mirror of
https://github.com/cloudflare/cloudflared.git
synced 2025-07-28 19:49:57 +00:00
RTG-1339 Support post-quantum hybrid key exchange
Func spec: https://wiki.cfops.it/x/ZcBKHw
This commit is contained in:
Bas Westerbaan
committed by
Devin Carr
Devin Carr
parent
3e0ff3a771
commit
11cbff4ff7
335
vendor/github.com/cloudflare/circl/kem/hybrid/hybrid.go
generated
vendored
Normal file
335
vendor/github.com/cloudflare/circl/kem/hybrid/hybrid.go
generated
vendored
Normal file
@@ -0,0 +1,335 @@
|
||||
// Package hybrid defines several hybrid classical/quantum KEMs.
|
||||
//
|
||||
// KEMs are combined by simple concatenation of shared secrets, cipher texts,
|
||||
// public keys, etc, see
|
||||
//
|
||||
// https://datatracker.ietf.org/doc/draft-ietf-tls-hybrid-design/
|
||||
// https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-56Cr2.pdf
|
||||
//
|
||||
// Note that this is only fine if the shared secret is used in its entirety
|
||||
// in a next step, such as being hashed or used as key.
|
||||
//
|
||||
// For deriving a KEM keypair deterministically and encapsulating
|
||||
// deterministically, we expand a single seed to both using SHAKE256,
|
||||
// so that a non-uniform seed (such as a shared secret generated by a hybrid
|
||||
// KEM where one of the KEMs is weak) doesn't impact just one of the KEMs.
|
||||
//
|
||||
// Of our XOF (SHAKE256), we desire two security properties:
|
||||
//
|
||||
// 1. The internal state of the XOF should be big enough so that we
|
||||
// do not loose entropy.
|
||||
// 2. From one of the new seeds, we shouldn't be able to derive
|
||||
// the other or the original seed.
|
||||
//
|
||||
// SHAKE256, and all siblings in the SHA3 family, have a 200B internal
|
||||
// state, so (1) is fine if our seeds are less than 200B.
|
||||
// If SHAKE256 is computationally indistinguishable from a random
|
||||
// sponge, then it affords us 256b security against (2) by the
|
||||
// flat sponge claim [https://keccak.team/files/SpongeFunctions.pdf].
|
||||
// None of the implemented schemes claim more than 256b security
|
||||
// and so SHAKE256 will do fine.
|
||||
package hybrid
|
||||
|
||||
import (
|
||||
"errors"
|
||||
|
||||
"github.com/cloudflare/circl/internal/sha3"
|
||||
"github.com/cloudflare/circl/kem"
|
||||
"github.com/cloudflare/circl/kem/kyber/kyber1024"
|
||||
"github.com/cloudflare/circl/kem/kyber/kyber512"
|
||||
"github.com/cloudflare/circl/kem/kyber/kyber768"
|
||||
)
|
||||
|
||||
var ErrUninitialized = errors.New("public or private key not initialized")
|
||||
|
||||
// Returns the hybrid KEM of Kyber512 and X25519.
|
||||
func Kyber512X25519() kem.Scheme { return kyber512X }
|
||||
|
||||
// Returns the hybrid KEM of Kyber768 and X25519.
|
||||
func Kyber768X25519() kem.Scheme { return kyber768X }
|
||||
|
||||
// Returns the hybrid KEM of Kyber768 and X448.
|
||||
func Kyber768X448() kem.Scheme { return kyber768X4 }
|
||||
|
||||
// Returns the hybrid KEM of Kyber1024 and X448.
|
||||
func Kyber1024X448() kem.Scheme { return kyber1024X }
|
||||
|
||||
var kyber512X kem.Scheme = &scheme{
|
||||
"Kyber512-X25519",
|
||||
x25519Kem,
|
||||
kyber512.Scheme(),
|
||||
}
|
||||
|
||||
var kyber768X kem.Scheme = &scheme{
|
||||
"Kyber768-X25519",
|
||||
x25519Kem,
|
||||
kyber768.Scheme(),
|
||||
}
|
||||
|
||||
var kyber768X4 kem.Scheme = &scheme{
|
||||
"Kyber768-X448",
|
||||
x448Kem,
|
||||
kyber768.Scheme(),
|
||||
}
|
||||
|
||||
var kyber1024X kem.Scheme = &scheme{
|
||||
"Kyber1024-X448",
|
||||
x448Kem,
|
||||
kyber1024.Scheme(),
|
||||
}
|
||||
|
||||
// Public key of a hybrid KEM.
|
||||
type publicKey struct {
|
||||
scheme *scheme
|
||||
first kem.PublicKey
|
||||
second kem.PublicKey
|
||||
}
|
||||
|
||||
// Private key of a hybrid KEM.
|
||||
type privateKey struct {
|
||||
scheme *scheme
|
||||
first kem.PrivateKey
|
||||
second kem.PrivateKey
|
||||
}
|
||||
|
||||
// Scheme for a hybrid KEM.
|
||||
type scheme struct {
|
||||
name string
|
||||
first kem.Scheme
|
||||
second kem.Scheme
|
||||
}
|
||||
|
||||
func (sch *scheme) Name() string { return sch.name }
|
||||
func (sch *scheme) PublicKeySize() int {
|
||||
return sch.first.PublicKeySize() + sch.second.PublicKeySize()
|
||||
}
|
||||
|
||||
func (sch *scheme) PrivateKeySize() int {
|
||||
return sch.first.PrivateKeySize() + sch.second.PrivateKeySize()
|
||||
}
|
||||
|
||||
func (sch *scheme) SeedSize() int {
|
||||
first := sch.first.SeedSize()
|
||||
second := sch.second.SeedSize()
|
||||
ret := second
|
||||
if first > second {
|
||||
ret = first
|
||||
}
|
||||
return ret
|
||||
}
|
||||
|
||||
func (sch *scheme) SharedKeySize() int {
|
||||
return sch.first.SharedKeySize() + sch.second.SharedKeySize()
|
||||
}
|
||||
|
||||
func (sch *scheme) CiphertextSize() int {
|
||||
return sch.first.CiphertextSize() + sch.second.CiphertextSize()
|
||||
}
|
||||
|
||||
func (sch *scheme) EncapsulationSeedSize() int {
|
||||
first := sch.first.EncapsulationSeedSize()
|
||||
second := sch.second.EncapsulationSeedSize()
|
||||
ret := second
|
||||
if first > second {
|
||||
ret = first
|
||||
}
|
||||
return ret
|
||||
}
|
||||
|
||||
func (sk *privateKey) Scheme() kem.Scheme { return sk.scheme }
|
||||
func (pk *publicKey) Scheme() kem.Scheme { return pk.scheme }
|
||||
|
||||
func (sk *privateKey) MarshalBinary() ([]byte, error) {
|
||||
if sk.first == nil || sk.second == nil {
|
||||
return nil, ErrUninitialized
|
||||
}
|
||||
first, err := sk.first.MarshalBinary()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
second, err := sk.second.MarshalBinary()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return append(first, second...), nil
|
||||
}
|
||||
|
||||
func (sk *privateKey) Equal(other kem.PrivateKey) bool {
|
||||
oth, ok := other.(*privateKey)
|
||||
if !ok {
|
||||
return false
|
||||
}
|
||||
if sk.first == nil && sk.second == nil && oth.first == nil && oth.second == nil {
|
||||
return true
|
||||
}
|
||||
if sk.first == nil || sk.second == nil || oth.first == nil || oth.second == nil {
|
||||
return false
|
||||
}
|
||||
return sk.first.Equal(oth.first) && sk.second.Equal(oth.second)
|
||||
}
|
||||
|
||||
func (sk *privateKey) Public() kem.PublicKey {
|
||||
return &publicKey{sk.scheme, sk.first.Public(), sk.second.Public()}
|
||||
}
|
||||
|
||||
func (pk *publicKey) Equal(other kem.PublicKey) bool {
|
||||
oth, ok := other.(*publicKey)
|
||||
if !ok {
|
||||
return false
|
||||
}
|
||||
if pk.first == nil && pk.second == nil && oth.first == nil && oth.second == nil {
|
||||
return true
|
||||
}
|
||||
if pk.first == nil || pk.second == nil || oth.first == nil || oth.second == nil {
|
||||
return false
|
||||
}
|
||||
return pk.first.Equal(oth.first) && pk.second.Equal(oth.second)
|
||||
}
|
||||
|
||||
func (pk *publicKey) MarshalBinary() ([]byte, error) {
|
||||
if pk.first == nil || pk.second == nil {
|
||||
return nil, ErrUninitialized
|
||||
}
|
||||
first, err := pk.first.MarshalBinary()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
second, err := pk.second.MarshalBinary()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return append(first, second...), nil
|
||||
}
|
||||
|
||||
func (sch *scheme) GenerateKeyPair() (kem.PublicKey, kem.PrivateKey, error) {
|
||||
pk1, sk1, err := sch.first.GenerateKeyPair()
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
pk2, sk2, err := sch.second.GenerateKeyPair()
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
|
||||
return &publicKey{sch, pk1, pk2}, &privateKey{sch, sk1, sk2}, nil
|
||||
}
|
||||
|
||||
func (sch *scheme) DeriveKeyPair(seed []byte) (kem.PublicKey, kem.PrivateKey) {
|
||||
if len(seed) != sch.SeedSize() {
|
||||
panic(kem.ErrSeedSize)
|
||||
}
|
||||
h := sha3.NewShake256()
|
||||
_, _ = h.Write(seed)
|
||||
first := make([]byte, sch.first.SeedSize())
|
||||
second := make([]byte, sch.second.SeedSize())
|
||||
_, _ = h.Read(first)
|
||||
_, _ = h.Read(second)
|
||||
|
||||
pk1, sk1 := sch.first.DeriveKeyPair(first)
|
||||
pk2, sk2 := sch.second.DeriveKeyPair(second)
|
||||
|
||||
return &publicKey{sch, pk1, pk2}, &privateKey{sch, sk1, sk2}
|
||||
}
|
||||
|
||||
func (sch *scheme) Encapsulate(pk kem.PublicKey) (ct, ss []byte, err error) {
|
||||
pub, ok := pk.(*publicKey)
|
||||
if !ok {
|
||||
return nil, nil, kem.ErrTypeMismatch
|
||||
}
|
||||
|
||||
ct1, ss1, err := sch.first.Encapsulate(pub.first)
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
|
||||
ct2, ss2, err := sch.second.Encapsulate(pub.second)
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
|
||||
return append(ct1, ct2...), append(ss1, ss2...), nil
|
||||
}
|
||||
|
||||
func (sch *scheme) EncapsulateDeterministically(
|
||||
pk kem.PublicKey, seed []byte,
|
||||
) (ct, ss []byte, err error) {
|
||||
if len(seed) != sch.EncapsulationSeedSize() {
|
||||
return nil, nil, kem.ErrSeedSize
|
||||
}
|
||||
|
||||
h := sha3.NewShake256()
|
||||
_, _ = h.Write(seed)
|
||||
first := make([]byte, sch.first.EncapsulationSeedSize())
|
||||
second := make([]byte, sch.second.EncapsulationSeedSize())
|
||||
_, _ = h.Read(first)
|
||||
_, _ = h.Read(second)
|
||||
|
||||
pub, ok := pk.(*publicKey)
|
||||
if !ok {
|
||||
return nil, nil, kem.ErrTypeMismatch
|
||||
}
|
||||
|
||||
ct1, ss1, err := sch.first.EncapsulateDeterministically(pub.first, first)
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
ct2, ss2, err := sch.second.EncapsulateDeterministically(pub.second, second)
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
return append(ct1, ct2...), append(ss1, ss2...), nil
|
||||
}
|
||||
|
||||
func (sch *scheme) Decapsulate(sk kem.PrivateKey, ct []byte) ([]byte, error) {
|
||||
if len(ct) != sch.CiphertextSize() {
|
||||
return nil, kem.ErrCiphertextSize
|
||||
}
|
||||
|
||||
priv, ok := sk.(*privateKey)
|
||||
if !ok {
|
||||
return nil, kem.ErrTypeMismatch
|
||||
}
|
||||
|
||||
firstSize := sch.first.CiphertextSize()
|
||||
ss1, err := sch.first.Decapsulate(priv.first, ct[:firstSize])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
ss2, err := sch.second.Decapsulate(priv.second, ct[firstSize:])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return append(ss1, ss2...), nil
|
||||
}
|
||||
|
||||
func (sch *scheme) UnmarshalBinaryPublicKey(buf []byte) (kem.PublicKey, error) {
|
||||
if len(buf) != sch.PublicKeySize() {
|
||||
return nil, kem.ErrPubKeySize
|
||||
}
|
||||
firstSize := sch.first.PublicKeySize()
|
||||
pk1, err := sch.first.UnmarshalBinaryPublicKey(buf[:firstSize])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
pk2, err := sch.second.UnmarshalBinaryPublicKey(buf[firstSize:])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return &publicKey{sch, pk1, pk2}, nil
|
||||
}
|
||||
|
||||
func (sch *scheme) UnmarshalBinaryPrivateKey(buf []byte) (kem.PrivateKey, error) {
|
||||
if len(buf) != sch.PrivateKeySize() {
|
||||
return nil, kem.ErrPrivKeySize
|
||||
}
|
||||
firstSize := sch.first.PrivateKeySize()
|
||||
sk1, err := sch.first.UnmarshalBinaryPrivateKey(buf[:firstSize])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
sk2, err := sch.second.UnmarshalBinaryPrivateKey(buf[firstSize:])
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return &privateKey{sch, sk1, sk2}, nil
|
||||
}
|
||||
208
vendor/github.com/cloudflare/circl/kem/hybrid/xkem.go
generated
vendored
Normal file
208
vendor/github.com/cloudflare/circl/kem/hybrid/xkem.go
generated
vendored
Normal file
@@ -0,0 +1,208 @@
|
||||
package hybrid
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
cryptoRand "crypto/rand"
|
||||
"crypto/subtle"
|
||||
|
||||
"github.com/cloudflare/circl/dh/x25519"
|
||||
"github.com/cloudflare/circl/dh/x448"
|
||||
"github.com/cloudflare/circl/internal/sha3"
|
||||
"github.com/cloudflare/circl/kem"
|
||||
)
|
||||
|
||||
type xPublicKey struct {
|
||||
scheme *xScheme
|
||||
key []byte
|
||||
}
|
||||
type xPrivateKey struct {
|
||||
scheme *xScheme
|
||||
key []byte
|
||||
}
|
||||
type xScheme struct {
|
||||
size int
|
||||
}
|
||||
|
||||
var (
|
||||
x25519Kem = &xScheme{x25519.Size}
|
||||
x448Kem = &xScheme{x448.Size}
|
||||
)
|
||||
|
||||
func (sch *xScheme) Name() string {
|
||||
switch sch.size {
|
||||
case x25519.Size:
|
||||
return "X25519"
|
||||
case x448.Size:
|
||||
return "X448"
|
||||
}
|
||||
panic(kem.ErrTypeMismatch)
|
||||
}
|
||||
|
||||
func (sch *xScheme) PublicKeySize() int { return sch.size }
|
||||
func (sch *xScheme) PrivateKeySize() int { return sch.size }
|
||||
func (sch *xScheme) SeedSize() int { return sch.size }
|
||||
func (sch *xScheme) SharedKeySize() int { return sch.size }
|
||||
func (sch *xScheme) CiphertextSize() int { return sch.size }
|
||||
func (sch *xScheme) EncapsulationSeedSize() int { return sch.size }
|
||||
|
||||
func (sk *xPrivateKey) Scheme() kem.Scheme { return sk.scheme }
|
||||
func (pk *xPublicKey) Scheme() kem.Scheme { return pk.scheme }
|
||||
|
||||
func (sk *xPrivateKey) MarshalBinary() ([]byte, error) {
|
||||
ret := make([]byte, len(sk.key))
|
||||
copy(ret, sk.key)
|
||||
return ret, nil
|
||||
}
|
||||
|
||||
func (sk *xPrivateKey) Equal(other kem.PrivateKey) bool {
|
||||
oth, ok := other.(*xPrivateKey)
|
||||
if !ok {
|
||||
return false
|
||||
}
|
||||
if oth.scheme != sk.scheme {
|
||||
return false
|
||||
}
|
||||
return subtle.ConstantTimeCompare(oth.key, sk.key) == 1
|
||||
}
|
||||
|
||||
func (sk *xPrivateKey) Public() kem.PublicKey {
|
||||
pk := xPublicKey{sk.scheme, make([]byte, sk.scheme.size)}
|
||||
switch sk.scheme.size {
|
||||
case x25519.Size:
|
||||
var sk2, pk2 x25519.Key
|
||||
copy(sk2[:], sk.key)
|
||||
x25519.KeyGen(&pk2, &sk2)
|
||||
copy(pk.key, pk2[:])
|
||||
case x448.Size:
|
||||
var sk2, pk2 x448.Key
|
||||
copy(sk2[:], sk.key)
|
||||
x448.KeyGen(&pk2, &sk2)
|
||||
copy(pk.key, pk2[:])
|
||||
}
|
||||
return &pk
|
||||
}
|
||||
|
||||
func (pk *xPublicKey) Equal(other kem.PublicKey) bool {
|
||||
oth, ok := other.(*xPublicKey)
|
||||
if !ok {
|
||||
return false
|
||||
}
|
||||
if oth.scheme != pk.scheme {
|
||||
return false
|
||||
}
|
||||
return bytes.Equal(oth.key, pk.key)
|
||||
}
|
||||
|
||||
func (pk *xPublicKey) MarshalBinary() ([]byte, error) {
|
||||
ret := make([]byte, pk.scheme.size)
|
||||
copy(ret, pk.key)
|
||||
return ret, nil
|
||||
}
|
||||
|
||||
func (sch *xScheme) GenerateKeyPair() (kem.PublicKey, kem.PrivateKey, error) {
|
||||
seed := make([]byte, sch.SeedSize())
|
||||
_, err := cryptoRand.Read(seed)
|
||||
if err != nil {
|
||||
return nil, nil, err
|
||||
}
|
||||
pk, sk := sch.DeriveKeyPair(seed)
|
||||
return pk, sk, nil
|
||||
}
|
||||
|
||||
func (sch *xScheme) DeriveKeyPair(seed []byte) (kem.PublicKey, kem.PrivateKey) {
|
||||
if len(seed) != sch.SeedSize() {
|
||||
panic(kem.ErrSeedSize)
|
||||
}
|
||||
sk := xPrivateKey{scheme: sch, key: make([]byte, sch.size)}
|
||||
|
||||
h := sha3.NewShake256()
|
||||
_, _ = h.Write(seed)
|
||||
_, _ = h.Read(sk.key)
|
||||
|
||||
return sk.Public(), &sk
|
||||
}
|
||||
|
||||
func (sch *xScheme) Encapsulate(pk kem.PublicKey) (ct, ss []byte, err error) {
|
||||
seed := make([]byte, sch.EncapsulationSeedSize())
|
||||
_, err = cryptoRand.Read(seed)
|
||||
if err != nil {
|
||||
return
|
||||
}
|
||||
return sch.EncapsulateDeterministically(pk, seed)
|
||||
}
|
||||
|
||||
func (pk *xPublicKey) X(sk *xPrivateKey) []byte {
|
||||
if pk.scheme != sk.scheme {
|
||||
panic(kem.ErrTypeMismatch)
|
||||
}
|
||||
|
||||
switch pk.scheme.size {
|
||||
case x25519.Size:
|
||||
var ss2, pk2, sk2 x25519.Key
|
||||
copy(pk2[:], pk.key)
|
||||
copy(sk2[:], sk.key)
|
||||
x25519.Shared(&ss2, &sk2, &pk2)
|
||||
return ss2[:]
|
||||
case x448.Size:
|
||||
var ss2, pk2, sk2 x448.Key
|
||||
copy(pk2[:], pk.key)
|
||||
copy(sk2[:], sk.key)
|
||||
x448.Shared(&ss2, &sk2, &pk2)
|
||||
return ss2[:]
|
||||
}
|
||||
panic(kem.ErrTypeMismatch)
|
||||
}
|
||||
|
||||
func (sch *xScheme) EncapsulateDeterministically(
|
||||
pk kem.PublicKey, seed []byte,
|
||||
) (ct, ss []byte, err error) {
|
||||
if len(seed) != sch.EncapsulationSeedSize() {
|
||||
return nil, nil, kem.ErrSeedSize
|
||||
}
|
||||
pub, ok := pk.(*xPublicKey)
|
||||
if !ok || pub.scheme != sch {
|
||||
return nil, nil, kem.ErrTypeMismatch
|
||||
}
|
||||
|
||||
pk2, sk2 := sch.DeriveKeyPair(seed)
|
||||
ss = pub.X(sk2.(*xPrivateKey))
|
||||
ct, _ = pk2.MarshalBinary()
|
||||
return
|
||||
}
|
||||
|
||||
func (sch *xScheme) Decapsulate(sk kem.PrivateKey, ct []byte) ([]byte, error) {
|
||||
if len(ct) != sch.CiphertextSize() {
|
||||
return nil, kem.ErrCiphertextSize
|
||||
}
|
||||
|
||||
priv, ok := sk.(*xPrivateKey)
|
||||
if !ok || priv.scheme != sch {
|
||||
return nil, kem.ErrTypeMismatch
|
||||
}
|
||||
|
||||
pk, err := sch.UnmarshalBinaryPublicKey(ct)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
ss := pk.(*xPublicKey).X(priv)
|
||||
return ss, nil
|
||||
}
|
||||
|
||||
func (sch *xScheme) UnmarshalBinaryPublicKey(buf []byte) (kem.PublicKey, error) {
|
||||
if len(buf) != sch.PublicKeySize() {
|
||||
return nil, kem.ErrPubKeySize
|
||||
}
|
||||
ret := xPublicKey{sch, make([]byte, sch.size)}
|
||||
copy(ret.key, buf)
|
||||
return &ret, nil
|
||||
}
|
||||
|
||||
func (sch *xScheme) UnmarshalBinaryPrivateKey(buf []byte) (kem.PrivateKey, error) {
|
||||
if len(buf) != sch.PrivateKeySize() {
|
||||
return nil, kem.ErrPrivKeySize
|
||||
}
|
||||
ret := xPrivateKey{sch, make([]byte, sch.size)}
|
||||
copy(ret.key, buf)
|
||||
return &ret, nil
|
||||
}
|
||||
Reference in New Issue
Block a user