All About AuthZ

Over the past 10 years we've seen the rise of SaaS companies that sell products for dev and infra teams. Payments, communications, authentication, and observability (to name a few) have all been revolutionized by companies like Stripe, Twilio, Auth0 and Datadog.

In a world where users are starting to care more about their privacy, expect collaboration capabilities from their software, and where adhering to compliance standards is table stakes, Authorization is starting to become one of those concerns to be addressed.

In this talk we'll go over what Authorization is, some of its core concepts, the context that is making it a rising topic, and review some of the alternatives (both buy and build) to solve Authorization.

Transcript

1. All about AuthZ @dschenkelman
2. Building a SaaS in 2021…
3. Security
4. Privacy
5. Compliance
6. Table Stakes https://medium.com/pm-insights/how-to-pick-winning-product- features-7b03abcf7d12
7. Collaboration
8. Sharing
9. Partnerships
10. Differentiator https://medium.com/pm-insights/how-to-pick-winning-product- features-7b03abcf7d12
11. Authorization
12. NOT Authentication
13. Authorization
14. In the beginning… RBAC DELETE /customers/{id} const user = await db.users.get(cookie.userId); if (user.role === "admin")) { // delete customer // return 204 } else { // return 403 } select role from users where userId == {uid};
15. In the beginning… RBAC DELETE /customers/{id} const user = await db.users.get(cookie.userId); if (user.role === "admin")) { // delete customer // return 204 } else { // return 403 } select role from users where userId == {uid};
16. In the beginning… RBAC DELETE /customers/{id} const user = await db.users.get(cookie.userId); if (user.role === "admin")) { // delete customer // return 204 } else { // return 403 } select role from users where userId == {uid};
17. In the beginning… RBAC DELETE /customers/{id} const user = await db.users.get(cookie.userId); if (user.role === "admin")) { // delete customer // return 204 } else { // return 403 } select role from users where userId == {uid};
18. In the beginning… RBAC DELETE /customers/{id} const user = await db.users.get(cookie.userId); if (user.role === "admin")) { // delete customer // return 204 } else { // return 403 } select role from users where userId == {uid};
19. I want to use attributes from subject and object… ABAC DELETE /customers/{id} const user = await db.users.get(cookie.userId); const customer = await db.customers.get(req.path.id); if (user.department === "IT" && !customer.subscribed)) { // delete customer // return 204 } else { // return 403 } select department from users where id == {uid}; select subscribed from customers where id == {cid};
20. I want to use attributes from subject and object… ABAC DELETE /customers/{id} const user = await db.users.get(cookie.userId); const customer = await db.customers.get(req.path.id); if (user.department === "IT" && !customer.subscribed)) { // delete customer // return 204 } else { // return 403 } select department from users where id == {uid}; select subscribed from customers where id == {cid};
21. I want to use attributes from subject and object… ABAC DELETE /customers/{id} const user = await db.users.get(cookie.userId); const customer = await db.customers.get(req.path.id); if (user.department === "IT" && !customer.subscribed)) { // delete customer // return 204 } else { // return 403 } select department from users where id == {uid}; select subscribed from customers where id == {cid};
22. I want to use attributes from subject and object… ABAC DELETE /customers/{id} const user = await db.users.get(cookie.userId); const customer = await db.customers.get(req.path.id); if (user.department === "IT" && !customer.subscribed)) { // delete customer // return 204 } else { // return 403 } select department from users where id == {uid}; select subscribed from customers where id == {cid};
23. I want to use attributes from subject and object… ABAC DELETE /customers/{id} const user = await db.users.get(cookie.userId); const customer = await db.customers.get(req.path.id); if (user.department === "IT" && !customer.subscribed)) { // delete customer // return 204 } else { // return 403 } select department from users where id == {uid}; select subscribed from customers where id == {cid};
24. I want to use attributes from subject and object… ABAC DELETE /customers/{id} const user = await db.users.get(cookie.userId); const customer = await db.customers.get(req.path.id); if (user.department === "IT" && !customer.subscribed)) { // delete customer // return 204 } else { // return 403 } select department from users where id == {uid}; select subscribed from customers where id == {cid};
25. I want to know who did what… DELETE /customers/{id} // log: cookie.userId requesting authz to delete customer const user = await db.users.get(cookie.userId); const customer = await db.customers.get(req.path.id); if (user.department === "IT" && customer.unsubscribed)) { // log: cookie.userId authorized to delete customer // delete customer // return 204 } else { // log: cookie.userId unauthorized to delete customer // return 403 } select department from users where id == {uid}; select unsubscribed from customers where id == {cid};
26. I want to know who did what… DELETE /customers/{id} // log: cookie.userId requesting authz to delete customer const user = await db.users.get(cookie.userId); const customer = await db.customers.get(req.path.id); if (user.department === "IT" && customer.unsubscribed)) { // log: cookie.userId authorized to delete customer // delete customer // return 204 } else { // log: cookie.userId unauthorized to delete customer // return 403 } select department from users where id == {uid}; select unsubscribed from customers where id == {cid};
27. I want to know who did what… DELETE /customers/{id} // log: cookie.userId requesting authz to delete customer const user = await db.users.get(cookie.userId); const customer = await db.customers.get(req.path.id); if (user.department === "IT" && customer.unsubscribed)) { // log: cookie.userId authorized to delete customer // delete customer // return 204 } else { // log: cookie.userId unauthorized to delete customer // return 403 } select department from users where id == {uid}; select unsubscribed from customers where id == {cid};
28. I want it to be reliable and fast… DELETE /customers/{id} // log: cookie.userId requesting authz to delete customer const user = await db.users.get(cookie.userId); const customer = await db.customers.get(req.path.id); if (user.department === "IT" && customer.unsubscribed)) { // log: cookie.userId authorized to delete customer // delete customer // return 204 } else { // log: cookie.userId unauthorized to delete customer // return 403 } select department from users where id == {uid}; select unsubscribed from customers where id == {cid};
29. Access Review? Who can access what?
30. Approval? Change Management
31. Auditing? What happened?
32. Reliability?
33. Latency?
34. Developer SaaS
35. Approach #1: Policies
36. Policy
37. XACML http://docs.oasis-open.org/xacml/3.0/xacml-3.0-core-spec-os-en.html
38. Rego https://www.openpolicyagent.org/docs/latest/policy-language/
39. Polar https://docs.osohq.com/reference/polar/polar-syntax.html
40. Architecture Abstract 4. get user and customer data 2. can user delete customer? 1. can user delete customer? Manage Policies Distribute Policies PAP PEP PDP PIP (the original DB) 6. delete customer 5. user is authorized Policy Repository 3. evaluate policy
41. Architecture Concrete 4. get user and customer data 2. can user delete customer? 1. can user delete customer? Manage Policies Distribute Policies PAP PEP PDP PIP (the original DB) 6. delete customer 5. user is authorized Policy Repository
42. Alternatives
43. Advantages • Auditing is implemented outside of business logic • Authorization change management is simpler than having it in code • Easier to understand what authorization logic applies
44. Disadvantages • Requires operating more components
45. Architecture Services 4.1. get user data 2. can user delete customer? 1. can user delete customer? PEP PDP PIP (users service) 5. user is authorized PIP (customer service) 4.2. get customer data
46. us-west-2 us-east-1 Architecture Services + Multiregion PEP PDP PIP PIP 4.1. get user 2. can user delete customer? 1. can user delete customer? PEP PDP PIP 5. user is authorized PIP 4.2 get customer
47. us-west-2 us-east-1 Architecture Services + Multi-region + Failure PEP PDP PIP PIP PEP PDP PIP PIP
48. Disadvantages • Requires operating more components • Does not handle storage of authz data • 👉 latency + reliability + scale
49. Approach #2: "Zanzibar"
50. Zanzibar Not this one…
51. Google Zanzibar https://research.google/pubs/pub48190/
52. ReBAC
53. Multi-region
54. Sweet spot Policies (AuthZ needs) DBaaS (handles data) Zanzibar "as a Service”
55. Alternatives (disclaimer: I work on “Sandcastle") "Sandcastle"
56. DEMO
57. Architecture Sandcastle in "PDP Mode" 2. check(user, delete, customer) 1. can user delete customer? Customer Service PDP Sandcastle 4. delete customer 3. user is authorized nginx
58. Enforcement
59. us-west-2 us-east-1 Architecture Services + Multi-region + Sandcastle Users Service Customers Service Sandcastle Sandcastle nginx Customers Service Users Service nginx check(user, delete, customer) check(user, delete, customer)
60. Advantages • Auditing is part of "aaS" • Authorization change management is simpler than having it in code • Easier to understand what authorization logic applies • Multi-region and operated by someone else
61. Disadvantages • Many things are a relationship, but not everything (e.g. time of day)
62. Approach #3: Combined
63. Architecture Sandcastle in "PIP Mode" 4. check(user, delete, customer) 2. can user delete customer? 1. can user delete customer? Manage Policies Distribute Policies PAP PEP PDP PIP Sandcastle 6. delete customer 5. user is authorized Policy Repository 3. evaluate policy
64. us-west-2 us-east-1 Architecture Services + Multi-region + Sandcastle + Policies PEP PDP Users Service Customers Service Sandcastle Sandcastle PEP PDP Customers Service Users Service
65. Sandcastle + OPA
66. Final Thoughts
67. @auth0lab Resources • Sandcastle playground: https://learn.sandcastle.cloud/ • Auth0 Lab discord: https://t.co/ybHn8hEOBl?amp=1 • Authorization in Software: Subject Matter Expert Chats: https:// www.youtube.com/playlist? list=PLZuCrkqyqw9wY0bCosGYDMI9enFpg_tk- • @auth0lab: https://twitter.com/auth0lab
68. Resources • OPA: https://www.openpolicyagent.org/ • Styra: https://www.styra.com/ • OSOHQ: https://docs.osohq.com/ • XACML: http://docs.oasis-open.org/xacml/3.0/xacml-3.0-core-spec-os-en.html • NIST ABAC: https://nvlpubs.nist.gov/nistpubs/specialpublications/NIST.sp.800-162.pdf • RBAC: https://csrc.nist.gov/CSRC/media/Publications/conference-paper/1992/10/13/ role-based-access-controls/documents/ferraiolo-kuhn-92.pdf
69. Resources • Facebook TAO: https://www.usenix.org/system/ fi les/conference/atc13/atc13- bronson.pdf • Google Zanzibar: https://research.google/pubs/pub48190/ • Himeji (Zanzibar @ Airbnb): https://medium.com/airbnb-engineering/himeji-a- scalable-centralized-system-for-authorization-at-airbnb-341664924574 • AuthZ (Zanzibar @ Carta): https://medium.com/building-carta/authz-cartas-highly- scalable-permissions-system-782a7f2c840f • Authzed: https://authzed.com/ • Ory Keto: https://www.ory.sh/keto/docs/
70. Questions?
71. Thanks! @dschenkelman @auth0lab