JWT - To authentication & beyond! (v2)

Tokens are widely used to identify resources and try to add some security to insecure environments, but sometimes the management of those identifiers can get a bit complex - even more on distributed systems. What if we could have an intelligent token, one that simplifies the way things works without losing integrity or security?
In this talk we present JSON Web Tokens as an alternative for smart and self contained tokens, explaining how to use each claim and giving some common use cases.

Transcript

1. JWT To infinity
 & beyond! authentication Luís Cobucci
 @lcobucci https://goo.gl/gbd3H5
2. Tokens? https://goo.gl/C0LI6F
3. Browser Server DB
4. Browser Server 1. presents credentials POST /login 
 {
 "email": "aa@aa.com", "password": "amazing!"
 } DB
5. Browser Server DB 1. presents credentials 2. validates and starts a session
6. Browser Server DB 1. presents credentials 2. validates and starts a session 200 OK Set-Cookie: PHPSESSIONID=ABC123; Domain=foo.bar; Secure; HttpOnly; Expires=Thu, 1 Jun 2017 12:00:00 GMT
7. Browser Server DB 1. presents credentials 2. validates and starts a session 200 OK Set-Cookie: PHPSESSIONID=ABC123; Domain=foo.bar; Secure; HttpOnly; Expires=Thu, 1 Jun 2017 12:00:00 GMT
8. Browser Server DB 1. presents credentials 2. validates and starts a session 3. sends cookies on next requests GET / Cookie: PHPSESSIONID=ABC123
9. Browser Server DB 1. presents credentials 2. validates and starts a session 3. sends cookies on next requests 4. reads session data and returns a specific response for logged user 200 OK Hello John!
10. “ (…) Each request from any client contains all the information necessary to service the request, and session state is held in the client. Representational State Transfer - Wikipedia
11. A mission http://goo.gl/RfVHNu
12. { "token": "abc123", "uid": 1, "expiration": "…",
 "scope": ["a", "b", "c"] }
13. { "token": "abc123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] }
14. { "token": "abc123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] } { "token": "abc456", "uid": 3,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def456", "uid": 4,
 "expiration": "…", "scope": ["a", "b"] }
15. { "token": "abc123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] } { "token": "abc456", "uid": 3,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def456", "uid": 4,
 "expiration": "…", "scope": ["a", "b"] } { "token": "abc789", "uid": 5,
 "expiration": "…", "scope": ["a", "b"] } { "token": "def789", "uid": 6,
 "expiration": "…", "scope": ["a"] } { "token": "ghi123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "jkl123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] } { "token": "ghi456", "uid": 3,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "jkl456", "uid": 4,
 "expiration": "…", "scope": ["a", "b"] } { "token": "ghi789", "uid": 5,
 "expiration": "…", "scope": ["a", "b"] } { "token": "jkl789", "uid": 6,
 "expiration": "…", "scope": ["a"] }
16. { "token": "abc123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] } { "token": "abc456", "uid": 3,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def456", "uid": 4,
 "expiration": "…", "scope": ["a", "b"] } { "token": "abc789", "uid": 5,
 "expiration": "…", "scope": ["a", "b"] } { "token": "def789", "uid": 6,
 "expiration": "…", "scope": ["a"] } { "token": "ghi123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "jkl123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] } { "token": "ghi456", "uid": 3,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "jkl456", "uid": 4,
 "expiration": "…", "scope": ["a", "b"] } { "token": "ghi789", "uid": 5,
 "expiration": "…", "scope": ["a", "b"] } { "token": "jkl789", "uid": 6,
 "expiration": "…", "scope": ["a"] } { "token": "abc123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] } { "token": "abc456", "uid": 3,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def456", "uid": 4,
 "expiration": "…", "scope": ["a", "b"] } { "token": "abc789", "uid": 5,
 "expiration": "…", "scope": ["a", "b"] } { "token": "def789", "uid": 6,
 "expiration": "…", "scope": ["a"] } { "token": "ghi123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "jkl123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] } { "token": "ghi456", "uid": 3,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "jkl456", "uid": 4,
 "expiration": "…", "scope": ["a", "b"] } { "token": "ghi789", "uid": 5,
 "expiration": "…", "scope": ["a", "b"] } { "token": "jkl789", "uid": 6,
 "expiration": "…", "scope": ["a"] } { "token": "abc123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] } { "token": "abc456", "uid": 3,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def456", "uid": 4,
 "expiration": "…", "scope": ["a", "b"] } { "token": "abc789", "uid": 5,
 "expiration": "…", "scope": ["a", "b"] } { "token": "def789", "uid": 6,
 "expiration": "…", "scope": ["a"] } { "token": "ghi123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "jkl123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] } { "token": "ghi456", "uid": 3,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "jkl456", "uid": 4,
 "expiration": "…", "scope": ["a", "b"] } { "token": "ghi789", "uid": 5,
 "expiration": "…", "scope": ["a", "b"] } { "token": "jkl789", "uid": 6,
 "expiration": "…", "scope": ["a"] } { "token": "abc123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] } { "token": "abc456", "uid": 3,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "def456", "uid": 4,
 "expiration": "…", "scope": ["a", "b"] } { "token": "abc789", "uid": 5,
 "expiration": "…", "scope": ["a", "b"] } { "token": "def789", "uid": 6,
 "expiration": "…", "scope": ["a"] } { "token": "ghi123", "uid": 1,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "jkl123", "uid": 2,
 "expiration": "…", "scope": ["a", "b"] } { "token": "ghi456", "uid": 3,
 "expiration": "…", "scope": ["a", "b", "c"] } { "token": "jkl456", "uid": 4,
 "expiration": "…", "scope": ["a", "b"] } { "token": "ghi789", "uid": 5,
 "expiration": "…", "scope": ["a", "b"] } { "token": "jkl789", "uid": 6,
 "expiration": "…", "scope": ["a"] }
17. Wonderful, right? http://goo.gl/9jQFkj
18. No! http://goo.gl/XHI1fw
19. We need
 SIMPLE ! it
20. Luís Cobucci
 @lcobucci https://jobs.usabilla.com
21. JOSE JSON Object Signing and Encryption
22. JOSE JSON Object Signing and Encryption jws jwa jwt jwe jwk
23. eyJ0eXAiOiJKV1QiLCJhbGciOiJ IUzI1NiJ9.eyJ1c2VyIjp7ImlkI joxLCJuYW1lIjoiTHXDrXMgQ29i dWNjaSJ9fQ.
24. eyJ0eXAiOiJKV1QiLCJhbGciOiJ IUzI1NiJ9.eyJ1c2VyIjp7ImlkI joxLCJuYW1lIjoiTHXDrXMgQ29i dWNjaSJ9fQ. base64_encode()
25. eyJ0eXAiOiJKV1QiLCJhbGciOiJ IUzI1NiJ9.eyJ1c2VyIjp7ImlkI joxLCJuYW1lIjoiTHXDrXMgQ29i dWNjaSJ9fQ.
26. eyJ0eXAiOiJKV1QiLCJhbGciOiJ IUzI1NiJ9 . eyJ1c2VyIjp7ImlkIjoxLCJuYW1 lIjoiTHXDrXMgQ29idWNjaSJ9fQ .
27. Base64URL eyJ0eXAiOiJKV1QiLCJhbGciOiJ IUzI1NiJ9 . eyJ1c2VyIjp7ImlkIjoxLCJuYW1 lIjoiTHXDrXMgQ29idWNjaSJ9fQ .
28. + → -
 / → _
 = → (removed) TeSJWlQ/ S4YaOgK5tz7j+3KxBA g3HTONa9NP80R+9mY= TeSJWlQ_S4YaOgK5tz7 j-3KxBAg3HTONa9NP80 R-9mY
29. function base64url_encode(string $data): string { $data = base64_encode($data); 
 return rtrim(
 strtr($data, '+/', '-_'), '=' ); }
30. function base64url_decode(string $data): string {
 if ($remainder = strlen($data) % 4) { $data .= str_repeat('=', 4 - $remainder); } return base64_decode(
 strtr($data, '-_', '+/') ); }
31. eyJ0eXAiOiJKV1QiLCJhbGciOiJ IUzI1NiJ9 . eyJ1c2VyIjp7ImlkIjoxLCJuYW1 lIjoiTHXDrXMgQ29idWNjaSJ9fQ .
32. {
 "typ": "JWT",
 "alg": "none"
 } {
 "user": {
 "id": 1,
 "name": "Luís Cobucci"
 }
 }
33. The JSON! http://goo.gl/gH0hsx
34. {
 "typ": "JWT",
 "alg": "none"
 } {
 "user": {
 "id": 1,
 "name": "Luís Cobucci"
 }
 }
35. 401
 Unauthorised http://goo.gl/yyZ7oC
36. Client API DB
37. 1. presents credentials POST /auth 
 {
 "email": "aa@aa.com", "password": "amazing!"
 } Client API DB
38. 1. presents credentials 2. validates and creates a token Client API - issuer: auth.example.com - permitted to: client.example.com - expires in 300 seconds DB
39. 1. presents credentials 2. validates and creates a token 201 Created 
 {
 "token": "…"
 } Client API DB
40. 1. presents credentials 2. validates and creates a token 3. sends the issued token GET / Authorization: … Client API DB
41. 1. presents credentials 2. validates and creates a token 3. sends the issued token 4. verifies the signature, validates the claims and processes the request - is it valid? - client allowed? - expected issuer? - can it be used at this moment? Client API DB
42. How about OAuth2?
43. Sessions https://goo.gl/KNrl16
44. file Webserver Set-Cookie:
 SESSION_ID=123abc
45. file a Webserver Client SESSION_ID=123abc
46. file a Webserver 1 Client SESSION_ID=123abc file b Webserver 2 file c Webserver 3 Load balancer
47. Webserver 1 Client SESSION=eyJ0eXAiOiJKV1QiLCJhbGciO iJIUzI1NiJ9.eyJ1c2VyIjp7ImlkIjoxL CJuYW1lIjoiTHXDrXMgQ29idWNjaSJ9fQ .hv9V7gBBJPeWMbwFFmRP7clLuof7r9fV JzZbLZIxBTs Webserver 2 Webserver 3 Load balancer
48. ! 1. cannot store private information in the session
 
 2. sessions cannot be (easily) invalidated 
 3. increased network traffic
 
 4. race conditions with highly concurrent HTTP requests writing to session
 
 5. limit on the amount of data stored in session
50. More!! https://goo.gl/gEjEMm
51. https://goo.gl/GB6YkQ Let’s investigate it
52. {
 "typ": "JWT",
 "alg": "none"
 } {
 "user": {
 "id": 1,
 "name": "Luís Cobucci"
 }
 }
53. headers {
 "typ": "JWT",
 "alg": "none"
 } {
 "user": {
 "id": 1,
 "name": "Luís Cobucci"
 }
 }
54. headers {
 "typ": "JWT",
 "alg": "none"
 } {
 "user": {
 "id": 1,
 "name": "Luís Cobucci"
 }
 } claims
55. Base64URL( )
 + "." + 
 Base64URL( )
 + "." headers claims
56. headers {
 "typ": "JWT",
 "alg": "none"
 } {
 "user": {
 "id": 1,
 "name": "Luís Cobucci"
 }
 } claims
57. eyJhbGciOiJub25lIiwidHlwIjo iSldUIn0
 .
 eyJ1c2VyIjp7ImlkIjoxLCJuYW1 lIjoiTHXDrXMgQ29idWNjaSJ9fQ
 .
58. Can you trust it? https://goo.gl/EeeIdu
59. Base64URL( )
 + "." + 
 Base64URL( ) headers claims payload
60. Base64URL( )
 + "." + 
 Base64URL( ) headers claims payload = alg( , ) payload key signature
61. Base64URL( )
 + "." + 
 Base64URL( )
 + "." + 
 Base64URL( ) headers claims signature
62. function jwt_create( array $headers, array $claims, string $key ): string {
 $headers = base64url_encode(json_encode($headers));
 $claims = base64url_encode(json_encode($claims)); $payload = $headers . '.' . $claims; $signature = base64url_encode(
 hash_hmac('sha256', $payload, $key, true)
 ); return $payload . '.' . $signature; }
63. What algorithms? https://goo.gl/qNTg3D
64. HS256 HS384 HS512 RS256 RS384 RS512 ES256 ES384 ES512 PS256 PS384 PS512 none HMAC RSA ECDSA RSASSA-PSS
65. HS256 HS384 HS512 RS256 RS384 RS512 ES256 ES384 ES512 PS256 PS384 PS512 none HMAC RSA ECDSA RSASSA-PSS
66. HS256 HS384 HS512 RS256 RS384 RS512 ES256 ES384 ES512 PS256 PS384 PS512 none HMAC RSA ECDSA RSASSA-PSS
67. headers {
 "typ": "JWT",
 "alg": "HS256"
 } {
 "user": {
 "id": 1,
 "name": "Luís Cobucci"
 }
 } claims key Hello JWT+JWS!
68. eyJhbGciOiJub25lIiwidHlwIjo iSldUIn0
 .
 eyJ1c2VyIjp7ImlkIjoxLCJuYW1 lIjoiTHXDrXMgQ29idWNjaSJ9fQ
 .
 hv9V7gBBJPeWMbwFFmRP7clLuof 7r9fVJzZbLZIxBTs
69. How much data? https://goo.gl/eHFQwO
70. iat (NumericDate) exp (NumericDate) nbf (NumericDate) jti (String) iss (StringOrUri) aud (StringOrUri[]) sub (StringOrUri)
71. iat (NumericDate) exp (NumericDate) nbf (NumericDate) jti (String) iss (StringOrUri) aud (StringOrUri[]) sub (StringOrUri) case-sensitive
72. https://goo.gl/bkXMeq Revoke tokens?
73. {
 "user": {
 "id": 1,
 "name": "Luís Cobucci"
 }
 }
74. {
 "jti": "1245456",
 "exp": 1527417474,
 "user": {
 "id": 1,
 "name": "Luís Cobucci"
 }
 } Blacklist Whitelist
75. PHP libraries! https://goo.gl/bGP8u8
78. declare(strict_types=1); require 'vendor/autoload.php'; use Lcobucci\JWT\Configuration; use Lcobucci\JWT\Signer\Key; use Lcobucci\JWT\Signer\Hmac\Sha256; return Configuration::forSymmetricSigner( new Sha256(), new Key('my super secret key') );
79. declare(strict_types=1); require 'vendor/autoload.php'; use Lcobucci\JWT\Configuration; use Lcobucci\JWT\Signer\Key; use Lcobucci\JWT\Signer\Rsa\Sha256; return Configuration::forAsymmetricSigner( new Sha256(), new Key('file://private.pem', 'testing'), new Key('file://public.pem') );
80. declare(strict_types=1); $config = require 'config.php';
 assert($config instanceof \Lcobucci\JWT\Configuration); $signer = $config->getSigner(); $key = $config->getSigningKey(); $token = $config->createBuilder() ->withClaim('uid', 1) ->getToken($signer, $key);
81. declare(strict_types=1); $config = require 'config.php';
 assert($config instanceof \Lcobucci\JWT\Configuration);
 $signer = $config->getSigner(); $key = $config->getSigningKey(); $token = $config->createBuilder() ->withClaim('uid', 1) ->identifiedBy(bin2hex(random_bytes(16))) ->getToken($signer, $key);
82. declare(strict_types=1); $config = require 'config.php';
 assert($config instanceof \Lcobucci\JWT\Configuration);
 $signer = $config->getSigner(); $key = $config->getSigningKey(); $token = $config->createBuilder() ->withClaim('uid', 1) ->identifiedBy(bin2hex(random_bytes(16))) ->issuedBy('https://foo.bar') ->getToken($signer, $key);
83. declare(strict_types=1); $config = require 'config.php';
 assert($config instanceof \Lcobucci\JWT\Configuration);
 
 $signer = $config->getSigner(); $key = $config->getSigningKey(); $token = $config->createBuilder() ->withClaim('uid', 1) ->identifiedBy(bin2hex(random_bytes(16))) ->issuedBy('https://foo.bar')
 ->permittedFor('https://client1.bar')
 ->permittedFor('https://client2.bar') ->getToken($signer, $key);
84. declare(strict_types=1); $config = require 'config.php';
 assert($config instanceof \Lcobucci\JWT\Configuration); $signer = $config->getSigner(); $key = $config->getSigningKey(); $now = new DateTimeImmutable(); $token = $config->createBuilder() ->withClaim('uid', 1) ->identifiedBy(bin2hex(random_bytes(16))) ->issuedBy('https://foo.bar')
 ->permittedFor('https://client1.bar')
 ->permittedFor('https://client2.bar')
 ->issuedAt($now)
 ->canOnlyBeUsedAfter($now->modify('+5 minutes'))
 ->expiresAt($now->modify('+1 hour')) ->getToken($signer, $key);
85. eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9
 .
 eyJ1aWQiOjEsImp0aSI6ImFhMzk3YzA2ZDUwZmRhNjYyYWUwZGE4OTU2ODdmN zY3IiwiaXNzIjoiaHR0cHM6Ly9mb28uYmFyIiwiYXVkIjpbImh0dHBzOi8vY2 xpZW50MS5iYXIiLCJodHRwczovL2NsaWVudDIuYmFyIl0sImlhdCI6IjE0OTU xNzg5MDQuODY4ODc5IiwibmJmIjoiMTQ5NTE3OTIwNC44Njg4NzkiLCJleHAi OiIxNDk1MTgyNTA0Ljg2ODg3OSJ9
 .
 jwXzXjm8cU92yxP3XcENg_ZnDvW1MkRTzSoaAwOYCTlSdQ5rv- dCLn_7_XPLHSuiACt_aFTnB093GYTpJQKRnqIFPYteK2jVnQALXNPxntnp- v6SMiFBxofCaVSjgKTWdqkWB4agWrTR77HK_iKdFoZMIdpr8UUBJatkc_MCoD vDMtuDRXwIEBfjs9baICtBvTZyDD7iiMmF4F_qvp2mWd_Qy93gZCrePKAJsgY - sujg84iQFOs-6I3GjybzA0U0Y_bTmCmQHfhRUX5_gL21bZxBFef38OFKW73Vx ehBxM4Ok_nWRbGY7ehsMBshXkJQfp97TJ1cV35a9zyAVXC04A
86. {
 "typ": "JWT",
 "alg": "RS256"
 } {
 "uid": 1, "jti": "aa397c06d50fda662ae0da895687f767", "iss": "https://foo.bar", "aud": ["https://client1.bar", “https://client2.bar”], "iat": "1495178904.868879", "nbf": "1495179204.868879", "exp": "1495182504.868879"
 }
87. declare(strict_types=1); $config = require 'config.php';
 assert($config instanceof \Lcobucci\JWT\Configuration);
 $jwt = 'eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJ1aWQiOjEsImp0aSI6ImFh' . 'Mzk3YzA2ZDUwZmRhNjYyYWUwZGE4OTU2ODdmNzY3IiwiaXNzIjoiaHR0cHM6L' . 'y9mb28uYmFyIiwiYXVkIjpbImh0dHBzOi8vY2xpZW50MS5iYXIiLCJodHRwcz' . 'ovL2NsaWVudDIuYmFyIl0sImlhdCI6IjE0OTUxNzg5MDQuODY4ODc5IiwibmJ'
 . 'mIjoiMTQ5NTE3OTIwNC44Njg4NzkiLCJleHAiOiIxNDk1MTgyNTA0Ljg2ODg3' . 'OSJ9.jwXzXjm8cU92yxP3XcENg_ZnDvW1MkRTzSoaAwOYCTlSdQ5rv-dCLn_7'
 . '_XPLHSuiACt_aFTnB093GYTpJQKRnqIFPYteK2jVnQALXNPxntnp-v6SMiFBx'
 . 'ofCaVSjgKTWdqkWB4agWrTR77HK_iKdFoZMIdpr8UUBJatkc_MCoDvDMtuDRX'
 . 'wIEBfjs9baICtBvTZyDD7iiMmF4F_qvp2mWd_Qy93gZCrePKAJsgY-sujg84i'
 . 'QFOs-6I3GjybzA0U0Y_bTmCmQHfhRUX5_gL21bZxBFef38OFKW73VxehBxM4O'
 . 'k_nWRbGY7ehsMBshXkJQfp97TJ1cV35a9zyAVXC04A';
 
 $token = $config->getParser()->parse($jwt);
88. declare(strict_types=1); use Lcobucci\Clock\SystemClock;
 use Lcobucci\JWT\Validation\Constraint; $config = require 'config.php';
 assert($config instanceof \Lcobucci\JWT\Configuration); $signer = $config->getSigner(); $key = $config->getVerificationKey();
 $token = $config->getParser()->parse('eyJ0eNiJ9 (...)'); $constraints = [ new Constraint\IssuedBy('https://foo.bar', 'https://bar.foo'), new Constraint\PermittedFor('https://client2.bar'),
 new Constraint\ValidAt(new SystemClock()),
 new Constraint\SignedWith($signer, $key)
 ];
 
 $config->getValidator()->assert($token, ...$constraints);
89. declare(strict_types=1); use Lcobucci\Clock\SystemClock;
 use Lcobucci\JWT\Validation\Constraint; $config = require 'config.php';
 assert($config instanceof \Lcobucci\JWT\Configuration);
 $signer = $config->getSigner(); $key = $config->getVerificationKey();
 $token = $config->getParser()->parse('eyJ0eNiJ9 (...)'); $constraints = [ new Constraint\IssuedBy('https://foo.bar', 'https://bar.foo'), new Constraint\PermittedFor('https://client2.bar'),
 new Constraint\ValidAt(new SystemClock()),
 new Constraint\SignedWith($signer, $key)
 ];
 
 var_dump($config->getValidator()->validate($token, ...$constraints));
90. Criticism https://goo.gl/wfYBKA
91. In summary… https://goo.gl/TVhdnm
92. JWT To infinity
 & beyond! authentication Luís Cobucci
 @lcobucci https://goo.gl/gbd3H5
93. Thanks! @lcobucci