Fix: Validate CNAME targets (check for "/") #37

pkg/normalize/validate.go

@@ -10,6 +10,7 @@ import (
 	"github.com/StackExchange/dnscontrol/providers"
 	"github.com/miekg/dns"
 	"github.com/miekg/dns/dnsutil"
+	"github.com/pkg/errors"
 )
 
 // Returns false if target does not validate.
@@ -36,6 +37,9 @@ func checkTarget(target string) error {
 	if len(target) < 1 {
 		return fmt.Errorf("empty target")
 	}
+	if strings.ContainsAny(target, `'" +,|!£$%&/()=?^*ç°§;:_<>[]()@`) {
+		return errors.Errorf("target (%v) includes invalid char", target)
+	}
 	// If it containts a ".", it must end in a ".".
 	if strings.ContainsRune(target, '.') && target[len(target)-1] != '.' {
 		return fmt.Errorf("target (%v) must end with a (.) [Required if target is not single label]", target)

pkg/normalize/validate_test.go

@@ -64,6 +64,10 @@ func Test_assert_valid_target(t *testing.T) {
 		{"foo.bar.", false},
 		{"foo.", false},
 		{"foo.bar", true},
+		{"foo&bar", true},
+		{"foo bar", true},
+		{"elb21.freshdesk.com/", true},
+		{"elb21.freshdesk.com/.", true},
 	}
 
 	for _, test := range tests {