WORK IN PROGRESS
Introduction: A1-PMS Compliance with O-RAN Specifications
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When integrating Istio with Keycloak for JWT-based authorization, the typical workflow involves clients obtaining a JWT (JSON Web Token) from Keycloak, which is then used to access services secured by Istio. Keycloak acts as an identity provider (IdP), issuing tokens that contain various claims about the authenticated user or client.
A JWT from Keycloak includes three parts: the header, payload, and signature. The payload carries the claims about the user or client, and it is used by Istio to make authorization decisions.
1. Header: This part of the token contains metadata about the token itself, such as the type of token and the signing algorithm used. For Keycloak, this often looks like:
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Client ID
The client_id is a common parameter in the payload of a JWT, particularly in tokens issued as part of OAuth 2.0 or OpenID Connect flows.
https://www.keycloak.org/docs-api/latest/rest-api/index.html#ApplicationRepresentation
Curl Examples:
Getting Admin Token
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curl -k -sS |
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--request POST \ |
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--url "http://$KEYCLOAK_HOST/auth/realms/$REALM_NAME/protocol/openid-connect/token" \ |
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--data client_id=$CLIENT_ID \ |
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--data username=$USERNAME \ |
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--data password=$PASSWORD \ |
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--data grant_type=password \ |
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--data scope=openid |
Getting Client Secret
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curl -k -sS |
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-X GET "http://$KEYCLOAK_HOST/auth/admin/realms/$REALM_NAME/clients/$CLIENT_ID/client-secret" \ |
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-H "Content-Type: application/json" \ |
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-H "Authorization: Bearer $ACCESS_TOKEN" |
Demo with tokens and clientId extraction for using it as serviceId
To generate a JWT token and parse a value from it demonstration.
Below, I'll outline the steps to achieve this, including generating a JWT, sending it in a request header, and then parsing a value (like `client_id`) from the JWT payload.
Generating a JWT Token using Bash
Note that this example is for educational purposes and doesn't include proper security practices like using secure keys.
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#!/bin/bash
header='{"alg": "HS256", "typ": "JWT"}'
payload='{"iss": "example_issuer", "sub": "1234567890", "aud": "myclient", "exp": 3000000000, "client_id": "myclient", "role": "user"}'
# Base64 encode the header and payload without padding
header_base64=$(echo -n "$header" | openssl base64 -e | tr -d '=' | tr '/+' '_-' )
payload_base64=$(echo -n "$payload" | openssl base64 -e -A | tr -d '=' | tr '/+' '_-')
# Create a signature
secret="mysecret"
signature_base64=$(echo -n "${header_base64}.${payload_base64}" | openssl dgst -sha256 -hmac "${secret}" -binary | openssl base64 -e | tr -d '=' | tr '/+' '_-')
# Combine to form the JWT
jwt="${header_base64}.${payload_base64}.${signature_base64}"
echo "$jwt" |
This script generates a JWT and prints it out. Replace "your-256-bit-secret" with a proper secret key.
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eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJleGFtcGxlX2lzc3VlciIsInN1YiI6IjEyMzQ1Njc4OTAiLCJhdWQiOiJteWNsaWVudCIsImV4cCI6MzAwMDAwMDAwMCwiY2xpZW50X2lkIjoibXljbGllbnQiLCJyb2xlIjoidXNlciJ9.O5QN_SWN4J1mWKyXk_-PCvOA6GF3ypv1rSdg2uTb_Ls |
Note: for the expiration time
$ ([DateTime]('1970,1,1')).AddSeconds(3000000000)
24 January 2065 05:20:00
Sending the JWT in a REST Request Header
You can use curl to send the JWT in a request header:
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curl -H "Authorization: Bearer $jwt" http://A1PMS/policy.. |
Parsing the JWT Payload in Java
Here's an example of how to parse the `client_id` from the JWT in Java:
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import java.util.Base64;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
public class ParseJWT {
public String parseServiceId(String token) {
// Split token into its parts
String[] chunks = token.split("\\.");
Base64.Decoder decoder = Base64.getUrlDecoder();
// Decode payload
String payload = new String(decoder.decode(chunks[1]));
// Parse JSON using Gson
JsonObject jsonObject = JsonParser.parseString(payload).getAsJsonObject();
// Extract the client_id
String clientId = jsonObject.get("client_id").getAsString();
return clientId;
}
} |
In the create policy code check if there is an header and if there is a clientId use it as serviceId, other cases are covered having default serviceId (If there is no header, if there is an header but not a clientId)
Policy Creation Scenario
In this example I want to log the Bearer Token given to the call: PUT
In Postman I use the generated token I got from the bash script as Bearer Token:
It would be equivalent to:
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curl -v -X 'PUT' 'http://localhost:8081/a1-policy/v2/policies' \
-H 'Content-Type: application/json' \
-H 'Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJleGFtcGxlX2lzc3VlciIsInN1YiI6IjEyMzQ1Njc4OTAiLCJhdWQiOiJteWNsaWVudCIsImV4cCI6MzAwMDAwMDAwMCwiY2xpZW50X2lkIjoibXljbGllbnQiLCJyb2xlIjoidXNlciJ9.O5QN_SWN4J1mWKyXk_-PCvOA6GF3ypv1rSdg2uTb_Ls' \
-d '
{
"ric_id": "ric1",
"policy_id": "aa8feaa88d944d919ef0e83f2172a51001",
"is_transient": true,
"service_id": "service-1",
"policy_data": {
"scope": {
"ueId": "ue5100",
"qosId": "qos5100"
},
"qosObjectives": {
"priorityLevel": 5100.0
}
},
"status_notification_uri": "http://callback-receiver:8090/callbacks/test",
"policytype_id": "1"
}' |
In org.onap.ccsdk.oran.a1policymanagementservice.controllers.v2.PolicyController
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private void logHeaders(ServerWebExchange exchange) {
HttpHeaders headers = exchange.getRequest().getHeaders();
String authHeader = headers.getFirst(HttpHeaders.AUTHORIZATION);
if (authHeader != null && authHeader.startsWith("Bearer ")) {
String token = authHeader.substring(7);
logger.info("Token: " + token);
logger.info("ServiceId: " + parseServiceId(token));
} else {
logger.info("Authorization header is missing or does not contain a Bearer token");
}
}
public String parseServiceId(String token) {
String[] chunks = token.split("\\.");
Base64.Decoder decoder = Base64.getUrlDecoder();
String payload = new String(decoder.decode(chunks[1]));
JsonObject jsonObject = JsonParser.parseString(payload).getAsJsonObject();
String clientId = jsonObject.get("client_id").getAsString();
return clientId;
} |
Output of the call:
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2024-07-30 13:32:55 2024-07-30 12:32:55.413 [INFO ] [http-nio-8081-exec-3] o.o.c.o.a.c.v.PolicyController - Token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJleGFtcGxlX2lzc3VlciIsInN1YiI6IjEyMzQ1Njc4OTAiLCJhdWQiOiJteWNsaWVudCIsImV4cCI6MzAwMDAwMDAwMCwiY2xpZW50X2lkIjoibXljbGllbnQiLCJyb2xlIjoidXNlciJ9.O5QN_SWN4J1mWKyXk_-PCvOA6GF3ypv1rSdg2uTb_Ls
2024-07-30 13:32:55 2024-07-30 12:32:55.415 [INFO ] [http-nio-8081-exec-3] o.o.c.o.a.c.v.PolicyController - ServiceId: myclient |
TODO and topic to follow
- Evaluate the necessity of optional fields: Determine if certain optional fields can be removed or if their use can be better documented to avoid dead data.
- Consider adopting more specific schemas for critical operations: This can improve both the documentation and the generated code quality. Leverage OpenAPI Features: Use OpenAPI's advanced features like `allOf`,
- Prepare for code adaptations: Implement patterns like Adapter/Builder/Transformer to handle translations between similar objects, facilitating easier maintenance and adaptation to specification changes.
- Regular compliance checks.
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