MySQL Keyring supports keys of different types (encryption algorithms) and lengths:MySQL Keyring支持不同类型（加密算法）和长度的密钥：
The available key types depend on which keyring plugin is installed.可用的密钥类型取决于安装了哪个密钥环插件。
The permitted key lengths are subject to multiple factors:允许的密钥长度受多种因素影响：
General keyring loadable-function interface limits (for keys managed using one of the keyring functions described in Section 6.4.4.14, “General-Purpose Keyring Key-Management Functions”), or limits from back end implementations. These length limits can vary by key operation type.通用密钥环可加载功能接口限制（适用于使用第6.4.4.14节，“通用密钥环密钥管理功能”中描述的密钥环功能之一管理的密钥），或后端实现的限制。这些长度限制可能因按键操作类型而异。
In addition to the general limits, individual keyring plugins may impose restrictions on key lengths per key type.除了一般限制外，单个钥匙圈插件可能会对每种钥匙类型的钥匙长度施加限制。
Table 6.26, “General Keyring Key Length Limits” shows the general key-length limits. 表6.26“通用钥匙圈钥匙长度限制”显示了通用钥匙长度限制。(The lower limits for （keyring_aws的下限是由aws KMS接口而不是密钥环函数施加的。）keyring_aws are imposed by the AWS KMS interface, not the keyring functions.) For keyring plugins, Table 6.27, “Keyring Plugin Key Types and Lengths” shows the key types each keyring plugin permits, as well as any plugin-specific key-length restrictions. 对于钥匙圈插件，表6.27“钥匙圈插件密钥类型和长度”显示了每个钥匙圈插件允许的密钥类型，以及任何特定于插件的密钥长度限制。For keyring components, the general key-length limits apply and there are no key-type restrictions.对于钥匙圈组件，适用一般钥匙长度限制，没有钥匙类型限制。
Table 6.26 General Keyring Key Length Limits通用钥匙圈钥匙长度限制
16,384 bytes (2,048 prior to MySQL 8.0.18); 1,024 for |
|
16,384 bytes (2,048 prior to MySQL 8.0.18); 4,096 for |
|
16,384 bytes (2,048 prior to MySQL 8.0.18); 4,096 for |
Table 6.27 Keyring Plugin Key Types and Lengths钥匙圈插件钥匙类型和长度
keyring_aws |
| 16, 24, or 32 bytes None |
|---|---|---|
keyring_encrypted_file |
| None None None None |
keyring_file |
| None None None None |
keyring_hashicorp |
| None None None None |
keyring_oci |
| 16, 24, or 32 bytes |
keyring_okv |
| 16, 24, or 32 bytes None |
The 从MySQL 8.0.19开始提供的SECRET key type, available as of MySQL 8.0.19, is intended for general-purpose storage of sensitive data using the MySQL keyring, and is supported by all keyring components and most keyring plugins. SECRET密钥类型旨在使用MySQL密钥环对敏感数据进行通用存储，并得到所有密钥环组件和大多数密钥环插件的支持。The keyring encrypts and decrypts 密钥环在存储和检索时将SECRET data as a byte stream upon storage and retrieval.SECRET数据加密和解密为字节流。
Example keyring operations involving the 涉及SECRET key type:SECRET密钥类型的密钥环操作示例：
SELECT keyring_key_generate('MySecret1', 'SECRET', 20);
SELECT keyring_key_remove('MySecret1');
SELECT keyring_key_store('MySecret2', 'SECRET', 'MySecretData');
SELECT keyring_key_fetch('MySecret2');
SELECT keyring_key_length_fetch('MySecret2');
SELECT keyring_key_type_fetch('MySecret2');
SELECT keyring_key_remove('MySecret2');