6.4.6 Supported Keyring Key Types and Lengths

MySQL Keyring supports keys of different types (encryption algorithms) and lengths:

• The available key types depend on which keyring plugin is installed.

• The permitted key lengths are subject to multiple factors:

  • General keyring loadable-function interface limits (for keys managed using one of the keyring functions described in Section 6.4.8, “General-Purpose Keyring Key-Management Functions”), or limits from back end implementations. These length limits can vary by key operation type.

  • In addition to the general limits, individual keyring plugins may impose restrictions on key lengths per key type.

Table 6.16, “General Keyring Key Length Limits” shows the general key-length limits. (The lower limits for keyring_aws are imposed by the AWS KMS interface, not the keyring functions.) Table 6.17, “Keyring Plugin Key Types and Lengths” shows the key types each keyring plugin permits, as well as any plugin-specific key-length restrictions.

Table 6.16 General Keyring Key Length Limits

Key Operation	Maximum Key Length
Generate key	2,048 bytes; 1,024 for keyring_aws
Store key	2,048 bytes
Fetch key	2,048 bytes

Table 6.17 Keyring Plugin Key Types and Lengths

Plugin Name	Permitted Key Type	Plugin-Specific Length Restrictions
keyring_aws	AES	16, 24, or 32 bytes
keyring_encrypted_file	AES DSA RSA	None None None
keyring_file	AES DSA RSA	None None None
keyring_okv	AES	16, 24, or 32 bytes