minor waf fixes (#2693)

pkg/acquisition/modules/appsec/appsec.go

@@ -335,7 +335,7 @@ func (w *AppsecSource) appsecHandler(rw http.ResponseWriter, r *http.Request) {
 	}
 
 	// parse the request only once
-	parsedRequest, err := appsec.NewParsedRequestFromRequest(r)
+	parsedRequest, err := appsec.NewParsedRequestFromRequest(r, w.logger)
 	if err != nil {
 		w.logger.Errorf("%s", err)
 		rw.WriteHeader(http.StatusInternalServerError)

pkg/appsec/appsec_rule/appsec_rule.go

@@ -28,6 +28,7 @@ rules:
 type match struct {
 	Type  string `yaml:"type"`
 	Value string `yaml:"value"`
+	Not   bool   `yaml:"not,omitempty"`
 }
 
 type CustomRule struct {
@@ -40,7 +41,8 @@ type CustomRule struct {
 	Transform []string     `yaml:"transform"` //t:lowercase, t:uppercase, etc
 	And       []CustomRule `yaml:"and,omitempty"`
 	Or        []CustomRule `yaml:"or,omitempty"`
-	BodyType  string       `yaml:"body_type,omitempty"`
+
+	BodyType string `yaml:"body_type,omitempty"`
 }
 
 func (v *CustomRule) Convert(ruleType string, appsecRuleName string) (string, []uint32, error) {

pkg/appsec/appsec_rule/modsec_rule_test.go

@@ -18,6 +18,22 @@ func TestVPatchRuleString(t *testing.T) {
 			},
 			expected: `SecRule ARGS_GET:foo "@rx [^a-zA-Z]" "id:2203944045,phase:2,deny,log,msg:'Base Rule',tag:'crowdsec-Base Rule',t:lowercase"`,
 		},
+		{
+			name: "Base Rule #2",
+			rule: CustomRule{
+				Zones: []string{"METHOD"},
+				Match: match{Type: "startsWith", Value: "toto"},
+			},
+			expected: `SecRule REQUEST_METHOD "@beginsWith toto" "id:2759779019,phase:2,deny,log,msg:'Base Rule #2',tag:'crowdsec-Base Rule #2'"`,
+		},
+		{
+			name: "Base Negative Rule",
+			rule: CustomRule{
+				Zones: []string{"METHOD"},
+				Match: match{Type: "startsWith", Value: "toto", Not: true},
+			},
+			expected: `SecRule REQUEST_METHOD "!@beginsWith toto" "id:3966251995,phase:2,deny,log,msg:'Base Negative Rule',tag:'crowdsec-Base Negative Rule'"`,
+		},
 		{
 			name: "Multiple Zones",
 			rule: CustomRule{

pkg/appsec/appsec_rule/modsecurity.go

@@ -44,6 +44,7 @@ var matchMap map[string]string = map[string]string{
 	"lt":              "@lt",
 	"gte":             "@ge",
 	"lte":             "@le",
+	"eq":              "@eq",
 }
 
 var bodyTypeMatch map[string]string = map[string]string{
@@ -141,7 +142,11 @@ func (m *ModsecurityRule) buildRules(rule *CustomRule, appsecRuleName string, an
 
 	if rule.Match.Type != "" {
 		if match, ok := matchMap[rule.Match.Type]; ok {
-			r.WriteString(fmt.Sprintf(`"%s %s"`, match, rule.Match.Value))
+			prefix := ""
+			if rule.Match.Not {
+				prefix = "!"
+			}
+			r.WriteString(fmt.Sprintf(`"%s%s %s"`, prefix, match, rule.Match.Value))
 		} else {
 			return nil, fmt.Errorf("unknown match type '%s'", rule.Match.Type)
 		}

pkg/appsec/request.go

@@ -11,6 +11,7 @@ import (
 	"regexp"
 
 	"github.com/google/uuid"
+	"github.com/sirupsen/logrus"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -267,7 +268,7 @@ func (r *ReqDumpFilter) ToJSON() error {
 }
 
 // Generate a ParsedRequest from a http.Request. ParsedRequest can be consumed by the App security Engine
-func NewParsedRequestFromRequest(r *http.Request) (ParsedRequest, error) {
+func NewParsedRequestFromRequest(r *http.Request, logger *logrus.Entry) (ParsedRequest, error) {
 	var err error
 	contentLength := r.ContentLength
 	if contentLength < 0 {
@@ -282,26 +283,23 @@ func NewParsedRequestFromRequest(r *http.Request) (ParsedRequest, error) {
 		}
 	}
 
-	// the real source of the request is set in 'x-client-ip'
 	clientIP := r.Header.Get(IPHeaderName)
 	if clientIP == "" {
 		return ParsedRequest{}, fmt.Errorf("missing '%s' header", IPHeaderName)
 	}
-	// the real target Host of the request is set in 'x-client-host'
-	clientHost := r.Header.Get(HostHeaderName)
-	if clientHost == "" {
-		return ParsedRequest{}, fmt.Errorf("missing '%s' header", HostHeaderName)
-	}
-	// the real URI of the request is set in 'x-client-uri'
+
 	clientURI := r.Header.Get(URIHeaderName)
 	if clientURI == "" {
 		return ParsedRequest{}, fmt.Errorf("missing '%s' header", URIHeaderName)
 	}
-	// the real VERB of the request is set in 'x-client-uri'
 	clientMethod := r.Header.Get(VerbHeaderName)
 	if clientMethod == "" {
 		return ParsedRequest{}, fmt.Errorf("missing '%s' header", VerbHeaderName)
 	}
+	clientHost := r.Header.Get(HostHeaderName)
+	if clientHost == "" { //this might be empty
+		logger.Debugf("missing '%s' header", HostHeaderName)
+	}
 
 	// delete those headers before coraza process the request
 	delete(r.Header, IPHeaderName)