This will be a 3 post series exploring ways to enable SSO with an OAuth2 provider for Spring Boot 2 based applications. I will cover the following in these posts:
1. Ways to bootstrap an OpenID Connect compliant OAuth2 Authorization Server/OpenID Provider.
2. Legacy Spring Boot/Spring 5 approach to integrating with an OAuth2 Authorization Server/OpenID Provider.
3. Newer Spring Boot 2/Spring 5 approach to integrating with an OAuth2 Authorization Server/OpenID Provider.
This post will cover ways to bootstrap an OpenID Connect compliant OAuth2 Authorization Server running on a local machine.
The post is essentially a rehash of an earlier post which went into details of bootstrapping an OAuth2 authorization server using the excellent Cloud Foundry UAA project. There are a few changes since my previous post and I wanted to capture afresh the steps to bring up an Authorization server with a little more emphasis on changes to make it OpenID Connect compliant.
The best way to get a local version of a robust OAuth2 Authorization server running is to use the excellent Cloud Foundry UAA project.
Step 1: Clone the project:
git clone https://github.com/cloudfoundry/uaa
Step 2: Generate a keypair
UAA can make use of an asymmetric RSA keypair for signing and let clients verify the signature. I have a handy script available here which generates a keypair and generates a configuration file that can used for bootstrapping UAA:
When run this executes a UAA configuration which looks like this:
jwt:
token:
signing-key: |
-----BEGIN RSA PRIVATE KEY-----
MIIEpAIBAAKCAQEAuE5Ds...5Nka1vOTnjDgKIfsN
NTAI25qNNCZOXXnGp71gMWsXcLFq4JDJTovL4/rzPIip/1xU0LjFSw==
-----END RSA PRIVATE KEY-----
verification-key: |
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuE5DsCmjfvWArlCIOL6n
ZwIDAQAB
-----END PUBLIC KEY-----Step 3: Use the configuration to start up the UAA server:
UAA_CONFIG_URL=file://$PWD/uaa_config.yml ./gradlew run
Step 4: Validate
A quick way to validate if the UAA has started up is to check the JWKS_URI, this is an endpoint which exposes the set of verification keys that a client can use to validate the token. For UAA, this is available at “/token_keys” endpoint, with either curl or httpie this endpoint can be validated:
http GET http://localhost:8080/uaa/token_keys # OR curl http://localhost:8080/uaa/token_keys
if things are configured okay, an output of the following form is expected from this endpoint:
{
"keys": [
{
"alg": "RS256",
"e": "AQAB",
"kid": "legacy-token-key",
"kty": "RSA",
"n": "APLeBV3dcUrWuVEXRyFzNaOTeKOLwFjscxbWFGofCkxrp3r0nRbBBb4ElG4qYzmbStg5o-zXAPCOu7Pqy2j4PtC3OxLHWnKsflNOEWTeXhLkPE0IptHPbc6zgVPP3EoiG_umpm0BYeJPZZc-7tA11uU_3NqidY9wnpOgKBuwNmdoyUrjb4fBDoMr_Wk2_sn_mtHSG8HaX8eJ9SbC9xRCJySjJDApOYR_dKjuwpbcM2ITfbTzD9M2J7yOtoJRkFhd1Ug2t_6AA_z47BBws-x9BBfSNbYGsVlDAbe6NK_jUE",
"use": "sig",
"value": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA8t4FXd1xSta5URdHIXM1\no5N4o4vAWOxzFtYUah8KTGunevSdFsEFvgSUbipjOZtK2Dmj7NcA8I67s+rLaPg+\n0Lc7Esdacqx+U04RZN5eEuQ8TQim0c9tzrOBU8/cSiIb+6ambQF62glGQWF3VSDa3/oAD/PjsEHCz7H0EF9I1tgaxWUMBt7o0r+N\nQQIDAQAB\n-----END PUBLIC KEY-----"
}
]
}Step 5: Populate Data
UAA has a companion CLI application called uaac, available here. Assuming that you have the uaac cli downloaded and UAA started up at its default port of 8080, let us start by pointing the uaac to the uaa application:
uaac target http://localhost:8080/uaa
and log into it using one of the canned client credentials(admin/adminsecret):
uaac token client get admin -s adminsecret
Now that a client has logged in, the token can be explored using :
uaac token decode
which should display the details of the logged in client:
jti: 4457847692b7464ca0320f08271a9e98 sub: admin authorities: clients.read clients.secret clients.write uaa.admin clients.admin scim.write scim.read scope: clients.read clients.secret clients.write uaa.admin clients.admin scim.write scim.read client_id: admin cid: admin azp: admin grant_type: client_credentials rev_sig: 3c12911 iat: 1518332992 exp: 1518376192 iss: http://localhost:8080/uaa/oauth/token zid: uaa
the raw jwt token can be obtained using the following command:
uaac context
with an output which looks like this:
[3]*[http://localhost:8080/uaa]
skip_ssl_validation: true
[2]*[admin]
client_id: admin
access_token: eyJhbGciOiJSUzI1NiIsImtpZCI6ImxlZ2FjeS10b2tlbi1rZXkiLCJ0eXAiOiJKV1QifQ.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.ZEcUc4SvuwQYwdE0OeG5-l8Jh1HsP0JFI3aCob8A1zOcGOGjqso4j1-k_Lzm__pGZ702v4_CkoXOBXoqaaRbfVgJybBvOWbWsUZupMVMlEsyaR_j8DWY8utFAIiN2EsQgjG3qLrsf0K8lm0I3_UIEjaNZhSkWSLDLyY9wr_2SRanSf8LkcEJoSTTgDdO0aP8MvwNpDG7iQ2Om1HZEN08Bed1hHj6e1E277d9Kw7gutgCBht5GZDPFnI6Rjn0O5wimgrAa6FEDjdCpR7hy2P5RiOTcTvjj3rXtVJyVcQcxGKymZrY2WOx1mIEzEIAj8NYlw0TLuSVVOiNZ9fKlRiMpw
token_type: bearer
expires_in: 43199
scope: clients.read clients.secret clients.write uaa.admin clients.admin scim.write scim.read
jti: 4457847692b7464ca0320f08271a9e98Finally to add a client with creds of client1/client1 and a user with a creds of user1/user1:
uaac client add client1 \ --name client1 \ --scope resource.read,resource.write,openid \ -s client1 \ --authorized_grant_types authorization_code,refresh_token,client_credentials,password \ --authorities uaa.resource \ --redirect_uri http://localhost:8888/** # Add a user called user1/user1 uaac user add user1 -p user1 --emails user1@user1.com # Add two scopes resource.read, resource.write uaac group add resource.read uaac group add resource.write # Assign user1 both resource.read, resource.write scopes.. uaac member add resource.read user1 uaac member add resource.write user1
At this point we have a working Authorization Server with a sample client and a sample user available. The subsequent posts will make use of this data to enable authentication for a Sample Spring Boot2 application. I will update the links in this post as I complete the newer posts.
| Published on Java Code Geeks with permission by Biju Kunjummen, partner at our JCG program. See the original article here: Spring Boot 2 Applications and OAuth 2 – Setting up an Authorization Server Opinions expressed by Java Code Geeks contributors are their own. |
