Recently I was building a thousand-piece puzzle with my girlfriend. Experienced puzzle builders have some techniques to finish the task successfully. For example, in the puzzle I built above with my girlfriend, we started by building the frame, then we gathered the pieces of trees, ground, castle and sky separately.
We built each block separately, then at the end we collected all the bigger blocks together to have our full puzzle. This is the same for software! However, a lot of the teams were still struggling with this approach. A single error in a small module could bring the entire solution down. Also, any update to any of the components meant that you would have to build the entire solution again.
There is no widely accepted definition for Microservices, but there is consensus about the characteristics. The graph above illustrates the structure of a typical microservice.
All of the microservices communicate through messaging. While a microservices architecture makes building software easier, managing the security of microservices has become a challenge. Managing the security of the traditional monolithic applications is quite different than managing the security of a microservices application. For example, in the monolithic application, it is easy to implement a centralized security module that manages authentication, authorization, and other security operations; with the distributed nature of microservices, having a centralized security module could impact efficiency and defeat the main purpose of the architecture.
Probably the most obvious approach to communicating with microservices from the external world is having an API Gateway. The API Gateway is the entry point to all the services that your application is providing. From the security point of view, API Gateways usually handle the authentication and authorization from the external callers to the microservice level.
While there is no one right approach to do this, I found using OAuth delegated authorization along with JSON Web Tokens JWT to be the most efficient and scalable solution for authentication and authorization for microservices. The microservice will then decide to either grant the user the resource if the user has the required permissions or not.
The approach above is much more scalable than the traditional centralized session management. It allows every individual microservice to handle the security of its own resources. If a centralized decision is needed, the OAuth server is there to share permissions with the different microservices.Here at Keyhole Software, we have implemented countless login and authentication approaches for applications, along with simple to sophisticated authorization schemes enforcing access control of applications.
However, these standards are not always utilized in enterprise environments. Many enterprises will have a single authentication mechanism that exploits a federated operating system network such as LDAP.
A login UI still has to be created and authorization rules still have to be applied to each application. Over the last few years, we have helped organizations transition away from monolithic-based applications to isolated microservice-based architectures.
With Microservices, authentication and authorization logic is now spread across many decoupled distributed processes. It was a bit simpler with monolithic architectures as only a single process is authenticated and contains access control rules defined. In this blog, we discuss a design pattern for authorization and authentication for use in a distributed microservices environment. When the browser-resident SPA authenticates i. A valid Access token can be a random unique opaque token that has no intrinsic meaning.
You could also implement a homegrown mechanism or existing credential access mechanism i. Two-factor authentication can also be introduced at this stage. A reasonable timeout request should be applied to this access token and is used by the SPA produced by the authentication service.
The access token is used only by the Auth service to validate access and will be replaced with a JWT token non-opaque for its journey to the downstream microservice infrastructure.
This approach keeps the JWT token away from browser client applications. This information could be some kind of OP code s that the Auth-Z mechanism stores and associates with a specific identified user i. The JWT should be very short-lived; ideally being valid just long enough to ensure it can traverse the entire transaction path multiple microservices could be involved.
Since the JWT token has encoded access and identity information, it can move from the API gateway through to the other service implementations, which can then apply and validate this information. Each service ie. Traditionally, enterprises will use some kind of symmetric key-based authorization when authenticating one server process talking to another service process. This means a single secret is provided to accessing processes.
Then, if this secret is ever compromised, it will be difficult to tell who the nefarious accessor is, forcing the secret to change and having to replace it on all participating entities i. This type of asymmetric authentication approach is built into server TLS transport layer security mechanisms where digital certificates are used to authenticate access, as well as support encrypted communication on the wire. That said, we believe the performance hit and management tasks are outweighed by a secure system.
However, it can be applied successfully with.
Microservices Authorization using Open Policy Agent and Traefik (API Gateway)
For ex. Also, it seems like every request to the server will require a hit on both the authentication data store to validate userand on the authorization data store to check permissions. Can you recommend any patterns for this that lightens the load on those data stores? For example, should the user information be cached to limit the number of database hits, or are there some patterns you could recommend?
Thanks for your question, let me give your check permissions questions a try. So our idea of an API gateway is that it is built for a given Application domain.
It would not be used by other applications. The JWT token will also be passed to the services responsible for data access and business logic… services can be reused across applications… and therefore API gateways…. If you have a requirement to apply role access to business logic and data access, then yes, roles defined in the JWT token will have to be applied at the service level. So, these roles should be enterprise-wide since the service are. So adding a new role-specific to a user of an application does not couple the service to this new role even though the role will be visible to the token.
Regarding your authorization question: When the user logs in successfully, an access token is returned to the UI and is used and validated on each request from the UI to the API gateway.
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We have not had performance issues with this process happening on each request, and yes, you can use caching, etc. Also, a token timeout is traditionally applied, requiring users to re-login after a certain amount of inactivity.Comment 3. This post was triggered by this Reddit post. We have the usual concerns about users in our application:.
Authentication itself is a fairly simple process. You need to authenticate a user, and that is one of those things that is generally such a common concern that you can take an off the shelve solution and go with that. Authorization is a lot more interesting. Note that we have three separate ways to ask the same question.
It might be better to give concrete examples about what I mean for each one of them. Can the user create a new order? Can they check the recent product updates, etc? Can the user view this order? Can they change the shipping address? Can the help desk guy check the status of an order for a particular customer?
In this case, we have a user that is explicitly doing an action on behalf on another user. We might allow it or notbut we almost always want to make a special note of this. The interesting thing about this kind of system is that there are very different semantics for each of those operations. That is important. And not just for the architectural purity of the system, one of the most common reasons for performance issues in systems is the cost of authorization checks.
If you make that go over the network, that is going to kill your system. Therefore, we need to consider how to enable proper encapsulation of concerns. An easy to do that is to have the client hold that state. In other words, as part off the authentication process, the client is going to get a token, which it can use for the next call s. Naturally, that state is not something that the client can modify, and is protected with cryptography.
A good example of that would be JWT. The authorization service generates a token with a key that is trusted by the other services. You can verify most authorization actions without leaving your service boundary. This is easy for operations such as creating a new order, but how do you handle authorization on a specific entity? Instead, you combine the allowed operations and the semantics of the operation itself. A more complex process is required when you have operations on behalf of others. This creates an audit trail of such actions and allows the authorization service to decide if a particular user should have the authority to act on behalf of a particular user.
See the original article here. Over a million developers have joined DZone. Let's be friends:. Authentication and Authorization in Microservice Architecture. DZone 's Guide to. Securing microservices can be hard due to their separation of concerns. Read on for advice on the subject from an expert dev. Free Resource. Like After authentication, ASP. This process allows a service to make APIs available to some authenticated users, but not to all.
Authorization can be done based on users' roles or based on custom policy, which might include inspecting claims or other heuristics. Restricting access to an ASP. NET Core MVC route is as easy as applying an Authorize attribute to the action method or to the controller's class if all the controller's actions require authorizationas shown in following example:.
By default, adding an Authorize attribute without parameters will limit access to authenticated users for that controller or action. To further restrict an API to be available for only specific users, the attribute can be expanded to specify required roles or policies that users must satisfy.
NET Core Identity has a built-in concept of roles. In addition to users, ASP. NET Core Identity stores information about different roles used by the application and keeps track of which users are assigned to which roles.
These assignments can be changed programmatically with the RoleManager type that updates roles in persisted storage, and the UserManager type that can grant or revoke roles from users. To limit access to an MVC action or controller to users in specific roles, you can include a Roles parameter in the Authorize annotation attributeas shown in the following code fragment:. To require a user be in multiple roles, you use multiple Authorize attributes, as shown in the following example:. Custom authorization rules can also be written using authorization policies.
This section provides an overview. For more information, see the ASP. NET Authorization Workshop. How to Secure Micro services - oAuth2 Server part 01 - [Micro services in and out 008]
Custom authorization policies are registered in the Startup. ConfigureServices method using the service. AddAuthorization method.
This method takes a delegate that configures an AuthorizationOptions argument. As shown in the example, policies can be associated with different types of requirements.Comment 4. Microservices architecture has been gaining a lot of ground as the preferred architecture for implementing solutions, as it provides benefits like scalability, logical and physical separation, small teams managing a part of the functionality, flexibility in technology, etc.
But since microservices are distributed the complexity of managing them increases. One of the key challenges is how to implement authentication and authorization in microservices so that we can manage security and access control. In this post, we will try to explore a few approaches that are available and see how we should implement them.
In my opinion, the third option is the best one, as most of the applications have a common authentication mechanism, thus global authentication makes perfect sense. Microservices can be accessed from multiple applications and clients and they might have different data needs so global authorization becomes a limiting factor on what each application can see.
With local authorization, microservices can make sure that the client application is only authorized to see what it needs to see. My organization implemented the same approach in one of the projects that we were working on recently. We built an authentication service that was mainly responsible for integration with the LDAP system for verifying the user and then contacting the RBAC Role-Based Access Control service to populate the permission matrix based on the role the user is playing in the context of the application, e.
So we need to understand the context from which the user is coming in and RBAC is the place where we decode the context and populate the relevant set of permissions.
The permission matrix was then sent to the microservice as a part of claims in the JWT token. Please see the below diagram to see how we orchestrate the flow.
See the original article here. Over a million developers have joined DZone. Let's be friends:. Authentication and Authorization in Microservices. DZone 's Guide to. We look into three basic patterns for adding authentication and authorization into microservices and what they imply for our microservice architecture at large. Free Resource. Like Join the DZone community and get the full member experience. Join For Free.
There are three approaches that we can follow: Local Authentication and Authorization Microservices are responsible for Authentication and Authorization Pros Different authentication mechanisms can be implemented for each microservice. Authorization can be more fine-grained Cons The code gets bulkier.
The probability of each service using different authentication is very low so code gets duplicated. The developer needs to know the permission matrix and should understand what each permission will do.
The probability of making mistakes is quite high. Global Authentication and Authorization It is an All or Nothing approach if the authorization for a service is there then it is accessible for all else none Pros Authentication and authorization so there's no repetition of code. A future change to the authentication mechanism is easy, as there's only one place to change the code.
Microservices' code is very light and focuses on business logic only. Cons Microservices have no control over what the user can access or not, and finer level permissions cannot be granted.Authentication and authorization in a microservices environment is non-trivial to implement correctly. This becomes especially true when identity and authorization controls are distributed across different applications.
There has been multiple cases where authorization controls implemented for one application was missed for another application with similar feature and data access resulting in a breach.
While OpenID Connect serves as an excellent standard for sharing verifiable user identity across microservices, we did not find a standard approach for enforcing authorization controls before a request hits a backend microservice. Additionally, we wanted to ensure that the ID Token is verified and authorization controls are enforced in the API Gateway itself before the request reaches a backend service. This allows us to create an architecture where authentication and authorization controls are enforced as a security gate for all backend microservices.
We present a solution along with a proof of concept implementation for the problem described above — To be able to perform authentication and authorization for microservices in the API Gateway itself. A complete proof of concept implementation for the solution presented in this article is available in our Github repository. To implement our requirements, we need two things.
While choosing OPA for  may be a no brainer for some, we selected it for our use-case due to. Traefik supports middleware for transforming or validating a request before it is forwarded to a backend service. Among them, the ForwardAuth middleware is particularly interesting for us as it delegates decision making to an external application.
For this use-case, we define a simple policy that authorizes requests based on path based microservice routing and role definition in JWT provided by the client. Refer to the proof of concept implementation for all technical details. The outcome is all requests passing through Traefik is authorized by our policy in OPA.
We have our API Gateway act as a security gate for the microservices infrastructure. Special thanks to Etermax Engineering blog for writing about their use-case. At Appsecco we provide advice, testing and training around software, infra, web and mobile apps, especially that are cloud hosted. We also specialise in auditing complex cloud native microservices infrastructure and help product teams secure the same by assisting with threat modelling and security architecture review.
D rop us an email, contact appsecco. Sign in. Abhisek Datta Follow. Hire Appsecco to help you secure your microservices infrastructure At Appsecco we provide advice, testing and training around software, infra, web and mobile apps, especially that are cloud hosted. Appsecco Making sense of application security for everyone.
Appsecco Follow. Write the first response. More From Medium. More on Devsecops from Appsecco. Riyaz Walikar in Appsecco. Abhisek Datta in Appsecco. Sunesh Govindaraj in Appsecco.A microservices architecture -- as the name implies -- is a complex coalition of code, databases, application functions and programming logic spread across servers and platforms.
Certain fundamental components of a microservices architecture bring all these entities together cohesively across a distributed system.
In this article, we review five key components of microservices architecture that developers and application architects need to understand if they plan to take the distributed service route. Start with microservices themselves, then learn about service mesh as an additional layer, app management via service discovery, container-based deployment and API gateways. Microservices make up the foundation of a microservices architecture.
The term illustrates the method of breaking down an application into generally small, self-contained serviceswritten in any language, that communicate over lightweight protocols.
With independent microservices, software teams can implement iterative development processes, as well as create and upgrade features flexibly.
Teams need to decide the proper size for microservices, keeping in mind that an overly granular collection of too-segmented services creates high overhead and management needs. Developers should thoroughly decouple services in order to minimize dependencies between them and promote service autonomy.
Containers are units of software that package services and their dependencies, maintaining a consistent unit through development, test and production. Containers are not necessary for microservices deployment, nor are microservices needed to use containers.
About authorization in .NET microservices and web applications
However, containers can potentially improve deployment time and app efficiency in a microservices architecture more so than other deployment techniques, such as VMs.
The major difference between containers and VMs is that containers can share an OS and middleware components, whereas each VM includes an entire OS for its use. By eliminating the need for each VM to provide an individual OS for each small service, organizations can run a larger collection of microservices on a single server.
The other advantage of containers is their ability to deploy on-demand without negatively impacting application performance. Developers can also replace, move and replicate them with fairly minimal effort. The independence and consistency of containers is a critical part of scaling certain pieces of a microservices architecture -- according to workloads -- rather than the whole application.
It also supports the ability to redeploy microservices in a failure. Docker, which started as an open-source platform for container management, is one of the most recognizable providers in the container space. However, Docker's success caused a large tooling ecosystem to evolve around it, spawning popular container orchestrators like Kubernetes. In a microservices architecture, the service mesh creates a dynamic messaging layer to facilitate communication. It abstracts the communication layerwhich means developers don't have to code in inter-process communication when they create the application.
Service mesh tooling typically uses a sidecar patternwhich creates a proxy container that sits beside the containers that have either a single microservice instance or a collection of services.
The sidecar routes traffic to and from the container, and directs communication with other sidecar proxies to maintain service connections.
Both Istio and Linkerd are tied to Kubernetes, though they feature notable differences in areas such as support for non-container environments and traffic control capabilities.
Whether it's due to changing workloads, updates or failure mitigation, the number of microservice instances active in a deployment fluctuate. It can be difficult to keep track of large numbers of services that reside in distributed network locations throughout the application architecture. Service discovery helps service instances adapt in a changing deployment, and distribute load between the microservices accordingly.
The service discovery component is made up of three parts:. Service discovery also consists of two major discovery patterns :. Data residing in the service registry should always be current, so that related services can find their related service instances at runtime.
If the service registry is down, it will hinder all the services, so enterprises typically use a distributed database, such as Apache ZooKeeper, to avoid regular failures.
Another important component of a microservices architecture is an API gateway. API gateways are vital for communication in a distributed architecture, as they can create the main layer of abstraction between microservices and the outside clients.
The API gateway will handle a large amount of the communication and administrative roles that typically occur within a monolithic application, allowing the microservices to remain lightweight.