API Security Fundamentals: Everything You Need to Know | Dreamfactory

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Diagram showing API security fundamentals

You've probably heard of the Internet of Things (IoT); all those everyday objects that incorporate computing functions. For example, the IoT allows you to connect your phone to your refrigerator. This way, you can know exactly what to buy at the supermarket for that impromptu dinner that night. Perhaps you're part of a DevOps team, using microservices and containers to build and deploy legacy and cloud-native applications quickly and iteratively. APIs are one of the most common methods of communication between microservices and containers, as are systems and applications. But have you considered some API security fundamentals?

Here's the key things to know about API Security fundamentals:

  • API security is crucial for protecting sensitive data and preventing data leaks.
  • REST and SOAP are two common web API architectures, each with its security considerations.
  • REST APIs rely on HTTPS and token-based authentication, while SOAP APIs offer built-in security features.
  • GraphQL, an open-source API language, allows flexible data requests, posing unique security challenges.
  • Mitigating GraphQL security risks involves query throttling, depth limits, and query timeouts.

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Why is API security important?

Companies use APIs to connect services and transfer data. The most significant data leaks are due to faulty, vulnerable, or hacked APIs, as these can reveal sensitive medical, financial, and personal data to the general public. That said, not all data is created equal and does not require the same level of protection. Your API security strategy should depend on the type of data being transferred.  

If your API connects to a third-party application, you need to consider how that application redistributes information to the Internet. To use the example above, you may not care if someone finds out what's in your refrigerator, but you'd be more concerned if they could use the same API to locate you. 

What is REST API security and SOAP API security?

Web API security is about data transfer via APIs connected to the Internet. For access delegation, there is an open standard called OAuth (Open Authorization). It allows users to grant third parties access to web resources without having to share their passwords. OAuth is the standard protocol that allows you to share, for example, a dog video on social networks by simply pressing the "Share" button.

REST APIs are based on HTTP and support Transport Layer Security (TLS) encryption. The TLS standard keeps an Internet connection private and ensures that data exchanged between two systems (a server and a server, or a server and a client) is encrypted and unmodifiable. In other words, if a hacker tries to steal your credit card information from an online shopping site, he will not be able to read or modify it. When a website is TLS-protected, its URL begins with "HTTPS" (HyperText Transfer Protocol Secure). 

REST APIs also use the JSON (JavaScript Object Notation) file format, which facilitates data transfer via web browsers. By using the HTTP protocol and JSON format, REST APIs do not need to store data or recreate packets, making them faster than SOAP APIs.

SOAP APIs, on the other hand, use built-in protocols known as WS Security (Web Services Security). These protocols define a set of rules that allow for added privacy and authentication. SOAP APIs support the standards established by the two largest international standards bodies: OASIS (Organization for the Advancement of Structured Information Standards) and W3C (World Wide Web Consortium). They combine XML encryption, XML signatures, and SAML tokens to verify authentication and authorization. SOAP APIs are generally recognized for their more comprehensive security measures, but they require a higher level of management. For this reason, they are particularly well-suited for companies that deal with sensitive data.

What are the most common best practices for API security?

You probably don't hide your savings under your mattress. Most people put their money in a safe place (a bank) and use various methods to authorize and authenticate their payments. API security works on the same principle. You need a trusted environment that enforces authentication and authorization policies.

Here's a list of the most common ways to strengthen your API security:

  • Use tokens: set up verified identities, then control access to services and resources with their assigned tokens.  
  • Use encryption and signatures: Encrypt your data using a protocol, such as TLS (see above). Require signatures to ensure that only authorized users decrypt and modify your data.
  • Identify vulnerabilities: keep your operating system, network, drivers, and API components up to date. Examine how all of these elements interact to identify vulnerabilities that could be used to break into your APIs. Use packet analyzers to detect security issues and spot data leaks.
  • Use quotas and query limiting: Set quotas on how often your API can be called and track its usage in the history. An increase in the number of calls may indicate that the API is being abused. It may also be a programming error, such as an infinite loop that keeps calling the API. Set up request throttling rules to protect your APIs from traffic spikes and denial-of-service attacks.
  • Use an API gateway: API gateways govern API traffic. With a good gateway, you can authenticate traffic as well as monitor and analyze API usage

Common Forms of API Abuse

APIs, while powerful, can be vulnerable to various forms of abuse. Unauthorized access is a straightforward abuse, where attackers breach an API's authentication or authorization mechanisms. Theft of API keys is another risk, often achieved by intercepting keys in transit or exploiting application vulnerabilities.

Credential stuffing is a concern when APIs rely on usernames and passwords. Attackers use stolen credentials from previous data breaches to gain unauthorized access. Denial of Service (DoS) attacks disrupt APIs by overwhelming them with excessive requests, causing service disruption.

SQL injection is a risk when APIs interact with databases. Attackers inject malicious SQL queries through API requests, exploiting input validation weaknesses. Cross-Site Scripting (XSS) may compromise APIs that return data displayed in web applications.

Data scraping abuses APIs for unauthorized data extraction using automated scripts or bots. Brute force attacks guess authentication credentials, while parameter manipulation exploits API parameter or payload vulnerabilities.

Unauthorized function execution occurs when attackers misuse API functions without proper authentication, potentially leading to unintended actions or data exposure. Mitigating these abuses requires robust security measures, including authentication, authorization, monitoring, and security testing. Staying informed about emerging threats is essential to protect APIs in the interconnected digital landscape.

API Security Standards

In the age of data-driven projects, safeguarding data is paramount. To ensure API security, it's crucial to adhere to essential standards and practices:

  • Vulnerabilities: Identify weaknesses within your system's API lifecycle and proactively address them. Watch out for signature-based attacks like SQL injections, enforce stricter rules for JSON paths and schemas, and implement rate limits to protect API backends.
  • Tokens: Security tokens are central to API authentication. They require authentication on both ends of a communication before allowing it to proceed, serving as access control mechanisms.
  • Encryption: Encryption disguises data on one end of communication, only permitting deciphering at the other end with the correct decryption key, rendering data unreadable to unauthorized users.
  • OAuth and OpenID Connect: OAuth defines access token acquisition for client-side applications, while OpenID Connect (OIDC) adds an authentication layer. Together, they enhance authentication and authorization, limiting data transfer to authenticated parties.
  • Throttling and Quotas: These measures protect bandwidth by limiting system access, thwarting attacks like DDoS assaults.
  • API Gateway: Positioned as a reverse proxy, an API gateway authenticates traffic, ensuring only authorized requests proceed.
  • Zero-Trust Approach: This security model treats all traffic as untrusted until authenticated, preventing unauthorized access, even from imposter devices.

API Security for SOAP, REST, and GraphQL

API security is a critical concern regardless of the architectural style of your APIs. SOAP, REST, and GraphQL are three common API architecture patterns, each with its unique characteristics and security considerations.

SOAP API Security

SOAP (Simple Object Access Protocol) is known for its enterprise-level security features. It uses XML as its message format and can be carried over various lower-level protocols, including HTTP and SMTP. SOAP APIs are typically secured through a combination of transport layer security, such as HTTPS, and message-level security, including XML digital signatures and encryption.

SOAP API security benefits from protocol extensions specifically designed to address security issues. SOAP adheres to the Web Services (WS) specifications, offering features like WS-ReliableMessaging, which enhances error handling support, ensuring robust security for all web services.

REST API Security

REST (Representational State Transfer) APIs, on the other hand, rely on a more straightforward approach with JSON data transfer and HTTP/S as the transfer protocol. While this simplicity is an advantage, RESTful APIs lack built-in security provisions, placing the onus on API design and implementation.

Security for RESTful APIs often involves leveraging transport layer security, such as HTTPS, and token-based authentication. A common architectural choice is to deploy REST APIs behind an API gateway, which simplifies security management but may not cover all security threats comprehensively.

GraphQL API Security

GraphQL is an open-source API language that allows clients to request specific data from single or multiple sources. Its flexibility in defining data structures for requests poses unique security challenges. GraphQL allows clients to craft customized and potentially complex queries, which can be both a strength and a vulnerability.

Mitigating GraphQL API security risks involves implementing measures like query throttling, setting a maximum query depth, and implementing query timeouts. These controls help defend against large or malicious queries that could strain server resources or compromise data integrity.

Wrapping up, API security remains a top priority regardless of whether you are working with SOAP, REST, or GraphQL APIs. Each architectural style has its strengths and security considerations, and implementing appropriate security measures is essential to protect your APIs and the data they handle.

Getting Started With DreamFactory

Handwriting code for database APIs can be a complex, time consuming, and expensive process. It also exposes businesses to a number of risks including consistency, quality, and developer effort. DreamFactory is a REST API generation tool for a number of databases. It gives you the ability to generate secure and fully documented APIs in a matter of minutes. Ready to get started?  Sign up for a 14-day free trial and start creating your APIs today.

Related reading:

How to Secure REST APIs: API Keys Vs. OAuth

Frequently Asked Questions - API Security

What is API security, and why is it important?

API security refers to the practices and measures in place to protect Application Programming Interfaces (APIs) from unauthorized access, data breaches, and misuse. It is essential because APIs facilitate data exchange between systems and applications, making them potential targets for cyberattacks and data theft.

What are some common API security threats?

Common API security threats include unauthorized access, API key theft, credential stuffing, denial of service (DoS) attacks, SQL injection, cross-site scripting (XSS), data scraping, brute force attacks, parameter manipulation, and unauthorized function execution.

How can I secure my APIs against unauthorized access?

To secure APIs against unauthorized access, implement strong authentication mechanisms such as API keys, OAuth, or JWT tokens. Ensure proper authorization by defining access control rules and user permissions.

What role does encryption play in API security?

Encryption is crucial for API security as it ensures data confidentiality. It protects data during transmission and storage by making it unreadable to unauthorized users. Technologies like TLS (Transport Layer Security) are commonly used for encryption.

What are OAuth and OpenID Connect, and how do they enhance API security?

OAuth is an open standard for access delegation that allows users to grant third parties access to resources without sharing their passwords. OpenID Connect (OIDC) is an authentication layer built on OAuth, verifying user identities. Together, they strengthen authentication and authorization in API interactions.

How can I protect my APIs against DoS attacks?

To safeguard APIs from DoS attacks, implement rate limiting, throttling, and access controls. Monitor API traffic for unusual spikes and use solutions like Content Delivery Networks (CDNs) for additional protection.

What are best practices for preventing SQL injection in APIs?

To prevent SQL injection, employ input validation, parameterized queries, and prepared statements in your API code. Avoid dynamically constructing SQL queries with user input.

How can I ensure API security in a microservices architecture?

In a microservices architecture, secure inter-service communication, implement identity and access management (IAM), and use API gateways for centralized security control. Monitor and audit API interactions between microservices.