jcoffey-dev
85bbf5f828
Forms are YAML in forms/, rendered by {{ form }} with a small script and stylesheet the build publishes. cl-cms endpoint serves /_cl/ for any number of sites by host: it checks Origin, a per-IP rate limit, text-only bodies, a trap field, a signed 3 s to 24 h token and optional Turnstile, then the declared fields (types, lengths, options, no line breaks in single-line fields), and delivers by SMTP over TLS, optionally appending to a 0600 JSONL file. It also answers search from a collection's search.json, so a site can search in the browser or from the endpoint. cl-cms serve can pass /_cl/ to an endpoint, and -reload=false leaves out the live-reload script for headless browsers.
50 lines
1.2 KiB
Go
50 lines
1.2 KiB
Go
package endpoint
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import (
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"sync"
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"time"
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)
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// limiter counts attempts per key in a sliding window, in memory. Behind a
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// load balancer each endpoint counts on its own, so the effective limit is
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// the configured one times the number of endpoints; for a contact form that
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// is fine. A shared limit would need shared state, which is the first thing
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// here that would ask for a data store.
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type limiter struct {
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mu sync.Mutex
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count int
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window time.Duration
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hits map[string][]time.Time
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calls int
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}
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func newLimiter(count int, window time.Duration) *limiter {
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return &limiter{count: count, window: window, hits: map[string][]time.Time{}}
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}
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// allow records an attempt and reports whether it is within the limit.
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func (l *limiter) allow(key string, now time.Time) bool {
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l.mu.Lock()
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defer l.mu.Unlock()
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l.calls++
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if l.calls%1000 == 0 { // now and then, forget addresses that have gone quiet
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for k, ts := range l.hits {
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if len(ts) == 0 || now.Sub(ts[len(ts)-1]) > l.window {
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delete(l.hits, k)
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}
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}
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}
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ts := l.hits[key]
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cut := 0
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for cut < len(ts) && now.Sub(ts[cut]) > l.window {
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cut++
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}
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ts = ts[cut:]
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if len(ts) >= l.count {
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l.hits[key] = ts
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return false
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}
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l.hits[key] = append(ts, now)
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return true
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}
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