d4s-cdn-setup/conf/pep/pep.js

324 lines
11 KiB
JavaScript

export default { enforce };
import defaultExport from './config.js';
function log(c, s){
c.request.error(s)
}
function enforce(r) {
var context = {
request: r ,
config : defaultExport["config"],
backend : (defaultExport.backend ? defaultExport.backend : "@backend")
}
log(context, "Inside NJS enforce for " + r.method + " @ " + r.headersIn.host + "/" + r.uri)
context = computeProtection(context)
wkf.run(wkf.build(context), context)
}
// ######## WORKFLOW FUNCTIONS ###############
var wkf = {
build : (context)=>{
var actions = [
"export_pep_credentials",
"parse_authentication",
"check_authentication",
"export_authn_token",
"pip",
"pdp",
"export_backend_headers",
"pass"
]
return actions
},
run : (actions, context) => {
context.request.error("Starting workflow with " + njs.dump(actions))
var w = actions.reduce(
(acc, f) => { return acc.then(typeof(f) === "function" ? f : wkf[f]) },
Promise.resolve().then(()=>context)
)
w.catch(e => { context.request.error(njs.dump(e)); context.request.return(401)} )
},
export_pep_credentials : exportPepCredentials,
export_authn_token : exportAuthToken,
export_backend_headers : exportBackendHeaders,
parse_authentication : parseAuthentication,
check_authentication : checkAuthentication,
verify_token : verifyToken,
request_token : requestToken,
pip : pipExecutor,
pdp : pdpExecutor,
pass : pass,
//PIP utilities
"get-path-component" : (c, i) => c.request.uri.split("/")[i],
"get-token-field" : getTokenField,
"get-contexts" : (c) => {
var ra = c.authn.verified_token["resource_access"]
if(ra){
var out = [];
for(var k in ra){
if(ra[k].roles && ra[k].roles.length !== 0) out.push(k)
}
}
return out;
}
}
function getTokenField(context, f){
return context.authn.verified_token[f]
}
function exportVariable(context, name, value){
context.request.variables[name] = value
log(context, "Exported variables:" + njs.dump(context.request.variables))
return context
}
function exportBackendHeaders(context){
exportVariable(context, "user", context.authn.verified_token.preferred_username)
exportVariable(context, "user_display", context.authn.verified_token.name)
return context
}
function exportPepCredentials(context){
if(!context.config["pep-credentials"]){
throw new Error("Need PEP credentials")
}
return exportVariable(context, "pep_credentials", "Basic " + context.config["pep-credentials"])
}
function exportAuthToken(context){
return exportVariable(context, "auth_token", context.authn.token)
}
function checkAuthentication(context){
return context.authn.type === "bearer" ? wkf.verify_token(context) : wkf.request_token(context)
}
function parseAuthentication(context){
context.request.log("Inside parseAuthentication")
var incomingauth = context.request.headersIn["Authorization"]
if(!incomingauth) throw new Error("Authentication required");
var arr = incomingauth.trim().replace(/\s\s+/g, " ").split(" ")
if(arr.length != 2) throw new Error("Unknown authentication scheme");
var type = arr[0].toLowerCase()
if(type === "basic" && context.authz.host && context.authz.host["allow-basic-auth"]){
var unamepass = Buffer.from(arr[1], 'base64').toString().split(":")
if(unamepass.length != 2) return null;
context.authn = { type : type, raw : arr[1], user : unamepass[0], password : unamepass[1]}
return context
}else if(type === "bearer"){
context.authn = { type : type, raw : arr[1], token : arr[1]}
return context
}
throw new Error("Unknown authentication scheme");
}
function verifyToken(context){
log(context, "Inside verifyToken")
log(context, "Token is " + context.authn.token)
var options = {
"body" : "token=" + context.authn.token + "&token_type_hint=access_token"
}
return context.request.subrequest("/jwt_verify_request", options)
.then(reply=>{
if (reply.status === 200) {
var response = JSON.parse(reply.responseBody);
if (response.active === true) {
return response
} else {
throw new Error("Unauthorized: " + reply.responseBody)
}
} else {
throw new Error("Unauthorized: " + reply.responseBody)
}
}).then(verified_token => {
context.authn.verified_token =
JSON.parse(Buffer.from(context.authn.token.split('.')[1], 'base64url').toString())
return context
})
}
function requestToken(context){
log(context, "Inside requestToken")
var options = {
"body" : "grant_type=password&username="+context.authn.user+"&password="+context.authn.password
}
return context.request.subrequest("/jwt_request", options)
.then(reply=>{
if (reply.status === 200) {
var response = JSON.parse(reply.responseBody);
context.authn.token = response.access_token
context.authn.verified_token =
JSON.parse(Buffer.from(context.authn.token.split('.')[1], 'base64url').toString())
return context
} else if (reply.status === 400 || reply.status === 401){
var options = {
"body" : "grant_type=password&username="+context.authn.user+"&password="+context.authn.password
}
return context.request.subrequest("/jwt_request", options)
.then( reply=>{
if (reply.status === 200) {
var response = JSON.parse(reply.responseBody);
context.authn.token = response.access_token
context.authn.verified_token =
JSON.parse(Buffer.from(context.authn.token.split('.')[1], 'base64url').toString())
return context
} else{
throw new Error("Unauthorized " + reply.status)
}
})
} else {
throw new Error("Unauthorized " + reply.status)
}
})
}
function pipExecutor(context){
log(context, "Inside extra claims PIP")
context.authz.pip.forEach(extra =>{
//call extra claim pip function
try{
var operator = extra.operator
var result = wkf[operator](context, extra.args)
//ensure array and add to extra_claims
if(!(result instanceof Array)) result = [result]
if(!context.extra_claims) context.extra_claims = {};
context.extra_claims[extra.claim] = result
} catch (error){
log(context, "Skipping invalid extra claim " + njs.dump(error))
}
})
log(context, "Extra claims are " + njs.dump(context.extra_claims))
return context
}
function pdpExecutor(context){
log(context, "Inside PDP")
return context.authz.pdp(context)
}
function umaCall(context){
log(context, "Inside UMA call")
var options = { "body" : computePermissionRequestBody(context) };
return context.request.subrequest("/permission_request", options)
.then(reply =>{
if(reply.status === 200){
return context
}else{
throw new Error("Response for authorization request is not ok " + reply.status + " " + njs.dump(reply.responseBody))
}
})
}
function pass(context){
log(context, "Inside pass");
if(typeof(context.backend) === "string") context.request.internalRedirect(context.backend);
else if (typeof(context.backend) === "function") context.request.internalRedirect(context.backend(context))
return context;
}
// ######## AUTHORIZATION PART ###############
function computePermissionRequestBody(context){
if(!context.authz.host || !context.authz.path ){
throw new Error("Enforcemnt mode is always enforcing. Host or path not found...")
}
var audience = computeAudience(context)
var grant = "grant_type=urn:ietf:params:oauth:grant-type:uma-ticket"
var mode = "response_mode=decision"
var permissions = computePermissions(context)
var extra = ""
if(context.extra_claims){
extra =
"claim_token_format=urn:ietf:params:oauth:token-type:jwt&claim_token=" +
JSON.stringify(context.extra_claims).toString("base64url")
}
var body = audience + "&" + grant + "&" + permissions + "&" + mode + "&" + extra
context.request.error("Computed permission request body is " + body)
return body
}
function computeAudience(context){
var aud = context.request.headersIn.host
if(context.authz.host){
aud = context.authz.host.audience||context.authz.host.host
}
return "audience=" + aud
}
function computePermissions(context){
var resource = context.request.uri
if(context.authz.path){
resource = context.authz.path.name||context.authz.path.path
}
var scopes = []
if(context.authz.method && context.authz.method.scopes){
scopes = context.authz.method.scopes
}
if(scopes.length > 0){
return scopes.map(s=>"permission=" + resource + "#" + s).join("&")
}
return "permission=" + resource
}
function getPath(hostconfig, incomingpath, incomingmethod){
var paths = hostconfig.paths || []
var matchingpaths = paths
.filter(p => {return incomingpath.match(p.path) != null})
.reduce((acc, p) => {
if (!p.methods || p.methods.length === 0) acc.weak.push({ path: p});
else{
var matchingmethods = p.methods.filter(m=>m.method.toUpperCase() === incomingmethod)
if(matchingmethods.length > 0) acc.strong.push({ method : matchingmethods[0], path: p});
}
return acc;
}, { strong: [], weak: []})
return matchingpaths.strong.concat(matchingpaths.weak)[0]
}
function getHost(config, host){
var matching = config.hosts.filter(h=>{
return h.host === host
})
return matching.length > 0 ? matching[0] : null
}
function computeProtection(context){
log(context, "Getting by host " + context.request.headersIn.host)
context.authz = {}
context.authz.host = getHost(context.config, context.request.headersIn.host)
if(context.authz.host !== null){
log(context, "Host found:" + context.authz.host)
context.authz.pip = context.authz.host.pip ? context.authz.host.pip : [];
context.authz.pdp = context.authz.host.pdp ? context.authz.host.pdp : umaCall;
var pathandmethod = getPath(context.authz.host, context.request.uri, context.request.method);
if(pathandmethod){
context.authz.path = pathandmethod.path;
context.authz.pip = context.authz.path.pip ? context.authz.pip.concat(context.authz.path.pip) : context.authz.pip;
context.authz.pdp = context.authz.path.pdp ? context.authz.path.pdp : context.authz.pdp;
context.authz.method = pathandmethod.method;
if(context.authz.method){
context.authz.pip = context.authz.method.pip ? context.authz.pip.concat(context.authz.method.pip) : context.authz.pip;
context.authz.pdp = context.authz.method.pdp ? context.authz.method.pdp : context.authz.pdp;
}
}
}
log(context, "Leaving protection computation: ")
return context
}