Skip to content

AthenZ/athenz-authorizer

Repository files navigation

Athenz authorizer

License: Apache GitHub release (latest by date) Go Report Card GoDoc Contributor Covenant

What is Athenz authorizer

Athenz authorizer is a library to cache the policies of Athenz to authorizer authentication and authorization check of user request.

Overview

Usage

To initialize authorizer.

package main

import (
    "context"
    "crypto/x509"
    "encoding/pem"
    "log"

    authorizerd "github.com/AthenZ/athenz-authorizer/v5"
)

func main() {
    // Initialize authorizerd
    daemon, err := authorizerd.New(
        authorizerd.WithAthenzURL("www.athenz.io"), // set athenz URL
        authorizerd.WithAthenzDomains("domain1", "domain2", "domain N"), // set athenz domains
        authorizerd.WithPubkeyRefreshPeriod("12h"), // optional, default: 24h
        authorizerd.WithPolicyRefreshPeriod("1h"), // optional, default: 30m
    )
    if err != nil {
        // cannot initialize authorizer daemon
        log.Fatalf("daemon new error: %v", err)
    }

    // Start authorizer daemon
    ctx := context.Background() // user can control authorizer daemon lifetime using this context
    if err = daemon.Init(ctx); err != nil { // initialize internal daemons in dependency order (e.g. public keys before signed policies)
        // cannot initialize internal daemons inside authorizer
        log.Fatalf("daemon init error: %v", err)
    }
    errs := daemon.Start(ctx)
    go func() {
        for err := range errs {
            // user should handle errors return from the daemon
            log.Printf("daemon start error: %v", err)
        }
    }()

    act := "action"
    res := "resource"

    // Authorize with access token
    at := "<certificate bound access token>"
    certPEM := "<binding certificate>"
    block, _ := pem.Decode([]byte(certPEM))
    if block == nil {
        log.Fatalln("failed to parse certificate PEM")
    }
    cert, err := x509.ParseCertificate(block.Bytes)
    if err != nil {
        log.Fatalf("invalid x509 certificate: %v", err)
    }
    atp, err := daemon.AuthorizeAccessToken(ctx, at, act, res, cert)
    if err != nil {
        // NOT authorized, please take appropriate action
        log.Fatalf("access token not authorized: %v", err)
    }
    log.Printf("authorized principal in access token: %#v", atp)

    // Authorize with role token
    rt := "<role token>"
    rtp, err := daemon.AuthorizeRoleToken(ctx, rt, act, res)
    if err != nil {
        // NOT authorized, please take appropriate action
        log.Fatalf("role token not authorized: %v", err)
    }
    log.Printf("authorized principal in role token: %#v", rtp)
}

How it works

To do the authentication and authorization check, the user needs to specify which domain data to be cache. The authorizer will periodically refresh the policies and Athenz public key data to verify and decode the domain data. The verified domain data will cache into the memory, and use for authentication and authorization check.

The authorizer contains two sub-module, Athenz public key daemon (pubkeyd) and Athenz policy daemon (policyd).

Athenz public key daemon

Athenz public key daemon (pubkeyd) is responsible for periodically update the Athenz public key data from Athenz server to verify the policy data received from Athenz policy daemon and verify the role token.

Athenz policy daemon

Athenz policy daemon (policyd) is responsible for periodically update the policy data of specified Athenz domain from Athenz server. The received policy data will be verified using the public key got from pubkeyd, and cache into memory. Whenever user requesting for the access check, the verification check will be used instead of asking Athenz server every time.

Configuration

The authorizer uses functional options pattern to initialize the instance. All the options are defined here.

Option name Description Default Value Required Example
AthenzURL The Athenz server URL athenz.io/zts/v1 Yes "athenz.io/zts/v1"
AthenzDomains Athenz domain names that contain the RBAC policies [] Yes "domName1", "domName2"
HTTPClient The HTTP client for connecting to Athenz server http.Client{ Timeout: 30 * time.Second } No http.DefaultClient
CacheExp The TTL of the success cache 1 Minute No 1 * time.Minute
Enable/DisablePubkeyd Run public key daemon or not true No
PubkeySysAuthDomain System authority domain name to retrieve Athenz public key data sys.auth No "sys.auth"
PubkeyRefreshPeriod Period to refresh the Athenz public key data 24 Hours No "24h"
PubkeyETagExpiry ETag cache TTL of Athenz public key data 168 Hours (1 Week) No "168h"
PubkeyETagPurgePeriod ETag cache purge duration 84 Hours No "84h"
PubkeyRetryDelay Delay of next retry on request failed 1 Minute No "1m"
Enable/DisablePolicyd Run policy daemon or not true No
PolicyExpiryMargin Update the policy by a margin duration before the policy actually expires 3 Hours No "3h"
PolicyRefreshPeriod Period to refresh the Athenz policies 30 Minutes No "30m"
PolicyPurgePeriod Policy cache purge duration 1 Hours No "1h"
PolicyRetryDelay Delay of next retry on request fail 1 Minute No "1m"
PolicyRetryAttempts Maximum retry attempts on request fail 2 No 2
Enable/DisableJwkd Run JWK daemon or not true No
JwkRefreshPeriod Period to refresh the Athenz JWK 24 Hours No "24h"
JwkRetryDelay Delay of next retry on request fail 1 Minute No "1m"
jwkURLs URL to get jwk other than AthenzURL [] No "http://domain1/jwks", "http://domain2/jwks"
AccessTokenParam Use access token verification, details: AccessTokenParam Same as AccessTokenParam No {}
Enable/DisableRoleToken Use role token verification or not true No
RoleAuthHeader The HTTP header to extract role token Athenz-Role-Auth No "Athenz-Role-Auth"
Enable/DisableRoleCert Use role certificate verification or not true No
RoleCertURIPrefix Extract role from role certificate athenz://role/ No "athenz://role/"

AccessTokenParam

Option name Description Default Value Required Example
enable Use access token verification or not true No true
verifyCertThumbprint Use certificate bound access token verification true No true
certBackdateDur Backdate duration of the issue time of the certificate 1 Hour No "1h"
certOffsetDur Offset window to accept access token with a mismatching certificate thumbprint 1 Hour No "1h"
verifyClientID Use authorized client ID verification false No false
authorizedClientIDs Authorized client ID to certificate common name map nil No { "atClientID": { "certCN1", "certCN2" } }

About releases

  • Releases
    • GitHub release (latest by date)

Authors