Authentication
The process of verifying the identity of a client or user. HTTP supports multiple authentication schemes: Basic (base64 username:password), Bearer (token-based, common in OAuth 2.0), Digest (hash-based), and others. A failed authentication attempt returns 401 Unauthorized, while insufficient permissions after authentication returns 403 Forbidden.
Protocoles associés
Mentionné dans les guides
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HTTP Fundamentals
Essential HTTP Headers Every Developer Should Know
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HTTP Cookies: SameSite, Secure, and HttpOnly Explained
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SMTP Reply Codes: What Your Email Server Is Telling You
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Improving Email Deliverability: SPF, DKIM, and DMARC Setup
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Diagnosing Email Bounces: Soft (4xx) vs Hard (5xx)
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Email Header Analysis: Tracing Delivery Path
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Bulk Email Delivery: Avoiding the Spam Folder
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DMARC Reporting: Analyzing Aggregate and Forensic Reports
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IP Warming for Email: Building Sender Reputation from Scratch
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DNS Record Types Explained: A, AAAA, CNAME, MX, TXT, and Beyond
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WebRTC Signaling with SIP and WebSocket
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RFC 9110: HTTP Semantics Deep Dive
Protocol Deep Dives
RFC 5321: SMTP Protocol Deep Dive
Protocol Deep Dives
RFC 959: FTP Protocol Deep Dive
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RFC 3261: SIP Protocol Deep Dive
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Scénarios associés
Getting 401 Instead of 403 (or Vice Versa)
HTTP
403 Forbidden Due to CORS Misconfiguration
HTTP
403 Forbidden Due to CSRF Token Mismatch
HTTP
550 Relay Access Denied — Cannot Send Through SMTP Server
SMTP
535 Authentication Failed — App Password Required
SMTP
503 Bad Sequence of Commands — AUTH Before STARTTLS
SMTP
gRPC PERMISSION_DENIED — Auth and Authorization Issues
gRPC
UNAUTHENTICATED — Missing or Invalid gRPC Metadata
gRPC
1008 Policy Violation — Authentication Timeout
WebSocket
530 Login Authentication Failed
FTP
Défini dans
RFC 9110
HTTP Semantics
RFC 6749
The OAuth 2.0 Authorization Framework
RFC 6750
The OAuth 2.0 Authorization Framework: Bearer Token Usage
RFC 7519
JSON Web Token (JWT)
RFC 7235
Hypertext Transfer Protocol (HTTP/1.1): Authentication
RFC 959
File Transfer Protocol (FTP)
RFC 2228
FTP Security Extensions
RFC 3261
SIP: Session Initiation Protocol
Guides de décision
Voir aussi
Status Code
HTTP Concepts
Session
HTTP Concepts
CORS (Cross-Origin Resource Sharing)
Security
CSRF (Cross-Site Request Forgery)
Security
SQL Injection
Security
OAuth 2.0
Security
JWT (JSON Web Token)
Security
API Key
Security
Bearer Token
Security
SMTP Authentication (SMTP AUTH)
Email & SMTP
Proxy Authentication
Web Standards
FTP Anonymous Access
FTP & File Transfer
MFA (Multi-Factor Authentication)
Authentication & OAuth
TOTP (Time-Based One-Time Password)
Authentication & OAuth
HTTP Basic Authentication
Authentication & OAuth
HTTP Digest Authentication
Authentication & OAuth
Passkey (WebAuthn)
Authentication & OAuth