Configuring MACs

The MAC (Message Authentication Code) algorithm(s) used for data integrity verification can be selected in the sshd2_config file:

MACs                hmac-sha1,hmac-md5

The system will attempt to use the different HMAC algorithms in the sequence they are specified on the line. The supported MAC names are the following:

hmac-md5
hmac-md5-96
hmac-sha1
hmac-sha1-96
hmac-sha256-2@ssh.com
hmac-sha224@ssh.com
hmac-sha256@ssh.com
hmac-sha384@ssh.com
hmac-sha512@ssh.com

Special values for this option are the following:

Any: allows all the MAC values including none
AnyStd: allows only those MACs mentioned in the IETF-SecSh draft (hmac-md5, hmac- md5-96, hmac-sha1, hmac-sha1-96) and none
none: means that no cryptographic data integrity method is used
AnyMac: the same as Any but excludes none
AnyStdMac: the same as AnyStd but exludes none

The default MAC algorithms are:

hmac-sha1
hmac-sha1-96
hmac-sha256-2@ssh.com
hmac-sha224@ssh.com
hmac-sha256@ssh.com
hmac-sha384@ssh.com
hmac-sha512@ssh.com