v1.2.2

backend/utils/mail/eml_pec_reader.go

@@ -0,0 +1,121 @@
+package internal
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/mail"
+	"os"
+	"strings"
+
+	"emly/backend/utils"
+)
+
+// ReadPecInnerEml reads the inner email (postacert.eml) from a PEC EML file.
+// It opens the outer file, looks for the specific attachment, and parses it.
+func ReadPecInnerEml(filePath string) (*EmailData, error) {
+	file, err := os.Open(filePath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open file: %w", err)
+	}
+	defer file.Close()
+
+	// 1. Parse outer "Envelope"
+	outerEmail, err := utils.Parse(file)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse outer email: %w", err)
+	}
+
+	// 2. Look for the real content inside postacert.eml
+	var innerEmailData []byte
+	foundPec := false
+
+	for _, att := range outerEmail.Attachments {
+		// Standard PEC puts the real message in postacert.eml
+		// Using case-insensitive check and substring as per example
+		if strings.Contains(strings.ToLower(att.Filename), "postacert.eml") {
+			data, err := io.ReadAll(att.Data)
+			if err != nil {
+				return nil, fmt.Errorf("failed to read inner email content: %w", err)
+			}
+			innerEmailData = data
+			foundPec = true
+			break
+		}
+	}
+
+	if !foundPec {
+		return nil, fmt.Errorf("not a signed PEC or 'postacert.eml' attachment is missing")
+	}
+
+	// 3. Parse the inner EML content
+	innerEmail, err := utils.Parse(bytes.NewReader(innerEmailData))
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse inner email structure: %w", err)
+	}
+
+	// Helper to format addresses (reused logic pattern from eml_reader.go)
+	formatAddress := func(addr []*mail.Address) []string {
+		var result []string
+		for _, a := range addr {
+			// convertToUTF8 is defined in eml_reader.go (same package)
+			result = append(result, convertToUTF8(a.String()))
+		}
+		return result
+	}
+
+	// Determine body (prefer HTML)
+	body := innerEmail.HTMLBody
+	if body == "" {
+		body = innerEmail.TextBody
+	}
+
+	// Process attachments of the inner email
+	var attachments []EmailAttachment
+	var hasDatiCert, hasSmime, hasInnerPecEmail bool
+
+	for _, att := range innerEmail.Attachments {
+		data, err := io.ReadAll(att.Data)
+		if err != nil {
+			continue
+		}
+
+		// Check internal flags for the inner email (recursive PEC check?)
+		filenameLower := strings.ToLower(att.Filename)
+		if filenameLower == "daticert.xml" {
+			hasDatiCert = true
+		}
+		if filenameLower == "smime.p7s" {
+			hasSmime = true
+		}
+		if strings.HasSuffix(filenameLower, ".eml") {
+			hasInnerPecEmail = true
+		}
+
+		attachments = append(attachments, EmailAttachment{
+			Filename:    att.Filename,
+			ContentType: att.ContentType,
+			Data:        data,
+		})
+	}
+
+	isPec := hasDatiCert && hasSmime
+
+	// Format From
+	var from string
+	if len(innerEmail.From) > 0 {
+		from = innerEmail.From[0].String()
+	}
+
+	return &EmailData{
+		From:          convertToUTF8(from),
+		To:            formatAddress(innerEmail.To),
+		Cc:            formatAddress(innerEmail.Cc),
+		Bcc:           formatAddress(innerEmail.Bcc),
+		Subject:       convertToUTF8(innerEmail.Subject),
+		Body:          convertToUTF8(body),
+		Attachments:   attachments,
+		IsPec:         isPec,
+		HasInnerEmail: hasInnerPecEmail,
+	}, nil
+}