MySQL provides these ways to create the SSL certificate and key files and RSA key-pair files required to support encrypted connections using SSL and secure password exchange using RSA over unencrypted connections, if those files are missing:
The server can autogenerate these files at startup, for MySQL distributions compiled using OpenSSL.
Users can invoke the mysql_ssl_rsa_setup utility manually.
For some distribution types, such as RPM packages, mysql_ssl_rsa_setup invocation occurs during data directory initialization. In this case, the MySQL distribution need not have been compiled using OpenSSL as long as the openssl command is available.
Server autogeneration and mysql_ssl_rsa_setup help lower the barrier to using SSL by making it easier to generate the required files. However, certificates generated by these methods are self-signed, which may not be very secure. After you gain experience using such files, consider obtaining certificate/key material from a registered certificate authority.
For MySQL distributions compiled using OpenSSL, the MySQL
server has the capability of automatically generating missing
SSL and RSA files at startup. The
system variables control automatic generation of these files.
These variables are enabled by default. They can be enabled at
startup and inspected but not set at runtime.
At startup, the server automatically generates server-side and
client-side SSL certificate and key files in the data
directory if the
variable is enabled, no SSL options other than
--ssl are specified, and the
server-side SSL files are missing from the data directory.
These files enable encrypted client connections using SSL; see
Section 6.3.1, “Configuring MySQL to Use Encrypted Connections”.
The server checks the data directory for SSL files with the following names:
ca.pem server-cert.pem server-key.pem
If any of those files are present, the server creates no SSL files. Otherwise, it creates them, plus some additional files:
ca.pem Self-signed CA certificate ca-key.pem CA private key server-cert.pem Server certificate server-key.pem Server private key client-cert.pem Client certificate client-key.pem Client private key
At startup, the server automatically generates RSA
private/public key-pair files in the data directory if all of
these conditions are true: The
system variable is enabled; no RSA options are specified; the
RSA files are missing from the data directory. These key-pair
files enable secure password exchange using RSA over
unencrypted connections for accounts authenticated by the
sha256_password plugin; see
Section 18.104.22.168, “SHA-256 Pluggable Authentication”.
The server checks the data directory for RSA files with the following names:
private_key.pem Private member of private/public key pair public_key.pem Public member of private/public key pair
If any of these files are present, the server creates no RSA files. Otherwise, it creates them.
MySQL distributions include a mysql_ssl_rsa_setup utility that can be invoked manually to generate SSL and RSA files. This utility is included with all MySQL distributions, but it does require that the openssl command be available. For usage instructions, see Section 4.4.5, “mysql_ssl_rsa_setup — Create SSL/RSA Files”.
SSL and RSA files created automatically by the server or by invoking mysql_ssl_rsa_setup have these characteristics:
SSL and RSA keys are have a size of 2048 bits.
The SSL CA certificate is self signed.
The SSL server and client certificates are signed with the CA certificate and key, using the
SSL certificates use these Common Name (CN) values, with the appropriate certificate type (CA, Server, Client):
ca.pem: MySQL_Server_suffix_Auto_Generated_CA_Certificate server-cert.pm: MySQL_Server_suffix_Auto_Generated_Server_Certificate client-cert.pm: MySQL_Server_suffix_Auto_Generated_Client_Certificate
For files generated by the server, if the resulting CN values exceed 64 characters, the
_portion of the name is omitted.
SSL files have blank values for Country (C), State or Province (ST), Organization (O), Organization Unit Name (OU) and email address.
SSL files created by the server or by mysql_ssl_rsa_setup are valid for ten years from the time of generation.
RSA files do not expire.
SSL files have different serial numbers for each certificate/key pair (1 for CA, 2 for Server, 3 for Client).
Files created automatically by the server are owned by the account that runs the server. Files created using mysql_ssl_rsa_setup are owned by the user who invoked that program. This can be changed on systems that support the
chown()system call if the program is invoked by
--uidoption is given to specify the user who should own the files.
On Unix and Unix-like systems, the file access mode is 644 for certificate files (that is, world readable) and 600 for key files (that is, accessible only by the account that runs the server).
To see the contents of an SSL certificate (for example, to check the range of dates over which it is valid), invoke openssl directly:
openssl x509 -text -in ca.pem openssl x509 -text -in server-cert.pem openssl x509 -text -in client-cert.pem
It is also possible to check SSL certificate expiration information using this SQL statement:
mysql> SHOW STATUS LIKE 'Ssl_server_not%'; +-----------------------+--------------------------+ | Variable_name | Value | +-----------------------+--------------------------+ | Ssl_server_not_after | Apr 28 14:16:39 2027 GMT | | Ssl_server_not_before | May 1 14:16:39 2017 GMT | +-----------------------+--------------------------+