSecret(box *secretbox.Box, secret string) (ciphertext, nonce []byte, err error) { |
| 32 | + if box == nil { |
| 33 | + return nil, nil, errors.New("webhook: nil box") |
| 34 | + } |
| 35 | + if secret == "" { |
| 36 | + return nil, nil, errors.New("webhook: empty secret") |
| 37 | + } |
| 38 | + return box.Seal([]byte(secret)) |
| 39 | +} |
| 40 | + |
| 41 | +// OpenSecret decrypts the stored ciphertext+nonce. Decryption failure |
| 42 | +// is a hard error: the deliverer disables the webhook with a precise |
| 43 | +// reason rather than silently signing with garbage. |
| 44 | +func OpenSecret(box *secretbox.Box, ciphertext, nonce []byte) (string, error) { |
| 45 | + if box == nil { |
| 46 | + return "", errors.New("webhook: nil box") |
| 47 | + } |
| 48 | + pt, err := box.Open(ciphertext, nonce) |
| 49 | + if err != nil { |
| 50 | + return "", err |
| 51 | + } |
| 52 | + return string(pt), nil |
| 53 | +} |
