# crypto library

## Function

 The crypto standard library is used to generate text digests, HMAC signatures and UUIDs.

## API List

| API | Description |
| ------ | ------ |
| [crypto.sha256](/en/docs/crypto/sha256) | Returns the SHA-256 lowercase hexadecimal digest. |
| [crypto.sha512](/en/docs/crypto/sha512) | Returns the SHA-512 lowercase hexadecimal digest. |
| [crypto.hmac_sha256](/en/docs/crypto/hmac_sha256) | Generate an HMAC-SHA256 signature using a key. |
| [crypto.hmac_sha512](/en/docs/crypto/hmac_sha512) | Generate an HMAC-SHA512 signature using a key. |
| [crypto.uuid](/en/docs/crypto/uuid) | Generate UUID v4 string. |
| [crypto.to_string](/en/docs/crypto/to_string) | Return the current input text. |

## Examples

```bt
result = crypto('BT').sha256()

// Output: 4ea3d68e3581fa27f86acaa247b297686a8e1a8fecd5523cd8314f14b6a28c31
print result
```

## Notes

 - SHA and HMAC return lowercase hexadecimal strings.
 - UUID uses v4 random UUID.