Extdom plugin protocol

SSSD on ipa client uses extdom plugin to translate SID to names and POSIX IDs. It can also return secondary groups for any user.

EXTDOM V0 (2.16.840.1.113730.3.8.10.4)

V0 request

/*
 * ExtdomRequestValue ::= SEQUENCE {
 *    inputType ENUMERATED {
 *        sid (1),
 *        name (2),
 *        posix uid (3),
 *        posix gid (4)
 *    },
 *    requestType ENUMERATED {
 *        simple (1),
 *        full (2)
 *    },
 *    data InputData
 * }
 *
 * InputData ::= CHOICE {
 *    sid OCTET STRING,
 *    name NameDomainData
 *    uid PosixUid,
 *    gid PosixGid
 * }
 *
 * NameDomainData ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    object_name OCTET STRING
 * }
 *
 * PosixUid ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    uid INTEGER
 * }
 *
 * PosixGid ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    gid INTEGER
 * }
 */

V0 reply

/*
 * ExtdomResponseValue ::= SEQUENCE {
 *    responseType ENUMERATED {
 *        sid (1),
 *        name (2),
 *        posix_user (3),
 *        posix_group (4)
 *    },
 *    data OutputData
 * }
 *
 * OutputData ::= CHOICE {
 *    sid OCTET STRING,
 *    name NameDomainData,
 *    user PosixUser,
 *    group PosixGroup
 * }
 *
 * NameDomainData ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    object_name OCTET STRING
 * }
 *
 * PosixUser ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    user_name OCTET STRING,
 *    uid INTEGER
 *    gid INTEGER
 * }
 *
 * PosixGroup ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    group_name OCTET STRING,
 *    gid INTEGER
 * }
 */

EXTDOM V1 (2.16.840.1.113730.3.8.10.4.1)

In V1 version the requestType is extended of full_with_groups. The response introduces new type posix_user_grouplist containing the list of groups

V1 request

/*
 * ExtdomRequestValue ::= SEQUENCE {
 *    inputType ENUMERATED {
 *        sid (1),
 *        name (2),
 *        posix uid (3),
 *        posix gid (4),
 *    },
 *    requestType ENUMERATED {
 *        simple (1),
 *        full (2),
 *        full_with_groups (3)
 *    },
 *    data InputData
 * }
 *
 * InputData ::= CHOICE {
 *    sid OCTET STRING,
 *    name NameDomainData
 *    uid PosixUid,
 *    gid PosixGid
 * }
 *
 * NameDomainData ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    object_name OCTET STRING
 * }
 *
 * PosixUid ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    uid INTEGER
 * }
 *
 * PosixGid ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    gid INTEGER
 * }
 */

V1 reply

/*
 * ExtdomResponseValue ::= SEQUENCE {
 *    responseType ENUMERATED {
 *        sid (1),
 *        name (2),
 *        posix_user (3),
 *        posix_group (4),
 *        posix_user_grouplist (5)
 *    },
 *    data OutputData
 * }
 *
 * OutputData ::= CHOICE {
 *    sid OCTET STRING,
 *    name NameDomainData,
 *    user PosixUser,
 *    group PosixGroup,
 *    user_grouplist PosixUserGrouplist
 * }
 *
 * NameDomainData ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    object_name OCTET STRING
 * }
 *
 * PosixUser ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    user_name OCTET STRING,
 *    uid INTEGER
 *    gid INTEGER
 * }
 *
 * GroupNameList ::= SEQUENCE OF groupname OCTET STRING
 *
 * PosixGroup ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    group_name OCTET STRING,
 *    gid INTEGER
 * }
 *
 * PosixUserGrouplist ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    user_name OCTET STRING,
 *    uid INTEGER
 *    gid INTEGER
 *    gecos OCTET STRING,
 *    home_directory OCTET STRING,
 *    shell OCTET STRING,
 *    grouplist GroupNameList
 * }
 *
 * GroupNameList ::= SEQUENCE OF groupname OCTET STRING
 *
 */

EXTDOM V2 (2.16.840.1.113730.3.8.10.4.2)

The name request tries to translate name to ID. It first tries translate it as if it is a user and when it fails, it tries to resolve is as group.

To make it more efficient when SSSD knows the type of requested object, two new inputTypes are defined - username and groupname.

The response is the same as in V1

V2 request

/*
 * ExtdomRequestValue ::= SEQUENCE {
 *    inputType ENUMERATED {
 *        sid (1),
 *        name (2),
 *        posix uid (3),
 *        posix gid (4),
 *        username (5),
 *        groupname (6)
 *    },
 *    requestType ENUMERATED {
 *        simple (1),
 *        full (2),
 *        full_with_groups (3)
 *    },
 *    data InputData
 * }
 *
 * InputData ::= CHOICE {
 *    sid OCTET STRING,
 *    name NameDomainData
 *    uid PosixUid,
 *    gid PosixGid
 * }
 *
 * NameDomainData ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    object_name OCTET STRING
 * }
 *
 * PosixUid ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    uid INTEGER
 * }
 *
 * PosixGid ::= SEQUENCE {
 *    domain_name OCTET STRING,
 *    gid INTEGER
 * }
 */