ACS System

About

WWIV now supports a simple expression language for supporting a basic Access Control System (ACS) to allow more fine grained access primitives for users on the BBS.

WWIV's ACS suppors the following objects:

Name Description
User Provides attributes about the current user
System Provides attributes about the bbs

Syntax

The ACS language allows conditional attribute-based access control for WWIV BBS system resources, such as message areas, conferences, file areas, chains, and menu items.
This allows the system to specify the conditions in a free-form DSL language that determines if access is granted.

Language Elements

WWIV's ACS grammar is comprised of:

  • Comparison Operators
  • Logical Operators
  • Object Attributes
  • Expressions


Data Types

ACS support the following datatypes:

Name Description
Number An integer value of 32 bits in size
String A variable length set of CP437 characters
Boolean Support either true of false. Convertible to Numbers as 0 and 1
Ar Contains the set of Ar values, supports equality checks against single Ar value specified as a string or character.


Operators

OP ::= COMPARE_OP | LOGICAL_OP

Only Binary Operators are supported in ACS. The operators may be either a comparison operator or a logical operator.


Comparison Operators

    LHS COMPARE_OP RHS

Comparison Operators are binary operators that compare the values of both operands and return a true or false boolean value.

WWIV ACS supports the following Comparison Operators with LHS as the Left Hand Side operand and RHS as the right hand side operand:

Name Symbol Description
Greater Than > True if LHS > RHS
Greater Than or Equal >= True if LHS >= RHS
Less Than < True if LHS < RHS
Less Than or Equal <= True if LHS <= RHS
Equal == True if LHS == RHS
Not Equal != True if LHS != RHS


Example:

  user.sl > 100


Logical Operators

    LHS LOGICAL_OP RHS

The name logical comes from boolean logic, although the operands on either side of the operator may be an expression or type that evaluates independently to a boolean.

WWIV ACS supports the following Logical Operators:

Name Symbol Description
AND && Both operands must evaluate to true for the result to be true.
OR || At least one operand must evaluate to true for the result to be true.


Example:

  user.sl > 100 || user.ar == 'A'


Expression

OP ::= COMPARE_OP | LOGICAL_OP
    EXPRESSION ::= EXPRESSION (OP EXPRESSION)?

The language is designed to evaluate a single expression. An expression may be a compound expression with multiple expressions combined using logical AND && or OR || operators.


Object Attributes

WWIV ACS supports attributes in the form Object.Attribute. For example "user.sl" is the current user's security level.
Note: Object and attribute names are case-insensitive, so both user.name and USER.NAME are equivalent.

Variable Type Meaning
bbs.name string Name of the BBS
bbs.sysopname string Name of the SysOp
bbs.phone string Phone Number of the BBS
bbs.node string Node number for this BBS instance
bbs.os string Operating System Name this node BBS is running on
bbs.version string WWIV Version #
bbs.reg string WWIV 4.x Registration Number
bbs.compiletime string Date and time the BBS binary was compiled
user.name string User's name or handle
user.sl number User's SL
user.dsl number User's DSL
user.age number User's Age
user.regnum number User's WWIV registration number
user.sysop boolean Is the user a sysop
user.cosysop boolean Is the user a co-sysop
user.guest boolean Is the user logged on as a guest
user.validated boolean Is the user validated
user.screenlines boolean User's screen lines
user.screenwidth boolean User's screen width
user.ansi boolean Does the user have ansi enabled
user.ansistr string describes user's ansi and color state
user.color boolean Is color enabled
user.pause boolean Is pause enabled
user.mailbox_state string Describes the mailbox state (i.e. forwarded to user ...)
user.extcolors boolean Are extra colors enabled
user.optional_lines number Number of optional message lines
user.conferencing boolean Is conferencing enabled
user.fs_reader boolean Is the full screen message reader enabled
user.email string User's internet email address
user.ignore_msgs boolean Ignore inter-instance messages
user.clear_screen boolean Clear screen before messages
user.auto_quote boolean Use WWIV auto-quote vs. standard quoting
user.protocol number default protocol number
user.callsign string User's HAM callsign (if provided)
user.street string User's street address (if provided)
user.city string User's city (if provided)
user.state string User's state (if provided)
user.zip_code string User's zipcode (if provided)
user.last_ipaddress string Last IP addressed used
user.last_bps number Last BPS rate (if over serial)
user.laston string Date (MMDDYY) last on BBS
user.voice_phone string User's voice phone (if provided)
user.data_phone string User's data phone (if provided)
user.gender char User's gender (as character, M/F) (if provided)
user.menuset string curent menuset
user.birthday_mmddyy string User's birthday (MMDDYY) (if provided)
user.email_waiting number Number of email waiting
user.messages_posted number number of messages posted
user.posts_today number number of messages posted today
user.posts_net number number of messages posted on a network
user.messages_read number number of messages read
user.email_today number number of email sent today
user.email_sent_local number number of email sent locally today
user.feedback_sent number number of feedback to sysop send
user.email_sent_net number number of email sent to the network
user.chains_run number number of chains execute
user.uploaded number number of files uploaded
user.uk number KB of files uploaded
user.downloaded number number of files downloaded
user.dk number KB of files downloaded
user.editorname string Fullscreen editor name
user.show_controlcodes boolean Show message lines with WWIV control codes and FTN kludge
user.twentyfour_clock boolean Show time using 24hr clock (i.e. 18:00, not 06:00 PM)

WWIV Security Attributes

SL AND DSL

Security Level (SL) and Download Security Level (DSL) are the primary ways to secure functionality in WWIV. Historically new users will have SL and DSL of 10, then validated users get 20 or 50 depending on the setup. Many modern setups grant 20-50 on the first call so people can see more of the BBS without needing to call back.

AR AND DAR

AR and DAR allow access specific activities (subboards, download subboards, chains, etc) when other attributes (like age, or security level), wouldn't be the choice, as that may apply to many more BBS callers than needed.

For example: Let's say you have a group of OS/2 callers on your bbs, selecting them by age or security level (SL) would not be appropriate. This is where AR works perfectely. There are 16 AR and DAR flags (A-P) that you can add as arestriction using the ACS language and also then grant this AR or DAR to the BBS callers to grant access to this area.

You use the user editor to grant AR and DAR to callers, and using ACS, add a condition requiring it for an area in the BBS.


Examples

Grant access to users with SL of 100 or more or AR of 'A':

  user.sl >= 100 || user.ar == 'A'

Grant access to users with SL of 20 or less, and also to Rushfan.

  user.sl <= 20 || user.name == "Rushfan"