Support for ipv6 in the overlay with v2 certificates

--------- Co-authored-by: Jack Doan <[email protected]>
slackhq · Oct 24, 2024 · f2c3242 · f2c3242
1 parent 3e6c755
commit f2c3242
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Showing 86 changed files with 5,681 additions and 3,269 deletions.
diff --git a/Makefile b/Makefile
@@ -196,7 +196,7 @@ bench-cpu-long:
 	go test -bench=. -benchtime=60s -cpuprofile=cpu.pprof
 	go tool pprof go-audit.test cpu.pprof
 
-proto: nebula.pb.go cert/cert.pb.go
+proto: nebula.pb.go cert/cert_v1.pb.go
 
 nebula.pb.go: nebula.proto .FORCE
 	go build github.com/gogo/protobuf/protoc-gen-gogofaster

diff --git a/calculated_remote.go b/calculated_remote.go
@@ -21,7 +21,11 @@ type calculatedRemote struct {
 	port  uint32
 }
 
-func newCalculatedRemote(maskCidr netip.Prefix, port int) (*calculatedRemote, error) {
+func newCalculatedRemote(cidr, maskCidr netip.Prefix, port int) (*calculatedRemote, error) {
+	if maskCidr.Addr().BitLen() != cidr.Addr().BitLen() {
+		return nil, fmt.Errorf("invalid mask: %s for cidr: %s", maskCidr, cidr)
+	}
+
 	masked := maskCidr.Masked()
 	if port < 0 || port > math.MaxUint16 {
 		return nil, fmt.Errorf("invalid port: %d", port)
@@ -38,32 +42,38 @@ func (c *calculatedRemote) String() string {
 	return fmt.Sprintf("CalculatedRemote(mask=%v port=%d)", c.ipNet, c.port)
 }
 
-func (c *calculatedRemote) Apply(ip netip.Addr) *Ip4AndPort {
-	// Combine the masked bytes of the "mask" IP with the unmasked bytes
-	// of the overlay IP
-	if c.ipNet.Addr().Is4() {
-		return c.apply4(ip)
-	}
-	return c.apply6(ip)
-}
-
-func (c *calculatedRemote) apply4(ip netip.Addr) *Ip4AndPort {
-	//TODO: IPV6-WORK this can be less crappy
+func (c *calculatedRemote) ApplyV4(addr netip.Addr) *V4AddrPort {
+	// Combine the masked bytes of the "mask" IP with the unmasked bytes of the overlay IP
 	maskb := net.CIDRMask(c.mask.Bits(), c.mask.Addr().BitLen())
 	mask := binary.BigEndian.Uint32(maskb[:])
 
 	b := c.mask.Addr().As4()
-	maskIp := binary.BigEndian.Uint32(b[:])
+	maskAddr := binary.BigEndian.Uint32(b[:])
 
-	b = ip.As4()
-	intIp := binary.BigEndian.Uint32(b[:])
+	b = addr.As4()
+	intAddr := binary.BigEndian.Uint32(b[:])
 
-	return &Ip4AndPort{(maskIp & mask) | (intIp & ^mask), c.port}
+	return &V4AddrPort{(maskAddr & mask) | (intAddr & ^mask), c.port}
 }
 
-func (c *calculatedRemote) apply6(ip netip.Addr) *Ip4AndPort {
-	//TODO: IPV6-WORK
-	panic("Can not calculate ipv6 remote addresses")
+func (c *calculatedRemote) ApplyV6(addr netip.Addr) *V6AddrPort {
+	mask := net.CIDRMask(c.mask.Bits(), c.mask.Addr().BitLen())
+	maskAddr := c.mask.Addr().As16()
+	calcAddr := addr.As16()
+
+	ap := V6AddrPort{Port: c.port}
+
+	maskb := binary.BigEndian.Uint64(mask[:8])
+	maskAddrb := binary.BigEndian.Uint64(maskAddr[:8])
+	calcAddrb := binary.BigEndian.Uint64(calcAddr[:8])
+	ap.Hi = (maskAddrb & maskb) | (calcAddrb & ^maskb)
+
+	maskb = binary.BigEndian.Uint64(mask[8:])
+	maskAddrb = binary.BigEndian.Uint64(maskAddr[8:])
+	calcAddrb = binary.BigEndian.Uint64(calcAddr[8:])
+	ap.Lo = (maskAddrb & maskb) | (calcAddrb & ^maskb)
+
+	return &ap
 }
 
 func NewCalculatedRemotesFromConfig(c *config.C, k string) (*bart.Table[[]*calculatedRemote], error) {
@@ -89,8 +99,7 @@ func NewCalculatedRemotesFromConfig(c *config.C, k string) (*bart.Table[[]*calcu
 			return nil, fmt.Errorf("config `%s` has invalid CIDR: %s", k, rawCIDR)
 		}
 
-		//TODO: IPV6-WORK this does not verify that rawValue contains the same bits as cidr here
-		entry, err := newCalculatedRemotesListFromConfig(rawValue)
+		entry, err := newCalculatedRemotesListFromConfig(cidr, rawValue)
 		if err != nil {
 			return nil, fmt.Errorf("config '%s.%s': %w", k, rawCIDR, err)
 		}
@@ -101,15 +110,15 @@ func NewCalculatedRemotesFromConfig(c *config.C, k string) (*bart.Table[[]*calcu
 	return calculatedRemotes, nil
 }
 
-func newCalculatedRemotesListFromConfig(raw any) ([]*calculatedRemote, error) {
+func newCalculatedRemotesListFromConfig(cidr netip.Prefix, raw any) ([]*calculatedRemote, error) {
 	rawList, ok := raw.([]any)
 	if !ok {
 		return nil, fmt.Errorf("calculated_remotes entry has invalid type: %T", raw)
 	}
 
 	var l []*calculatedRemote
 	for _, e := range rawList {
-		c, err := newCalculatedRemotesEntryFromConfig(e)
+		c, err := newCalculatedRemotesEntryFromConfig(cidr, e)
 		if err != nil {
 			return nil, fmt.Errorf("calculated_remotes entry: %w", err)
 		}
@@ -119,7 +128,7 @@ func newCalculatedRemotesListFromConfig(raw any) ([]*calculatedRemote, error) {
 	return l, nil
 }
 
-func newCalculatedRemotesEntryFromConfig(raw any) (*calculatedRemote, error) {
+func newCalculatedRemotesEntryFromConfig(cidr netip.Prefix, raw any) (*calculatedRemote, error) {
 	rawMap, ok := raw.(map[any]any)
 	if !ok {
 		return nil, fmt.Errorf("invalid type: %T", raw)
@@ -155,5 +164,5 @@ func newCalculatedRemotesEntryFromConfig(raw any) (*calculatedRemote, error) {
 		return nil, fmt.Errorf("invalid port (type %T): %v", rawValue, rawValue)
 	}
 
-	return newCalculatedRemote(maskCidr, port)
+	return newCalculatedRemote(cidr, maskCidr, port)
 }
diff --git a/calculated_remote_test.go b/calculated_remote_test.go
@@ -9,10 +9,9 @@ import (
 )
 
 func TestCalculatedRemoteApply(t *testing.T) {
-	ipNet, err := netip.ParsePrefix("192.168.1.0/24")
-	require.NoError(t, err)
-
-	c, err := newCalculatedRemote(ipNet, 4242)
+	// Test v4 addresses
+	ipNet := netip.MustParsePrefix("192.168.1.0/24")
+	c, err := newCalculatedRemote(ipNet, ipNet, 4242)
 	require.NoError(t, err)
 
 	input, err := netip.ParseAddr("10.0.10.182")
@@ -21,5 +20,62 @@ func TestCalculatedRemoteApply(t *testing.T) {
 	expected, err := netip.ParseAddr("192.168.1.182")
 	assert.NoError(t, err)
 
-	assert.Equal(t, NewIp4AndPortFromNetIP(expected, 4242), c.Apply(input))
+	assert.Equal(t, netAddrToProtoV4AddrPort(expected, 4242), c.ApplyV4(input))
+
+	// Test v6 addresses
+	ipNet = netip.MustParsePrefix("ffff:ffff:ffff:ffff::0/64")
+	c, err = newCalculatedRemote(ipNet, ipNet, 4242)
+	require.NoError(t, err)
+
+	input, err = netip.ParseAddr("beef:beef:beef:beef:beef:beef:beef:beef")
+	assert.NoError(t, err)
+
+	expected, err = netip.ParseAddr("ffff:ffff:ffff:ffff:beef:beef:beef:beef")
+	assert.NoError(t, err)
+
+	assert.Equal(t, netAddrToProtoV6AddrPort(expected, 4242), c.ApplyV6(input))
+
+	// Test v6 addresses part 2
+	ipNet = netip.MustParsePrefix("ffff:ffff:ffff:ffff:ffff::0/80")
+	c, err = newCalculatedRemote(ipNet, ipNet, 4242)
+	require.NoError(t, err)
+
+	input, err = netip.ParseAddr("beef:beef:beef:beef:beef:beef:beef:beef")
+	assert.NoError(t, err)
+
+	expected, err = netip.ParseAddr("ffff:ffff:ffff:ffff:ffff:beef:beef:beef")
+	assert.NoError(t, err)
+
+	assert.Equal(t, netAddrToProtoV6AddrPort(expected, 4242), c.ApplyV6(input))
+
+	// Test v6 addresses part 2
+	ipNet = netip.MustParsePrefix("ffff:ffff:ffff::0/48")
+	c, err = newCalculatedRemote(ipNet, ipNet, 4242)
+	require.NoError(t, err)
+
+	input, err = netip.ParseAddr("beef:beef:beef:beef:beef:beef:beef:beef")
+	assert.NoError(t, err)
+
+	expected, err = netip.ParseAddr("ffff:ffff:ffff:beef:beef:beef:beef:beef")
+	assert.NoError(t, err)
+
+	assert.Equal(t, netAddrToProtoV6AddrPort(expected, 4242), c.ApplyV6(input))
+}
+
+func Test_newCalculatedRemote(t *testing.T) {
+	c, err := newCalculatedRemote(netip.MustParsePrefix("1::1/128"), netip.MustParsePrefix("1.0.0.0/32"), 4242)
+	require.EqualError(t, err, "invalid mask: 1.0.0.0/32 for cidr: 1::1/128")
+	require.Nil(t, c)
+
+	c, err = newCalculatedRemote(netip.MustParsePrefix("1.0.0.0/32"), netip.MustParsePrefix("1::1/128"), 4242)
+	require.EqualError(t, err, "invalid mask: 1::1/128 for cidr: 1.0.0.0/32")
+	require.Nil(t, c)
+
+	c, err = newCalculatedRemote(netip.MustParsePrefix("1.0.0.0/32"), netip.MustParsePrefix("1.0.0.0/32"), 4242)
+	require.NoError(t, err)
+	require.NotNil(t, c)
+
+	c, err = newCalculatedRemote(netip.MustParsePrefix("1::1/128"), netip.MustParsePrefix("1::1/128"), 4242)
+	require.NoError(t, err)
+	require.NotNil(t, c)
 }
diff --git a/cert/README.md b/cert/README.md
@@ -2,14 +2,25 @@
 
 This is a library for interacting with `nebula` style certificates and authorities.
 
-A `protobuf` definition of the certificate format is also included
+There are now 2 versions of `nebula` certificates:
 
-### Compiling the protobuf definition
+## v1
 
-Make sure you have `protoc` installed.
+This version is deprecated.
+
+A `protobuf` definition of the certificate format is included at `cert_v1.proto`
+
+To compile the definition you will need `protoc` installed.
 
 To compile for `go` with the same version of protobuf specified in go.mod:
 
 ```bash
-make
+make proto
 ```
+
+## v2
+
+This is the latest version which uses asn.1 DER encoding. It can support ipv4 and ipv6 and tolerate
+future certificate changes better than v1.
+
+`cert_v2.asn1` defines the wire format and can be used to compile marshalers.
diff --git a/cert/asn1.go b/cert/asn1.go
@@ -0,0 +1,52 @@
+package cert
+
+import (
+	"golang.org/x/crypto/cryptobyte"
+	"golang.org/x/crypto/cryptobyte/asn1"
+)
+
+// readOptionalASN1Boolean reads an asn.1 boolean with a specific tag instead of a asn.1 tag wrapping a boolean with a value
+// https://github.com/golang/go/issues/64811#issuecomment-1944446920
+func readOptionalASN1Boolean(b *cryptobyte.String, out *bool, tag asn1.Tag, defaultValue bool) bool {
+	var present bool
+	var child cryptobyte.String
+	if !b.ReadOptionalASN1(&child, &present, tag) {
+		return false
+	}
+
+	if !present {
+		*out = defaultValue
+		return true
+	}
+
+	// Ensure we have 1 byte
+	if len(child) == 1 {
+		*out = child[0] > 0
+		return true
+	}
+
+	return false
+}
+
+// readOptionalASN1Byte reads an asn.1 uint8 with a specific tag instead of a asn.1 tag wrapping a uint8 with a value
+// Similar issue as with readOptionalASN1Boolean
+func readOptionalASN1Byte(b *cryptobyte.String, out *byte, tag asn1.Tag, defaultValue byte) bool {
+	var present bool
+	var child cryptobyte.String
+	if !b.ReadOptionalASN1(&child, &present, tag) {
+		return false
+	}
+
+	if !present {
+		*out = defaultValue
+		return true
+	}
+
+	// Ensure we have 1 byte
+	if len(child) == 1 {
+		*out = child[0]
+		return true
+	}
+
+	return false
+}
diff --git a/cert/ca_pool_test.go b/cert/ca_pool_test.go
@@ -63,31 +63,31 @@ IBNWYMep3ysx9zCgknfG5dKtwGTaqF++BWKDYdyl34KX
 
 	rootCA := certificateV1{
 		details: detailsV1{
-			Name: "nebula root ca",
+			name: "nebula root ca",
 		},
 	}
 
 	rootCA01 := certificateV1{
 		details: detailsV1{
-			Name: "nebula root ca 01",
+			name: "nebula root ca 01",
 		},
 	}
 
 	rootCAP256 := certificateV1{
 		details: detailsV1{
-			Name: "nebula P256 test",
+			name: "nebula P256 test",
 		},
 	}
 
 	p, err := NewCAPoolFromPEM([]byte(noNewLines))
 	assert.Nil(t, err)
-	assert.Equal(t, p.CAs[string("c9bfaf7ce8e84b2eeda2e27b469f4b9617bde192efd214b68891ecda6ed49522")].Certificate.Name(), rootCA.details.Name)
-	assert.Equal(t, p.CAs[string("5c9c3f23e7ee7fe97637cbd3a0a5b854154d1d9aaaf7b566a51f4a88f76b64cd")].Certificate.Name(), rootCA01.details.Name)
+	assert.Equal(t, p.CAs[string("c9bfaf7ce8e84b2eeda2e27b469f4b9617bde192efd214b68891ecda6ed49522")].Certificate.Name(), rootCA.details.name)
+	assert.Equal(t, p.CAs[string("5c9c3f23e7ee7fe97637cbd3a0a5b854154d1d9aaaf7b566a51f4a88f76b64cd")].Certificate.Name(), rootCA01.details.name)
 
 	pp, err := NewCAPoolFromPEM([]byte(withNewLines))
 	assert.Nil(t, err)
-	assert.Equal(t, pp.CAs[string("c9bfaf7ce8e84b2eeda2e27b469f4b9617bde192efd214b68891ecda6ed49522")].Certificate.Name(), rootCA.details.Name)
-	assert.Equal(t, pp.CAs[string("5c9c3f23e7ee7fe97637cbd3a0a5b854154d1d9aaaf7b566a51f4a88f76b64cd")].Certificate.Name(), rootCA01.details.Name)
+	assert.Equal(t, pp.CAs[string("c9bfaf7ce8e84b2eeda2e27b469f4b9617bde192efd214b68891ecda6ed49522")].Certificate.Name(), rootCA.details.name)
+	assert.Equal(t, pp.CAs[string("5c9c3f23e7ee7fe97637cbd3a0a5b854154d1d9aaaf7b566a51f4a88f76b64cd")].Certificate.Name(), rootCA01.details.name)
 
 	// expired cert, no valid certs
 	ppp, err := NewCAPoolFromPEM([]byte(expired))
@@ -97,13 +97,13 @@ IBNWYMep3ysx9zCgknfG5dKtwGTaqF++BWKDYdyl34KX
 	// expired cert, with valid certs
 	pppp, err := NewCAPoolFromPEM(append([]byte(expired), noNewLines...))
 	assert.Equal(t, ErrExpired, err)
-	assert.Equal(t, pppp.CAs[string("c9bfaf7ce8e84b2eeda2e27b469f4b9617bde192efd214b68891ecda6ed49522")].Certificate.Name(), rootCA.details.Name)
-	assert.Equal(t, pppp.CAs[string("5c9c3f23e7ee7fe97637cbd3a0a5b854154d1d9aaaf7b566a51f4a88f76b64cd")].Certificate.Name(), rootCA01.details.Name)
+	assert.Equal(t, pppp.CAs[string("c9bfaf7ce8e84b2eeda2e27b469f4b9617bde192efd214b68891ecda6ed49522")].Certificate.Name(), rootCA.details.name)
+	assert.Equal(t, pppp.CAs[string("5c9c3f23e7ee7fe97637cbd3a0a5b854154d1d9aaaf7b566a51f4a88f76b64cd")].Certificate.Name(), rootCA01.details.name)
 	assert.Equal(t, pppp.CAs[string("152070be6bb19bc9e3bde4c2f0e7d8f4ff5448b4c9856b8eccb314fade0229b0")].Certificate.Name(), "expired")
 	assert.Equal(t, len(pppp.CAs), 3)
 
 	ppppp, err := NewCAPoolFromPEM([]byte(p256))
 	assert.Nil(t, err)
-	assert.Equal(t, ppppp.CAs[string("a7938893ec8c4ef769b06d7f425e5e46f7a7f5ffa49c3bcf4a86b608caba9159")].Certificate.Name(), rootCAP256.details.Name)
+	assert.Equal(t, ppppp.CAs[string("a7938893ec8c4ef769b06d7f425e5e46f7a7f5ffa49c3bcf4a86b608caba9159")].Certificate.Name(), rootCAP256.details.name)
 	assert.Equal(t, len(ppppp.CAs), 1)
 }