1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
package rfc
/*
* ZLint Copyright 2024 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 (
"fmt"
"strings"
"github.com/zmap/zcrypto/x509"
"github.com/zmap/zlint/v3/lint"
"github.com/zmap/zlint/v3/util"
)
type extDuplicateExtension struct{}
/************************************************
"A certificate MUST NOT include more than one instance of a particular extension."
************************************************/
func init() {
lint.RegisterCertificateLint(&lint.CertificateLint{
LintMetadata: lint.LintMetadata{
Name: "e_ext_duplicate_extension",
Description: "A certificate MUST NOT include more than one instance of a particular extension",
Citation: "RFC 5280: 4.2",
Source: lint.RFC5280,
EffectiveDate: util.RFC2459Date,
},
Lint: NewExtDuplicateExtension,
})
}
func NewExtDuplicateExtension() lint.LintInterface {
return &extDuplicateExtension{}
}
func (l *extDuplicateExtension) CheckApplies(cert *x509.Certificate) bool {
return cert.Version == 3
}
func (l *extDuplicateExtension) Execute(cert *x509.Certificate) *lint.LintResult {
// Make two maps: one for all of the extensions in the cert, and one for any
// OIDs that are found more than once.
extensionOIDs := make(map[string]bool)
duplicateOIDs := make(map[string]bool)
// Iterate through the certificate extensions and update the maps.
for _, ext := range cert.Extensions {
// We can't use the `asn1.ObjectIdentifier` as a key (it's an int slice) so use
// the str representation.
oid := ext.Id.String()
if alreadySeen := extensionOIDs[oid]; alreadySeen {
duplicateOIDs[oid] = true
} else {
extensionOIDs[oid] = true
}
}
// If there were no duplicates we're done, the cert passes.
if len(duplicateOIDs) == 0 {
return &lint.LintResult{Status: lint.Pass}
}
// If there were duplicates turn the map keys into a list so we
// can join them for the details string.
var duplicateOIDsList []string
for oid := range duplicateOIDs {
duplicateOIDsList = append(duplicateOIDsList, oid)
}
return &lint.LintResult{
Status: lint.Error,
Details: fmt.Sprintf(
"The following extensions are duplicated: %s",
strings.Join(duplicateOIDsList, ", ")),
}
}
|
