# Functions to discover OpenID endpoints from identifiers.
require 'uri'
require 'openid/util'
require 'openid/fetchers'
require 'openid/urinorm'
require 'openid/message'
require 'openid/yadis/discovery'
require 'openid/yadis/xrds'
require 'openid/yadis/xri'
require 'openid/yadis/services'
require 'openid/yadis/filters'
require 'openid/consumer/html_parse'
require 'openid/yadis/xrires'
module OpenID
OPENID_1_0_NS = 'http://openid.net/xmlns/1.0'
OPENID_IDP_2_0_TYPE = 'http://specs.openid.net/auth/2.0/server'
OPENID_2_0_TYPE = 'http://specs.openid.net/auth/2.0/signon'
OPENID_1_1_TYPE = 'http://openid.net/signon/1.1'
OPENID_1_0_TYPE = 'http://openid.net/signon/1.0'
OPENID_1_0_MESSAGE_NS = OPENID1_NS
OPENID_2_0_MESSAGE_NS = OPENID2_NS
# Object representing an OpenID service endpoint.
class OpenIDServiceEndpoint
# OpenID service type URIs, listed in order of preference. The
# ordering of this list affects yadis and XRI service discovery.
OPENID_TYPE_URIS = [
OPENID_IDP_2_0_TYPE,
OPENID_2_0_TYPE,
OPENID_1_1_TYPE,
OPENID_1_0_TYPE,
]
# the verified identifier.
attr_accessor :claimed_id
# For XRI, the persistent identifier.
attr_accessor :canonical_id
attr_accessor :server_url, :type_uris, :local_id, :used_yadis
def initialize
@claimed_id = nil
@server_url = nil
@type_uris = []
@local_id = nil
@canonical_id = nil
@used_yadis = false # whether this came from an XRDS
@display_identifier = nil
end
def display_identifier
return @display_identifier if @display_identifier
return @claimed_id if @claimed_id.nil?
begin
parsed_identifier = URI.parse(@claimed_id)
rescue URI::InvalidURIError
raise ProtocolError, "Claimed identifier #{claimed_id} is not a valid URI"
end
return @claimed_id if not parsed_identifier.fragment
disp = parsed_identifier
disp.fragment = nil
return disp.to_s
end
def display_identifier=(display_identifier)
@display_identifier = display_identifier
end
def uses_extension(extension_uri)
return @type_uris.member?(extension_uri)
end
def preferred_namespace
if (@type_uris.member?(OPENID_IDP_2_0_TYPE) or
@type_uris.member?(OPENID_2_0_TYPE))
return OPENID_2_0_MESSAGE_NS
else
return OPENID_1_0_MESSAGE_NS
end
end
def supports_type(type_uri)
# Does this endpoint support this type?
#
# I consider C{/server} endpoints to implicitly support C{/signon}.
(
@type_uris.member?(type_uri) or
(type_uri == OPENID_2_0_TYPE and is_op_identifier())
)
end
def compatibility_mode
return preferred_namespace() != OPENID_2_0_MESSAGE_NS
end
def is_op_identifier
return @type_uris.member?(OPENID_IDP_2_0_TYPE)
end
def parse_service(yadis_url, uri, type_uris, service_element)
# Set the state of this object based on the contents of the
# service element.
@type_uris = type_uris
@server_url = uri
@used_yadis = true
if !is_op_identifier()
# XXX: This has crappy implications for Service elements that
# contain both 'server' and 'signon' Types. But that's a
# pathological configuration anyway, so I don't think I care.
@local_id = OpenID.find_op_local_identifier(service_element,
@type_uris)
@claimed_id = yadis_url
end
end
def get_local_id
# Return the identifier that should be sent as the
# openid.identity parameter to the server.
if @local_id.nil? and @canonical_id.nil?
return @claimed_id
else
return (@local_id or @canonical_id)
end
end
def self.from_basic_service_endpoint(endpoint)
# Create a new instance of this class from the endpoint object
# passed in.
#
# @return: nil or OpenIDServiceEndpoint for this endpoint object"""
type_uris = endpoint.match_types(OPENID_TYPE_URIS)
# If any Type URIs match and there is an endpoint URI specified,
# then this is an OpenID endpoint
if (!type_uris.nil? and !type_uris.empty?) and !endpoint.uri.nil?
openid_endpoint = self.new
openid_endpoint.parse_service(
endpoint.yadis_url,
endpoint.uri,
endpoint.type_uris,
endpoint.service_element)
else
openid_endpoint = nil
end
return openid_endpoint
end
def self.from_html(uri, html)
# Parse the given document as HTML looking for an OpenID
#
# @rtype: [OpenIDServiceEndpoint]
discovery_types = [
[OPENID_2_0_TYPE, 'openid2.provider', 'openid2.local_id'],
[OPENID_1_1_TYPE, 'openid.server', 'openid.delegate'],
]
link_attrs = OpenID.parse_link_attrs(html)
services = []
discovery_types.each { |type_uri, op_endpoint_rel, local_id_rel|
op_endpoint_url = OpenID.find_first_href(link_attrs, op_endpoint_rel)
if !op_endpoint_url
next
end
service = self.new
service.claimed_id = uri
service.local_id = OpenID.find_first_href(link_attrs, local_id_rel)
service.server_url = op_endpoint_url
service.type_uris = [type_uri]
services << service
}
return services
end
def self.from_xrds(uri, xrds)
# Parse the given document as XRDS looking for OpenID services.
#
# @rtype: [OpenIDServiceEndpoint]
#
# @raises L{XRDSError}: When the XRDS does not parse.
return Yadis::apply_filter(uri, xrds, self)
end
def self.from_discovery_result(discoveryResult)
# Create endpoints from a DiscoveryResult.
#
# @type discoveryResult: L{DiscoveryResult}
#
# @rtype: list of L{OpenIDServiceEndpoint}
#
# @raises L{XRDSError}: When the XRDS does not parse.
if discoveryResult.is_xrds()
meth = self.method('from_xrds')
else
meth = self.method('from_html')
end
return meth.call(discoveryResult.normalized_uri,
discoveryResult.response_text)
end
def self.from_op_endpoint_url(op_endpoint_url)
# Construct an OP-Identifier OpenIDServiceEndpoint object for
# a given OP Endpoint URL
#
# @param op_endpoint_url: The URL of the endpoint
# @rtype: OpenIDServiceEndpoint
service = self.new
service.server_url = op_endpoint_url
service.type_uris = [OPENID_IDP_2_0_TYPE]
return service
end
def to_s
return sprintf("<%s server_url=%s claimed_id=%s " +
"local_id=%s canonical_id=%s used_yadis=%s>",
self.class, @server_url, @claimed_id,
@local_id, @canonical_id, @used_yadis)
end
end
def self.find_op_local_identifier(service_element, type_uris)
# Find the OP-Local Identifier for this xrd:Service element.
#
# This considers openid:Delegate to be a synonym for xrd:LocalID
# if both OpenID 1.X and OpenID 2.0 types are present. If only
# OpenID 1.X is present, it returns the value of
# openid:Delegate. If only OpenID 2.0 is present, it returns the
# value of xrd:LocalID. If there is more than one LocalID tag and
# the values are different, it raises a DiscoveryFailure. This is
# also triggered when the xrd:LocalID and openid:Delegate tags are
# different.
# XXX: Test this function on its own!
# Build the list of tags that could contain the OP-Local
# Identifier
local_id_tags = []
if type_uris.member?(OPENID_1_1_TYPE) or
type_uris.member?(OPENID_1_0_TYPE)
# local_id_tags << Yadis::nsTag(OPENID_1_0_NS, 'openid', 'Delegate')
service_element.add_namespace('openid', OPENID_1_0_NS)
local_id_tags << "openid:Delegate"
end
if type_uris.member?(OPENID_2_0_TYPE)
# local_id_tags.append(Yadis::nsTag(XRD_NS_2_0, 'xrd', 'LocalID'))
service_element.add_namespace('xrd', Yadis::XRD_NS_2_0)
local_id_tags << "xrd:LocalID"
end
# Walk through all the matching tags and make sure that they all
# have the same value
local_id = nil
local_id_tags.each { |local_id_tag|
service_element.each_element(local_id_tag) { |local_id_element|
if local_id.nil?
local_id = local_id_element.text
elsif local_id != local_id_element.text
format = 'More than one %s tag found in one service element'
message = sprintf(format, local_id_tag)
raise DiscoveryFailure.new(message, nil)
end
}
}
return local_id
end
def self.normalize_xri(xri)
# Normalize an XRI, stripping its scheme if present
m = /^xri:\/\/(.*)/.match(xri)
xri = m[1] if m
return xri
end
def self.normalize_url(url)
# Normalize a URL, converting normalization failures to
# DiscoveryFailure
begin
normalized = URINorm.urinorm(url)
rescue URI::Error => why
raise DiscoveryFailure.new("Error normalizing #{url}: #{why.message}", nil)
else
defragged = URI::parse(normalized)
defragged.fragment = nil
return defragged.normalize.to_s
end
end
def self.best_matching_service(service, preferred_types)
# Return the index of the first matching type, or something higher
# if no type matches.
#
# This provides an ordering in which service elements that contain
# a type that comes earlier in the preferred types list come
# before service elements that come later. If a service element
# has more than one type, the most preferred one wins.
preferred_types.each_with_index { |value, index|
if service.type_uris.member?(value)
return index
end
}
return preferred_types.length
end
def self.arrange_by_type(service_list, preferred_types)
# Rearrange service_list in a new list so services are ordered by
# types listed in preferred_types. Return the new list.
# Build a list with the service elements in tuples whose
# comparison will prefer the one with the best matching service
prio_services = []
service_list.each_with_index { |s, index|
prio_services << [best_matching_service(s, preferred_types), index, s]
}
prio_services.sort!
# Now that the services are sorted by priority, remove the sort
# keys from the list.
(0...prio_services.length).each { |i|
prio_services[i] = prio_services[i][2]
}
return prio_services
end
def self.get_op_or_user_services(openid_services)
# Extract OP Identifier services. If none found, return the rest,
# sorted with most preferred first according to
# OpenIDServiceEndpoint.openid_type_uris.
#
# openid_services is a list of OpenIDServiceEndpoint objects.
#
# Returns a list of OpenIDServiceEndpoint objects.
op_services = arrange_by_type(openid_services, [OPENID_IDP_2_0_TYPE])
openid_services = arrange_by_type(openid_services,
OpenIDServiceEndpoint::OPENID_TYPE_URIS)
if !op_services.empty?
return op_services
else
return openid_services
end
end
def self.discover_yadis(uri)
# Discover OpenID services for a URI. Tries Yadis and falls back
# on old-style discovery if Yadis fails.
#
# @param uri: normalized identity URL
# @type uri: str
#
# @return: (claimed_id, services)
# @rtype: (str, list(OpenIDServiceEndpoint))
#
# @raises DiscoveryFailure: when discovery fails.
# Might raise a yadis.discover.DiscoveryFailure if no document
# came back for that URI at all. I don't think falling back to
# OpenID 1.0 discovery on the same URL will help, so don't bother
# to catch it.
response = Yadis.discover(uri)
yadis_url = response.normalized_uri
body = response.response_text
begin
openid_services = OpenIDServiceEndpoint.from_xrds(yadis_url, body)
rescue Yadis::XRDSError
# Does not parse as a Yadis XRDS file
openid_services = []
end
if openid_services.empty?
# Either not an XRDS or there are no OpenID services.
if response.is_xrds
# if we got the Yadis content-type or followed the Yadis
# header, re-fetch the document without following the Yadis
# header, with no Accept header.
return self.discover_no_yadis(uri)
end
# Try to parse the response as HTML.
#
openid_services = OpenIDServiceEndpoint.from_html(yadis_url, body)
end
return [yadis_url, self.get_op_or_user_services(openid_services)]
end
def self.discover_xri(iname)
endpoints = []
iname = self.normalize_xri(iname)
begin
canonical_id, services = Yadis::XRI::ProxyResolver.new().query(
iname, OpenIDServiceEndpoint::OPENID_TYPE_URIS)
if canonical_id.nil?
raise Yadis::XRDSError.new(sprintf('No CanonicalID found for XRI %s', iname))
end
flt = Yadis.make_filter(OpenIDServiceEndpoint)
services.each { |service_element|
endpoints += flt.get_service_endpoints(iname, service_element)
}
rescue Yadis::XRDSError => why
Util.log('xrds error on ' + iname + ': ' + why.to_s)
end
endpoints.each { |endpoint|
# Is there a way to pass this through the filter to the endpoint
# constructor instead of tacking it on after?
endpoint.canonical_id = canonical_id
endpoint.claimed_id = canonical_id
endpoint.display_identifier = iname
}
# FIXME: returned xri should probably be in some normal form
return [iname, self.get_op_or_user_services(endpoints)]
end
def self.discover_no_yadis(uri)
http_resp = OpenID.fetch(uri)
if http_resp.code != "200" and http_resp.code != "206"
raise DiscoveryFailure.new(
"HTTP Response status from identity URL host is not \"200\". "\
"Got status #{http_resp.code.inspect}", http_resp)
end
claimed_id = http_resp.final_url
openid_services = OpenIDServiceEndpoint.from_html(
claimed_id, http_resp.body)
return [claimed_id, openid_services]
end
def self.discover_uri(uri)
# Hack to work around URI parsing for URls with *no* scheme.
if uri.index("://").nil?
uri = 'http://' + uri
end
begin
parsed = URI::parse(uri)
rescue URI::InvalidURIError => why
raise DiscoveryFailure.new("URI is not valid: #{why.message}", nil)
end
if !parsed.scheme.nil? and !parsed.scheme.empty?
if !['http', 'https'].member?(parsed.scheme)
raise DiscoveryFailure.new(
"URI scheme #{parsed.scheme} is not HTTP or HTTPS", nil)
end
end
uri = self.normalize_url(uri)
claimed_id, openid_services = self.discover_yadis(uri)
claimed_id = self.normalize_url(claimed_id)
return [claimed_id, openid_services]
end
def self.discover(identifier)
if Yadis::XRI::identifier_scheme(identifier) == :xri
normalized_identifier, services = discover_xri(identifier)
else
return discover_uri(identifier)
end
end
end