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(define-module (webid-oidc server resource wac)
#:use-module (webid-oidc errors)
#:use-module (webid-oidc server resource path)
#:use-module (webid-oidc server resource content)
#:use-module (webid-oidc cache)
#:use-module (webid-oidc fetch)
#:use-module ((webid-oidc stubs) #:prefix stubs:)
#:use-module (webid-oidc rdf-index)
#:use-module ((webid-oidc refresh-token) #:prefix refresh:)
#:use-module (web uri)
#:use-module (web client)
#:use-module (rdf rdf)
#:use-module (turtle tordf)
#:use-module (rnrs bytevectors)
#:use-module (ice-9 exceptions)
#:use-module (ice-9 receive)
#:use-module (ice-9 optargs)
#:use-module (ice-9 iconv)
#:use-module (ice-9 textual-ports)
#:use-module (ice-9 binary-ports)
#:use-module (ice-9 threads)
#:use-module (rnrs bytevectors)
#:use-module (oop goops)
#:export
(
wac-get-modes
))
(define (group-member? http-get group-uri agent)
(when (string? group-uri)
(set! group-uri (string->uri group-uri)))
(when (string? agent)
(set! group-uri (string->uri agent)))
(let ((group-doc-uri
(build-uri (uri-scheme group-uri)
#:userinfo (uri-userinfo group-uri)
#:host (uri-host group-uri)
#:port (uri-port group-uri)
#:path (uri-path group-uri)
#:query (uri-query group-uri))))
(with-exception-handler
(lambda (error)
(raise-exception
(make-cannot-fetch-group group-uri error)
#:continuable? #t)
#f)
(lambda ()
(let ((data (fetch group-doc-uri #:http-get http-get)))
(with-index
data
(lambda (rdf-match)
(not (null?
(rdf-match (uri->string group-uri)
"http://www.w3.org/2006/vcard/ns#hasMember"
(uri->string agent))))))))
#:unwind? #t
#:unwind-for-type &cannot-fetch-linked-data)))
(define (with-rdf-source server-name path content-type static-content f)
(with-index
(case content-type
((text/turtle)
(turtle->rdf (string-append
"# This is not a file name\n"
(utf8->string static-content))
(uri->string
(build-uri (uri-scheme server-name)
#:userinfo (uri-userinfo server-name)
#:host (uri-host server-name)
#:port (uri-port server-name)
#:path (string-append path ".acl"))))))
f))
(define (check-authorization path check-default? server-name final-path http-get user rdf-match id)
;; The authorization should give accessTo path,
;; or to a prefix of final-path; and it should
;; be for agent user, or a group that contains
;; user.
(let ((access-to-ok
(and
;; We’re looking for acl:accessTo targetting path
(not
(null?
(rdf-match id "http://www.w3.org/ns/auth/acl#accessTo"
(uri->string
(build-uri (uri-scheme server-name)
#:userinfo (uri-userinfo server-name)
#:host (uri-host server-name)
#:port (uri-port server-name)
#:path path)))))
(or (not check-default?)
;; We’re also looking for acl:default statement
;; targetting a prefix of final-path
(let ((defaults
(map rdf-triple-object
(rdf-match id "http://www.w3.org/ns/auth/acl#default" #f))))
(define (default-ok? uri)
(and (string? uri)
(string->uri uri)
(let ((uri (string->uri uri)))
(and (eq? (uri-scheme uri)
(uri-scheme server-name))
(equal? (uri-userinfo uri)
(uri-userinfo server-name))
(equal? (uri-host uri)
(uri-host server-name))
(equal? (uri-port uri)
(uri-port server-name))
(let ((final-path-components
(split-and-decode-uri-path final-path))
(default-components
(split-and-decode-uri-path (uri-path uri))))
(define (prefix? x y)
(or (null? x)
(and (not (null? y))
(equal? (car x) (car y))
(prefix? (cdr x) (cdr y)))))
(prefix? default-components final-path-components))))))
(not (null? (filter default-ok? defaults)))))))
(agent-ok
(let ((groups
(map rdf-triple-object
(rdf-match id
"http://www.w3.org/ns/auth/acl#agentGroup"
#f)))
(specific-agent-ok?
(and user
(not (null?
(rdf-match id
"http://www.w3.org/ns/auth/acl#agent"
(uri->string user))))))
(public-access?
(not (null?
(rdf-match id
"http://www.w3.org/ns/auth/acl#agentClass"
"http://xmlns.com/foaf/0.1/Agent"))))
(authenticated-access?
(not (null?
(rdf-match id
"http://www.w3.org/ns/auth/acl#agentClass"
"http://www.w3.org/ns/auth/acl#AuthenticatedAgent")))))
(or public-access?
(and user authenticated-access?)
specific-agent-ok?
(and user
(not (null?
(filter (lambda (group)
(group-member? http-get group user))
groups))))))))
(or
(and access-to-ok
agent-ok
(filter
(lambda (x) x)
(map (lambda (triple)
(let ((mode (rdf-triple-object triple)))
(and (string? mode)
(string->uri mode))))
(rdf-match id
"http://www.w3.org/ns/auth/acl#mode"
#f))))
'())))
(define (check-authorizations path check-default? server-name final-path http-get user rdf-match
allowed-modes authorizations)
(if (null? authorizations)
(reverse allowed-modes)
(let ((new-modes
(check-authorization path check-default? server-name final-path http-get user rdf-match
(car authorizations))))
(check-authorizations
path check-default? server-name final-path http-get user rdf-match
(append (reverse new-modes) allowed-modes)
(cdr authorizations)))))
(define acl-aux (string->uri "http://www.w3.org/ns/auth/acl#accessControl"))
(define* (wac-get-modes server-name final-path user
#:key
(http-get http-get))
(with-session
(lambda (content-type contained static-content create delete)
(define (wac-check-recursive path check-default?)
(receive (main-etag auxiliary) (read-path path)
(let ((acl-etag (assoc-ref auxiliary acl-aux)))
(if acl-etag
(with-rdf-source
server-name path (content-type acl-etag) (static-content acl-etag)
(lambda (rdf-match)
(check-authorizations
path check-default? server-name final-path http-get user rdf-match
'()
(map rdf-triple-subject
(rdf-match #f
"http://www.w3.org/1999/02/22-rdf-syntax-ns#type"
"http://www.w3.org/ns/auth/acl#Authorization")))))
;; No existing ACL.
(let ((parent-path
(string-append
"/"
(encode-and-join-uri-path
(reverse
(cdr
(reverse
(split-and-decode-uri-path path)))))
"/")))
(when (equal? parent-path "//")
;; The parent is the root
(set! parent-path "/"))
(wac-check-recursive parent-path #t))))))
(let ((all-modes (wac-check-recursive final-path #f)))
(define (accumulate-unique accumulated list)
(cond
((null? list)
(reverse accumulated))
((or (null? accumulated) (not (equal? (car accumulated) (car list))))
(accumulate-unique (cons (car list) accumulated) (cdr list)))
(else
(accumulate-unique accumulated (cdr list)))))
(accumulate-unique
'()
(sort all-modes
(lambda (a b)
(string< (uri->string a) (uri->string b)))))))))
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