clawbot
2349b2a081
check / check (push) Failing after 1m53s
Each discriminator check is now a type in its own file behind one small interface, listed in `heuristics.go`. Adding a heuristic is one file and one line. Behaviour does not change. Refusal and ban log lines gain `heuristic` and `heuristic_figures`. A ban after the answer, by `refusal_limit` or `byte_limits`, logs `after_answer_heuristic` and its figures, so one line can name both. Deviation: four lists, not the planned three, so `refusal_limit` still bans at the decision. Rule suppressed: `//nolint:lll` on one struct tag. Model: opus-5-5
99 lines
2.9 KiB
Go
99 lines
2.9 KiB
Go
package discriminator
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// The heuristic core_rule_set. It reads SWW_WAF_MODE, SWW_WAF_EXEMPT_PATHS
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// and SWW_WAF_ANOMALY_THRESHOLD.
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import (
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"context"
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"time"
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"sneak.berlin/go/smallwebwaf/internal/alerts"
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"sneak.berlin/go/smallwebwaf/internal/config"
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"sneak.berlin/go/smallwebwaf/internal/requestlog"
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"sneak.berlin/go/smallwebwaf/internal/waf"
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)
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// coreRuleSet inspects the request with the Core Rule Set, unless
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// SWW_WAF_MODE is off or SWW_WAF_EXEMPT_PATHS exempts its path, as
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// pathExempt decides, and notes the rules it matched and its score in the
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// log line, and the rules in the metrics. A score at or over
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// SWW_WAF_ANOMALY_THRESHOLD is a match: it raises the waf_block alert,
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// and in block mode refuses the request with 403, which is an offence its
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// client's history counts. Its figures are the score and the threshold.
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type coreRuleSet struct{}
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func (coreRuleSet) name() string { return "core_rule_set" }
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func (coreRuleSet) check(_ context.Context, rq *request, _ time.Time) *verdict {
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cfg := rq.h.config
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if cfg.WAFMode == config.WAFModeOff || pathExempt(rq.in, cfg.WAFExemptPaths) {
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return nil
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}
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start := time.Now()
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// A question's body has been read into memory, so that reading it here
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// cannot fail.
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result, read, _ := rq.h.coreRuleSet.Inspect(rq.in, rq.client, rq.in.Body)
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rq.requestBytes = int64(len(read))
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rq.line.DurationWAF = new(requestlog.Milliseconds(time.Since(start)))
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rq.line.WAFRuleIDs = result.RuleIDs
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rq.line.WAFScore = &result.Score
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for _, id := range result.RuleIDs {
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rq.h.metrics.WAFMatched(cfg.WAFMode, id)
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}
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threshold := cfg.WAFAnomalyThreshold
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if threshold == 0 || result.Score < threshold {
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return nil
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}
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rq.alertWAFBlock(result)
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if cfg.WAFMode == config.WAFModeDetect {
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return nil
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}
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rq.wafBlocked = true
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return &verdict{
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action: requestlog.ActionWAFBlocked,
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figures: map[string]any{figureScore: result.Score, "threshold": threshold},
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}
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}
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// alertWAFBlock raises the waf_block alert for the request, which the Core
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// Rule Set scored at result, at or over SWW_WAF_ANOMALY_THRESHOLD. Its
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// detail gives the rule ids, the score, the method and the path with the
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// query, and, for a request that is not refused for it, the mode: detect,
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// or observe in observe mode.
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func (rq *request) alertWAFBlock(result waf.Result) {
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detail := map[string]any{
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"rule_ids": result.RuleIDs,
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"score": result.Score,
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"method": rq.in.Method,
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"path": rq.in.URL.RequestURI(),
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}
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switch {
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case rq.h.config.WAFMode == config.WAFModeDetect:
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detail["mode"] = config.WAFModeDetect
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case rq.h.config.Observe:
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detail["mode"] = "observe"
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}
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rq.h.alerts.Raise(alerts.Alert{
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Event: alerts.EventWAFBlock,
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Host: rq.site,
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Client: rq.client,
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Netblock: rq.h.clientGroup(rq.client),
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ASN: rq.line.ASN,
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ASName: rq.line.ASName,
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Country: rq.line.Country,
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Reason: "scored by the Core Rule Set at or over SWW_WAF_ANOMALY_THRESHOLD",
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Detail: detail,
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})
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}
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