Creating blacklist import rules

Creating a new generic blacklist rule and removing the older
specific ones. This will need configuration integration when
we have some.

The new test is immune to import aliasing but not shadowing

rulelist.go

@@ -39,7 +39,7 @@ func newRulelist() rulelist {
 	rs.rules = make(map[string]*ruleConfig)
 	rs.overwritten = false
 	rs.register("sql", rules.NewSqlStrConcat, rules.NewSqlStrFormat)
-	rs.register("crypto", rules.NewImportsWeakCryptography, rules.NewUsesWeakCryptography)
+	rs.register("crypto", rules.NewUsesWeakCryptography)
 	rs.register("hardcoded", rules.NewHardcodedCredentials)
 	rs.register("perms", rules.NewMkdirPerms, rules.NewChmodPerms)
 	rs.register("tempfile", rules.NewBadTempFile)
@@ -52,8 +52,8 @@ func newRulelist() rulelist {
 	rs.register("templates", rules.NewTemplateCheck)
 	rs.register("exec", rules.NewSubproc)
 	rs.register("errors", rules.NewNoErrorCheck)
-	rs.register("httpoxy", rules.NewHttpoxyTest)
 	rs.register("rand", rules.NewWeakRandCheck)
+	rs.register("blacklist_imports", rules.NewBlacklistImports)
 	return rs
 }
 

rules/blacklist.go

@@ -0,0 +1,66 @@
+// (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"
+
+	gas "github.com/HewlettPackard/gas/core"
+)
+
+type BlacklistImports struct {
+	BlacklistSet map[string]gas.MetaData
+}
+
+func (r *BlacklistImports) Match(n ast.Node, c *gas.Context) (gi *gas.Issue, err error) {
+	if node, ok := n.(*ast.ImportSpec); ok {
+		if data, ok := r.BlacklistSet[node.Path.Value]; ok {
+			return gas.NewIssue(c, n, data.What, data.Severity, data.Confidence), nil
+		}
+	}
+	return nil, nil
+}
+
+func NewBlacklistImports() (r gas.Rule, n ast.Node) {
+	// TODO(tkelsey): make this configurable
+	// TODO(tkelsey): make it so each item can be selected/excluded individually
+	r = &BlacklistImports{
+		BlacklistSet: map[string]gas.MetaData{
+			`"crypto/md5"`: gas.MetaData{
+				Severity:   gas.High,
+				Confidence: gas.High,
+				What:       "Use of weak cryptographic primitive",
+			},
+			`"crypto/des"`: gas.MetaData{
+				Severity:   gas.High,
+				Confidence: gas.High,
+				What:       "Use of weak cryptographic primitive",
+			},
+			`"crypto/rc4"`: gas.MetaData{
+				Severity:   gas.High,
+				Confidence: gas.High,
+				What:       "Use of weak cryptographic primitive",
+			},
+			`"net/http/cgi"`: gas.MetaData{
+				Severity:   gas.High,
+				Confidence: gas.Low,
+				What:       "Go code running under CGI is vulnerable to Httpoxy attack. (CVE-2016-5386)",
+			},
+		},
+	}
+
+	n = (*ast.ImportSpec)(nil)
+	return
+}

rules/httpoxy.go

@@ -1,50 +0,0 @@
-// (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"
-
-	gas "github.com/HewlettPackard/gas/core"
-)
-
-// Looks for "import net/http/cgi"
-type HttpoxyTest struct {
-	gas.MetaData
-	pattern *regexp.Regexp
-}
-
-func (r *HttpoxyTest) Match(n ast.Node, c *gas.Context) (gi *gas.Issue, err error) {
-	if node, ok := n.(*ast.ImportSpec); ok {
-		if r.pattern.MatchString(node.Path.Value) {
-			return gas.NewIssue(c, n, r.What, r.Severity, r.Confidence), nil
-		}
-	}
-	return
-}
-
-func NewHttpoxyTest() (r gas.Rule, n ast.Node) {
-	r = &HttpoxyTest{
-		MetaData: gas.MetaData{
-			Severity:   gas.High,
-			Confidence: gas.Low,
-			What:       "Go code running under CGI is vulnerable to Httpoxy attack. (CVE-2016-5386)",
-		},
-		pattern: regexp.MustCompile(`^"net/http/cgi"$`),
-	}
-	n = (*ast.ImportSpec)(nil)
-	return
-}

rules/httpoxy_test.go

@@ -22,16 +22,14 @@ import (
 
 func TestHttpoxy(t *testing.T) {
 	analyzer := gas.NewAnalyzer(false, nil, nil)
-	analyzer.AddRule(NewHttpoxyTest())
+	analyzer.AddRule(NewBlacklistImports())
 
 	issues := gasTestRunner(`
 		package main
-	        import (
+    import (
-                	"log"
+        "net/http/cgi"
-                	"net/http/cgi"
+  	)
-        	)
+		func main() {}`, analyzer)
-		func main() {
-		}`, analyzer)
 
 	checkTestResults(t, issues, 1, "Go code running under CGI is vulnerable to Httpoxy attack.")
 }

rules/weakcrypto.go

@@ -15,42 +15,12 @@
 package rules
 
 import (
-	gas "github.com/HewlettPackard/gas/core"
 	"go/ast"
-	"reflect"
 	"regexp"
+
+	gas "github.com/HewlettPackard/gas/core"
 )
 
-type ImportsWeakCryptography struct {
-	gas.MetaData
-	pattern *regexp.Regexp
-}
-
-func (r *ImportsWeakCryptography) Match(n ast.Node, c *gas.Context) (gi *gas.Issue, err error) {
-	a := reflect.TypeOf(&ast.ImportSpec{})
-	b := reflect.TypeOf(&ast.BasicLit{})
-	if node := gas.SimpleSelect(n, a, b); node != nil {
-		if str, _ := gas.GetString(node); r.pattern.MatchString(str) {
-			return gas.NewIssue(c, n, r.What, r.Severity, r.Confidence), nil
-		}
-	}
-	return
-}
-
-// Imports crypto/md5, crypto/des crypto/rc4
-func NewImportsWeakCryptography() (r gas.Rule, n ast.Node) {
-	r = &ImportsWeakCryptography{
-		pattern: regexp.MustCompile(`crypto/md5|crypto/des|crypto/rc4`),
-		MetaData: gas.MetaData{
-			Severity:   gas.Medium,
-			Confidence: gas.High,
-			What:       "Import of weak cryptographic primitive",
-		},
-	}
-	n = (*ast.ImportSpec)(nil)
-	return
-}
-
 type UsesWeakCryptography struct {
 	gas.MetaData
 	pattern *regexp.Regexp

rules/weakcrypto_test.go

@@ -22,7 +22,7 @@ import (
 
 func TestMD5(t *testing.T) {
 	analyzer := gas.NewAnalyzer(false, nil, nil)
-	analyzer.AddRule(NewImportsWeakCryptography())
+	analyzer.AddRule(NewBlacklistImports())
 	analyzer.AddRule(NewUsesWeakCryptography())
 
 	issues := gasTestRunner(`
@@ -43,7 +43,7 @@ func TestMD5(t *testing.T) {
 
 func TestDES(t *testing.T) {
 	analyzer := gas.NewAnalyzer(false, nil, nil)
-	analyzer.AddRule(NewImportsWeakCryptography())
+	analyzer.AddRule(NewBlacklistImports())
 	analyzer.AddRule(NewUsesWeakCryptography())
 
 	issues := gasTestRunner(`
@@ -82,7 +82,7 @@ func TestDES(t *testing.T) {
 
 func TestRC4(t *testing.T) {
 	analyzer := gas.NewAnalyzer(false, nil, nil)
-	analyzer.AddRule(NewImportsWeakCryptography())
+	analyzer.AddRule(NewBlacklistImports())
 	analyzer.AddRule(NewUsesWeakCryptography())
 
 	issues := gasTestRunner(`