Community hub
0 subscribers7 pages, 0 posts
Recent from talks
Be the first to start a discussion here.
Be the first to start a discussion here.
Be the first to start a discussion here.
Be the first to start a discussion here.
Contribute something
Welcome to the community hub built to collect knowledge and have discussions related to API key.
Nothing was collected or created yet.
API key
View on Wikipediafrom Wikipedia
 | This article needs additional citations for verification. (October 2018) |
An application programming interface (API) key is a secret unique identifier used to authenticate and authorize a user, developer, or calling program to an API.[1][2]
Cloud computing providers such as Google Cloud Platform and Amazon Web Services recommend that API keys only be used to authenticate projects, rather than human users.[3][4]
Usage
[edit]HTTP APIs
[edit]API keys for HTTP-based APIs can be sent in multiple ways:[5]
The access token is often a JSON Web Token (JWT) in the HTTP Authorization header:
POST /something HTTP/1.1
Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...
In the query string:
POST /something?api_key=abcdef12345 HTTP/1.1
As a request header:
GET /something HTTP/1.1
X-API-Key: abcdef12345
As a cookie:
GET /something HTTP/1.1
Cookie: X-API-KEY=abcdef12345
Security
[edit]API keys are generally not considered secure; they are typically accessible to clients, making it easy for someone to steal an API key. Keys often have no expiration, meaning a stolen key can be used indefinitely unless revoked or regenerated.[6] Keys are supposed to be a secret known only by the client and server, so they should not be communicated over an insecure channel and can only be considered secure when used in conjunction with other security mechanisms such as HTTPS.[5]
There are several risk scenarios when using API keys:
- Developers may write scripts that contain keys in plaintext.[2]
- Developers may hard-code keys into source code, and forget that when they release the code.[2]
- Having unprotected keys in mobile apps is dangerous.[2]
These risks generally stem from the key being in plaintext, which is potentially accessible to adversaries.[2]
Incidents
[edit]In 2017, Fallible, a Delaware-based security firm examined 16,000 Android apps and identified over 300 which contained hard-coded API keys for services like Dropbox, Twitter, and Slack.[7]
References
[edit]- ^ "API Key - What is an API Key?". Last Call - RapidAPI Blog. Retrieved 2019-09-20.
- ^ a b c d e Lu, HongQian 2014. Keeping Your API Keys in a Safe. IEEE 7th International Conference on Cloud Computing. doi:10.1109/CLOUD.2014.143.
{{cite conference}}: CS1 maint: numeric names: authors list (link) - ^ "What is an API Key? - API Keys and Tokens Explained - AWS". Amazon Web Services, Inc. Retrieved 2024-09-01.
- ^ "Why and when to use API keys | Cloud Endpoints with OpenAPI". Google Cloud. Retrieved 2024-09-01.
- ^ a b "API Keys". Archived from the original on 2019-10-17.
- ^ "Why and when to use API keys | Cloud Endpoints with OpenAPI". Google Cloud. Retrieved 2019-09-20.
- ^ "Hundreds of popular Android apps contain hard-coded secret keys". ZDNet. Retrieved 2022-06-20.
Book sources
[edit]- De, Brajesh (2017). API management: an architect's guide to developing and managing APIs for your organization (1st ed.). New York: Apress. ISBN 978-1-4842-1305-6. OCLC 978273106.
External links
[edit]
 | This computer-programming-related article is a stub. You can help Wikipedia by expanding it. |
API key
View on Grokipediafrom Grokipedia
An API key is a unique alphanumeric string that serves as a simple credential for authenticating and authorizing requests to an application programming interface (API), enabling controlled access to services without exposing user credentials.[1] Typically generated by the API provider, an API key identifies the client application or developer making the request and is often passed in HTTP headers or query parameters to validate access.[2] Common uses include integrating third-party services, such as embedding maps in applications or accessing cloud storage, where the key associates requests with a specific project for billing, quotas, and usage tracking.[2][3]
API keys provide a lightweight alternative to more complex authentication methods like OAuth, particularly for server-to-server communications or public data access, but they lack user-specific context and fine-grained permissions.[4] Developers register applications with the API provider to obtain keys, which are then bound to specific APIs or products to enforce access rules, such as rate limiting or endpoint restrictions.[3] For instance, in platforms like Google Cloud or Apigee, keys are validated by proxy policies that check validity, expiration, and approvals before granting access.[2][3]
Despite their simplicity, API keys pose security risks if mishandled, as they can grant broad access and remain valid for extended periods, potentially leading to unauthorized usage or unexpected costs if compromised.[5] Best practices include restricting keys to specific APIs and IP addresses, avoiding embedding them in client-side code or public repositories, and regularly rotating or deleting unused keys to minimize exposure.[5] Monitoring usage logs and preferring short-lived credentials over long-term keys further enhances security, with many providers recommending migration to token-based systems like OAuth for production environments requiring user authentication.[5][4]
Fundamentals
Definition and Purpose
An API key is a unique alphanumeric string that functions as a simple identifier for authenticating and authorizing a developer or application when accessing an application programming interface (API).[6] It is typically passed in API requests, such as via query parameters or headers, to verify the caller's legitimacy without exposing sensitive credentials like passwords. This mechanism assumes foundational knowledge of APIs as standardized protocols enabling software components to communicate and exchange data.[7] The primary purpose of an API key is to facilitate controlled access to API resources while supporting operational features like rate limiting, usage tracking, and billing. By associating requests with a specific key, providers can enforce quotas to prevent overload and abuse, monitor consumption patterns for analytics, and enable monetization through metered usage.[8] API keys also distinguish between public data access, which may be anonymous, and private resources requiring elevated privileges, serving as a lightweight alternative to complex authentication schemes like OAuth.[9] This approach balances security and usability, allowing developers to integrate services efficiently without full user authentication overhead.[10] API keys gained widespread adoption in the mid-2000s amid the rise of public web services, evolving as a practical solution for managing access in distributed systems. One seminal example is the Google Maps API, launched in June 2005, which introduced keys to authenticate developers and mitigate server strain from unchecked usage.[11] This marked a shift toward scalable API ecosystems, where keys enabled basic control without the intricacies of session-based logins prevalent in earlier web applications.[12]Historical Development
The concept of API keys originated in the late 1990s and early 2000s alongside the development of early web APIs, which provided programmatic access to online services. Pioneering examples included Salesforce's launch of the first commercial web API in 2000, followed by eBay's API in late 2000 and Amazon's APIs in 2002, where simple token-based identifiers began to manage developer access and usage tracking. These early implementations laid the groundwork for API keys as a mechanism to authenticate and authorize third-party integrations without exposing full user credentials.[13] API keys gained significant traction in 2004 with the public debut of Amazon Web Services (AWS), starting with Simple Queue Service (SQS) in November, which required access key IDs and secret access keys for authenticating API requests to its message queuing system. Concurrently, Flickr released its API in August 2004, mandating API keys to monitor usage and enable secure photo-sharing applications, marking one of the first widespread adoptions in social media platforms. By 2006, Google popularized keys further through version 2 of the Maps JavaScript API (launched April 3), where developers needed unique keys to embed interactive maps and prevent abuse. That September, Twitter introduced its initial API, relying on basic authentication but evolving toward key-based systems.[14][13][15][16] The 2010s marked a pivotal shift as cloud computing and RESTful API designs proliferated, integrating API keys with OAuth for enhanced security. AWS expanded key usage across services like Elastic Compute Cloud (EC2), launched in 2006, fueling the cloud boom and standardizing keys for scalable access control. Twitter fully transitioned to OAuth in August 2010, requiring consumer API keys (along with secrets) for all third-party apps to replace insecure basic auth. By mid-decade, platforms like Twilio (API launched 2008) and Stripe (launched September 2011) solidified keys as industry norms for communications and payments, emphasizing scoped permissions to limit exposure.[17] As of 2025, API key practices have adapted to AI-driven ecosystems, with OpenAI's API (debuted June 2020) relying on keys from inception to gate access to models like GPT series, including security enhancements in 2023 for organization-level key management and usage tracking. The rise of zero-trust security models has driven trends toward restricted, short-lived keys with fine-grained scopes, reducing risks in distributed systems across cloud and edge environments.[18][19]Technical Implementation
Generation and Structure
API keys are generated server-side to maintain control over the process and ensure security, typically employing cryptographically secure pseudorandom number generators (CSPRNGs) that produce high-entropy outputs resistant to prediction or brute-force attacks.[20] Common approaches involve creating a random byte sequence of sufficient length—often 16 to 32 bytes—and encoding it in formats like base64url or hexadecimal to yield strings of 22 to 64 characters, balancing usability with security.[20] For instance, UUID version 4 generates a 128-bit random value, providing adequate uniqueness for most applications without sequential predictability. While functions like PBKDF2 can derive keys from passphrases in certain contexts, direct random generation via CSPRNGs is preferred for API keys to avoid reliance on user inputs that might reduce entropy. The structure of an API key often includes a human-readable prefix to indicate its type or origin, followed by the random alphanumeric payload, and sometimes an optional checksum or version identifier for validation.[21] In OpenAI's implementation, keys begin with "sk-" for secret keys, appended to a base64-encoded random string, facilitating quick identification during development and debugging.[22] Similarly, AWS access key IDs use prefixes like "AKIA" for long-term IAM user keys, consisting of exactly 20 alphanumeric characters to encode the identifier while maintaining compactness.[21] Checksums, if included, typically employ algorithms like CRC32 or modular hashes to detect transmission errors, though they are not universal and prioritize brevity over exhaustive integrity checks. Once generated, API keys are managed through secure storage in databases, where the plaintext key is hashed—commonly using SHA-256—before persistence to prevent exposure in case of breaches, with the original only retained temporarily for issuance.[23] Associated metadata, such as creation date, expiration timestamp, associated user or application permissions, and usage limits, is stored alongside the hash to enable auditing and enforcement.[24] Revocation occurs by updating the database record to an inactive state or deleting the hash entirely, immediately invalidating the key without needing to regenerate dependent systems, though clients must be notified to transition smoothly.[25] Best practices for generation emphasize avoiding predictable patterns, such as sequential numbering or dictionary words, to thwart guessing attacks, while ensuring at least 128 bits of entropy to withstand computational brute-forcing within practical timeframes.[26] Implementations should leverage platform-specific CSPRNGs, like those in the Web Cryptography API or Java's SecureRandom, and incorporate regular key rotation policies, such as regenerating and replacing keys every 90 days or upon suspicion of compromise, to limit the impact of potential leaks.[27] Rotation involves generating a new key, updating permissions mappings, and phasing out the old one after a grace period, often automated via key management services to reduce human error.[20]Integration in API Calls
API keys are integrated into API calls primarily through HTTP requests to authenticate and authorize access to resources. The most common transmission methods include appending the key as a query parameter in the URL, such as?api_key=abc123 or ?key=API_KEY, which is straightforward for GET requests but exposes the key in logs and browser history.[28] Alternatively, keys can be sent in HTTP headers, like Authorization: Bearer <key> for token-based systems or custom headers such as X-API-Key: abcd1234 or x-goog-api-key: API_KEY, offering better security by keeping the key out of the URL.[29][30] Less commonly, keys may be included in cookies, though this is discouraged due to potential caching and sharing issues.[29] All transmissions must occur over HTTPS to prevent interception.[29]
In RESTful APIs, the integration follows a standard request-response flow where the client includes the API key with each call, and the server validates it before processing. For instance, a client might send a GET request to /data with the key in a header; the server extracts the key, checks it against stored values in a database or cache, and proceeds if valid, returning the requested data with a 200 OK status.[30] This validation typically occurs early in the request pipeline to avoid unnecessary computation on unauthorized requests.[29]
Server-side handling involves extracting the key from the request and performing a lookup or comparison. For security, keys are often stored hashed (e.g., using PBKDF2 or bcrypt) in the database, so the server hashes the incoming key and matches it against the stored hash rather than storing plaintext values.[23] If the key is invalid, missing, or unauthorized, the server responds with an HTTP 401 Unauthorized or 403 Forbidden status code, along with a message like "Invalid API key" to indicate the failure without revealing details.[31][32]
Edge cases, such as key expiration, are managed in real-time during validation; if a temporary key has expired, the server denies the request with a 403 Forbidden response to enforce time-bound access.[31] For auditing, servers log request metadata like timestamps, IP addresses, and endpoints accessed, but must sanitize logs to exclude the API key itself, preventing exposure in access logs or monitoring tools.[33]
Variations and Types
Restricted vs Unrestricted Keys
API keys can be classified as restricted or unrestricted based on the level of access they provide to an API's resources. Restricted keys limit usage to specific endpoints, HTTP methods (such as read-only GET requests), or data scopes, thereby enforcing granular control over permissions. This is typically implemented through access control lists (ACLs) or equivalent mechanisms on the server side, where the API provider validates the key against predefined rules during each request. For instance, Google Cloud API keys support restrictions that specify allowable APIs, client types (e.g., web applications via HTTP referrers or Android apps via package names), and IP addresses, ensuring the key cannot be misused beyond its intended context.[34] In contrast, unrestricted keys grant broad or full access to the API without such limitations, allowing calls to any endpoint or method. These were common in early API designs to facilitate rapid developer adoption and simplicity, but they are now strongly discouraged due to heightened security risks. A notable example is the initial versions of the Twitter API launched in 2006, which relied on basic authentication without scope-based restrictions, enabling unrestricted access until the introduction of OAuth in 2010 improved granular controls. Unrestricted keys remain a default option in some platforms but are strongly discouraged for production use, as they expose users to potential abuse if the key is compromised.[35] The primary trade-off between restricted and unrestricted keys lies in security versus convenience. Restricted keys significantly reduce the "blast radius" of a breach by containing potential damage to limited resources—for example, a read-only key prevents unauthorized data modifications even if exposed—while unrestricted keys amplify risks, such as unauthorized usage leading to excessive billing or data exfiltration. During key generation, restrictions are embedded via configuration, often specifying scopes in metadata (e.g.,{"read": true, "write": false} for permission flags), which the API server enforces without altering the key string itself. This approach balances usability for legitimate users with robust protection against misuse.[36]
Adoption of restricted keys has become standard among major API providers, reflecting industry best practices for security. For example, GitHub's personal access tokens default to scoped permissions, requiring explicit selection of read, write, or admin access for repositories and other resources, while AWS API keys for services like API Gateway are integrated with IAM policies that enforce fine-grained restrictions. Similarly, platforms like Stripe and SendGrid generate keys with optional permission sets to limit account-wide access.[37][38]
Temporary vs Permanent Keys
Temporary API keys are designed to automatically expire after a predefined period, such as 24 hours or upon single use, thereby limiting the window of potential exposure if compromised.[39] These keys are often generated dynamically for specific sessions or tasks, with expiration enforced server-side, often based on associated timestamps or policies, unlike self-contained tokens like JSON Web Tokens (JWTs) used in authentication flows.[40] For instance, in AWS Security Token Service (STS), temporary credentials are issued with durations ranging from minutes to hours and cannot be reused post-expiration, enhancing security by eliminating the need for manual revocation.[39] In contrast, permanent API keys lack a built-in expiration mechanism and remain valid indefinitely until manually revoked by the administrator.[21] This design suits scenarios requiring stable, long-term access but introduces higher risks, as a compromised key can provide prolonged unauthorized entry without automatic termination.[41] According to OWASP guidelines, long-lived secrets like these API keys are prevalent in cloud environments, with 60% of such keys exceeding one year in age, amplifying breach impacts.[41] Management of temporary keys focuses on automated lifecycle controls, where expiration is enforced via embedded timestamps or session-based validation, reducing administrative overhead.[40] Permanent keys, however, necessitate proactive strategies like scheduled rotation—often annually or upon personnel changes—to mitigate risks, including monitoring usage and immediate revocation if suspicious activity is detected.[21] Tools and platforms such as AWS IAM recommend preferring temporary credentials over long-term ones to align with least-privilege principles.[39] Temporary keys are ideal for user-facing applications, such as mobile apps or OAuth 2.0 flows, where short-lived access minimizes damage from client-side exposure during user sessions.[4] Permanent keys find use in infrastructure integrations, like continuous integration/continuous deployment (CI/CD) pipelines in GitHub Actions, where consistent server-to-server communication is required without frequent regeneration.[21] This distinction ensures temporary keys reduce overall attack surfaces in dynamic environments, while permanent ones support reliable, ongoing operations when secured through rigorous oversight.[41]Applications
Web and Cloud Services
API keys play a pivotal role in enabling secure and scalable access to web services, particularly in frontend applications where JavaScript clients interact with remote APIs. For instance, developers often embed API keys directly in client-side code, such as withinfetch() calls, to retrieve data from third-party services like weather forecasts. OpenWeatherMap, a popular weather API provider, requires users to include a unique API key in HTTP requests to authenticate and access current weather data or forecasts, ensuring that only authorized clients can query their endpoints.[42]
In cloud platforms, API keys are integral for managing resources and services, often serving as the first layer of authentication before more advanced mechanisms like IAM roles. Amazon Web Services (AWS) uses access keys (Access Key ID and Secret Access Key) for programmatic access to services such as Amazon Simple Storage Service (S3), where developers generate keys via the AWS Management Console to upload, download, or manage objects in buckets.[21] Similarly, Google Cloud Platform employs API keys for simpler integrations, such as read-only requests to certain APIs, and these keys integrate seamlessly with SDKs like the Google Cloud Client Libraries to automate tasks. For mutating operations like virtual machine provisioning in Compute Engine, OAuth 2.0 or service accounts are typically used.[43]
Microsoft Azure and DigitalOcean also exemplify this reliance, with Azure API Management using subscription keys to secure API gateways for hybrid cloud setups, while DigitalOcean's API tokens enable droplet creation and scaling through their RESTful API.[44][45] These implementations highlight how API keys facilitate automated provisioning in cloud environments, allowing scripts and applications to interact with infrastructure without full user credentials.
A key challenge in web services arises from the visibility of client-side requests in browser developer tools, which can expose API keys in JavaScript applications. Cross-Origin Resource Sharing (CORS) policies manage cross-origin requests but do not prevent this exposure. To mitigate this, developers commonly route requests through backend proxy servers, which handle authentication server-side and forward sanitized responses to the frontend, thereby concealing the API key from public exposure.