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

     1  package lints
     2  
     3  /*
     4   * ZLint Copyright 2018 Regents of the University of Michigan
     5   *
     6   * Licensed under the Apache License, Version 2.0 (the "License"); you may not
     7   * use this file except in compliance with the License. You may obtain a copy
     8   * of the License at http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
    13   * implied. See the License for the specific language governing
    14   * permissions and limitations under the License.
    15   */
    16  
    17  /*******************************************************************************************************
    18  "BRs: 6.1.6"
    19  RSA: The CA SHALL confirm that the value of the public exponent is an odd number equal to 3 or more. Additionally, the public exponent SHOULD be in the range between 2^16+1 and 2^256-1. The modulus SHOULD also have the following characteristics: an odd number, not the power of a prime, and have no factors smaller than 752. [Citation: Section 5.3.3, NIST SP 800-89].
    20  *******************************************************************************************************/
    21  
    22  import (
    23  	"crypto/rsa"
    24  
    25  	"github.com/zmap/zcrypto/x509"
    26  	"github.com/zmap/zlint/util"
    27  )
    28  
    29  type rsaParsedTestsExpBounds struct{}
    30  
    31  func (l *rsaParsedTestsExpBounds) Initialize() error {
    32  	return nil
    33  }
    34  
    35  func (l *rsaParsedTestsExpBounds) CheckApplies(c *x509.Certificate) bool {
    36  	_, ok := c.PublicKey.(*rsa.PublicKey)
    37  	return ok && c.PublicKeyAlgorithm == x509.RSA
    38  }
    39  
    40  func (l *rsaParsedTestsExpBounds) Execute(c *x509.Certificate) *LintResult {
    41  	key := c.PublicKey.(*rsa.PublicKey)
    42  	if key.E >= 3 { //If Cmp returns 1, means N > E
    43  		return &LintResult{Status: Pass}
    44  	} else {
    45  		return &LintResult{Status: Error}
    46  	}
    47  }
    48  
    49  func init() {
    50  	RegisterLint(&Lint{
    51  		Name:          "e_rsa_public_exponent_too_small",
    52  		Description:   "RSA: Value of public exponent is an odd number equal to 3 or more.",
    53  		Citation:      "BRs: 6.1.6",
    54  		Source:        CABFBaselineRequirements,
    55  		EffectiveDate: util.CABV113Date,
    56  		Lint:          &rsaParsedTestsExpBounds{},
    57  	})
    58  }