Split authentication.go in one file per check

pkg/analyzer/authentication_x_google_dkim.go

@@ -0,0 +1,73 @@
+// This file is part of the happyDeliver (R) project.
+// Copyright (c) 2025 happyDomain
+// Authors: Pierre-Olivier Mercier, et al.
+//
+// This program is offered under a commercial and under the AGPL license.
+// For commercial licensing, contact us at <contact@happydomain.org>.
+//
+// For AGPL licensing:
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package analyzer
+
+import (
+	"regexp"
+	"strings"
+
+	"git.happydns.org/happyDeliver/internal/api"
+)
+
+// parseXGoogleDKIMResult parses Google DKIM result from Authentication-Results
+// Example: x-google-dkim=pass (2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=fauiPVZ6
+func (a *AuthenticationAnalyzer) parseXGoogleDKIMResult(part string) *api.AuthResult {
+	result := &api.AuthResult{}
+
+	// Extract result (pass, fail, etc.)
+	re := regexp.MustCompile(`x-google-dkim=(\w+)`)
+	if matches := re.FindStringSubmatch(part); len(matches) > 1 {
+		resultStr := strings.ToLower(matches[1])
+		result.Result = api.AuthResultResult(resultStr)
+	}
+
+	// Extract domain (header.d or d)
+	domainRe := regexp.MustCompile(`(?:header\.)?d=([^\s;]+)`)
+	if matches := domainRe.FindStringSubmatch(part); len(matches) > 1 {
+		domain := matches[1]
+		result.Domain = &domain
+	}
+
+	// Extract selector (header.s or s) - though not always present in x-google-dkim
+	selectorRe := regexp.MustCompile(`(?:header\.)?s=([^\s;]+)`)
+	if matches := selectorRe.FindStringSubmatch(part); len(matches) > 1 {
+		selector := matches[1]
+		result.Selector = &selector
+	}
+
+	result.Details = api.PtrTo(strings.TrimPrefix(part, "x-google-dkim="))
+
+	return result
+}
+
+func (a *AuthenticationAnalyzer) calculateXGoogleDKIMScore(results *api.AuthenticationResults) (score int) {
+	if results.XGoogleDkim != nil {
+		switch results.XGoogleDkim.Result {
+		case api.AuthResultResultPass:
+			// pass: don't alter the score
+		default: // fail
+			return -100
+		}
+	}
+
+	return 0
+}