#11: implement MTA-STS, TLS-RPT & Autoconfig HTTP services

services/protocols/internal/domain/entity/dmarc_report.go

@@ -0,0 +1,103 @@
+package entity
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"time"
+)
+
+type DmarcRecord struct {
+	SourceIP        string
+	Count           int
+	Disposition     string
+	DKIMResult      string
+	SPFResult       string
+	HeaderFrom      string
+}
+
+type DmarcReport struct {
+	OrgName        string
+	ReportID       string
+	Domain         string
+	DateRangeBegin time.Time
+	DateRangeEnd   time.Time
+	Records        []DmarcRecord
+}
+
+type dmarcXmlReport struct {
+	ReportMetadata struct {
+		OrgName   string `xml:"org_name"`
+		ReportID  string `xml:"report_id"`
+		DateRange struct {
+			Begin int64 `xml:"begin"`
+			End   int64 `xml:"end"`
+		} `xml:"date_range"`
+	} `xml:"report_metadata"`
+	PolicyPublished struct {
+		Domain string `xml:"domain"`
+	} `xml:"policy_published"`
+	Record []struct {
+		Row struct {
+			SourceIP string `xml:"source_ip"`
+			Count    int    `xml:"count"`
+			PolicyEvaluated struct {
+				Disposition string `xml:"disposition"`
+				DKIM        string `xml:"dkim"`
+				SPF         string `xml:"spf"`
+			} `xml:"policy_evaluated"`
+		} `xml:"row"`
+		Identifiers struct {
+			HeaderFrom string `xml:"header_from"`
+		} `xml:"identifiers"`
+	} `xml:"record"`
+}
+
+// ParseDmarcXmlReport parses raw XML or gzipped XML DMARC aggregate report.
+func ParseDmarcXmlReport(payload []byte) (*DmarcReport, error) {
+	data := payload
+	if isGzip(payload) {
+		gz, err := gzip.NewReader(bytes.NewReader(payload))
+		if err != nil {
+			return nil, fmt.Errorf("gzip reader: %w", err)
+		}
+		defer gz.Close()
+		decompressed, err := io.ReadAll(gz)
+		if err != nil {
+			return nil, fmt.Errorf("decompress gzip: %w", err)
+		}
+		data = decompressed
+	}
+
+	var parsed dmarcXmlReport
+	if err := xml.Unmarshal(data, &parsed); err != nil {
+		return nil, fmt.Errorf("unmarshal dmarc xml: %w", err)
+	}
+
+	report := &DmarcReport{
+		OrgName:        parsed.ReportMetadata.OrgName,
+		ReportID:       parsed.ReportMetadata.ReportID,
+		Domain:         parsed.PolicyPublished.Domain,
+		DateRangeBegin: time.Unix(parsed.ReportMetadata.DateRange.Begin, 0),
+		DateRangeEnd:   time.Unix(parsed.ReportMetadata.DateRange.End, 0),
+	}
+
+	for _, r := range parsed.Record {
+		report.Records = append(report.Records, DmarcRecord{
+			SourceIP:    r.Row.SourceIP,
+			Count:       r.Row.Count,
+			Disposition: r.Row.PolicyEvaluated.Disposition,
+			DKIMResult:  r.Row.PolicyEvaluated.DKIM,
+			SPFResult:   r.Row.PolicyEvaluated.SPF,
+			HeaderFrom:  r.Identifiers.HeaderFrom,
+		})
+	}
+
+	return report, nil
+}
+
+func isGzip(payload []byte) bool {
+	return len(payload) >= 2 && payload[0] == 0x1f && payload[1] == 0x8b
+}