caddyhttp: Add support to resolve DN in CEL expression (#3608)

modules/caddyhttp/celmatcher_test.go

@@ -15,6 +15,11 @@
 package caddyhttp
 
 import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/pem"
+	"net/http/httptest"
 	"testing"
 
 	"github.com/caddyserver/caddy/v2"
@@ -27,7 +32,7 @@ func TestMatchExpressionProvision(t *testing.T) {
 		wantErr    bool
 	}{
 		{
-			name: "boolean mtaches succeed",
+			name: "boolean matches succeed",
 			expression: &MatchExpression{
 				Expr: "{http.request.uri.query} != ''",
 			},
@@ -49,3 +54,71 @@ func TestMatchExpressionProvision(t *testing.T) {
 		})
 	}
 }
+
+func TestMatchExpressionMatch(t *testing.T) {
+
+	clientCert := []byte(`-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----`)
+
+	tests := []struct {
+		name              string
+		expression        *MatchExpression
+		wantErr           bool
+		wantResult        bool
+		clientCertificate []byte
+	}{
+		{
+			name: "boolean matches succeed for placeholder http.request.tls.client.subject",
+			expression: &MatchExpression{
+				Expr: "{http.request.tls.client.subject} == 'CN=client.localdomain'",
+			},
+			clientCertificate: clientCert,
+			wantResult:        true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := tt.expression.Provision(caddy.Context{}); (err != nil) != tt.wantErr {
+				t.Errorf("MatchExpression.Provision() error = %v, wantErr %v", err, tt.wantErr)
+			}
+
+			req := httptest.NewRequest("GET", "https://example.com/foo", nil)
+			repl := caddy.NewReplacer()
+			ctx := context.WithValue(req.Context(), caddy.ReplacerCtxKey, repl)
+			req = req.WithContext(ctx)
+			addHTTPVarsToReplacer(repl, req, httptest.NewRecorder())
+
+			if tt.clientCertificate != nil {
+				block, _ := pem.Decode(clientCert)
+				if block == nil {
+					t.Fatalf("failed to decode PEM certificate")
+				}
+
+				cert, err := x509.ParseCertificate(block.Bytes)
+				if err != nil {
+					t.Fatalf("failed to decode PEM certificate: %v", err)
+				}
+
+				req.TLS = &tls.ConnectionState{
+					PeerCertificates: []*x509.Certificate{cert},
+				}
+			}
+
+			if tt.expression.Match(req) != tt.wantResult {
+				t.Errorf("MatchExpression.Match() expected to return '%t', for expression : '%s'", tt.wantResult, tt.expression)
+			}
+
+		})
+	}
+}