MySQL 8.4 Release Notes
MySQL Enterprise Encryption lets you limit keys to a length that provides adequate
security for your requirements while balancing this with resource
usage. You can also configure the functions provided by the
component_enterprise_encryption component to
support decryption and verification for content produced by the
old openssl_udf shared library functions.
By default, the functions provided by the
component_enterprise_encryption component do
not decrypt encrypted text, or verify signatures, that were
produced by the legacy functions provided in earlier releases by
the openssl_udf shared library. The component
functions assume that encrypted text uses the RSAES-OAEP padding
scheme, and signatures use the RSASSA-PSS signature scheme.
However, encrypted text produced by the legacy functions uses
the RSAES-PKCS1-v1_5 padding scheme, and signatures produced by
the legacy functions use the RSASSA-PKCS1-v1_5 signature scheme.
If you want the component functions to support content produced
by the legacy functions, set the
enterprise_encryption.rsa_support_legacy_padding
system variable to ON. This variable is
available when the component is installed. When you set it to
ON, the component functions first attempt to
decrypt or verify content assuming it has their normal schemes.
If that does not work, they also attempt to decrypt or verify
the content assuming it has the schemes used by the old
functions. This behavior is not the default because it increases
the time taken to process content that cannot be decrypted or
verified at all. If you are not handling content produced by the
old functions, let the system variable default to
OFF.
The amount of CPU resources required by MySQL Enterprise Encryption's key generation functions increases as the key length increases. For some installations, this might result in unacceptable CPU usage if applications frequently generate excessively long keys.
The functions provided by the
component_enterprise_encryption component
have a minimum key length of 2048 bits for RSA keys, which is in
line with current best practice for minimum key lengths. The
enterprise_encryption.maximum_rsa_key_size
system variable specifies the maximum key size.