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
15package rules
16
17import (
18	"go/ast"
19
20	"github.com/securego/gosec/v2"
21)
22
23type templateCheck struct {
24	gosec.MetaData
25	calls gosec.CallList
26}
27
28func (t *templateCheck) ID() string {
29	return t.MetaData.ID
30}
31
32func (t *templateCheck) Match(n ast.Node, c *gosec.Context) (*gosec.Issue, error) {
33	if node := t.calls.ContainsPkgCallExpr(n, c, false); node != nil {
34		for _, arg := range node.Args {
35			if _, ok := arg.(*ast.BasicLit); !ok { // basic lits are safe
36				return gosec.NewIssue(c, n, t.ID(), t.What, t.Severity, t.Confidence), nil
37			}
38		}
39	}
40	return nil, nil
41}
42
43// NewTemplateCheck constructs the template check rule. This rule is used to
44// find use of templates where HTML/JS escaping is not being used
45func NewTemplateCheck(id string, conf gosec.Config) (gosec.Rule, []ast.Node) {
46
47	calls := gosec.NewCallList()
48	calls.Add("html/template", "HTML")
49	calls.Add("html/template", "HTMLAttr")
50	calls.Add("html/template", "JS")
51	calls.Add("html/template", "URL")
52	return &templateCheck{
53		calls: calls,
54		MetaData: gosec.MetaData{
55			ID:         id,
56			Severity:   gosec.Medium,
57			Confidence: gosec.Low,
58			What:       "this method will not auto-escape HTML. Verify data is well formed.",
59		},
60	}, []ast.Node{(*ast.CallExpr)(nil)}
61}
62