gosec/rules/ssrf.go
2018-03-09 14:11:59 -05:00

70 lines
2 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"
"go/types"
"github.com/GoASTScanner/gas"
)
type ssrf struct {
gas.MetaData
gas.CallList
}
// ID returns the identifier for this rule
func (r *ssrf) ID() string {
return r.MetaData.ID
}
// TODO(jovon) identify these calls from type `http.Client`
// - https://github.com/go-resty/resty -- looks well maintained and popular
//
// Match inspects AST nodes to determine if certain net/http methods are called with variable input
func (r *ssrf) Match(n ast.Node, c *gas.Context) (*gas.Issue, error) {
if node := r.ContainsCallExpr(n, c); node != nil {
for _, arg := range node.Args {
if ident, ok := arg.(*ast.Ident); ok {
obj := c.Info.ObjectOf(ident)
if _, ok := obj.(*types.Var); ok && !gas.TryResolve(ident, c) {
return gas.NewIssue(c, n, r.What, r.Severity, r.Confidence), nil
}
}
}
}
return nil, nil
}
// NewSSRFCheck detects cases where HTTP requests are sent
func NewSSRFCheck(id string, conf gas.Config) (gas.Rule, []ast.Node) {
rule := &readfile{
CallList: gas.NewCallList(),
MetaData: gas.MetaData{
ID: id,
What: "Potential HTTP request made with variable url",
Severity: gas.Medium,
Confidence: gas.High,
},
}
rule.Add("net/http", "Do")
rule.Add("net/http", "Get")
rule.Add("net/http", "Head")
rule.Add("net/http", "Post")
rule.Add("net/http", "PostForm")
rule.Add("net/http", "RoundTrip")
return rule, []ast.Node{(*ast.CallExpr)(nil)}
}