编码器、解码器和哈希生成器
在 Base64、URL、HTML 实体和 hex 之间进行文本相互转换，并生成 MD5、SHA-1、SHA-256 和 SHA-512 哈希。全部在您的浏览器中完成。
编码、解码或哈希文本
工程师的日常编码工具
编码将文本转换为传输安全的格式；哈希则生成无法逆向的固定长度指纹。在调试 APIs、为强制门户构建重定向 URLs 或验证文件完整性时，这两者都必不可少。此工具完全在本地运行，敏感数据绝不会被上传。
该工具为您提供
- 支持 Base64、URL、HTML 实体和 hex 的双向转换，并在输入无效时提供清晰的错误提示。
- 根据任何文本输入生成 MD5、SHA-1、SHA-256 和 SHA-512 哈希。
- 说明哪些算法对安全是可靠的，哪些仅适用于旧版校验和。
Captive portal redirect parameters and URL encoding standards
When a wireless client associates with a guest WiFi network, the access point (AP) or wireless LAN controller (WLC) intercepts the initial HTTP request and issues an HTTP 302 redirect to the external captive portal splash page. To maintain state across the onboarding flow, the controller appends essential hardware and network context to the query string.
1. Cisco Meraki splash parameters
Meraki MR access points pass base_grant_url (the endpoint to authorise the client), user_continue_url (the guest's target URL), node_mac (AP MAC address), and client_mac. Correct percent-encoding of the grant and continue URLs is essential to prevent redirection loops.
2. Aruba ClearPass and Instant AP parameters
Aruba Instant APs and controller-managed architectures pass cmd=login, mac, ip, essid, apname, and url. Nested original destination URLs must be safely decoded when constructing post-login landing pages.
3. Ruckus SmartZone and ZoneDirector parameters
Ruckus controllers forward sip (controller IP), uip (client IP), mac (unformatted or colon-separated MAC), vlan, and url. Our tool detects MAC formats and automatically identifies Ruckus controller redirect structures.
For a complete technical overview of captive portal onboarding protocols, RADIUS authentication, and walled garden configurations, review our comprehensive captive portal technical guide and the RADIUS setup reference guide.
Cryptographic hash functions and webhook signature reference table
Cryptographic hashes produce deterministic, fixed-length digest outputs from arbitrary input data. Unlike encoding (which is fully reversible), cryptographic hashes are one-way functions designed to verify data integrity and authenticate API requests.
| Algorithm | Digest Output Length | Security Status | Primary Application | Standard Specification |
|---|---|---|---|---|
| HMAC-SHA256 | 256 bits (64 hex chars) | Strong (Recommended) | API authentication, webhook signature validation (Purple Webhooks, Stripe) | RFC 2104 / FIPS 198 |
| SHA-256 | 256 bits (64 hex chars) | Strong (Recommended) | TLS certificates, digital signatures, blockchain proof-of-work | FIPS 180-4 / NIST |
| SHA-512 | 512 bits (128 hex chars) | Strong (Recommended) | High-security password hashing (with salt/KDF), data archiving | FIPS 180-4 / NIST |
| SHA-384 | 384 bits (96 hex chars) | Strong (Recommended) | NSA Suite B cryptography, enterprise VPN integrity checks | FIPS 180-4 / NIST |
| SHA-1 | 160 bits (40 hex chars) | Deprecated | Git commit hashes, legacy file integrity checks (insecure for TLS) | RFC 3174 (SHAttered attack 2017) |
| MD5 | 128 bits (32 hex chars) | Insecure / Broken | Legacy non-cryptographic file checksums and Content-MD5 headers | RFC 1321 (Collision vulnerable) |
| CRC32 | 32 bits (8 hex chars) | Non-Cryptographic | Ethernet frame check sequences (FCS), ZIP file archive integrity | IEEE 802.3 |
Understanding the differences: encoding, encryption, and hashing
Encoding (Reversible, No Key)
Transforms data into a format safe for transmission across networks or storage in text systems (e.g. Base64, URL percent-encoding). Anyone can decode encoded data without a secret key. Encoding does not provide confidentiality.
Hashing (One-Way, Deterministic)
Generates a fixed-size fingerprint from input data. It is computationally infeasible to reconstruct the original input from the hash (preimage resistance) or find two inputs with the same hash (collision resistance). Used for integrity checks.
Encryption (Reversible with Key)
Transforms plaintext into ciphertext using a mathematical cipher (e.g. AES-256, RSA) and a cryptographic secret key. Only holders of the decryption key can recover the original data. Provides confidentiality.
Automate guest WiFi onboarding and webhook data delivery
Eliminate manual captive portal scripting. Purple connects natively with Cisco Meraki, Aruba, Ruckus, Fortinet, and Extreme Networks to automate guest authentication, GDPR-compliant data capture, and real-time webhook delivery to your CRM.
Related network engineering tools and technical guides
RADIUS setup guide
Configure FreeRADIUS and Cloud RADIUS servers with Cisco, Aruba, and Ruckus controllers.
SSL certificate checker
Inspect TLS certificates, certificate chains, expiry dates, and SAN extensions for captive portal domains.
MAC address lookup
Identify OUI vendor details, device manufacturers, and randomisation status for connected clients.
Captive portal guide
Comprehensive architectural reference for guest WiFi authentication and compliance.
Frequently asked questions
编码、加密和哈希之间有什么区别？
编码（例如 Base64 或 URL 编码）是一种可逆的转换，旨在实现安全的数据传输；任何人无需密钥即可对其进行解码。加密则是使用机密加密密钥将数据转换为密文，以确保机密性，只有获得授权的密钥持有者才能对其进行解密。哈希是一种单向数学函数，可根据输入数据计算出唯一的固定长度摘要；它无法被解密，用于验证数据的完整性。
为什么强制门户重定向参数需要进行 URL 编码？
当无线局域网控制器 (WLC) 拦截 HTTP 请求以显示展示页面时，它会将重定向参数（如原始 URL、MAC 地址和授权端点）附加到查询字符串中。斜杠 (/)、冒号 (:) 和问号 (?) 等字符必须进行百分号编码，以免网页浏览器和代理服务器将嵌套参数误解析为 URL 分隔符。
Base64url 与标准 Base64 有何不同？
标准 Base64 (RFC 4648) 使用加号 (+) 和正斜杠 (/)，这些字符在 URL 和文件名中具有特殊的语法含义。Base64url (RFC 7515) 将加号替换为连字符 (-)，将斜杠替换为下划线 (_)，并去掉了末尾的填充等号 (=)，从而使令牌可以安全地用于 URL 查询字符串、HTTP 请求头和 JSON Web Tokens (JWT)。
如何验证 API Webhook 上的 HMAC-SHA256 签名？
当外部平台（例如 Purple、Stripe 或 GitHub）发送 Webhook 事件时，它会使用共享密钥通过 HMAC-SHA256 生成原始 HTTP 请求体的哈希值，并将其包含在签名头中。您的服务器会使用相同的密钥计算出相同的 HMAC-SHA256 哈希值，并使用恒定时间字符串比较来对比摘要，以验证其真实性。
2026 年哪些哈希算法对于网络凭据是安全的？
SHA-256、SHA-384 和 SHA-512（SHA-2 系列）以及 SHA-3 是 NIST 强烈推荐用于加密完整性和数字签名的算法。MD5 和 SHA-1 已被证实存在数学碰撞漏洞，绝不能用于安全目的或密码哈希。
此工具是否会将我的任何令牌、密钥或 URL 发送到外部服务器？
不会。所有编码、解码、JSON Web Token 解析和加密哈希计算均使用标准 JavaScript 和原生 HTML5 Web Crypto API (crypto.subtle) 100% 在您的浏览器本地运行。任何负载数据都不会传输到 Purple 或第三方服务器。
Building captive portals or webhook integrations?
Encoding redirect URLs and validating HMAC webhook signatures is part of every custom WiFi deployment. Purple automates the complete onboarding workflow, data validation, and CRM synchronisation across your entire access point fleet.
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