mirror of
https://github.com/securego/gosec.git
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112 lines
2.5 KiB
Go
112 lines
2.5 KiB
Go
// (c) Copyright 2016 Hewlett Packard Enterprise Development LP
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package rules
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import (
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"go/ast"
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"regexp"
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"strings"
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gas "github.com/GoASTScanner/gas/core"
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)
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type WeakRand struct {
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gas.MetaData
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pattern *regexp.Regexp
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packagePath string
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}
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type pkgFunc struct {
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packagePath string
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funcName string
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}
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// pkgId takes an import line and returns the identifier used
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// for that package in the rest of the file
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func pkgId(i *ast.ImportSpec) string {
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if i.Name != nil {
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return i.Name.String()
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}
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trim := strings.Trim(i.Path.Value, `"`)
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a := strings.Split(trim, "/")
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return a[len(a)-1]
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}
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// importIds returns a map of import names to their full paths
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func importIds(f *ast.File) map[string]string {
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pkgs := make(map[string]string)
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for _, v := range f.Imports {
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pkgs[pkgId(v)] = strings.Trim(v.Path.Value, `"`)
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}
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return pkgs
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}
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// matchPkgFunc will return package level function calls split
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// by full package path and function name
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func matchPkgFunc(n ast.Node, c *gas.Context) *pkgFunc {
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call, ok := n.(*ast.CallExpr)
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if !ok {
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return nil
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}
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sel, ok := call.Fun.(*ast.SelectorExpr)
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if !ok {
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return nil
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}
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id, ok := sel.X.(*ast.Ident)
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if !ok {
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return nil
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}
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if id.Obj != nil {
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return nil
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}
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i := importIds(c.Root)
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v, ok := i[id.Name]
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if !ok {
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return nil
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}
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return &pkgFunc{
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packagePath: v,
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funcName: sel.Sel.String(),
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}
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}
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func (w *WeakRand) Match(n ast.Node, c *gas.Context) (*gas.Issue, error) {
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call := matchPkgFunc(n, c)
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if call != nil && call.packagePath == w.packagePath && w.pattern.MatchString(call.funcName) {
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return gas.NewIssue(c, n, w.What, w.Severity, w.Confidence), nil
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}
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return nil, nil
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}
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func NewWeakRandCheck(conf map[string]interface{}) (r gas.Rule, n ast.Node) {
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r = &WeakRand{
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pattern: regexp.MustCompile(`^Read$`),
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packagePath: "math/rand",
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MetaData: gas.MetaData{
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Severity: gas.High,
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Confidence: gas.Medium,
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What: "Use of weak random number generator (math/rand instead of crypto/rand)",
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},
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}
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n = (*ast.CallExpr)(nil)
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return
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}
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