poslop
3facff3d1e
#1: server-side regex highlighter (highlight.go) for go/python/js/json/bash/sql; token span classes styled in app.css; per-line so gutter stays aligned. #2: in-memory token-bucket rate limiter (ratelimit.go) on POST /api/pastes, /api/guess-language and unlock POST; 429 + Retry-After + X-RateLimit headers. #26: new-page JS POSTs the password to /{id} with ?next= after creation; the unlock handler honors same-origin ?next= redirect so the creator lands on the unlocked paste. POST /{id} route added. Tests: ratelimit_test.go (burst/429, refill, unlock limit, highlight, auto- unlock e2e); existing tests updated for per-test limiter isolation.
88 lines
2.1 KiB
Go
88 lines
2.1 KiB
Go
package main
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import (
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"net/http"
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"strconv"
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"strings"
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"sync"
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"time"
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)
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// Per-IP token bucket rate limiting (#2). Goroutine-safe via mutex.
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type bucket struct {
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tokens float64
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last time.Time
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rate float64 // tokens per second
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burst float64
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}
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type limiter struct {
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mu sync.Mutex
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buckets map[string]*bucket
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}
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func newLimiter() *limiter {
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return &limiter{buckets: make(map[string]*bucket)}
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}
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func (l *limiter) allow(key string, rate, burst float64) bool {
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l.mu.Lock()
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defer l.mu.Unlock()
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now := time.Now()
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b, ok := l.buckets[key]
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if !ok {
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b = &bucket{tokens: burst, last: now, rate: rate, burst: burst}
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l.buckets[key] = b
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}
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elapsed := now.Sub(b.last).Seconds()
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b.tokens += elapsed * b.rate
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if b.tokens > b.burst {
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b.tokens = b.burst
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}
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b.last = now
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if b.tokens < 1 {
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return false
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}
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b.tokens--
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return true
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}
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// clientIP extracts the request IP (no reverse proxy header by default).
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func clientIP(r *http.Request) string {
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host := r.RemoteAddr
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if i := strings.LastIndex(host, ":"); i > 0 {
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host = host[:i]
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}
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return host
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}
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var globalLimiter = newLimiter()
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// rateLimitCreate: 1 req/sec refill, burst 5, per IP.
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func rateLimitCreate(r *http.Request) bool {
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return globalLimiter.allow("create:"+clientIP(r), 1, 5)
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}
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// rateLimitGuess: 1 req/sec refill, burst 5, per IP.
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func rateLimitGuess(r *http.Request) bool {
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return globalLimiter.allow("guess:"+clientIP(r), 1, 5)
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}
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// rateLimitUnlock: 5 per minute per IP+paste.
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func rateLimitUnlock(id string, r *http.Request) bool {
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return globalLimiter.allow("unlock:"+id+":"+clientIP(r), 5.0/60.0, 5)
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}
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// writeRateLimited responds 429 with Retry-After based on refill rate.
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func writeRateLimited(w http.ResponseWriter, retryAfterSecs int) {
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w.Header().Set("Retry-After", strconv.Itoa(retryAfterSecs))
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writeErr(w, 429, "rate limit exceeded")
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}
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// setRateLimitHeaders sets informational X-RateLimit headers for create/guess.
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func setRateLimitHeaders(w http.ResponseWriter, limit, burst int) {
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w.Header().Set("X-RateLimit-Limit", strconv.Itoa(limit))
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w.Header().Set("X-RateLimit-Burst", strconv.Itoa(burst))
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}
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