Method CheckBody

internal/check/dkim/dkim.go:122–255

(ctx context.Context, header textproto.Header, body buffer.Buffer)

}

func (d *dkimCheckState) CheckBody(ctx context.Context, header textproto.Header, body buffer.Buffer) module.CheckResult {
	defer trace.StartRegion(ctx, "check.dkim/CheckBody").End()

	if !header.Has("DKIM-Signature") {
		if d.c.noSigAction.Reject || d.c.noSigAction.Quarantine {
			d.log.Printf("no signatures present")
		} else {
			d.log.Debugf("no signatures present")
		}
		return d.c.noSigAction.Apply(module.CheckResult{
			Reason: &exterrors.SMTPError{
				Code:         550,
				EnhancedCode: exterrors.EnhancedCode{5, 7, 20},
				Message:      "No DKIM signatures",
				CheckName:    "check.dkim",
			},
			AuthResult: []authres.Result{
				&authres.DKIMResult{
					Value: authres.ResultNone,
				},
			},
		})
	}

	b := bytes.Buffer{}
	_ = textproto.WriteHeader(&b, header)
	bodyRdr, err := body.Open()
	if err != nil {
		return module.CheckResult{
			Reject: true,
			Reason: exterrors.WithTemporary(
				exterrors.WithFields(err, map[string]interface{}{
					"check":    "check.dkim",
					"smtp_msg": "Internal I/O error",
				}),
				true,
			),
		}
	}

	verifications, err := dkim.VerifyWithOptions(io.MultiReader(&b, bodyRdr), &dkim.VerifyOptions{
		LookupTXT: func(domain string) ([]string, error) {
			return d.c.resolver.LookupTXT(ctx, domain)
		},
	})
	if err != nil {
		return module.CheckResult{
			Reject: true,
			Reason: exterrors.WithTemporary(
				exterrors.WithFields(err, map[string]interface{}{
					"check":    "check.dkim",
					"smtp_msg": "Internal error during policy check",
				}),
				true,
			),
		}
	}