File ext: `*.tinyenc`

File format:

```text
[TAG; 2 bytes; short; BE; Always 1]
[LENGTH; 4 bytes; int; BE]
[META; LENGTH bytes]
[ENCRYPTED_DATA; n bytes; AES/GCM]
```

Meta format:

| Field   | Type    | Comment                                      |
|---------|---------|----------------------------------------------|
| version | String  | Constant value: `1.1`                        |
| created | Long    | Created time, Unix Epoch                     |
| userAgent | String  | User Agent, e.g. `TinyEncrypt v0.5.1@MacOS`  |
| comment | String  | `optinonal` Plain text comment               |
| encryptedComment | String  | `optinonal` Encrypted comment                |
| pgpEnvelop | String  | `deprecated` PGP Publickey Encrypted DataKey |
| pgpFingerprint | String  | `deprecated` Hex(Sha256(PGP Publickey))      |
| envelop | String  | `deprecated` KMS Encrypted DataKey           |
| envelops | Envelop[] | Envelop Array                                |
| nonce | byte[]  | GCM Nonce                                    |
| fileLength | Long    | File Length                                  |
| fileLastModified | Long    | File Last Modified                           |
| compress | Boolean | Compress or not                              |

Envelop format:

| Field        | Type   | Comment           |
|--------------|--------|-------------------|
| type         | String | `kms`, `pgp`, ... |
| kid          | String | Key ID            |
| encryptedKey | String | Encrypted Key     |