Be more clear about ipv4 in nebula-cert (#604)

cmd/nebula-cert/ca.go

@@ -37,8 +37,8 @@ func newCaFlags() *caFlags {
 	cf.outCertPath = cf.set.String("out-crt", "ca.crt", "Optional: path to write the certificate to")
 	cf.outQRPath = cf.set.String("out-qr", "", "Optional: output a qr code image (png) of the certificate")
 	cf.groups = cf.set.String("groups", "", "Optional: comma separated list of groups. This will limit which groups subordinate certs can use")
-	cf.ips = cf.set.String("ips", "", "Optional: comma separated list of ip and network in CIDR notation. This will limit which ip addresses and networks subordinate certs can use")
+	cf.ips = cf.set.String("ips", "", "Optional: comma separated list of ipv4 address and network in CIDR notation. This will limit which ipv4 addresses and networks subordinate certs can use for ip addresses")
-	cf.subnets = cf.set.String("subnets", "", "Optional: comma separated list of ip and network in CIDR notation. This will limit which subnet addresses and networks subordinate certs can use")
+	cf.subnets = cf.set.String("subnets", "", "Optional: comma separated list of ipv4 address and network in CIDR notation. This will limit which ipv4 addresses and networks subordinate certs can use in subnets")
 	return &cf
 }
 
@@ -82,6 +82,9 @@ func ca(args []string, out io.Writer, errOut io.Writer) error {
 				if err != nil {
 					return newHelpErrorf("invalid ip definition: %s", err)
 				}
+				if ip.To4() == nil {
+					return newHelpErrorf("invalid ip definition: can only be ipv4, have %s", rs)
+				}
 
 				ipNet.IP = ip
 				ips = append(ips, ipNet)
@@ -98,6 +101,9 @@ func ca(args []string, out io.Writer, errOut io.Writer) error {
 				if err != nil {
 					return newHelpErrorf("invalid subnet definition: %s", err)
 				}
+				if s.IP.To4() == nil {
+					return newHelpErrorf("invalid subnet definition: can only be ipv4, have %s", rs)
+				}
 				subnets = append(subnets, s)
 			}
 		}

cmd/nebula-cert/ca_test.go

@@ -31,7 +31,7 @@ func Test_caHelp(t *testing.T) {
 			"  -groups string\n"+
 			"    \tOptional: comma separated list of groups. This will limit which groups subordinate certs can use\n"+
 			"  -ips string\n"+
-			"    \tOptional: comma separated list of ip and network in CIDR notation. This will limit which ip addresses and networks subordinate certs can use\n"+
+			"    \tOptional: comma separated list of ipv4 address and network in CIDR notation. This will limit which ipv4 addresses and networks subordinate certs can use for ip addresses\n"+
 			"  -name string\n"+
 			"    \tRequired: name of the certificate authority\n"+
 			"  -out-crt string\n"+
@@ -41,7 +41,7 @@ func Test_caHelp(t *testing.T) {
 			"  -out-qr string\n"+
 			"    \tOptional: output a qr code image (png) of the certificate\n"+
 			"  -subnets string\n"+
-			"    \tOptional: comma separated list of ip and network in CIDR notation. This will limit which subnet addresses and networks subordinate certs can use\n",
+			"    \tOptional: comma separated list of ipv4 address and network in CIDR notation. This will limit which ipv4 addresses and networks subordinate certs can use in subnets\n",
 		ob.String(),
 	)
 }
@@ -55,6 +55,16 @@ func Test_ca(t *testing.T) {
 	assert.Equal(t, "", ob.String())
 	assert.Equal(t, "", eb.String())
 
+	// ipv4 only ips
+	assertHelpError(t, ca([]string{"-name", "ipv6", "-ips", "100::100/100"}, ob, eb), "invalid ip definition: can only be ipv4, have 100::100/100")
+	assert.Equal(t, "", ob.String())
+	assert.Equal(t, "", eb.String())
+
+	// ipv4 only subnets
+	assertHelpError(t, ca([]string{"-name", "ipv6", "-subnets", "100::100/100"}, ob, eb), "invalid subnet definition: can only be ipv4, have 100::100/100")
+	assert.Equal(t, "", ob.String())
+	assert.Equal(t, "", eb.String())
+
 	// failed key write
 	ob.Reset()
 	eb.Reset()

cmd/nebula-cert/sign.go

@@ -37,14 +37,14 @@ func newSignFlags() *signFlags {
 	sf.caKeyPath = sf.set.String("ca-key", "ca.key", "Optional: path to the signing CA key")
 	sf.caCertPath = sf.set.String("ca-crt", "ca.crt", "Optional: path to the signing CA cert")
 	sf.name = sf.set.String("name", "", "Required: name of the cert, usually a hostname")
-	sf.ip = sf.set.String("ip", "", "Required: ip and network in CIDR notation to assign the cert")
+	sf.ip = sf.set.String("ip", "", "Required: ipv4 address and network in CIDR notation to assign the cert")
 	sf.duration = sf.set.Duration("duration", 0, "Optional: how long the cert should be valid for. The default is 1 second before the signing cert expires. Valid time units are seconds: \"s\", minutes: \"m\", hours: \"h\"")
 	sf.inPubPath = sf.set.String("in-pub", "", "Optional (if out-key not set): path to read a previously generated public key")
 	sf.outKeyPath = sf.set.String("out-key", "", "Optional (if in-pub not set): path to write the private key to")
 	sf.outCertPath = sf.set.String("out-crt", "", "Optional: path to write the certificate to")
 	sf.outQRPath = sf.set.String("out-qr", "", "Optional: output a qr code image (png) of the certificate")
 	sf.groups = sf.set.String("groups", "", "Optional: comma separated list of groups")
-	sf.subnets = sf.set.String("subnets", "", "Optional: comma separated list of subnet this cert can serve for")
+	sf.subnets = sf.set.String("subnets", "", "Optional: comma separated list of ipv4 address and network in CIDR notation. Subnets this cert can serve for")
 	return &sf
 
 }
@@ -114,6 +114,9 @@ func signCert(args []string, out io.Writer, errOut io.Writer) error {
 	if err != nil {
 		return newHelpErrorf("invalid ip definition: %s", err)
 	}
+	if ip.To4() == nil {
+		return newHelpErrorf("invalid ip definition: can only be ipv4, have %s", *sf.ip)
+	}
 	ipNet.IP = ip
 
 	groups := []string{}
@@ -135,6 +138,9 @@ func signCert(args []string, out io.Writer, errOut io.Writer) error {
 				if err != nil {
 					return newHelpErrorf("invalid subnet definition: %s", err)
 				}
+				if s.IP.To4() == nil {
+					return newHelpErrorf("invalid subnet definition: can only be ipv4, have %s", rs)
+				}
 				subnets = append(subnets, s)
 			}
 		}

cmd/nebula-cert/sign_test.go

@@ -39,7 +39,7 @@ func Test_signHelp(t *testing.T) {
 			"  -in-pub string\n"+
 			"    \tOptional (if out-key not set): path to read a previously generated public key\n"+
 			"  -ip string\n"+
-			"    \tRequired: ip and network in CIDR notation to assign the cert\n"+
+			"    \tRequired: ipv4 address and network in CIDR notation to assign the cert\n"+
 			"  -name string\n"+
 			"    \tRequired: name of the cert, usually a hostname\n"+
 			"  -out-crt string\n"+
@@ -49,7 +49,7 @@ func Test_signHelp(t *testing.T) {
 			"  -out-qr string\n"+
 			"    \tOptional: output a qr code image (png) of the certificate\n"+
 			"  -subnets string\n"+
-			"    \tOptional: comma separated list of subnet this cert can serve for\n",
+			"    \tOptional: comma separated list of ipv4 address and network in CIDR notation. Subnets this cert can serve for\n",
 		ob.String(),
 	)
 }
@@ -59,7 +59,6 @@ func Test_signCert(t *testing.T) {
 	eb := &bytes.Buffer{}
 
 	// required args
-
 	assertHelpError(t, signCert([]string{"-ca-crt", "./nope", "-ca-key", "./nope", "-ip", "1.1.1.1/24", "-out-key", "nope", "-out-crt", "nope"}, ob, eb), "-name is required")
 	assert.Empty(t, ob.String())
 	assert.Empty(t, eb.String())
@@ -160,6 +159,13 @@ func Test_signCert(t *testing.T) {
 	assert.Empty(t, ob.String())
 	assert.Empty(t, eb.String())
 
+	ob.Reset()
+	eb.Reset()
+	args = []string{"-ca-crt", caCrtF.Name(), "-ca-key", caKeyF.Name(), "-name", "test", "-ip", "100::100/100", "-out-crt", "nope", "-out-key", "nope", "-duration", "100m"}
+	assertHelpError(t, signCert(args, ob, eb), "invalid ip definition: can only be ipv4, have 100::100/100")
+	assert.Empty(t, ob.String())
+	assert.Empty(t, eb.String())
+
 	// bad subnet cidr
 	ob.Reset()
 	eb.Reset()
@@ -168,6 +174,13 @@ func Test_signCert(t *testing.T) {
 	assert.Empty(t, ob.String())
 	assert.Empty(t, eb.String())
 
+	ob.Reset()
+	eb.Reset()
+	args = []string{"-ca-crt", caCrtF.Name(), "-ca-key", caKeyF.Name(), "-name", "test", "-ip", "1.1.1.1/24", "-out-crt", "nope", "-out-key", "nope", "-duration", "100m", "-subnets", "100::100/100"}
+	assertHelpError(t, signCert(args, ob, eb), "invalid subnet definition: can only be ipv4, have 100::100/100")
+	assert.Empty(t, ob.String())
+	assert.Empty(t, eb.String())
+
 	// mismatched ca key
 	_, caPriv2, _ := ed25519.GenerateKey(rand.Reader)
 	caKeyF2, err := ioutil.TempFile("", "sign-cert-2.key")