关于dubbo:聊聊dubbogo的ProviderAuthFilter

序

本文次要钻研一下 dubbo-go 的 ProviderAuthFilter

ProviderAuthFilter

dubbo-go-v1.4.2/filter/filter_impl/auth/provider_auth.go

type ProviderAuthFilter struct {
}

func init() {extension.SetFilter(constant.PROVIDER_AUTH_FILTER, getProviderAuthFilter)
}

• ProviderAuthFilter 的 init 办法设置了 getProviderAuthFilter

getProviderAuthFilter

dubbo-go-v1.4.2/filter/filter_impl/auth/provider_auth.go

func getProviderAuthFilter() filter.Filter {return &ProviderAuthFilter{}
}

• getProviderAuthFilter 实例化了 ProviderAuthFilter

Invoke

dubbo-go-v1.4.2/filter/filter_impl/auth/provider_auth.go

func (paf *ProviderAuthFilter) Invoke(ctx context.Context, invoker protocol.Invoker, invocation protocol.Invocation) protocol.Result {logger.Infof("invoking providerAuth filter.")
    url := invoker.GetUrl()

    err := doAuthWork(&url, func(authenticator filter.Authenticator) error {return authenticator.Authenticate(invocation, &url)
    })
    if err != nil {logger.Infof("auth the request: %v occur exception, cause: %s", invocation, err.Error())
        return &protocol.RPCResult{Err: err,}
    }

    return invoker.Invoke(ctx, invocation)
}

• Invoke 办法通过 doAuthWork 来进行 auth，其传递的 func 执行 authenticator.Authenticate(invocation, &url)

OnResponse

dubbo-go-v1.4.2/filter/filter_impl/auth/default_authenticator.go

func (paf *ProviderAuthFilter) OnResponse(ctx context.Context, result protocol.Result, invoker protocol.Invoker, invocation protocol.Invocation) protocol.Result {return result}

• OnResponse 办法间接返回 result

doAuthWork

dubbo-go-v1.4.2/filter/filter_impl/auth/default_authenticator.go

func doAuthWork(url *common.URL, do func(filter.Authenticator) error) error {shouldAuth := url.GetParamBool(constant.SERVICE_AUTH_KEY, false)
    if shouldAuth {authenticator := extension.GetAuthenticator(url.GetParam(constant.AUTHENTICATOR_KEY, constant.DEFAULT_AUTHENTICATOR))
        return do(authenticator)
    }
    return nil
}

• doAuthWork 办法先从 url 读取 constant.SERVICE_AUTH_KEY 判断是否须要 auth，需要的话，则获取 authenticator，执行 do(authenticator)

Authenticate

dubbo-go-v1.4.2/filter/filter_impl/auth/default_authenticator.go

func (authenticator *DefaultAuthenticator) Authenticate(invocation protocol.Invocation, url *common.URL) error {accessKeyId := invocation.AttachmentsByKey(constant.AK_KEY, "")

    requestTimestamp := invocation.AttachmentsByKey(constant.REQUEST_TIMESTAMP_KEY, "")
    originSignature := invocation.AttachmentsByKey(constant.REQUEST_SIGNATURE_KEY, "")
    consumer := invocation.AttachmentsByKey(constant.CONSUMER, "")
    if IsEmpty(accessKeyId, false) || IsEmpty(consumer, false) ||
        IsEmpty(requestTimestamp, false) || IsEmpty(originSignature, false) {return errors.New("failed to authenticate your ak/sk, maybe the consumer has not enabled the auth")
    }

    accessKeyPair, err := getAccessKeyPair(invocation, url)
    if err != nil {return errors.New("failed to authenticate , can't load the accessKeyPair")
    }

    computeSignature, err := getSignature(url, invocation, accessKeyPair.SecretKey, requestTimestamp)
    if err != nil {return err}
    if success := computeSignature == originSignature; !success {return errors.New("failed to authenticate, signature is not correct")
    }
    return nil
}

• Authenticate 办法从 invocation 的 attachment 获取 requestTimestamp 及 originSignature，而后通过 getAccessKeyPair 从 accesskeyStorage.GetAccessKeyPair 获取 accessKeyPair，之后通过 getSignature 计算 signature，而后比照 computeSignature 与 originSignature 是否一样，不一样则返回 error

小结

ProviderAuthFilter 的 Invoke 办法通过 doAuthWork 来进行 auth，其传递的 func 执行 authenticator.Authenticate(invocation, &url)

doc

• provider_auth