Add a rule to detect the usage of ssh InsecureIgnoreHostKey function

rules/ssh.go

@@ -0,0 +1,47 @@
+// (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"
+
+	"github.com/GoASTScanner/gas"
+)
+
+type sshHostKey struct {
+	gas.MetaData
+	pkg   string
+	calls []string
+}
+
+func (r *sshHostKey) Match(n ast.Node, c *gas.Context) (gi *gas.Issue, err error) {
+	if _, matches := gas.MatchCallByPackage(n, c, r.pkg, r.calls...); matches {
+		return gas.NewIssue(c, n, r.What, r.Severity, r.Confidence), nil
+	}
+	return nil, nil
+}
+
+// NewSSHHostKey rule detects the use of insecure ssh HostKeyCallback.
+func NewSSHHostKey(conf gas.Config) (gas.Rule, []ast.Node) {
+	return &sshHostKey{
+		pkg:   "golang.org/x/crypto/ssh",
+		calls: []string{"InsecureIgnoreHostKey"},
+		MetaData: gas.MetaData{
+			What:       "Use of ssh InsecureIgnoreHostKey should be audited",
+			Severity:   gas.Medium,
+			Confidence: gas.High,
+		},
+	}, []ast.Node{(*ast.CallExpr)(nil)}
+}