Files
smallwebwaf/internal/proxy/coreruleset.go
T
clawbot ac1a69e863
check / check (push) Failing after 23m49s
rproxy and servewaf replace the one-process smallwebwaf (closes #172, closes #165)
`smallwebwaf` with no command now prints the commands and exits with status 2.
The image runs rproxy, or servewaf with SMALLWEBWAF_COMMAND=servewaf. The
passing-on code, its settings and its log fields and metric go. internal/proxy
keeps the checks, answers, reports and own endpoints; its tests run through the
real rproxy. The documents describe the pair.

Judgement call: clients.json keeps token_refused, since state files refuse unknown fields.
Deviation: script/gitea-requests sets SWWAF_LOG_REQUEST_HEADERS, to label requests.

Model: opus-5-5
2026-11-05 10:33:24 +00:00

89 lines
2.6 KiB
Go

package proxy
import (
"time"
"sneak.berlin/go/smallwebwaf/internal/alerts"
"sneak.berlin/go/smallwebwaf/internal/config"
"sneak.berlin/go/smallwebwaf/internal/requestlog"
"sneak.berlin/go/smallwebwaf/internal/waf"
)
// checkCoreRuleSet inspects the request with the Core Rule Set, unless
// SWWAF_WAF_MODE is off or SWWAF_WAF_EXEMPT_PATHS exempts its path, as
// pathExempt decides, and notes the rules it matched and its score in the
// log line, and the rules in the metrics. A score at or over
// SWWAF_WAF_ANOMALY_THRESHOLD is a match: it raises the waf_block alert,
// and in block mode refuses the request, which is an offence its client's
// history counts, and so returns ActionWAFBlocked. It returns "" for a
// request it does not refuse.
func (rq *request) checkCoreRuleSet() string {
cfg := rq.h.config
if cfg.WAFMode == config.WAFModeOff || pathExempt(rq.in, cfg.WAFExemptPaths) {
return ""
}
start := time.Now()
// A question's body has been read into memory, so that reading it here
// cannot fail.
result, read, _ := rq.h.coreRuleSet.Inspect(rq.in, rq.client, rq.in.Body)
rq.requestBytes = int64(len(read))
rq.line.DurationWAF = new(requestlog.Milliseconds(time.Since(start)))
rq.line.WAFRuleIDs = result.RuleIDs
rq.line.WAFScore = &result.Score
for _, id := range result.RuleIDs {
rq.h.metrics.WAFMatched(cfg.WAFMode, id)
}
threshold := cfg.WAFAnomalyThreshold
if threshold == 0 || result.Score < threshold {
return ""
}
rq.alertWAFBlock(result)
if cfg.WAFMode == config.WAFModeDetect {
return ""
}
rq.wafBlocked = true
return requestlog.ActionWAFBlocked
}
// alertWAFBlock raises the waf_block alert for the request, which the Core
// Rule Set scored at result, at or over SWWAF_WAF_ANOMALY_THRESHOLD. Its
// detail gives the rule ids, the score, the method and the path with the
// query, and, for a request that is not refused for it, the mode: detect,
// or observe in observe mode.
func (rq *request) alertWAFBlock(result waf.Result) {
detail := map[string]any{
"rule_ids": result.RuleIDs,
"score": result.Score,
"method": rq.in.Method,
"path": rq.in.URL.RequestURI(),
}
switch {
case rq.h.config.WAFMode == config.WAFModeDetect:
detail["mode"] = config.WAFModeDetect
case rq.h.config.Observe:
detail["mode"] = "observe"
}
rq.h.alerts.Raise(alerts.Alert{
Event: alerts.EventWAFBlock,
Host: rq.site,
Client: rq.client,
Netblock: rq.h.clientGroup(rq.client),
ASN: rq.line.ASN,
ASName: rq.line.ASName,
Country: rq.line.Country,
Reason: "scored by the Core Rule Set at or over SWWAF_WAF_ANOMALY_THRESHOLD",
Detail: detail,
})
}