gosec/rules/sql.go
2017-12-13 22:35:47 +10:00

105 lines
3.1 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/GoASTScanner/gas"
)
type sqlStatement struct {
gas.MetaData
pattern *regexp.Regexp
}
type sqlStrConcat struct {
sqlStatement
}
// see if we can figure out what it is
func (s *sqlStrConcat) checkObject(n *ast.Ident) bool {
if n.Obj != nil {
return n.Obj.Kind != ast.Var && n.Obj.Kind != ast.Fun
}
return false
}
// Look for "SELECT * FROM table WHERE " + " ' OR 1=1"
func (s *sqlStrConcat) Match(n ast.Node, c *gas.Context) (*gas.Issue, error) {
if node, ok := n.(*ast.BinaryExpr); ok {
if start, ok := node.X.(*ast.BasicLit); ok {
if str, e := gas.GetString(start); s.pattern.MatchString(str) && e == nil {
if _, ok := node.Y.(*ast.BasicLit); ok {
return nil, nil // string cat OK
}
if second, ok := node.Y.(*ast.Ident); ok && s.checkObject(second) {
return nil, nil
}
return gas.NewIssue(c, n, s.What, s.Severity, s.Confidence), nil
}
}
}
return nil, nil
}
// NewSQLStrConcat looks for cases where we are building SQL strings via concatenation
func NewSQLStrConcat(conf gas.Config) (gas.Rule, []ast.Node) {
return &sqlStrConcat{
sqlStatement: sqlStatement{
pattern: regexp.MustCompile(`(?)(SELECT|DELETE|INSERT|UPDATE|INTO|FROM|WHERE) `),
MetaData: gas.MetaData{
Severity: gas.Medium,
Confidence: gas.High,
What: "SQL string concatenation",
},
},
}, []ast.Node{(*ast.BinaryExpr)(nil)}
}
type sqlStrFormat struct {
sqlStatement
calls gas.CallList
}
// Looks for "fmt.Sprintf("SELECT * FROM foo where '%s', userInput)"
func (s *sqlStrFormat) Match(n ast.Node, c *gas.Context) (*gas.Issue, error) {
// TODO(gm) improve confidence if database/sql is being used
if node := s.calls.ContainsCallExpr(n, c); node != nil {
if arg, e := gas.GetString(node.Args[0]); s.pattern.MatchString(arg) && e == nil {
return gas.NewIssue(c, n, s.What, s.Severity, s.Confidence), nil
}
}
return nil, nil
}
// NewSQLStrFormat looks for cases where we're building SQL query strings using format strings
func NewSQLStrFormat(conf gas.Config) (gas.Rule, []ast.Node) {
rule := &sqlStrFormat{
calls: gas.NewCallList(),
sqlStatement: sqlStatement{
pattern: regexp.MustCompile("(?)(SELECT|DELETE|INSERT|UPDATE|INTO|FROM|WHERE) "),
MetaData: gas.MetaData{
Severity: gas.Medium,
Confidence: gas.High,
What: "SQL string formatting",
},
},
}
rule.calls.AddAll("fmt", "Sprint", "Sprintf", "Sprintln")
return rule, []ast.Node{(*ast.CallExpr)(nil)}
}