Hacktoberfest 2026: los issues que los mantenedores marcaron para octubre, abiertos y aptos para principiantes. Explorar issues de Hacktoberfest

[Bug]: Merchant sample verifies checkout using embedded JWT without independent checkout-hash context

Abierto
  • ¿Algo no está bien?
#331 0 comentarios 0 reacciones 0 asignados Ver en GitHub

Nadie ha tomado este issue todavía.

Evaluación

Dificultad
3/5
Tiempo estimado
1-2 días
Aptitud para principiantes
56/100
Tipo de issue
Error
Claridad
Bien especificado
Estado de actividad
Activo
Stack tecnológico
python
Área
backend, payments, security

Línea de trabajo

Read code/sdk/python/ap2/sdk/checkout_mandate_chain.py around lines 44–125 and the merchant sample at code/samples/python/src/roles/merchant_agent_mcp/server.py around lines 872–944. Trace how expected_*_hash is checked during verification and how the sample continues processing decoded JWT data. Review the schema at code/sdk/schemas/ap2/*_mandate.json to understand the hash binding; done means verification binds the closed mandate to an independently expected hash before the sample uses its data.

Escrito por el modelo de indexación a partir del texto del issue.

Descripción

What happened?

Description

AP2 closed Checkout Mandates contain a merchant-signed checkout_jwt and a checkout_hash that binds the mandate to that checkout.

The Python SDK's CheckoutMandateChain.verify() accepts expected_checkout_hash as optional. If it is omitted, the SDK evaluates checkout constraints against the supplied checkout_jwt but does not check the closed mandate's checkout_hash against an independently expected checkout hash.

The Python Merchant MCP sample passes checkout_jwt=chain.closed_mandate.checkout_jwt but does not pass expected_checkout_hash. It then decodes that embedded JWT payload and continues checkout processing.

Impact

A merchant verifier can validate checkout constraints against checkout data carried inside the closed mandate, rather than binding the mandate to an independently created merchant checkout session.

This weakens the protection against manipulated or unrelated checkout data being used to complete an order.

Steps to Reproduce

  1. Review code/sdk/schemas/ap2/checkout_mandate.json:20-28. checkout_jwt is the merchant-signed checkout payload, and checkout_hash uniquely identifies that JWT.

  2. Review code/sdk/python/ap2/sdk/checkout_mandate_chain.py:44-100. expected_checkout_hash is optional and checkout_hash is checked only when that value is provided.

  3. Review code/sdk/python/ap2/sdk/checkout_mandate_chain.py:112-125. The SDK extracts checkout data by decoding the JWT payload.

  4. Review code/samples/python/src/roles/merchant_agent_mcp/server.py:872-883. The Merchant sample verifies the checkout mandate using checkout_jwt from the closed mandate, without passing expected_checkout_hash.

  5. Review code/samples/python/src/roles/merchant_agent_mcp/server.py:900-944. The sample decodes the embedded checkout JWT payload and continues checkout processing from that data.

Relevant log output
Code of Conduct
  • I agree to follow this project's Code of Conduct
Lenguaje dominante
Python
Estrellas
3.2k
Forks
514
Sin PR fusionados en 30 d

Preparar el entorno

Este proyecto no incluye contenedor de desarrollo, Dockerfile ni guía de contribución, así que la configuración corre por tu cuenta: empieza por su README y consulta nuestra guía para la primera contribución para los pasos generales.

Primeros pasos

  1. Lee el issue completo y luego la guía de contribución del proyecto.
  2. Comenta en el issue que vas a ocuparte — evita que dos personas hagan lo mismo.
  3. Haz un fork del repositorio y trabaja en una rama.
  4. Abre un pull request que haga referencia al número del issue.

Más de google-agentic-commerce/AP2

Todos los issues de google-agentic-commerce/AP2

Issues similares

Más issues de Python

Recibe los nuevos issues en tu correo

Un resumen breve de issues de GitHub para principiantes.