smbcacls - Man Page

Set or get ACLs on an NT file or directory names

Synopsis

smbcacls {//server/share} {/filename} [-D|--delete=ACL] [-M|--modify=ACL] [-a|--add=ACL] [-S|--set=ACLS] [-C|--chown=USERNAME] [-G|--chgrp=GROUPNAME] [-I|--inherit=STRING] [--propagate-inheritance] [--numeric] [--sddl] [--query-security-info=INT] [--set-security-info=INT] [-t|--test-args] [--domain-sid=SID] [-x|--maximum-access] [-?|--help] [--usage] [-d|--debuglevel=DEBUGLEVEL] [--debug-stdout] [--configfile=CONFIGFILE] [--option=name=value] [-l|--log-basename=LOGFILEBASE] [--leak-report] [--leak-report-full] [-R|--name-resolve=NAME-RESOLVE-ORDER] [-O|--socket-options=SOCKETOPTIONS] [-m|--maxprotocol=MAXPROTOCOL] [-n|--netbiosname=NETBIOSNAME] [--netbios-scope=SCOPE] [-W|--workgroup=WORKGROUP] [--realm=REALM] [-U|--user=[DOMAIN/]USERNAME[%PASSWORD]] [-N|--no-pass] [--password=STRING] [--pw-nt-hash] [-A|--authentication-file=FILE] [-P|--machine-pass] [--simple-bind-dn=DN] [--use-kerberos=desired|required|off] [--use-krb5-ccache=CCACHE] [--use-winbind-ccache] [--client-protection=sign|encrypt|off] [-V|--version]

Description

This tool is part of the samba(7) suite.

The smbcacls program manipulates NT Access Control Lists (ACLs) on SMB file shares. An ACL is comprised zero or more Access Control Entries (ACEs), which define access restrictions for a specific user or group.

Options

The following options are available to the smbcacls program. The format of ACLs is described in the section Acl Format

-a|--add acl

Add the entries specified to the ACL. Existing access control entries are unchanged.

-M|--modify acl

Modify the mask value (permissions) for the ACEs specified on the command line. An error will be printed for each ACE specified that was not already present in the object's ACL.

-D|--delete acl

Delete any ACEs specified on the command line. An error will be printed for each ACE specified that was not already present in the object's ACL.

-S|--set acl

This command sets the ACL on the object with only what is specified on the command line. Any existing ACL is erased. Note that the ACL specified must contain at least a revision, type, owner and group for the call to succeed.

-C|--chown name

The owner of a file or directory can be changed to the name given using the -C option. The name can be a sid in the form S-1-x-y-z or a name resolved against the server specified in the first argument.

This command is a shortcut for -M OWNER:name.

-G|--chgrp name

The group owner of a file or directory can be changed to the name given using the -G option. The name can be a sid in the form S-1-x-y-z or a name resolved against the server specified n the first argument.

This command is a shortcut for -M GROUP:name.

-I|--inherit allow|remove|copy

Set or unset the windows "Allow inheritable permissions" check box using the -I option. To set the check box pass allow. To unset the check box pass either remove or copy. Remove will remove all inherited ACEs. Copy will copy all the inherited ACEs.

--propagate-inheritance

Add, modify, delete or set ACEs on an entire directory tree according to the inheritance flags. Refer to the Inheritance section for details.

--numeric

This option displays all ACL information in numeric format. The default is to convert SIDs to names and ACE types and masks to a readable string format.

-m|--max-protocol PROTOCOL_NAME

This allows the user to select the highest SMB protocol level that smbcacls will use to connect to the server. By default this is set to NT1, which is the highest available SMB1 protocol. To connect using SMB2 or SMB3 protocol, use the strings SMB2 or SMB3 respectively. Note that to connect to a Windows 2012 server with encrypted transport selecting a max-protocol of SMB3 is required.

-t|--test-args

Don't actually do anything, only validate the correctness of the arguments.

--query-security-info FLAGS

The security-info flags for queries.

--set-security-info FLAGS

The security-info flags for queries.

--sddl

Output and input acls in sddl format.

--domain-sid SID

SID used for sddl processing.

-x|--maximum-access

When displaying an ACL additionally query the server for effective maximum permissions. Note that this is only supported with SMB protocol version 2 or higher.

-?|--help

Print a summary of command line options.

--usage

Display brief usage message.

-d|--debuglevel=DEBUGLEVEL

level is an integer from 0 to 10. The default value if this parameter is not specified is 1 for client applications.

The higher this value, the more detail will be logged to the log files about the activities of the server. At level 0, only critical errors and serious warnings will be logged. Level 1 is a reasonable level for day-to-day running - it generates a small amount of information about operations carried out.

Levels above 1 will generate considerable amounts of log data, and should only be used when investigating a problem. Levels above 3 are designed for use only by developers and generate HUGE amounts of log data, most of which is extremely cryptic.

Note that specifying this parameter here will override the log level parameter in the smb.conf file.

--debug-stdout

This will redirect debug output to STDOUT. By default all clients are logging to STDERR.

--configfile=<configuration file>

The file specified contains the configuration details required by the client. The information in this file can be general for client and server or only provide client specific like options such as client smb encrypt. See smb.conf for more information. The default configuration file name is determined at compile time.

--option=<name>=<value>

Set the smb.conf(5) option "<name>" to value "<value>" from the command line. This overrides compiled-in defaults and options read from the configuration file. If a name or a value includes a space, wrap whole --option=name=value into quotes.

-l|--log-basename=logdirectory

Base directory name for log/debug files. The extension ".progname" will be appended (e.g. log.smbclient, log.smbd, etc...). The log file is never removed by the client.

--leak-report

Enable talloc leak reporting on exit.

--leak-report-full

Enable full talloc leak reporting on exit.

-V|--version

Prints the program version number.

-R|--name-resolve=NAME-RESOLVE-ORDER

This option is used to determine what naming services and in what order to resolve host names to IP addresses. The option takes a space-separated string of different name resolution options. The best ist to wrap the whole --name-resolve=NAME-RESOLVE-ORDER into quotes.

The options are: "lmhosts", "host", "wins" and "bcast". They cause names to be resolved as follows:

  • lmhosts: Lookup an IP address in the Samba lmhosts file. If the line in lmhosts has no name type attached to the NetBIOS name (see the lmhosts(5) for details) then any name type matches for lookup.
  • host: Do a standard host name to IP address resolution, using the system /etc/hosts, NIS, or DNS lookups. This method of name resolution is operating system dependent, for instance on IRIX or Solaris this may be controlled by the /etc/nsswitch.conf file). Note that this method is only used if the NetBIOS name type being queried is the 0x20 (server) name type, otherwise it is ignored.
  • wins: Query a name with the IP address listed in the wins server parameter. If no WINS server has been specified this method will be ignored.
  • bcast: Do a broadcast on each of the known local interfaces listed in the interfaces parameter. This is the least reliable of the name resolution methods as it depends on the target host being on a locally connected subnet.

If this parameter is not set then the name resolve order defined in the smb.conf file parameter (name resolve order) will be used.

The default order is lmhosts, host, wins, bcast. Without this parameter or any entry in the name resolve order parameter of the smb.conf file, the name resolution methods will be attempted in this order.

-O|--socket-options=SOCKETOPTIONS

TCP socket options to set on the client socket. See the socket options parameter in the smb.conf manual page for the list of valid options.

-m|--maxprotocol=MAXPROTOCOL

The value of the parameter (a string) is the highest protocol level that will be supported by the client.

Note that specifying this parameter here will override the client max protocol parameter in the smb.conf file.

-n|--netbiosname=NETBIOSNAME

This option allows you to override the NetBIOS name that Samba uses for itself. This is identical to setting the netbios name parameter in the smb.conf file. However, a command line setting will take precedence over settings in smb.conf.

--netbios-scope=SCOPE

This specifies a NetBIOS scope that nmblookup will use to communicate with when generating NetBIOS names. For details on the use of NetBIOS scopes, see rfc1001.txt and rfc1002.txt. NetBIOS scopes are very rarely used, only set this parameter if you are the system administrator in charge of all the NetBIOS systems you communicate with.

-W|--workgroup=WORKGROUP

Set the SMB domain of the username. This overrides the default domain which is the domain defined in smb.conf. If the domain specified is the same as the servers NetBIOS name, it causes the client to log on using the servers local SAM (as opposed to the Domain SAM).

Note that specifying this parameter here will override the workgroup parameter in the smb.conf file.

-r|--realm=REALM

Set the realm for the domain.

Note that specifying this parameter here will override the realm parameter in the smb.conf file.

-U|--user=[DOMAIN\]USERNAME[%PASSWORD]

Sets the SMB username or username and password.

If %password is not specified, the user will be prompted. The client will first check the USER environment variable, then the LOGNAME variable and if either exists, the string is uppercased. If these environmental variables are not found, the username GUEST is used.

A third option is to use a credentials file which contains the plaintext of the username and password. This option is mainly provided for scripts where the admin does not wish to pass the credentials on the command line or via environment variables. If this method is used, make certain that the permissions on the file restrict access from unwanted users. See the -A for more details.

Be cautious about including passwords in scripts. For security it is better to let the client ask for the password if needed.

-N|--no-pass

If specified, this parameter suppresses the normal password prompt from the client to the user. This is useful when accessing a service that does not require a password.

Unless a password is specified on the command line or this parameter is specified, the client will request a password.

If a password is specified on the command line and this option is also defined the password on the command line will be silently ignored and no password will be used.

--password

Specify the password on the commandline.

Be cautious about including passwords in scripts. For security it is better to let the client ask for the password if needed.

--pw-nt-hash

The supplied password is the NT hash.

-A|--authentication-file=filename

This option allows you to specify a file from which to read the username and password used in the connection. The format of the file is:

				username = <value>
				password = <value>
				domain   = <value>

Make certain that the permissions on the file restrict access from unwanted users!

-P|--machine-pass

Use stored machine account password.

--simple-bind-dn=DN

DN to use for a simple bind.

--use-kerberos=desired|required|off

This parameter determines whether Samba client tools will try to authenticate using Kerberos. For Kerberos authentication you need to use dns names instead of IP addresses when connnecting to a service.

Note that specifying this parameter here will override the client use kerberos parameter in the smb.conf file.

--use-krb5-ccache=CCACHE

Specifies the credential cache location for Kerberos authentication.

This will set --use-kerberos=required too.

--use-winbind-ccache

Try to use the credential cache by winbind.

--client-protection=sign|encrypt|off

Sets the connection protection the client tool should use.

Note that specifying this parameter here will override the client protection parameter in the smb.conf file.

In case you need more fine grained control you can use: --option=clientsmbencrypt=OPTION, --option=clientipcsigning=OPTION, --option=clientsigning=OPTION.

Acl Format

The format of an ACL is one or more entries separated by either commas or newlines. An ACL entry is one of the following:

 
REVISION:<revision number>
OWNER:<sid or name>
GROUP:<sid or name>
ACL:<sid or name>:<type>/<flags>/<mask>

Control bits related to automatic inheritance

  • OD - "Owner Defaulted" - Indicates that the SID of the owner of the security descriptor was provided by a default mechanism.
  • GD - "Group Defaulted" - Indicates that the SID of the security descriptor group was provided by a default mechanism.
  • DP - "DACL Present" - Indicates a security descriptor that has a discretionary access control list (DACL).
  • DD - "DACL Defaulted" - Indicates a security descriptor with a default DACL.
  • SP - "SACL Present" - Indicates a security descriptor that has a system access control list (SACL).
  • SD - "SACL Defaulted" - A default mechanism, rather than the original provider of the security descriptor, provided the SACL.
  • DT - "DACL Trusted"
  • SS - "Server Security"
  • DR - "DACL Inheritance Required" - Indicates a required security descriptor in which the DACL is set up to support automatic propagation of inheritable access control entries (ACEs) to existing child objects.
  • SR - "SACL Inheritance Required" - Indicates a required security descriptor in which the SACL is set up to support automatic propagation of inheritable ACEs to existing child objects.
  • DI - "DACL Auto Inherited" - Indicates a security descriptor in which the DACL is set up to support automatic propagation of inheritable access control entries (ACEs) to existing child objects.
  • SI - "SACL Auto Inherited" - Indicates a security descriptor in which the SACL is set up to support automatic propagation of inheritable ACEs to existing child objects.
  • PD - "DACL Protected" - Prevents the DACL of the security descriptor from being modified by inheritable ACEs.
  • PS - "SACL Protected" - Prevents the SACL of the security descriptor from being modified by inheritable ACEs.
  • RM - "RM Control Valid" - Indicates that the resource manager control is valid.
  • SR - "Self Relative" - Indicates a self-relative security descriptor.

The revision of the ACL specifies the internal Windows NT ACL revision for the security descriptor. If not specified it defaults to 1. Using values other than 1 may cause strange behaviour.

The owner and group specify the owner and group sids for the object. If a SID in the format S-1-x-y-z is specified this is used, otherwise the name specified is resolved using the server on which the file or directory resides.

ACEs are specified with an "ACL:" prefix, and define permissions granted to an SID. The SID again can be specified in S-1-x-y-z format or as a name in which case it is resolved against the server on which the file or directory resides. The type, flags and mask values determine the type of access granted to the SID.

The type can be either ALLOWED or DENIED to allow/deny access to the SID.

The flags field defines how the ACE should be considered when performing inheritance. smbcacls uses these flags when run with --propagate-inheritance.

Flags can be specified as decimal or hexadecimal values, or with the respective (XX) aliases, separated by a vertical bar "|".

  • (OI) Object Inherit 0x1
  • (CI) Container Inherit 0x2
  • (NP) No Propagate Inherit 0x4
  • (IO) Inherit Only 0x8
  • (I) ACE was inherited 0x10

The mask is a value which expresses the access right granted to the SID. It can be given as a decimal or hexadecimal value, or by using one of the following text strings which map to the NT file permissions of the same name.

  • R - Allow read access
  • W - Allow write access
  • X - Execute permission on the object
  • D - Delete the object
  • P - Change permissions
  • O - Take ownership

The following combined permissions can be specified:

  • READ - Equivalent to 'RX' permissions
  • CHANGE - Equivalent to 'RXWD' permissions
  • FULL - Equivalent to 'RWXDPO' permissions

Inheritance

Per-ACE inheritance flags can be set in the ACE flags field. By default, inheritable ACEs e.g. those marked for object inheritance (OI) or container inheritance (CI), are not propagated to sub-files or folders. However, with the --propagate-inheritance argument specified, such ACEs are automatically propagated according to some inheritance rules.

  • Inheritable (OI)(OI) ACE flags can only be applied to folders.
  • Any inheritable ACEs applied to sub-files or folders are marked with the inherited (I) flag. Inheritable ACE(s) are applied to folders unless the no propagation (NP) flag is set.
  • When an ACE with the (OI) flag alone set is progagated to a child folder the inheritance only flag (IO) is also applied. This indicates the permissions associated with the ACE don't apply to the folder itself (only to it's child files). When applying the ACE to a child file the ACE is inherited as normal.
  • When an ace with the (CI) flag alone set is propagated to a child file there is no effect, when propagated to a child folder it is inherited as normal.
  • When an ACE that has both (OI) & (CI) flags set the ACE is inherited as normal by both folders and files.

(OI)(READ) added to parent folder

+-parent/        (OI)(READ)
| +-file.1       (I)(READ)
| +-nested/      (OI)(IO)(I)(READ)
  |   +-file.2   (I)(READ)

(CI)(READ) added to parent folder

+-parent/        (CI)(READ)
| +-file.1
| +-nested/      (CI)(I)(READ)
  |   +-file.2

(OI)(CI)(READ) added to parent folder

+-parent/        (OI)(CI)(READ)
| +-file.1       (I)(READ)
| +-nested/      (OI)(CI)(I)(READ)
  |   +-file.2   (I)(READ)

(OI)(NP)(READ) added to parent folder

+-oi_dir/        (OI)(NP)(READ)
| +-file.1       (I)(READ)
| +-nested/
|   +-file.2

(CI)(NP)(READ) added to parent folder

+-oi_dir/        (CI)(NP)(READ)
| +-file.1
| +-nested/      (I)(READ)
|   +-file.2

(OI)(CI)(NP)(READ) added to parent folder

+-parent/        (CI)(OI)(NP)(READ)
| +-file.1       (I)(READ)
| +-nested/      (I)(READ)
|   +-file.2

Files and folders with protected ACLs do not allow inheritable permissions (set with -I). Such objects will not receive ACEs flagged for inheritance with (CI) or (OI).

Exit Status

The smbcacls program sets the exit status depending on the success or otherwise of the operations performed. The exit status may be one of the following values.

If the operation succeeded, smbcacls returns and exit status of 0. If smbcacls couldn't connect to the specified server, or there was an error getting or setting the ACLs, an exit status of 1 is returned. If there was an error parsing any command line arguments, an exit status of 2 is returned.

Version

This man page is part of version 4.15.0rc1 of the Samba suite.

Author

The original Samba software and related utilities were created by Andrew Tridgell. Samba is now developed by the Samba Team as an Open Source project similar to the way the Linux kernel is developed.

smbcacls was written by Andrew Tridgell and Tim Potter.

The conversion to DocBook for Samba 2.2 was done by Gerald Carter. The conversion to DocBook XML 4.2 for Samba 3.0 was done by Alexander Bokovoy.

Referenced By

samba(7).

07/19/2021 Samba 4.15.0rc1