The SIGNON function is supported.

Note: The SIGNON API verifies the username and password using standard Microsoft Windows authentication, and sets the appropriate status (normal or an error code). It does not change the user account that the application runs under, nor change its permissions.
Operand Support
ESMREASON (data-area) Validated
ESMRESP (data-area) Validated
GROUPID (data-value) Full
LANGINUSE (data-area) Validated
LANGUAGECODE (data-value) Validated
NATLANG (data-value) Validated
NATLANGINUSE (data-area) Validated
NEWPASSWORD (data-value) Full
OIDCARD (data-value) Validated
PASSWORD (data-value) Full
USERID (data-value) Full