gosec/rules/tempfiles.go
2023-03-20 10:25:45 +01:00

88 lines
2.7 KiB
Go

// (c) Copyright 2016 Hewlett Packard Enterprise Development LP
//
// 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.
package rules
import (
"go/ast"
"regexp"
"github.com/securego/gosec/v2"
"github.com/securego/gosec/v2/issue"
)
type badTempFile struct {
issue.MetaData
calls gosec.CallList
args *regexp.Regexp
argCalls gosec.CallList
nestedCalls gosec.CallList
}
func (t *badTempFile) ID() string {
return t.MetaData.ID
}
func (t *badTempFile) findTempDirArgs(n ast.Node, c *gosec.Context, suspect ast.Node) *issue.Issue {
if s, e := gosec.GetString(suspect); e == nil {
if t.args.MatchString(s) {
return c.NewIssue(n, t.ID(), t.What, t.Severity, t.Confidence)
}
return nil
}
if ce := t.argCalls.ContainsPkgCallExpr(suspect, c, false); ce != nil {
return c.NewIssue(n, t.ID(), t.What, t.Severity, t.Confidence)
}
if be, ok := suspect.(*ast.BinaryExpr); ok {
if ops := gosec.GetBinaryExprOperands(be); len(ops) != 0 {
return t.findTempDirArgs(n, c, ops[0])
}
return nil
}
if ce := t.nestedCalls.ContainsPkgCallExpr(suspect, c, false); ce != nil {
return t.findTempDirArgs(n, c, ce.Args[0])
}
return nil
}
func (t *badTempFile) Match(n ast.Node, c *gosec.Context) (gi *issue.Issue, err error) {
if node := t.calls.ContainsPkgCallExpr(n, c, false); node != nil {
return t.findTempDirArgs(n, c, node.Args[0]), nil
}
return nil, nil
}
// NewBadTempFile detects direct writes to predictable path in temporary directory
func NewBadTempFile(id string, _ gosec.Config) (gosec.Rule, []ast.Node) {
calls := gosec.NewCallList()
calls.Add("io/ioutil", "WriteFile")
calls.AddAll("os", "Create", "WriteFile")
argCalls := gosec.NewCallList()
argCalls.Add("os", "TempDir")
nestedCalls := gosec.NewCallList()
nestedCalls.Add("path", "Join")
nestedCalls.Add("path/filepath", "Join")
return &badTempFile{
calls: calls,
args: regexp.MustCompile(`^(/(usr|var))?/tmp(/.*)?$`),
argCalls: argCalls,
nestedCalls: nestedCalls,
MetaData: issue.MetaData{
ID: id,
Severity: issue.Medium,
Confidence: issue.High,
What: "File creation in shared tmp directory without using ioutil.Tempfile",
},
}, []ast.Node{(*ast.CallExpr)(nil)}
}