Correct lint attribution for dnsname_etc lints and limit scope to jus…

…t DNS SAN entries (#609)

Adding an RFC5280 specific version that does not check for CommonName of the dnsname lints that are already present in CABF lints

v3/integration/config.json

@@ -306,6 +306,9 @@
     "e_dnsname_empty_label": {
       "ErrCount": 11
     },
+    "e_rfc_dnsname_empty_label": {
+      "ErrCount": 10
+    },
     "e_dnsname_hyphen_in_sld": {},
     "e_dnsname_label_too_long": {},
     "e_dnsname_left_label_wildcard_correct": {
@@ -317,6 +320,9 @@
     "e_dnsname_underscore_in_sld": {
       "ErrCount": 1
     },
+    "e_rfc_dnsname_underscore_in_sld": {
+      "ErrCount": 1
+    },
     "e_dnsname_wildcard_only_in_left_label": {},
     "e_dsa_correct_order_in_subgroup": {},
     "e_dsa_improper_modulus_or_divisor_size": {},
@@ -670,6 +676,9 @@
     "w_dnsname_underscore_in_trd": {
       "WarnCount": 339
     },
+    "w_rfc_dnsname_underscore_in_trd": {
+      "WarnCount": 339
+    },
     "w_eku_critical_improperly": {},
     "w_ext_aia_access_location_missing": {
       "WarnCount": 284

v3/lints/rfc/lint_dnsname_contains_empty_label.go

@@ -0,0 +1,63 @@
+package rfc
+
+/*
+ * ZLint Copyright 2021 Regents of the University of Michigan
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+import (
+	"strings"
+
+	"github.com/zmap/zcrypto/x509"
+	"github.com/zmap/zlint/v3/lint"
+	"github.com/zmap/zlint/v3/util"
+)
+
+type DNSNameEmptyLabel struct{}
+
+func init() {
+	lint.RegisterLint(&lint.Lint{
+		Name:          "e_rfc_dnsname_empty_label",
+		Description:   "DNSNames should not have an empty label.",
+		Citation:      "RFC5280: 4.2.1.6",
+		Source:        lint.RFC5280,
+		EffectiveDate: util.RFC5280Date,
+		Lint:          NewDNSNameEmptyLabel,
+	})
+}
+
+func NewDNSNameEmptyLabel() lint.LintInterface {
+	return &DNSNameEmptyLabel{}
+}
+
+func (l *DNSNameEmptyLabel) CheckApplies(c *x509.Certificate) bool {
+	return util.IsSubscriberCert(c) && util.DNSNamesExist(c)
+}
+
+func domainHasEmptyLabel(domain string) bool {
+	labels := strings.Split(domain, ".")
+	for _, elem := range labels {
+		if elem == "" {
+			return true
+		}
+	}
+	return false
+}
+
+func (l *DNSNameEmptyLabel) Execute(c *x509.Certificate) *lint.LintResult {
+	for _, dns := range c.DNSNames {
+		if domainHasEmptyLabel(dns) {
+			return &lint.LintResult{Status: lint.Error}
+		}
+	}
+	return &lint.LintResult{Status: lint.Pass}
+}

v3/lints/rfc/lint_dnsname_contains_empty_label_test.go

@@ -0,0 +1,40 @@
+package rfc
+
+/*
+ * ZLint Copyright 2021 Regents of the University of Michigan
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+import (
+	"testing"
+
+	"github.com/zmap/zlint/v3/lint"
+	"github.com/zmap/zlint/v3/test"
+)
+
+func TestDNSNameEmptyLabel(t *testing.T) {
+	inputPath := "dnsNameEmptyLabel.pem"
+	expected := lint.Error
+	out := test.TestLint("e_rfc_dnsname_empty_label", inputPath)
+	if out.Status != expected {
+		t.Errorf("%s: expected %s, got %s", inputPath, expected, out.Status)
+	}
+}
+
+func TestDNSNameNotEmptyLabel(t *testing.T) {
+	inputPath := "dnsNameNotEmptyLabel.pem"
+	expected := lint.Pass
+	out := test.TestLint("e_rfc_dnsname_empty_label", inputPath)
+	if out.Status != expected {
+		t.Errorf("%s: expected %s, got %s", inputPath, expected, out.Status)
+	}
+}

v3/lints/rfc/lint_dnsname_hyphen_in_sld.go

@@ -0,0 +1,58 @@
+package rfc
+
+/*
+ * ZLint Copyright 2021 Regents of the University of Michigan
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+import (
+	"strings"
+
+	"github.com/zmap/zcrypto/x509"
+	"github.com/zmap/zlint/v3/lint"
+	"github.com/zmap/zlint/v3/util"
+)
+
+type DNSNameHyphenInSLD struct{}
+
+func init() {
+	lint.RegisterLint(&lint.Lint{
+		Name:          "e_rfc_dnsname_hyphen_in_sld",
+		Description:   "DNSName should not have a hyphen beginning or ending the SLD",
+		Citation:      "RFC5280: 4.2.1.6",
+		Source:        lint.RFC5280,
+		EffectiveDate: util.RFC5280Date,
+		Lint:          NewDNSNameHyphenInSLD,
+	})
+}
+
+func NewDNSNameHyphenInSLD() lint.LintInterface {
+	return &DNSNameHyphenInSLD{}
+}
+
+func (l *DNSNameHyphenInSLD) CheckApplies(c *x509.Certificate) bool {
+	return util.IsSubscriberCert(c) && util.DNSNamesExist(c)
+}
+
+func (l *DNSNameHyphenInSLD) Execute(c *x509.Certificate) *lint.LintResult {
+	parsedSANDNSNames := c.GetParsedDNSNames(false)
+	for i := range c.GetParsedDNSNames(false) {
+		if parsedSANDNSNames[i].ParseError != nil {
+			return &lint.LintResult{Status: lint.NA}
+		}
+		if strings.HasPrefix(parsedSANDNSNames[i].ParsedDomain.SLD, "-") ||
+			strings.HasSuffix(parsedSANDNSNames[i].ParsedDomain.SLD, "-") {
+			return &lint.LintResult{Status: lint.Error}
+		}
+	}
+	return &lint.LintResult{Status: lint.Pass}
+}

v3/lints/rfc/lint_dnsname_hyphen_in_sld_test.go

@@ -0,0 +1,58 @@
+package rfc
+
+/*
+ * ZLint Copyright 2021 Regents of the University of Michigan
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+import (
+	"testing"
+
+	"github.com/zmap/zlint/v3/lint"
+	"github.com/zmap/zlint/v3/test"
+)
+
+func TestDNSNameHyphenBeginningSLD(t *testing.T) {
+	inputPath := "dnsNameHyphenBeginningSLD.pem"
+	expected := lint.Error
+	out := test.TestLint("e_rfc_dnsname_hyphen_in_sld", inputPath)
+	if out.Status != expected {
+		t.Errorf("%s: expected %s, got %s", inputPath, expected, out.Status)
+	}
+}
+
+func TestDNSNameHyphenEndingSLD(t *testing.T) {
+	inputPath := "dnsNameHyphenEndingSLD.pem"
+	expected := lint.Error
+	out := test.TestLint("e_rfc_dnsname_hyphen_in_sld", inputPath)
+	if out.Status != expected {
+		t.Errorf("%s: expected %s, got %s", inputPath, expected, out.Status)
+	}
+}
+
+func TestDNSNameNoHyphenInSLD(t *testing.T) {
+	inputPath := "dnsNameWildcardCorrect.pem"
+	expected := lint.Pass
+	out := test.TestLint("e_rfc_dnsname_hyphen_in_sld", inputPath)
+	if out.Status != expected {
+		t.Errorf("%s: expected %s, got %s", inputPath, expected, out.Status)
+	}
+}
+
+func TestDNSNamePrivatePublicSuffixNoHyphenInSLD(t *testing.T) {
+	inputPath := "dnsNamePrivatePublicSuffix.pem"
+	expected := lint.Pass
+	out := test.TestLint("e_rfc_dnsname_hyphen_in_sld", inputPath)
+	if out.Status != expected {
+		t.Errorf("%s: expected %s, got %s", inputPath, expected, out.Status)
+	}
+}

v3/lints/rfc/lint_dnsname_label_too_long.go

@@ -0,0 +1,64 @@
+package rfc
+
+/*
+ * ZLint Copyright 2021 Regents of the University of Michigan
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+import (
+	"strings"
+
+	"github.com/zmap/zcrypto/x509"
+	"github.com/zmap/zlint/v3/lint"
+	"github.com/zmap/zlint/v3/util"
+)
+
+type DNSNameLabelLengthTooLong struct{}
+
+func init() {
+	lint.RegisterLint(&lint.Lint{
+		Name:          "e_rfc_dnsname_label_too_long",
+		Description:   "DNSName labels MUST be less than or equal to 63 characters",
+		Citation:      "RFC 5280: 4.2.1.6, citing RFC 1035",
+		Source:        lint.RFC5280,
+		EffectiveDate: util.RFC5280Date,
+		Lint:          NewDNSNameLabelLengthTooLong,
+	})
+}
+
+func NewDNSNameLabelLengthTooLong() lint.LintInterface {
+	return &DNSNameLabelLengthTooLong{}
+}
+
+func (l *DNSNameLabelLengthTooLong) CheckApplies(c *x509.Certificate) bool {
+	return util.IsSubscriberCert(c) && util.DNSNamesExist(c)
+}
+
+func labelLengthTooLong(domain string) bool {
+	labels := strings.Split(domain, ".")
+	for _, label := range labels {
+		if len(label) > 63 {
+			return true
+		}
+	}
+	return false
+}
+
+func (l *DNSNameLabelLengthTooLong) Execute(c *x509.Certificate) *lint.LintResult {
+	for _, dns := range c.DNSNames {
+		labelTooLong := labelLengthTooLong(dns)
+		if labelTooLong {
+			return &lint.LintResult{Status: lint.Error}
+		}
+	}
+	return &lint.LintResult{Status: lint.Pass}
+}

v3/lints/rfc/lint_dnsname_label_too_long_test.go

@@ -0,0 +1,31 @@
+package rfc
+
+/*
+ * ZLint Copyright 2021 Regents of the University of Michigan
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+import (
+	"testing"
+
+	"github.com/zmap/zlint/v3/lint"
+	"github.com/zmap/zlint/v3/test"
+)
+
+func TestDNSNameLabelTooLong(t *testing.T) {
+	inputPath := "dnsNameLabelTooLong.pem"
+	expected := lint.Error
+	out := test.TestLint("e_rfc_dnsname_label_too_long", inputPath)
+	if out.Status != expected {
+		t.Errorf("%s: expected %s, got %s", inputPath, expected, out.Status)
+	}
+}