gopkg.in/alecthomas/gometalinter.v3@v3.0.0/_linters/src/github.com/securego/gosec/rules/rsa.go (about)

     1  // (c) Copyright 2016 Hewlett Packard Enterprise Development LP
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package rules
    16  
    17  import (
    18  	"fmt"
    19  	"go/ast"
    20  
    21  	"github.com/securego/gosec"
    22  )
    23  
    24  type weakKeyStrength struct {
    25  	gosec.MetaData
    26  	calls gosec.CallList
    27  	bits  int
    28  }
    29  
    30  func (w *weakKeyStrength) ID() string {
    31  	return w.MetaData.ID
    32  }
    33  
    34  func (w *weakKeyStrength) Match(n ast.Node, c *gosec.Context) (*gosec.Issue, error) {
    35  	if callExpr := w.calls.ContainsCallExpr(n, c); callExpr != nil {
    36  		if bits, err := gosec.GetInt(callExpr.Args[1]); err == nil && bits < (int64)(w.bits) {
    37  			return gosec.NewIssue(c, n, w.ID(), w.What, w.Severity, w.Confidence), nil
    38  		}
    39  	}
    40  	return nil, nil
    41  }
    42  
    43  // NewWeakKeyStrength builds a rule that detects RSA keys < 2048 bits
    44  func NewWeakKeyStrength(id string, conf gosec.Config) (gosec.Rule, []ast.Node) {
    45  	calls := gosec.NewCallList()
    46  	calls.Add("crypto/rsa", "GenerateKey")
    47  	bits := 2048
    48  	return &weakKeyStrength{
    49  		calls: calls,
    50  		bits:  bits,
    51  		MetaData: gosec.MetaData{
    52  			ID:         id,
    53  			Severity:   gosec.Medium,
    54  			Confidence: gosec.High,
    55  			What:       fmt.Sprintf("RSA keys should be at least %d bits", bits),
    56  		},
    57  	}, []ast.Node{(*ast.CallExpr)(nil)}
    58  }