github.com/zmap/zlint@v1.1.0/lints/lint_san_dns_name_duplicate.go (about)

     1  /*
     2   * ZLint Copyright 2017 Regents of the University of Michigan
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License"); you may not
     5   * use this file except in compliance with the License. You may obtain a copy
     6   * of the License at http://www.apache.org/licenses/LICENSE-2.0
     7   *
     8   * Unless required by applicable law or agreed to in writing, software
     9   * distributed under the License is distributed on an "AS IS" BASIS,
    10   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
    11   * implied. See the License for the specific language governing
    12   * permissions and limitations under the License.
    13   */
    14  
    15  package lints
    16  
    17  import (
    18  	"strings"
    19  
    20  	"github.com/zmap/zcrypto/x509"
    21  	"github.com/zmap/zlint/util"
    22  )
    23  
    24  type SANDNSDuplicate struct{}
    25  
    26  func (l *SANDNSDuplicate) Initialize() error {
    27  	return nil
    28  }
    29  
    30  func (l *SANDNSDuplicate) CheckApplies(c *x509.Certificate) bool {
    31  	return util.IsExtInCert(c, util.SubjectAlternateNameOID)
    32  }
    33  
    34  func (l *SANDNSDuplicate) Execute(c *x509.Certificate) *LintResult {
    35  	checkedDNSNames := map[string]struct{}{}
    36  	for _, dns := range c.DNSNames {
    37  		normalizedDNSName := strings.ToLower(dns)
    38  		if _, isPresent := checkedDNSNames[normalizedDNSName]; isPresent {
    39  			return &LintResult{Status: Notice}
    40  		}
    41  
    42  		checkedDNSNames[normalizedDNSName] = struct{}{}
    43  	}
    44  
    45  	return &LintResult{Status: Pass}
    46  }
    47  
    48  func init() {
    49  	RegisterLint(&Lint{
    50  		Name:          "n_san_dns_name_duplicate",
    51  		Description:   "SAN DNSName contains duplicate values",
    52  		Citation:      "awslabs certlint",
    53  		Source:        AWSLabs,
    54  		EffectiveDate: util.ZeroDate,
    55  		Lint:          &SANDNSDuplicate{},
    56  	})
    57  }