Let’s dive into your login manager system design and discuss the concepts at a high level. I’ll break this down into the three main components—login/auth system, signup system, and user admin system—while refining and suggesting improvements where applicable. The goal here is to enhance clarity, security, scalability, and practicality without diving into code.

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1. Login/Auth System (HAProxy, .c Backend, Redis)

Your design uses HAProxy as a reverse proxy, a C-based backend for authentication logic, and Redis as the database. The flow protects a "/protect/" area, redirecting unauthenticated users to "/login", and handles password verification with SHA256 hashing. Let’s refine it:

• Flow and Components:
  • HAProxy intercepts requests to "/protect/" and checks for auth status. If not authenticated, it redirects to "/login".
  • "/login" serves a page with JavaScript that submits username + SHA256(password) to "/login/req".
  • HAProxy forwards "/login/req" to a UNIX socket (e.g., /loginDAEMON/unix.login.req.sock), where the .c backend listens.
  • The .c backend queries Redis (via another UNIX socket, /wwwFS.in/u98/unix.redis.sock) to verify credentials.
  • Redis returns "yes" or "no," and the backend signals HAProxy accordingly.
• Refinements:
  • Hashing Security: SHA256 alone isn’t ideal for passwords—it’s fast and vulnerable to brute-force attacks. Consider using a slow, salted hash like Argon2, bcrypt, or PBKDF2. The client could still send SHA256(password) for simplicity, but the backend should re-hash it with a salt stored in Redis (e.g., username:hash and username:salt keys).
  • Session Management: Your design implies HAProxy decides access based on the backend’s response. To make "/protect/" accessible post-login, you’ll need a session mechanism. HAProxy can set a cookie (e.g., auth_token) on "yes" responses, with a timeout (like 3600s). The .c backend could generate this token and store it in Redis (session:token -> username, expiry).
  • HAProxy Auth Levels: You asked about Nginx’s ability to return more than "yes/no" (e.g., zones, timeouts). You’re correct—Nginx’s auth_request module can return headers or status codes with additional context. HAProxy supports similar functionality via ACLs and HTTP headers. The .c backend could return a custom header (e.g., X-Auth-Level: 5 or X-Auth-Zone: premium) alongside a 200 (success) or 401 (fail) status. HAProxy can then route based on these headers or store them in cookies.
  • Rate Limiting: Recording user/ip in Redis (select 1) with a TTL of 3600s and a max of 10 tries is solid. For suspected bots (e.g., 10 failed attempts on "user01" from one IP), your idea to "keep the connection open but not respond" is clever—it’s a tarpit strategy. However, HAProxy isn’t built for this natively; you’d need the .c backend to delay responses (e.g., sleep(10)) or HAProxy to use a custom Lua script. Be cautious—tarpits can consume server resources too.
• Potential Issues:
  • UNIX sockets are fast but limit scalability across machines. If you scale to multiple servers, consider TCP sockets or a message queue (e.g., RabbitMQ) instead.
  • What happens if Redis is down? Add a fallback (e.g., deny all logins or log to a file).
• Additional Cases:
  • Concurrent Logins: Should one user be allowed on multiple IPs? If not, store the active session IP in Redis and invalidate old sessions.
  • Password Reset: No mechanism exists yet—consider adding a "/reset" endpoint.

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2. Signup System (HAProxy, .c2 Backend, Redis)

This system allows self-signup via "/signup", with rate limits and basic validation. Here’s the conceptual discussion:

• Flow and Components:
  • HAProxy listens on "/signup" and forwards requests to a second C backend (.c2) via a socket or endpoint.
  • .c2 uses Redis (select 5) to track user/ip signup attempts with a 3600s TTL.
  • If the IP has signed up within 3600s, it redirects to an error page. Otherwise, it validates the username (starts with a-zA-Z, contains a-zA-Z0-9, 8+ chars) and registers it in Redis (select 0?) with TTL 30 days and level 0.
• Refinements:
  • Database Selection: Storing new users in "select 0" makes sense as a default namespace, but clarify its purpose (e.g., "active users"). Use key patterns like user:username:info for structure (e.g., user:johndoe:pass, user:johndoe:level).
  • Rate Limiting: Blocking IPs after one signup in 3600s is strict. Consider allowing 2-3 attempts before blocking, or use a CAPTCHA after the first signup to deter bots while allowing legit retries.
  • Validation Feedback: Returning "failed reason" (e.g., "username too short") is user-friendly but could leak info to attackers (e.g., "username exists"). Use generic errors like "signup failed" unless the user’s intent is verified.
  • TTL and Levels: A 30-day TTL for new accounts is a good trial period. Level 0 (no privileges) is fine, but define what levels 1-9 mean (e.g., 1 = basic access, 9 = admin).
• Potential Issues:
  • No email verification—bots could flood signups. Add a "/verify" step with a token sent via email, stored in Redis (e.g., verify:token -> username).
  • What if two users try the same username simultaneously? Use Redis’s atomic SETNX (set if not exists) to prevent duplicates.
• Additional Cases:
  • Username Reuse: If an account expires (TTL hits 0), can the username be reused? Decide if expired accounts are archived or deleted.
  • Signup Flooding: An attacker could try many IPs. Consider a global rate limit (e.g., 100 signups/hour across all IPs).

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3. User Admin System (HAProxy, .go Backend, Redis)

This system provides an admin GUI via Go, with IP whitelisting and user management. Let’s refine it:

• Flow and Components:
  • HAProxy listens on "/useradmin" and forwards to a Go backend.
  • The Go backend checks admin credentials against Redis (select 3) and the client IP against a whitelist (select 11).
  • Rate limits differ: whitelisted IPs get 10 tries/3600s (select 12), others get 1 try/3600s (select 13).
  • On success, "/useradmin/allow" serves a GUI where admins can view, approve, modify, or delete users.
• Refinements:
  • IP Whitelisting: Storing IPs in "select 11" is fine, but consider a key like whitelist:ip for clarity. Use a set (SADD, SISMEMBER) for fast lookups.
  • Rate Limiting: 1 try for non-whitelisted IPs is harsh—legit admins might mistype. Bump it to 3, or add a CAPTCHA after 1 failure.
  • Admin Levels: All admins seem equal now. Use levels (e.g., 9 = superadmin, 8 = moderator) to limit actions (e.g., only level 9 can delete users).
  • User Management: Approving a user removes its TTL—good idea. Store levels in Redis (e.g., user:johndoe:level = 5). For deletions, consider soft deletes (e.g., user:johndoe:deleted = 1) to preserve audit trails.
• Potential Issues:
  • No audit logging—admins could abuse power. Log actions in Redis (select 14?) like audit:timestamp -> admin, action, target.
  • GUI security—ensure "/useradmin/allow" requires a fresh auth check, not just a cookie, to prevent session hijacking.
• Additional Cases:
  • Admin Lockout: What if an admin’s IP changes (e.g., VPN)? Add a manual override (e.g., superadmin approval).
  • User Search: For many users, the GUI needs pagination or filtering—plan for this in the Go backend.

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Overall Improvements

• Consistency: Use meaningful Redis database numbers (e.g., 0 = users, 1 = sessions, 3 = admins, 5 = signup tracking) and document them.
• Scalability: UNIX sockets work for a single server but not clusters. Consider TCP or a load balancer in front of HAProxy.
• Security: Add TLS everywhere (HAProxy, Redis, backends) and rate-limit all endpoints globally to prevent DDoS.
• Error Handling: Define fallback behaviors (e.g., Redis down = 503 response) and log errors for debugging.

Your design is a strong start—modular, lightweight, and Redis-centric. With these tweaks, it’s more robust and ready for real-world challenges. What do you think about these refinements, or is there a specific part you’d like to dive deeper into?

Let’s continue refining your design based on your feedback and decisions. I’ll address each point you raised, keeping it conceptual and incorporating your preferences while suggesting improvements where applicable. Here we go:

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1. Hashing Security

• Your Decision: Browser submits username:sha256(passwd), Redis stores username:random16byte_hex_ascii:sha384(argon2id(username:sha256(passwd))).
• Discussion: This is a solid choice. The client sends a SHA256 hash (fast for transmission), and the backend enhances it with a 16-byte random salt (in hex ASCII) and applies Argon2id (via SHA384 for extra strength). The salt prevents rainbow table attacks, and Argon2id’s computational cost deters brute-forcing. Redis key could look like username:salt and username:hash. No arguments here—your call is final and secure.

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2. Session Management

• Your Decision: Adopt my suggestion (cookie-based session with HAProxy and Redis).
• Discussion: HAProxy sets an auth_token cookie on successful login, tied to a Redis entry (e.g., session:token -> username, expiry=3600). The .c backend generates the token (e.g., a random UUID) and stores it. HAProxy checks this cookie for "/protect/" access. Works perfectly with your setup and keeps state lightweight.

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3. HAProxy Auth Levels

• Your Decision: Level 0 = new register (no privileges), levels 1-9 map to /protect/1/ through /protect/9/.
• Discussion: This hierarchical access is clear—level 3 can access /protect/1/, /protect/2/, and /protect/3/, while level 9 sees all. HAProxy can enforce this by reading a header (e.g., X-Auth-Level: 3) from the .c backend and using ACLs to route or deny requests. Redis stores user:username:level for quick lookups. Clean and extensible.

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4. Rate Limiting

• Your Decision: No sleep/tarpit, just reject. You recall HAProxy having a DoS mitigation feature (half-connect or delay).
• Discussion: You’re right—HAProxy has DoS protection features. It doesn’t "half-connect" per se, but it supports connection throttling and stick-tables to track and limit requests. For example, a stick-table can monitor user/ip pairs, reject after 10 failed attempts in 3600s, and silently drop connections (not informing the client) using tcp-request connection reject. The docs (e.g., HAProxy 2.8) mention silent-drop for bots—closing the connection without a response, which aligns with your memory. We’ll use this: reject outright after 10 tries, leveraging HAProxy’s native DoS tools.

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5. UNIX Sockets

• Your Decision: Keep UNIX sockets, switch to TCP/queue only if needed later.
• Discussion: Fair enough—UNIX sockets are fast for single-server setups. We’ll stick with /loginDAEMON/unix.login.req.sock and /wwwFS.in/u98/unix.redis.sock for now. Scalability can wait.

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6. Redis Downtime Fallback

• Your Decision: Agree to add a fallback (deny logins or log to file).
• Discussion: If Redis is down, the .c backend could return a 503 (service unavailable) to HAProxy, effectively denying logins. Logging to a file (e.g., /var/log/auth_fails) as a backup is also viable for debugging. I’d lean toward "deny all" as the default—it’s safer and simpler.

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7. Multiple IPs per User

• Your Decision: Yes, allow multiple IPs (real-world mobile use case).
• Discussion: Makes sense—mobile users switch IPs often. The session token in Redis (session:token -> username) doesn’t need IP binding, so concurrent logins from different IPs are naturally supported. No changes needed.

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8. Password Reset

• Your Decision: No automated recovery (email/phone); users call admin, who resets via "/useradmin".
• Discussion: Prioritizing privacy by avoiding recovery mechanisms is a bold stance—users must re-signup or contact an admin. Adding a "reset password" option to "/useradmin" (e.g., generate a temp password, stored as user:username:temp_pass) fits your manual approach. Admins can communicate it offline. Works well with your privacy-first philosophy.

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9. Database Selection

• Your Decision: I design the Redis structure, using username as the key for GET/SET or HGET/HSET.
• Discussion: I’ll propose a structure using hashes for clarity:
  • user:username (hash): {hash: sha384(argon2id(...)), salt: random16byte_hex_ascii, level: 0-9}
  • session:token (string): username (TTL 3600s)
  • attempts:user:ip (string): count (TTL 3600s, max 10)
  • Keeps username as the primary key, leveraging Redis hashes for structured data.

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10. Signup IP Blocking & CAPTCHA

• Your Decision: 1 signup per IP in 3600s isn’t strict; no Google CAPTCHA, but self-hosted CAPTCHA for login/signup/admin.
• Discussion: Your reasoning—why need multiple accounts in 3600s?—is fair for a privacy-focused system. Redis (select 5) tracks signup:ip with TTL 3600s. For CAPTCHAs, self-hosted options include:
  • TextCAPTCHA: Simple math/text questions (e.g., "2 + 3 = ?"), stored in Redis (e.g., captcha:session_id -> answer), lightweight but less secure.
  • Image-based (DIY): Generate images with distorted text in .c2/.go, store answers in Redis, and verify client input. Tools like ImageMagick or FreeType can help.
  • hCaptcha (self-hosted): Open-source, privacy-focused, but requires setup. I’d suggest a DIY image CAPTCHA—fits your control/privacy goals and integrates with HAProxy redirecting to "/captcha" on rate limit triggers.

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11. Validation Feedback

• Your Decision: Agree to use generic errors.
• Discussion: Signup/login will return "failed" instead of specifics (e.g., "username exists"). Enhances security—no changes needed.

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12. TTL and Levels

• Your Decision: Level 9 ≠ admin (admins are separate); levels 1-9 map to /protect/1-9/, higher levels see lower areas.
• Discussion: Admins in "select 10" are distinct from users (select 0), and user levels 1-9 define access scope. HAProxy ACLs can enforce this (e.g., hdr(X-Auth-Level) ge 3 for /protect/3/). Clear and logical.

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13. No Email Verification

• Your Decision: No email/phone; atomic username locking.
• Discussion: Privacy-first means no verification—users re-signup if passwords are lost. For atomicity, .c2 uses SETNX on user:username during signup to prevent race conditions. Simple and effective.

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14. Username Reuse

• Your Decision: Expired TTL (new users) = delete fully, reusable; deleted/suspended by admin = keep, reject login.
• Discussion: New users (level 0, TTL 30 days) vanish from Redis on expiry, freeing the username. Admin-deleted/suspended users get a flag (e.g., user:username:status = deleted), blocking login but preserving history. Solid rules.

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15. Database Correction

• Your Decision: "Select 3" → "select 10" for admin functions.
• Discussion: Updated—admins use "select 10" (e.g., admin:username:hash). Post-10 namespaces are admin-related. Noted.

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16. IP Whitelisting

• Your Decision: Use my suggestion.
• Discussion: Redis (select 11) stores whitelist:ip as a set (SADD, SISMEMBER). HAProxy or .go checks this before allowing "/useradmin" access. Simple and fast.

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17. Admin Rate Limiting

• Your Decision: No leniency—1 try for non-whitelisted, self-hosted CAPTCHA.
• Discussion: Strict is fine for security—non-whitelisted IPs get 1 try (select 13), whitelisted get 10 (select 12), both TTL 3600s. Add the DIY image CAPTCHA here too, redirecting to "/admin/captcha" on failure.

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18. Admin Levels

• Your Decision: Different admin privileges.
• Discussion: Admins in "select 10" get levels (e.g., admin:username:level = 9 for superadmin, 8 for moderator). Superadmins (9) can reset passwords/delete, moderators (8) can approve users. HAProxy/.go enforces this via headers.

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19. User Management

• Your Decision: TTL expiry = full delete; admin delete = keep record.
• Discussion: Already aligned—TTL expiry clears user:username, admin actions set user:username:status = deleted. Done.

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20. Audit Logging

• Your Decision: Add it, use a new database if needed.
• Discussion: Use "select 14" for audits: audit:timestamp -> admin, action, target (e.g., "2025-04-03T12:00:00 -> admin1, delete, user:johndoe"). TTL optional (e.g., 90 days). Keeps history separate.

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21. GUI Security

• Your Decision: All "/useradmin/*" paths require admin auth.
• Discussion: HAProxy protects "/useradmin/" and subpaths with an auth check (cookie + Redis session). .go re-validates credentials on sensitive actions (e.g., "/useradmin/allow") to prevent hijacking. Robust combo.

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22. Admin Lockout

• Your Decision: Add it.
• Discussion: If an admin’s IP changes, a superadmin (level 9) can update the whitelist (select 11) or issue a temp token (e.g., admin:username:temp_token, TTL 24h) for recovery. Manual but secure.

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23. User Search

• Your Decision: Add it.
• Discussion: The .go GUI queries user:* keys in Redis (select 0) with filters (e.g., level, status) and paginates results (e.g., 50 per page). Simple and scalable.

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24. Password Change

• Your Decision: Users/admins can change passwords if logged in; lost passwords = re-signup (users) or superadmin reset (admins).
• Discussion: Agreed—add "/change_pass" for users (via .c) and "/admin/change_pass" for admins (via .go). Flow:
  • User submits current sha256(passwd) and new sha256(new_passwd).
  • Backend verifies session, re-hashes new password with salt+Argon2id, updates user:username:hash. Same for admins in "select 10". Fits your privacy model perfectly.

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Refined Redis Structure

• Select 0: Users (user:username -> {hash, salt, level, status})
• Select 1: Login attempts (attempts:user:ip -> count)
• Select 5: Signup tracking (signup:ip -> 1)
• Select 10: Admins (admin:username -> {hash, salt, level})
• Select 11: Whitelist (whitelist:ip)
• Select 12: Whitelisted admin attempts (attempts:admin:ip)
• Select 13: Non-whitelisted admin attempts (attempts:admin:ip)
• Select 14: Audit logs (audit:timestamp -> admin, action, target)

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Your design is now tighter—privacy-first, secure, and functional. The self-hosted CAPTCHA and password change features round it out nicely. Thoughts? Anything else to tweak?

I understand you perfectly! You want a summarized version of the entire design, followed by breaking it down into distinct pieces (or "jobs"), each with its own target/summary. This way, you can discuss each piece separately in new conversations without copying tons of text. I’ll provide a high-level summary first, then split the design into logical components with summaries for each. Here we go:

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High-Level Summary of the Entire Design

The system is a privacy-focused, secure login manager with three main subsystems: Login/Auth, Signup, and User Admin. It uses HAProxy as a reverse proxy, C/Go backends for logic, and Redis for storage. Key features include:

• Login/Auth: Protects "/protect/1-9/" areas with username+SHA256(password) from clients, enhanced by salted Argon2id in Redis. Session tokens (cookies) manage access, with rate limiting (10 tries/3600s) and HAProxy DoS protection.
• Signup: Self-service at "/signup" with IP limits (1 signup/3600s), atomic username locking, and a self-hosted CAPTCHA. New users get level 0 and a 30-day TTL.
• User Admin: Admin GUI at "/useradmin/" (Go-based) with IP whitelisting, strict rate limits, and audit logging. Admins (select 10) manage users (approve, delete, reset passwords) separately from self-signed users (levels 1-9).
• Privacy: No email/phone recovery; lost passwords mean re-signup (users) or admin reset (admins). Password changes are self-service for logged-in users/admins.
• Security: Self-hosted CAPTCHA, atomic operations, and Redis fallbacks (deny logins if down) ensure robustness.

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Breakdown into Pieces (Jobs) with Targets/Summaries

Piece 1: Login/Auth System

• Components: HAProxy, .c backend, Redis (select 0, 1).
• Target: Securely authenticate users and grant access to "/protect/1-9/" based on levels (0-9), with session management and rate limiting.
• Summary: HAProxy routes "/protect/*" requests, redirecting unauthenticated users to "/login". The client submits username:sha256(passwd), and the .c backend verifies it against user:username:hash (salted Argon2id) in Redis (select 0). Successful logins get a session token (cookie, stored in Redis), and HAProxy enforces level-based access (e.g., level 3 sees "/protect/1-3/"). Rate limits (10 tries/3600s per user/IP, select 1) use HAProxy’s silent-drop for DoS protection. Redis downtime triggers a deny-all fallback.

Piece 2: Signup System

• Components: HAProxy, .c2 backend, Redis (select 0, 5).
• Target: Allow self-signup with privacy and bot protection, assigning level 0 and a 30-day TTL to new users.
• Summary: HAProxy listens on "/signup", forwarding to .c2. The backend checks signup:ip (select 5, 1 signup/3600s), enforces username rules (a-zA-Z start, 8+ chars), and uses SETNX for atomic user:username creation in Redis (select 0). A self-hosted image CAPTCHA (DIY, Redis-backed) deters bots. New users get level: 0 and TTL 30 days; expired users are fully deleted, freeing usernames.

Piece 3: User Admin System

• Components: HAProxy, .go backend, Redis (select 10, 11, 12, 13, 14).
• Target: Provide a secure admin GUI for managing users (approve, delete, reset passwords) with audit trails and privilege separation.
• Summary: HAProxy routes "/useradmin/*" to .go, protected by admin auth (select 10, admin:username:hash). IP whitelisting (select 11) allows 10 tries/3600s (select 12), non-whitelisted get 1 try (select 13), with a self-hosted CAPTCHA. Admins (levels 8-9) approve users (set level 1-9, remove TTL), delete (mark status: deleted), or reset passwords (temp pass). Audit logs (select 14) track actions. Superadmins (level 9) handle lockouts via whitelist updates.

Piece 4: Password Change System

• Components: HAProxy, .c (users), .go (admins), Redis (select 0, 10).
• Target: Enable logged-in users and admins to change their passwords securely.
• Summary: "/change_pass" (via .c) and "/admin/change_pass" (via .go) allow password updates. Clients submit current sha256(passwd) and new sha256(new_passwd); backends verify sessions, re-hash the new password (salted Argon2id), and update user:username:hash (select 0) or admin:username:hash (select 10). No recovery—lost passwords mean re-signup (users) or superadmin reset (admins).

Piece 5: CAPTCHA System

• Components: HAProxy, .c/.c2/.go backends, Redis (flexible select, e.g., 6).
• Target: Prevent bot abuse across login, signup, and admin systems with a privacy-respecting, self-hosted solution.
• Summary: A DIY image CAPTCHA (e.g., distorted text) is served at "/captcha" (login), "/signup/captcha", and "/admin/captcha". Generated by backends (.c, .c2, .go), answers are stored in Redis (e.g., captcha:session_id -> answer, TTL 5 min). HAProxy redirects to CAPTCHA on rate limit triggers, ensuring bot resistance without external dependencies.

Piece 6: Redis Structure and Fallbacks

• Components: Redis (all selects: 0, 1, 5, 6, 10, 11, 12, 13, 14).
• Target: Organize data efficiently and handle Redis downtime gracefully.
• Summary: Redis namespaces:
  • 0: Users (user:username -> {hash, salt, level, status})
  • 1: Login attempts (attempts:user:ip)
  • 5: Signup tracking (signup:ip)
  • 6: CAPTCHA (e.g., captcha:session_id)
  • 10: Admins (admin:username -> {hash, salt, level})
  • 11: Whitelist (whitelist:ip)
  • 12/13: Admin attempts (attempts:admin:ip)
  • 14: Audit logs (audit:timestamp) Fallback: deny logins if Redis is down, log to file for debugging.

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How to Proceed

You can now start a new conversation for each piece (e.g., "Let’s discuss Piece 1: Login/Auth System"). Just reference the piece number and its summary—I’ll know exactly what we’re talking about without needing you to copy everything. This keeps our discussions focused and manageable. Which piece would you like to dive into first, or do you want to adjust the breakdown further?