Merge pull request #138 from jonmcclintock/sqli-format-whitelist

Adjust SQL format-string rules to ignore inherently safe formats
This commit is contained in:
Grant Murphy 2018-01-23 07:50:52 +10:00 committed by GitHub
commit 51b4a4ddc8
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 47 additions and 6 deletions

View file

@ -23,7 +23,19 @@ import (
type sqlStatement struct {
gas.MetaData
pattern *regexp.Regexp
// Contains a list of patterns which must all match for the rule to match.
patterns []*regexp.Regexp
}
// See if the string matches the patterns for the statement.
func (s sqlStatement) MatchPatterns(str string) bool {
for _, pattern := range s.patterns {
if !pattern.MatchString(str) {
return false
}
}
return true
}
type sqlStrConcat struct {
@ -42,7 +54,10 @@ func (s *sqlStrConcat) checkObject(n *ast.Ident) bool {
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 str, e := gas.GetString(start); e == nil {
if !s.MatchPatterns(str) {
return nil, nil
}
if _, ok := node.Y.(*ast.BasicLit); ok {
return nil, nil // string cat OK
}
@ -60,7 +75,9 @@ func (s *sqlStrConcat) Match(n ast.Node, c *gas.Context) (*gas.Issue, error) {
func NewSQLStrConcat(conf gas.Config) (gas.Rule, []ast.Node) {
return &sqlStrConcat{
sqlStatement: sqlStatement{
pattern: regexp.MustCompile(`(?)(SELECT|DELETE|INSERT|UPDATE|INTO|FROM|WHERE) `),
patterns: []*regexp.Regexp{
regexp.MustCompile(`(?)(SELECT|DELETE|INSERT|UPDATE|INTO|FROM|WHERE) `),
},
MetaData: gas.MetaData{
Severity: gas.Medium,
Confidence: gas.High,
@ -80,7 +97,7 @@ 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 {
if arg, e := gas.GetString(node.Args[0]); s.MatchPatterns(arg) && e == nil {
return gas.NewIssue(c, n, s.What, s.Severity, s.Confidence), nil
}
}
@ -92,7 +109,10 @@ 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) "),
patterns: []*regexp.Regexp{
regexp.MustCompile("(?)(SELECT|DELETE|INSERT|UPDATE|INTO|FROM|WHERE) "),
regexp.MustCompile("%[^bdoxXfFp]"),
},
MetaData: gas.MetaData{
Severity: gas.Medium,
Confidence: gas.High,

View file

@ -206,7 +206,28 @@ func main(){
panic(err)
}
defer rows.Close()
}`, 1}, {
}`, 1}, {`
// Format string false positive, safe string spec.
package main
import (
"database/sql"
"fmt"
"os"
//_ "github.com/mattn/go-sqlite3"
)
func main(){
db, err := sql.Open("sqlite3", ":memory:")
if err != nil {
panic(err)
}
q := fmt.Sprintf("SELECT * FROM foo where id = %d", os.Args[1])
rows, err := db.Query(q)
if err != nil {
panic(err)
}
defer rows.Close()
}`, 0}, {
`
// Format string false positive
package main