auth

Overview ¶

Package auth provides authentication related filters.

Basic - Check Basic Authentication ¶

The filter accepts two parameters, the first mandatory one is the path to the htpasswd file usually used with Apache or nginx. The second one is the optional realm name that will be displayed in the browser. Each incoming request will be validated against the password file, for more information which formats are currently supported check "https://github.com/abbot/go-http-auth". Assuming that the MD5 version will be used, new entries can be generated like

htpasswd -nbm myName myPassword

Embedding the filter in routes:

generic: * -> basicAuth("/path/to/htpasswd") -> "https://internal.example.org";

myRealm: Host("my.example.org")
  -> basicAuth("/path/to/htpasswd", "My Website")
  -> "https://my-internal.example.org";

OAuth2 - Check Bearer Tokens ¶

The auth filter takes the incoming request, and tries to extract the Bearer token from the Authorization header. Then it validates against a configured service. Depending on the settings, it also can check if the owner of the token belongs to a specific OAuth2 realm, and it can check if it has at least one of the predefined scopes. If any of the expectations are not met, it doesn't forward the request to the target endpoint, but returns with status 401.

OAuth2 - Provider Configuration - Tokeninfo ¶

To enable OAuth2 tokeninfo filters you have to set the CLI argument -oauth2-tokeninfo-url=<OAuthTokeninfoURL>. Scopes and key value pairs depend on the OAuth2 tokeninfo provider. AccessTokens has to be accepted by your OAuth2 provider's TokeninfoURL. Filter names starting with oauthTokeninfo will work on the returned data from TokeninfoURL. The request from skipper to TokeninfoURL will use the `Authorization: Bearer <access_token>` Header to do the request.

Additionally, you can also pass CLI argument -oauth2-tokeninfo-timeout=<OAuthTokeninfoTimeout> to control the default timeout duration for OAuth validation request. The default tokeninfo timeout is 2s.

Example json output of the tokeninfo response could be:

{
  "access_token": "<mytoken>",
  "client_id": "ztoken",
  "cn": "Jane Doe",
  "expires_in": "300",
  "grant_type": "password",
  "realm": "/employees",
  "scope": [
    "uid",
    "foo-r",
    "bar-w",
    "qux-rw"
  ],
  "token_type": "Bearer",
  "uid": "jdoe"
}

OAuth2 - oauthTokeninfoAnyScope filter ¶

The filter oauthTokeninfoAnyScope allows access if one of the scopes is satisfied by the request.

a: Path("/a") -> oauthTokeninfoAnyScope("uid") -> "https://internal.example.org/";
b: Path("/b") -> oauthTokeninfoAnyScope("uid", "bar") -> "https://internal.example.org/";

OAuth - oauthTokeninfoAllScope() filter ¶

The filter oauthTokeninfoAllScope allows access if all of the scopes are satisfied by the request:

a: Path("/a") -> oauthTokeninfoAllScope("uid") -> "https://internal.example.org/";
b: Path("/b") -> oauthTokeninfoAllScope("uid", "bar") -> "https://internal.example.org/";

OAuth - oauthTokeninfoAnyKV() filter ¶

The filter oauthTokeninfoAnyKV allows access if the token information returned by OAuthTokeninfoURL has the given key and the given value.

The following route has a filter definition, that one of the keys "uid" or "foo" has the value "jdoe" or "bar". Additionally the second will check if there is a "realm" "/employees":

a: Path("/") -> oauthTokeninfoAnyKV("uid", "jdoe", "foo", "bar") -> "https://internal.example.org/";

b: Path("/") -> oauthTokeninfoAnyKV("realm","/employees", "uid", "jdoe", "foo", "bar") -> "https://internal.example.org/";

The same as route `a` above, but you also allow "uid=mstar" to access:

a: Path("/") -> oauthTokeninfoAnyKV("uid", "jdoe", "uid", "mstar") -> "https://internal.example.org/";

Example json output of this tokeninfo response:

{
  "access_token": "<mytoken>",
  "client_id": "ztoken",
  "cn": "Jane Doe",
  "expires_in": "300",
  "grant_type": "password",
  "realm": "/employees",
  "scope": [
    "uid",
    "foo-r",
    "bar-w",
    "qux-rw"
  ],
  "token_type": "Bearer",
  "uid": "jdoe"
}

OAuth - oauthTokeninfoAllKV() filter ¶

The filter oauthTokeninfoAllKV allows access if the token information returned by OAuthTokeninfoURL has the given key and the given value.

The following route has a filter definition, that will check if all of the key value pairs match. Here "uid" has to have the value "jdoe" and "foo" has to have the value "bar". Additionally the second will check if there is a "realm" "/employees":

a: Path("/") -> oauthTokeninfoAllKV("uid", "jdoe", "foo", "bar") -> "https://internal.example.org/";
b: Path("/") -> oauthTokeninfoAllKV("realm", "/employees", "uid", "jdoe", "foo", "bar") -> "https://internal.example.org/";

Example json output of this information response:

{
  "access_token": "<mytoken>",
  "client_id": "ztoken",
  "cn": "John Doe",
  "expires_in": "300",
  "grant_type": "password",
  "foo": "bar",
  "realm": "/employees",
  "scope": [
    "uid",
    "foo-r",
    "bar-w",
    "qux-rw"
  ],
  "token_type": "Bearer",
  "uid": "jdoe"
}

In case you are using any of the above 4 filters in your custom build, you can call the `Close()` method to close the `quit` channel and free up goroutines, to avoid goroutine leak

OAuth2 - Provider Configuration - Tokenintrospection ¶

Provider configuration is dynamically done by https://tools.ietf.org/html/draft-ietf-oauth-discovery-06#section-5, which means a GET /.well-known/openid-configuration to the issuer URL. Skipper will use the `introspection_endpoint` to configure the target to query for information and use `claims_supported` to validate valid filter configurations.

Example response from the openid-configuration endpoint:

{
  "issuer"                : "https://issuer.example.com",
  "token_endpoint"        : "https://issuer.example.com/token",
  "introspection_endpoint": "https://issuer.example.com/token/introspect",
  "revocation_endpoint"   : "https://issuer.example.com/token/revoke",
  "authorization_endpoint": "https://issuer.example.com/login",
  "userinfo_endpoint"     : "https://issuer.example.com/userinfo",
  "jwks_uri"              : "https://issuer.example.com/token/certs",
  "response_types_supported": [
    "code",
    "token",
    "id_token",
    "code token",
    "code id_token",
    "token id_token",
    "code token id_token",
    "none"
  ],
  "subject_types_supported": [
    "public"
  ],
  "id_token_signing_alg_values_supported": [
    "RS256"
  ],
  "scopes_supported": [
    "openid",
    "email",
    "profile"
  ],
  "token_endpoint_auth_methods_supported": [
    "client_secret_post",
    "client_secret_basic"
  ],
  "claims_supported": [
    "aud",
    "email",
    "email_verified",
    "exp",
    "family_name",
    "given_name",
    "iat",
    "iss",
    "locale",
    "name",
    "picture",
    "sub"
  ],
  "code_challenge_methods_supported": [
    "plain",
    "S256"
  ]
}

Additionally, you can also pass CLI argument -oauth2-tokenintrospect-timeout=<OAuthTokenintrospectTimeout> to control the default timeout duration for OAuth validation request. The default tokenintrospect timeout is 2s.

All oauthTokenintrospection* filters will work on the tokenintrospect response.

Example json output of the tokenintrospect response could be:

{
  "access_token": "<mytoken>",
  "client_id": "ztoken",
  "name": "Jane Doe",
  "expires_in": "300",
  "grant_type": "password",
  "active": true,
  "sub": "a-sub",
  "iss": "https://issuer.example.com"
  "realm": "/employees",
  "claims": {
    "uid": "jdoe",
    "email": "jdoe@example.com"
  },
  "scope": [
    "email",
    "foo-r",
  ],
  "token_type": "Bearer",
}

OAuth2 - oauthTokenintrospectionAnyClaims filter ¶

The filter oauthTokenintrospectionAnyClaims can be configured with claims validated from the openid-configuration `claims_supported` and will use the `introspection_endpoint` endpoint to query for the token information.

The filter oauthTokenintrospectionAnyClaims allows access if the token information has at least one of the claims in the token as configured in the filter.

The following route has a filter definition, that will check if there is one of the following claims in the token: "uid" or "email":

a: Path("/") -> oauthTokenintrospectionAnyClaims("https://issuer.example.com", "uid", "email") -> "https://internal.example.org/";

OAuth2 - oauthTokenintrospectionAllClaims filter ¶

The filter oauthTokenintrospectionAllClaims can be configured with claims validated from the openid-configuration `claims_supported` and will use the `introspection_endpoint` endpoint to query for the token information.

The filter oauthTokenintrospectionAllClaims allows access if the token information has at least one of the claims in the token as configured in the filter.

The following route has a filter definition, that will check if there all of the following claims in the token: "uid" and "email":

a: Path("/") -> oauthTokenintrospectionAllClaims("https://issuer.example.com", "uid", "email") -> "https://internal.example.org/";

OAuth2 - oauthTokenintrospectionAnyKV filter ¶

The filter oauthTokenintrospectionAnyKV will use the `introspection_endpoint` endpoint from the openid-configuration to query for the token information.

The filter oauthTokenintrospectionAnyKV allows access if the token information has at least one of the key-value pairs in the token as configured in the filter.

The following route has a filter definition, that will check if there one of the following key-value pairs in the token: "uid=jdoe" or "iss=https://issuer.example.com":

a: Path("/") -> oauthTokenintrospectionAnyKV("https://issuer.example.com", "uid", "jdoe", "iss", "https://issuer.example.com") -> "https://internal.example.org/";

The same as route `a` above, but you also allow "uid=mstar" to access:

a: Path("/") -> oauthTokenintrospectionAnyKV("https://issuer.example.com", "uid", "jdoe", "uid", "mstar", "iss", "https://issuer.example.com") -> "https://internal.example.org/";

OAuth2 - oauthTokenintrospectionAllKV filter ¶

The filter oauthTokenintrospectionAllKV will use the `introspection_endpoint` endpoint from the openid-configuration to query for the token information.

The filter oauthTokenintrospectionAnyKV allows access if the token information has all of the key-value pairs in the token as configured in the filter.

The following route has a filter definition, that will check if there are all of the following key-value pairs in the token: "uid=jdoe" or "iss=https://issuer.example.com":

a: Path("/") -> oauthTokenintrospectionAllKV("https://issuer.example.com", "uid", "jdoe", "iss", "https://issuer.example.com") -> "https://internal.example.org/";

OpenID - oauthOidcUserInfo filter ¶

The filter oauthOidcUserInfo is a filter for OAuth Implicit Flow authentication of users through OpenID Connect. It verifies that the token provided by the user upon authentication contains all the fields specified in the filter.

a: Path("/") -> oauthOidcUserInfo("https://accounts.identity-provider.com", "some-client-id", "some-client-secret",
	"http://callback.com/auth/provider/callback", "scope1 scope2", "field1 field2") -> "https://internal.example.org";

OpenID - oauthOidcAnyClaims filter ¶

The filter oauthOidcAnyClaims is a filter for OAuth Implicit Flow authentication scheme for users through OpenID Connect. It verifies that the token provided by the user upon authentication with the authentication provider contains at least one of the claims specified in the filter.

a: Path("/") -> oauthOidcAnyClaims("https://accounts.identity-provider.com", "some-client-id", "some-client-secret",
	"http://callback.com/auth/provider/callback", "scope1 scope2","claim1 claim2 claim3") -> "https://internal.example.org";

OpenID - oauthOidcAllClaims filter The filter oauthOidcAnyClaims is a filter for OAuth Implicit Flow authentication scheme for users through OpenID Connect. It verifies that the token provided by the user upon authentication with the authentication provider contains all of the claims specified in the filter.

a: Path("/") -> oauthOidcAllClaims("https://accounts.identity-provider.com", "some-client-id", "some-client-secret",
"http://callback.com/auth/provider/callback", "scope1 scope2", "claim1 claim2") -> "https://internal.example.org";

OAuth - auditLog() filter ¶

The filter auditLog allows you to have an audit log for all requests. This filter should be always set, before checking with auth filters. To see only permitted access, you can set the auditLog() filter after the auth filter.

a: Path("/only-allowed-audit-log") -> oauthTokeninfoAnyScope("bar-w") -> auditLog() -> "https://internal.example.org/";
b: Path("/all-access-requests-audit-log") -> auditLog() -> oauthTokeninfoAnyScope("foo-r") -> "https://internal.example.org/";

Webhook - webhook() filter ¶

The filter webhook allows you to have a custom authentication and authorization endpoint for a route. Headers from the webhook response can be copied into the continuing request by specifying the headers to copy as an optional second argument to the filter

a: Path("/only-allowed-by-webhook") -> webhook("https://custom-webhook.example.org/auth") -> "https://protected-backend.example.org/";
b: Path("/copy-webhook-headers") -> webhook("https://custom-webhook.example.org/auth", "X-Copy-This-Header") -> "https://protected-backend.example.org/";

Forward Token - forwardToken() filter ¶

The filter is used to forward the result of token introspection or token info to the backend.

a: Path("/tokeninfo-protected") -> oauthTokeninfoAnyScope("uid") -> forwardToken("X-Tokeninfo-Forward") -> "https://internal.example.org";
b: Path("tokenintrospection-protected") -> oauthTokenintrospectionAnyKV("uid") -> forwardToken("X-Tokenintrospection-Forward") -> "http://internal.example.org";