This project evaluates the spring-security-oauth2 as an option for securing our resource servers as we evolve our platform on a spring-cloud stack.
- Resource Servers - a-service, b-service, c-service all have copies of the same resource server configuration, and demonstrate the token exchange, token-relay and declarative expression-based access control capabilities. The resource servers are aligned to the AuthN investigations we have been doing.
- Authorization server - uaa-service, this custom authorization server is a throw away work, since we have already an existing identity server. So in this POC the scope of the
uaa-serviceis just for setting up data, issuing tokens and to an extent evaluate the potential ofspring-security-oauth2as an identity server.
In this POC we request an endpoint at a-service:8001, that would call another endpoint at b-service:8002 which would call the c-service:8003 to finally return a string back to the client.
The call to a-service:8001 is made using an opaque access token, within the Authorization: Bearer header. The resource server would exchange the opaque token with an equivalent JWT from the uaa-service:9191 before the call gets to any RestController. The JWT will be stored as a part of OAuth2Authentication within the SecurityContext. The OAuth2RestTemplate and FeignClient will relay this JWT to the downstream server b-service:8002 which again would relay the same to the c-service:8003 which sends the final response back.
The above interaction displays the capabilities of token relay from service to service, and also the AuthN awareness of the resource servers. If and only if the incoming access token is an opaque one, the resource server would consult the uaa-service:9191 for exchanging the token with a JWT, otherwise if the incoming access token is a JWT it will be honored as is.
Following is the zipkin dependency graph for this interaction,
Also it has been made sure that the FeignClient + Hystrix + Ribbon works fine along with the Oauth2RestTemplate for relaying the tokens without issues.
Please follow the steps
bash-3.2$ git clone https://github.com/alwaysastudent/spring-security-oauth2-poc.git
bash-3.2$ cd spring-security-oauth2-poc
bash-3.2$ mvn clean install
split your terminal and run each of the 4 services individually or you can run them concurrently, if you like, from a single command line and monitor the logs on stdout.
bash-3.2$ java -jar ./uaa-service/target/uaa-service-0.0.1-SNAPSHOT.jar
bash-3.2$ java -jar ./a-service/target/a-service-0.0.1-SNAPSHOT.jar
bash-3.2$ java -jar ./a-service/target/b-service-0.0.1-SNAPSHOT.jar
bash-3.2$ java -jar ./a-service/target/c-service-0.0.1-SNAPSHOT.jar
bash-3.2$ trap 'kill %1; kill %2; kill %3' SIGINT; java -jar ./uaa-service/target/uaa-service-0.0.1-SNAPSHOT.jar & java -jar ./a-service/target/a-service-0.0.1-SNAPSHOT.jar & java -jar ./b-service/target/b-service-0.0.1-SNAPSHOT.jar & java -jar ./c-service/target/c-service-0.0.1-SNAPSHOT.jar
it will take around a minute to start if your machine is doing well
Note - For stopping hit Ctrl+C couple of times. Also don't forget to remove the trap. After that verify all your processes are gone using jps
trap - SIGINT
verify from the other terminal if all 4 are still running
bash-3.2$ jps | grep SNAPSHOT
59557 uaa-service-0.0.1-SNAPSHOT.jar
59558 a-service-0.0.1-SNAPSHOT.jar
59559 b-service-0.0.1-SNAPSHOT.jar
59560 c-service-0.0.1-SNAPSHOT.jar
The uua-service comes preset with a client web:secret and 2 users - [email protected]/password, [email protected]/password
Read more on uaa-service
curl -v -X POST -H "Accept: application/json" --user web:secret -d "[email protected]&password=password&grant_type=password&scope=read+write&client_secret=secret&client_id=web" http://localhost:9191/uaa/oauth/token
< HTTP/1.1 200
{
"access_token": "99b644da-5610-44e4-bf32-afae742b97a2",
"token_type": "bearer",
"refresh_token": "9386f20b-8106-4e78-b1b9-f056cf216310",
"expires_in": 43199,
"scope": "read write",
"refresh_token_expires_in": 2591999,
"user_guid": "6a7ecdaf-c8f1-4f1a-a351-49197d391b68"
}
export TOKEN=99b644da-5610-44e4-bf32-afae742b97a2
curl -v -H "Authorization: Bearer $TOKEN" http://localhost:8001/
< HTTP/1.1 200
a-service -> b-service -> c-service
------
curl -v -H "Authorization: Bearer $TOKEN" http://localhost:8001/?useFeign=true
< HTTP/1.1 200
a-service -> b-service -> c-service
You would get the logs similar to the below, where you could see the exchange call from a-service and also the JWTs being propagated and logged.
2017-06-27 10:57:39.207 INFO [a-service,5200fdcfecb89f02,5200fdcfecb89f02,false] 71819 --- [nio-8001-exec-6] c.s.cloud.poc.a.ResourceServerConfig : Exchanging the opaque token, 1b255221-59c6-480f-8783-22bc2a900c28 for a JWT
2017-06-27 10:57:39.212 INFO [uaa-service,5200fdcfecb89f02,c25dd461eeed1046,false] 71818 --- [nio-9191-exec-9] c.s.c.p.u.r.TokenExchangeRestController : Giving the JWT for [email protected]
2017-06-27 10:57:39.219 INFO [a-service,5200fdcfecb89f02,5200fdcfecb89f02,false] 71819 --- [nio-8001-exec-6] c.s.cloud.poc.a.SampleRestController : The jwt is eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJyZWZyZXNoX3Rva2VuX2V4cGlyZXNfaW4iOjI1OTIwMDAsInVzZXJfbmFtZSI6ImZvb0B5YWhvby5jb20iLCJzY29wZSI6WyJyZWFkIiwid3JpdGUiXSwidXNlcl9ndWlkIjoiNTc0NTk5N2MtMDZmMy00ZDMwLThiYjUtNjliYjE5MzNhMjdmIiwiZXhwIjoxNDk4NjI5NDQzLCJhdXRob3JpdGllcyI6WyJST0xFX0JVWUVSIiwiUk9MRV9VU0VSIiwiUk9MRV9TRUxMRVIiXSwianRpIjoiMWIyNTUyMjEtNTljNi00ODBmLTg3ODMtMjJiYzJhOTAwYzI4IiwiY2xpZW50X2lkIjoid2ViIn0.L2Q_1M3d5lntvATq52YlbbstnErEAnKIzUU2gQVl1rbhR3uI6IBy6WqLwjGJmizw8rx4IiUAWvMkeYzsF3GxpBEh4fJDonUaqVZDoIOtzj7ntaE121A4F43Y7chhsfVo5uX_2EkNUpTIBemLo3Jeknnb2bGdNKgLmlQ2-nEgC1c
2017-06-27 10:57:39.228 INFO [b-service,5200fdcfecb89f02,2e0742648c2b1533,false] 71820 --- [nio-8002-exec-3] c.s.cloud.poc.b.SampleRestController : The jwt is eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJyZWZyZXNoX3Rva2VuX2V4cGlyZXNfaW4iOjI1OTIwMDAsInVzZXJfbmFtZSI6ImZvb0B5YWhvby5jb20iLCJzY29wZSI6WyJyZWFkIiwid3JpdGUiXSwidXNlcl9ndWlkIjoiNTc0NTk5N2MtMDZmMy00ZDMwLThiYjUtNjliYjE5MzNhMjdmIiwiZXhwIjoxNDk4NjI5NDQzLCJhdXRob3JpdGllcyI6WyJST0xFX0JVWUVSIiwiUk9MRV9VU0VSIiwiUk9MRV9TRUxMRVIiXSwianRpIjoiMWIyNTUyMjEtNTljNi00ODBmLTg3ODMtMjJiYzJhOTAwYzI4IiwiY2xpZW50X2lkIjoid2ViIn0.L2Q_1M3d5lntvATq52YlbbstnErEAnKIzUU2gQVl1rbhR3uI6IBy6WqLwjGJmizw8rx4IiUAWvMkeYzsF3GxpBEh4fJDonUaqVZDoIOtzj7ntaE121A4F43Y7chhsfVo5uX_2EkNUpTIBemLo3Jeknnb2bGdNKgLmlQ2-nEgC1c
2017-06-27 10:57:39.237 INFO [c-service,5200fdcfecb89f02,dd8f9d32641a6c45,false] 71821 --- [nio-8003-exec-3] c.s.cloud.poc.c.SampleRestController : The jwt is eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJyZWZyZXNoX3Rva2VuX2V4cGlyZXNfaW4iOjI1OTIwMDAsInVzZXJfbmFtZSI6ImZvb0B5YWhvby5jb20iLCJzY29wZSI6WyJyZWFkIiwid3JpdGUiXSwidXNlcl9ndWlkIjoiNTc0NTk5N2MtMDZmMy00ZDMwLThiYjUtNjliYjE5MzNhMjdmIiwiZXhwIjoxNDk4NjI5NDQzLCJhdXRob3JpdGllcyI6WyJST0xFX0JVWUVSIiwiUk9MRV9VU0VSIiwiUk9MRV9TRUxMRVIiXSwianRpIjoiMWIyNTUyMjEtNTljNi00ODBmLTg3ODMtMjJiYzJhOTAwYzI4IiwiY2xpZW50X2lkIjoid2ViIn0.L2Q_1M3d5lntvATq52YlbbstnErEAnKIzUU2gQVl1rbhR3uI6IBy6WqLwjGJmizw8rx4IiUAWvMkeYzsF3GxpBEh4fJDonUaqVZDoIOtzj7ntaE121A4F43Y7chhsfVo5uX_2EkNUpTIBemLo3Jeknnb2bGdNKgLmlQ2-nEgC1c
The spring-security-oauth2 based uaa-service, tries to mimic our identity server by issuing “opaque tokens” instead of JWT. This is a throw away work, since we have got an identity server already. But it was still worth investigating to learn the possibilities with this framework. It took a bit of traveling through the spring-securtity-oauth2 code to figure some of these out, because spring-security-oauth2 does not by default give an opaque token for a JWT.
The primary work in this POC are for supporting opaque tokens, embed custom claims within the JWT and protect the resources under the server itself.
Coming to the point, the uaa-service has got primarily the following endpoints in it
POST /uaa/oauth/token- generate access tokens and refresh tokens based on the grant_type(client_credentials, password). The tokens will have scopes and roles associated to them. Roles are associated to the user, where as scopes is defined as a part of authorized clients. For configurations check AuthServerConfigurationGET /uaa/token/exchange- exchanges the opaque token from theAuthorization: Bearerfor the authenticated JWT. Normally used by the AuthN resource servers to exchange opaque tokens with their associated JWT. Check TokenExchangeRestControllerPOST uaa/oauth/check_token- gives out the claims map associated with a token; protected with Basic auth--user web:secretGET /uaa/oauth/token_key- gives out the public key for verifying the JWT signature
Check UserServiceRestController
POST /uaa/user/create- creates users for whom you can specify the roles from an enumeration of ROLE_ADMIN, ROLE_SELLER, ROLE_BUYER, ROLE_CS, ROLE_USER. Use the access token generated with thegrant_type=client_credentials.GET /uaa/user- self lookup which shows user details and the associated roles; protected by RBAC and scopeGET /uaa/user/{guid}- self or proxy lookup protected by an RBAC policyPUT /uaa/user/update/{guid}– updates the user details including the associated roles
Note - The opaque tokens are stored in memory cache and by default the user details are stored in the H2, which can be moved to oracle.
The resource servers are based on spring-mvc and spring-security-oauth2. They try to implement 'AuthN' mechanism with some minimum customization/configurations. The challenging part is that the documentation is all over the place and very generic, you have to dig through the code for figuring out some of the customizations. But like any other spring project, spring-security-oauth2 comes with a lot of hooks to latch on and customize to our needs.
The resource server configuration support
- Awareness of opaque tokens on the Authorization header - the same will be exchanged with a JWT on entry
- Acceptance of JWT on the Authorization header
- Token relay using OAuth2RestTemplate + Hystrix
- Token relay while client side load-balancing using FeignClient + Hystrix + Ribbon
- Expression-based access control
Following are the some of the customizations done in order to secure the spring-mvc endpoints and conduct the token relay.
- Setting up a ResourceServerTokenServices which would exchange the opaque token for a JWT. If the token in the JWT format, it won't make this exchange call.
- A custom OAuth2ClientContext with a line of code to override the default behavior – This is to work around a flaw with the default setup that flops while using Hystrix. Hystrix wraps the calls outbound in its own threads/callables and the request attributes and security context has to be shared appropriately. I am working on a PR to fix this issue.
- A custom AccessTokenConverter to add all the additional claims into the OAuth2Authentication as additional details.
All the resource server configurations can be found in the ResourceServerConfig and on the application.yml .
Spring security gives the ability to use SpEL expressions as an access control mechanism which allows us to encapsulate complicated Boolean logic to be in a single expression. It comes with a dozen of built-in expressions and more over allows us to write custom expressions. Some of this capabilities are used in this project and can be found under