MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
This section describes options supported by most MySQL client programs that control how client programs establish connections to the server and whether connections are encrypted. These options can be given on the command line or in an option file.
This section describes options that control how client programs establish connections to the server. For additional information and examples showing how to use them, see Section 4.2.4, “Connecting to the MySQL Server Using Command Options”.
Table 4.3 Connection-Establishment Option Summary
Option Name | Description | Deprecated |
---|---|---|
--default-auth | Authentication plugin to use | |
--host | Host on which MySQL server is located | |
--password | Password to use when connecting to server | |
--pipe | Connect to server using named pipe (Windows only) | |
--plugin-dir | Directory where plugins are installed | |
--port | TCP/IP port number for connection | |
--protocol | Transport protocol to use | |
--secure-auth | Do not send passwords to server in old (pre-4.1) format | Yes |
--shared-memory-base-name | Shared-memory name for shared-memory connections (Windows only) | |
--socket | Unix socket file or Windows named pipe to use | |
--user | MySQL user name to use when connecting to server |
A hint about which client-side authentication plugin to use. See Section 6.2.13, “Pluggable Authentication”.
--host=
,
host_name
-h
host_name
The host on which the MySQL server is running. The value can
be a host name, IPv4 address, or IPv6 address. The default
value is localhost
.
--password[=
,
pass_val
]-p[
pass_val
]
The password of the MySQL account used for connecting to the
server. The password value is optional. If not given, the
program prompts for one. If given, there must be
no space between
--password=
or
-p
and the password following it. If no
password option is specified, the default is to send no
password.
Specifying a password on the command line should be considered insecure. To avoid giving the password on the command line, use an option file. See Section 6.1.2.1, “End-User Guidelines for Password Security”.
To explicitly specify that there is no password and that the
client program should not prompt for one, use the
--skip-password
option.
--pipe
, -W
On Windows, connect to the server using a named pipe. This
option applies only if the server was started with the
named_pipe
system variable
enabled to support named-pipe connections. In addition, the
user making the connection must be a member of the Windows
group specified by the
named_pipe_full_access_group
system variable.
The directory in which to look for plugins. Specify this
option if the --default-auth
option is used to specify an authentication plugin but the
client program does not find it. See
Section 6.2.13, “Pluggable Authentication”.
--port=
,
port_num
-P
port_num
For TCP/IP connections, the port number to use. The default port number is 3306.
--protocol={TCP|SOCKET|PIPE|MEMORY}
This option explicitly specifies which transport protocol to
use for connecting to the server. It is useful when other
connection parameters normally result in use of a protocol
other than the one you want. For example, connections on
Unix to localhost
are made using a Unix
socket file by default:
mysql --host=localhost
To force TCP/IP transport to be used instead, specify a
--protocol
option:
mysql --host=localhost --protocol=TCP
The following table shows the permissible
--protocol
option values and
indicates the applicable platforms for each value. The
values are not case-sensitive.
--protocol Value |
Transport Protocol Used | Applicable Platforms |
---|---|---|
TCP |
TCP/IP transport to local or remote server | All |
SOCKET |
Unix socket-file transport to local server | Unix and Unix-like systems |
PIPE |
Named-pipe transport to local server | Windows |
MEMORY |
Shared-memory transport to local server | Windows |
Do not send passwords to the server in old (pre-4.1) format. This prevents connections except for servers that use the newer password format.
As of MySQL 5.7.5, this option is deprecated; expect it to
be removed in a future MySQL release. It is always enabled
and attempting to disable it
(--skip-secure-auth
,
--secure-auth=0
) produces an
error. Before MySQL 5.7.5, this option is enabled by default
but can be disabled.
Passwords that use the pre-4.1 hashing method are less secure than passwords that use the native password hashing method and should be avoided. Pre-4.1 passwords are deprecated and support for them was removed in MySQL 5.7.5. For account upgrade instructions, see Section 6.4.1.3, “Migrating Away from Pre-4.1 Password Hashing and the mysql_old_password Plugin”.
--shared-memory-base-name=
name
On Windows, the shared-memory name to use for connections
made using shared memory to a local server. The default
value is MYSQL
. The shared-memory name is
case-sensitive.
This option applies only if the server was started with the
shared_memory
system
variable enabled to support shared-memory connections.
--socket=
,
path
-S
path
On Unix, the name of the Unix socket file to use for
connections made using a named pipe to a local server. The
default Unix socket file name is
/tmp/mysql.sock
.
On Windows, the name of the named pipe to use for
connections to a local server. The default Windows pipe name
is MySQL
. The pipe name is not
case-sensitive.
On Windows, this option applies only if the server was
started with the named_pipe
system variable enabled to support named-pipe connections.
In addition, the user making the connection must be a member
of the Windows group specified by the
named_pipe_full_access_group
system variable.
--user=
,
user_name
-u
user_name
The user name of the MySQL account to use for connecting to
the server. The default user name is ODBC
on Windows or your Unix login name on Unix.
This section describes options for client programs that specify whether to use encrypted connections to the server, the names of certificate and key files, and other parameters related to encrypted-connection support. For examples of suggested use and how to check whether a connection is encrypted, see Section 6.3.1, “Configuring MySQL to Use Encrypted Connections”.
These options have an effect only for connections that use a transport protocol subject to encryption; that is, TCP/IP and Unix socket-file connections. See Section 4.2.5, “Connection Transport Protocols”
For information about using encrypted connections from the MySQL C API, see C API Support for Encrypted Connections.
Table 4.4 Connection-Encryption Option Summary
Option Name | Description | Introduced |
---|---|---|
--get-server-public-key | Request RSA public key from server | 5.7.23 |
--server-public-key-path | Path name to file containing RSA public key | |
--skip-ssl | Disable connection encryption | |
--ssl | Enable connection encryption | |
--ssl-ca | File that contains list of trusted SSL Certificate Authorities | |
--ssl-capath | Directory that contains trusted SSL Certificate Authority certificate files | |
--ssl-cert | File that contains X.509 certificate | |
--ssl-cipher | Permissible ciphers for connection encryption | |
--ssl-crl | File that contains certificate revocation lists | |
--ssl-crlpath | Directory that contains certificate revocation-list files | |
--ssl-key | File that contains X.509 key | |
--ssl-mode | Desired security state of connection to server | 5.7.11 |
--ssl-verify-server-cert | Verify host name against server certificate Common Name identity | |
--tls-version | Permissible TLS protocols for encrypted connections | 5.7.10 |
Request from the server the public key required for RSA key
pair-based password exchange. This option applies to clients
that authenticate with the
caching_sha2_password
authentication
plugin. For that plugin, the server does not send the public
key unless requested. This option is ignored for accounts
that do not authenticate with that plugin. It is also
ignored if RSA-based password exchange is not used, as is
the case when the client connects to the server using a
secure connection.
If
--server-public-key-path=
is given and specifies a valid public key file, it takes
precedence over
file_name
--get-server-public-key
.
For information about the
caching_sha2_password
plugin, see
Section 6.4.1.4, “Caching SHA-2 Pluggable Authentication”.
The --get-server-public-key
option was added in MySQL 5.7.23.
--server-public-key-path=
file_name
The path name to a file in PEM format containing a
client-side copy of the public key required by the server
for RSA key pair-based password exchange. This option
applies to clients that authenticate with the
sha256_password
or
caching_sha2_password
authentication
plugin. This option is ignored for accounts that do not
authenticate with one of those plugins. It is also ignored
if RSA-based password exchange is not used, as is the case
when the client connects to the server using a secure
connection.
This option is available only if MySQL was built using OpenSSL.
For information about the sha256_password
and caching_sha2_password
plugins, see
Section 6.4.1.5, “SHA-256 Pluggable Authentication”, and
Section 6.4.1.4, “Caching SHA-2 Pluggable Authentication”.
The client-side --ssl
option is deprecated as of MySQL 5.7.11 and is removed in
MySQL 8.0. For client programs, use
--ssl-mode
instead:
Use
--ssl-mode=REQUIRED
instead of --ssl=1
or
--enable-ssl
.
Use
--ssl-mode=DISABLED
instead of --ssl=0
,
--skip-ssl
,
or
--disable-ssl
.
No explicit --ssl-mode
option is equivalent to no explicit
--ssl
option.
The server-side --ssl
option is not deprecated.
By default, MySQL client programs attempt to establish an
encrypted connection if the server supports encrypted
connections, with further control available through the
--ssl
option: The
client-side --ssl
option
works as follows:
In the absence of an
--ssl
option, clients
attempt to connect using encryption, falling back to an
unencrypted connection if an encrypted connection cannot
be established.
The presence of an explicit
--ssl
option or a
synonym (--ssl=1
,
--enable-ssl
)
is prescriptive: Clients require an encrypted connection
and fail if one cannot be established.
With an --ssl=0
option
or a synonym
(--skip-ssl
,
--disable-ssl
),
clients use an unencrypted connection.
To require use of encrypted connections by a MySQL account,
use CREATE USER
to create the
account with a REQUIRE SSL
clause, or use
ALTER USER
for an existing
account to add a REQUIRE SSL
clause. This
causes connection attempts by clients that use the account
to be rejected unless MySQL supports encrypted connections
and an encrypted connection can be established.
The REQUIRE
clause permits other
encryption-related options, which can be used to enforce
security requirements stricter than REQUIRE
SSL
. For additional details about which command
options may or must be specified by clients that connect
using accounts configured using the various
REQUIRE
options, see
CREATE USER SSL/TLS Options.
To specify additional parameters for encrypted connections,
consider setting at least the
ssl_cert
and
ssl_key
system variables on
the server side and the
--ssl-ca
option on the
client side. See
Section 6.3.1, “Configuring MySQL to Use Encrypted Connections”, which also
describes server capabilities for certificate and key file
autogeneration and autodiscovery.
The path name of the Certificate Authority (CA) certificate file in PEM format. The file contains a list of trusted SSL Certificate Authorities.
To tell the client not to authenticate the server
certificate when establishing an encrypted connection to the
server, specify neither
--ssl-ca
nor
--ssl-capath
. The server
still verifies the client according to any applicable
requirements established for the client account, and it
still uses any ssl_ca
or
ssl_capath
system variable
values specified on the server side.
To specify the CA file for the server, set the
ssl_ca
system variable.
The path name of the directory that contains trusted SSL certificate authority (CA) certificate files in PEM format. Support for this capability depends on the SSL library used to compile MySQL; see Section 6.3.4, “SSL Library-Dependent Capabilities”.
To tell the client not to authenticate the server
certificate when establishing an encrypted connection to the
server, specify neither
--ssl-ca
nor
--ssl-capath
. The server
still verifies the client according to any applicable
requirements established for the client account, and it
still uses any ssl_ca
or
ssl_capath
system variable
values specified on the server side.
To specify the CA directory for the server, set the
ssl_capath
system variable.
The path name of the client SSL public key certificate file in PEM format.
To specify the server SSL public key certificate file, set
the ssl_cert
system
variable.
The list of permissible ciphers for connection encryption. If no cipher in the list is supported, encrypted connections do not work.
For greatest portability,
cipher_list
should be a list of
one or more cipher names, separated by colons. This format
is understood both by OpenSSL and yaSSL. Examples:
--ssl-cipher=AES128-SHA --ssl-cipher=DHE-RSA-AES128-GCM-SHA256:AES128-SHA
OpenSSL supports a more flexible syntax for specifying ciphers, as described in the OpenSSL documentation at https://www.openssl.org/docs/manmaster/man1/ciphers.html. yaSSL does not, so attempts to use that extended syntax fail for a MySQL distribution compiled using yaSSL.
For information about which encryption ciphers MySQL supports, see Section 6.3.2, “Encrypted Connection TLS Protocols and Ciphers”.
To specify the encryption ciphers for the server, set the
ssl_cipher
system variable.
The path name of the file containing certificate revocation lists in PEM format. Support for revocation-list capability depends on the SSL library used to compile MySQL. See Section 6.3.4, “SSL Library-Dependent Capabilities”.
If neither --ssl-crl
nor
--ssl-crlpath
is given, no
CRL checks are performed, even if the CA path contains
certificate revocation lists.
To specify the revocation-list file for the server, set the
ssl_crl
system variable.
The path name of the directory that contains certificate revocation-list files in PEM format. Support for revocation-list capability depends on the SSL library used to compile MySQL. See Section 6.3.4, “SSL Library-Dependent Capabilities”.
If neither --ssl-crl
nor
--ssl-crlpath
is given, no
CRL checks are performed, even if the CA path contains
certificate revocation lists.
To specify the revocation-list directory for the server, set
the ssl_crlpath
system
variable.
The path name of the client SSL private key file in PEM format. For better security, use a certificate with an RSA key size of at least 2048 bits.
If the key file is protected by a passphrase, the client program prompts the user for the passphrase. The password must be given interactively; it cannot be stored in a file. If the passphrase is incorrect, the program continues as if it could not read the key.
To specify the server SSL private key file, set the
ssl_key
system variable.
This option specifies the desired security state of the connection to the server. These mode values are permissible, in order of increasing strictness:
DISABLED
: Establish an unencrypted
connection. This is like the legacy
--ssl=0
option or its
synonyms
(--skip-ssl
,
--disable-ssl
).
PREFERRED
: Establish an encrypted
connection if the server supports encrypted connections,
falling back to an unencrypted connection if an
encrypted connection cannot be established. This is the
default if --ssl-mode
is
not specified.
Connections over Unix socket files are not encrypted
with a mode of PREFERRED
. To enforce
encryption for Unix socket-file connections, use a mode
of REQUIRED
or stricter. (However,
socket-file transport is secure by default, so
encrypting a socket-file connection makes it no more
secure and increases CPU load.)
REQUIRED
: Establish an encrypted
connection if the server supports encrypted connections.
The connection attempt fails if an encrypted connection
cannot be established.
VERIFY_CA
: Like
REQUIRED
, but additionally verify the
server Certificate Authority (CA) certificate against
the configured CA certificates. The connection attempt
fails if no valid matching CA certificates are found.
VERIFY_IDENTITY
: Like
VERIFY_CA
, but additionally perform
host name identity verification by checking the host
name the client uses for connecting to the server
against the identity in the certificate that the server
sends to the client:
As of MySQL 5.7.23, if the client uses OpenSSL 1.0.2 or higher, the client checks whether the host name that it uses for connecting matches either the Subject Alternative Name value or the Common Name value in the server certificate. Host name identity verification also works with certificates that specify the Common Name using wildcards.
Otherwise, the client checks whether the host name that it uses for connecting matches the Common Name value in the server certificate.
The connection fails if there is a mismatch. For
encrypted connections, this option helps prevent
man-in-the-middle attacks. This is like the legacy
--ssl-verify-server-cert
option.
Host name identity verification with
VERIFY_IDENTITY
does not work with
self-signed certificates that are created
automatically by the server or manually using
mysql_ssl_rsa_setup (see
Section 6.3.3.1, “Creating SSL and RSA Certificates and Keys using MySQL”).
Such self-signed certificates do not contain the
server name as the Common Name value.
The --ssl-mode
option
interacts with CA certificate options as follows:
If --ssl-mode
is not
explicitly set otherwise, use of
--ssl-ca
or
--ssl-capath
implies
--ssl-mode=VERIFY_CA
.
For --ssl-mode
values of
VERIFY_CA
or
VERIFY_IDENTITY
,
--ssl-ca
or
--ssl-capath
is also
required, to supply a CA certificate that matches the
one used by the server.
An explicit --ssl-mode
option with a value other than
VERIFY_CA
or
VERIFY_IDENTITY
, together with an
explicit --ssl-ca
or
--ssl-capath
option,
produces a warning that no verification of the server
certificate is performed, despite a CA certificate
option being specified.
The --ssl-mode
option was
added in MySQL 5.7.11.
To require use of encrypted connections by a MySQL account,
use CREATE USER
to create the
account with a REQUIRE SSL
clause, or use
ALTER USER
for an existing
account to add a REQUIRE SSL
clause. This
causes connection attempts by clients that use the account
to be rejected unless MySQL supports encrypted connections
and an encrypted connection can be established.
The REQUIRE
clause permits other
encryption-related options, which can be used to enforce
security requirements stricter than REQUIRE
SSL
. For additional details about which command
options may or must be specified by clients that connect
using accounts configured using the various
REQUIRE
options, see
CREATE USER SSL/TLS Options.
The
--ssl-verify-server-cert
option is deprecated as of MySQL 5.7.11 and is removed in
MySQL 8.0. Use
--ssl-mode=VERIFY_IDENTITY
instead.
This option causes the client to perform host name identity verification by checking the host name the client uses for connecting to the server against the identity in the certificate that the server sends to the client:
As of MySQL 5.7.23, if the client uses OpenSSL 1.0.2 or higher, the client checks whether the host name that it uses for connecting matches either the Subject Alternative Name value or the Common Name value in the server certificate.
Otherwise, the client checks whether the host name that it uses for connecting matches the Common Name value in the server certificate.
The connection fails if there is a mismatch. For encrypted connections, this option helps prevent man-in-the-middle attacks. Host name identity verification is disabled by default.
Host name identity verification does not work with self-signed certificates created automatically by the server, or manually using mysql_ssl_rsa_setup (see Section 6.3.3.1, “Creating SSL and RSA Certificates and Keys using MySQL”). Such self-signed certificates do not contain the server name as the Common Name value.
Host name identity verification also does not work with certificates that specify the Common Name using wildcards because that name is compared verbatim to the server name.
This option specifies the TLS protocols the client permits for encrypted connections. The value is a list of one or more comma-separated protocol versions. For example:
mysql --tls-version="TLSv1.1,TLSv1.2"
The protocols that can be named for this option depend on the SSL library used to compile MySQL. Permitted protocols should be chosen such as not to leave “holes” in the list. For example, these values do not have holes:
--tls-version="TLSv1,TLSv1.1,TLSv1.2" --tls-version="TLSv1.1,TLSv1.2" --tls-version="TLSv1.2"
This value does have a hole and should not be used:
--tls-version="TLSv1,TLSv1.2"
For details, see Section 6.3.2, “Encrypted Connection TLS Protocols and Ciphers”.
This option was added in MySQL 5.7.10.
To specify which TLS protocols the server permits, set the
tls_version
system
variable.