mirror of
https://source.quilibrium.com/quilibrium/ceremonyclient.git
synced 2024-09-21 07:27:30 +00:00
453 lines
13 KiB
Go
453 lines
13 KiB
Go
package crypto
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// Uncomment with full release
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// import (
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// "crypto/aes"
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// "crypto/cipher"
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// "crypto/hmac"
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// "crypto/rand"
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// "crypto/sha512"
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// "crypto/subtle"
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// "encoding/binary"
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// "github.com/pkg/errors"
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// "golang.org/x/crypto/hkdf"
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// "source.quilibrium.com/quilibrium/monorepo/nekryptology/pkg/core/curves"
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// "source.quilibrium.com/quilibrium/monorepo/node/keys"
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// "source.quilibrium.com/quilibrium/monorepo/node/protobufs"
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// )
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// const PROTOCOL_VERSION = 1
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// const PROTOCOL = 1<<8 + PROTOCOL_VERSION
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// const CHAIN_KEY = 0x01
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// const MESSAGE_KEY = 0x02
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// const AEAD_KEY = 0x03
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// // Note: If an HSM with raw primitive access becomes available, the raw crypto
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// // mechanisms should be refactored into calls in KeyManager and implemented
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// // through the driver
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// type DoubleRatchetParticipant struct {
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// sendingEphemeralPrivateKey curves.Scalar
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// receivingEphemeralKey curves.Point
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// curve curves.Curve
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// keyManager keys.KeyManager
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// rootKey []byte
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// sendingChainKey []byte
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// currentSendingHeaderKey []byte
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// currentReceivingHeaderKey []byte
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// nextSendingHeaderKey []byte
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// nextReceivingHeaderKey []byte
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// receivingChainKey []byte
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// currentSendingChainLength uint32
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// previousSendingChainLength uint32
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// currentReceivingChainLength uint32
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// previousReceivingChainLength uint32
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// skippedKeysMap map[string]map[uint32][]byte
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// }
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// func NewDoubleRatchetParticipant(
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// sessionKey []byte,
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// sendingHeaderKey []byte,
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// nextReceivingHeaderKey []byte,
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// isSender bool,
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// sendingEphemeralPrivateKey curves.Scalar,
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// receivingEphemeralKey curves.Point,
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// curve curves.Curve,
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// keyManager keys.KeyManager,
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// ) (*DoubleRatchetParticipant, error) {
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// participant := &DoubleRatchetParticipant{}
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// participant.sendingEphemeralPrivateKey = sendingEphemeralPrivateKey
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// participant.skippedKeysMap = make(map[string]map[uint32][]byte)
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// participant.keyManager = keyManager
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// participant.currentSendingChainLength = 0
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// participant.previousSendingChainLength = 0
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// participant.currentReceivingChainLength = 0
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// participant.previousReceivingChainLength = 0
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// if sendingEphemeralPrivateKey.Point().CurveName() !=
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// receivingEphemeralKey.CurveName() || receivingEphemeralKey.CurveName() !=
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// curve.Name {
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// return nil, errors.New("curve mismatch")
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// }
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// participant.curve = curve
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// if isSender {
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// hash := hkdf.New(
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// sha512.New,
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// receivingEphemeralKey.Mul(
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// sendingEphemeralPrivateKey,
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// ).ToAffineCompressed(),
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// sessionKey,
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// []byte("quilibrium-double-ratchet"),
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// )
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// rkck := make([]byte, 96)
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// if _, err := hash.Read(rkck[:]); err != nil {
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// return nil, errors.Wrap(err, "failed establishing root key")
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// }
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// participant.currentSendingHeaderKey = sendingHeaderKey
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// participant.nextReceivingHeaderKey = nextReceivingHeaderKey
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// participant.rootKey = rkck[:32]
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// participant.sendingChainKey = rkck[32:64]
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// participant.nextSendingHeaderKey = rkck[64:96]
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// participant.receivingEphemeralKey = receivingEphemeralKey
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// } else {
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// participant.rootKey = sessionKey
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// participant.nextReceivingHeaderKey = sendingHeaderKey
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// participant.nextSendingHeaderKey = nextReceivingHeaderKey
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// }
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// return participant, nil
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// }
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// func (r *DoubleRatchetParticipant) RatchetEncrypt(
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// message []byte,
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// ) (*protobufs.P2PChannelEnvelope, error) {
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// envelope := &protobufs.P2PChannelEnvelope{
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// ProtocolIdentifier: PROTOCOL,
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// MessageHeader: &protobufs.MessageCiphertext{},
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// MessageBody: &protobufs.MessageCiphertext{},
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// }
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// newChainKey, messageKey, aeadKey := ratchetKeys(r.sendingChainKey)
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// r.sendingChainKey = newChainKey
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// var err error
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// header := r.encodeHeader()
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// envelope.MessageHeader, err = r.encrypt(
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// header,
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// r.currentSendingHeaderKey,
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// nil,
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// )
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// if err != nil {
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// return nil, errors.Wrap(err, "could not encrypt header")
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// }
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// envelope.MessageBody, err = r.encrypt(
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// message,
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// messageKey,
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// append(append([]byte{}, aeadKey...), envelope.MessageHeader.Ciphertext...),
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// )
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// if err != nil {
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// return nil, errors.Wrap(err, "could not encrypt message")
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// }
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// r.currentSendingChainLength++
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// return envelope, nil
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// }
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// func (r *DoubleRatchetParticipant) RatchetDecrypt(
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// envelope *protobufs.P2PChannelEnvelope,
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// ) ([]byte, error) {
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// plaintext, err := r.trySkippedMessageKeys(envelope)
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// if err != nil {
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// return nil, errors.Wrap(err, "could not decrypt from matching skipped key")
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// }
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// if plaintext != nil {
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// return plaintext, nil
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// }
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// header, shouldRatchet, err := r.decryptHeader(
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// envelope.MessageHeader,
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// r.currentReceivingHeaderKey,
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// )
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// if err != nil {
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// return nil, errors.Wrap(err, "could not decrypt header")
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// }
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// receivingEphemeralKey,
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// previousReceivingChainLength,
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// currentReceivingChainLength,
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// err := r.decodeHeader(header)
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// if err != nil {
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// return nil, errors.Wrap(err, "could not decode header")
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// }
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// if shouldRatchet {
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// if err := r.skipMessageKeys(previousReceivingChainLength); err != nil {
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// return nil, errors.Wrap(err, "could not skip previous message keys")
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// }
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// if err := r.ratchetEphemeralKeys(receivingEphemeralKey); err != nil {
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// return nil, errors.Wrap(err, "could not ratchet ephemeral keys")
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// }
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// }
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// if err := r.skipMessageKeys(currentReceivingChainLength); err != nil {
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// return nil, errors.Wrap(err, "could not skip message keys")
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// }
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// newChainKey, messageKey, aeadKey := ratchetKeys(r.receivingChainKey)
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// r.receivingChainKey = newChainKey
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// r.currentReceivingChainLength++
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// plaintext, err = r.decrypt(
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// envelope.MessageBody,
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// messageKey,
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// append(
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// append([]byte{}, aeadKey...),
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// envelope.MessageHeader.Ciphertext...,
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// ),
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// )
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// return plaintext, errors.Wrap(err, "could not decrypt message")
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// }
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// func (r *DoubleRatchetParticipant) ratchetEphemeralKeys(
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// newReceivingEphemeralKey curves.Point,
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// ) error {
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// r.previousSendingChainLength = r.currentSendingChainLength
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// r.currentSendingChainLength = 0
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// r.currentReceivingChainLength = 0
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// r.currentSendingHeaderKey = r.nextSendingHeaderKey
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// r.currentReceivingHeaderKey = r.nextReceivingHeaderKey
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// r.receivingEphemeralKey = newReceivingEphemeralKey
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// hash := hkdf.New(
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// sha512.New,
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// newReceivingEphemeralKey.Mul(
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// r.sendingEphemeralPrivateKey,
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// ).ToAffineCompressed(),
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// r.rootKey,
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// []byte("quilibrium-double-ratchet"),
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// )
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// rkck := make([]byte, 96)
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// if _, err := hash.Read(rkck[:]); err != nil {
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// return errors.Wrap(err, "failed ratcheting root key")
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// }
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// r.rootKey = rkck[:32]
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// r.receivingChainKey = rkck[32:64]
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// r.nextReceivingHeaderKey = rkck[64:]
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// r.sendingEphemeralPrivateKey = r.curve.NewScalar().Random(rand.Reader)
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// hash = hkdf.New(
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// sha512.New,
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// newReceivingEphemeralKey.Mul(
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// r.sendingEphemeralPrivateKey,
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// ).ToAffineCompressed(),
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// r.rootKey,
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// []byte("quilibrium-double-ratchet"),
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// )
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// rkck2 := make([]byte, 96)
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// if _, err := hash.Read(rkck2[:]); err != nil {
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// return errors.Wrap(err, "failed ratcheting root key")
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// }
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// r.rootKey = rkck2[:32]
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// r.sendingChainKey = rkck2[32:64]
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// r.nextSendingHeaderKey = rkck2[64:]
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// return nil
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// }
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// func (r *DoubleRatchetParticipant) trySkippedMessageKeys(
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// envelope *protobufs.P2PChannelEnvelope,
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// ) ([]byte, error) {
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// for receivingHeaderKey, skippedKeys := range r.skippedKeysMap {
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// header, _, err := r.decryptHeader(
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// envelope.MessageHeader,
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// []byte(receivingHeaderKey),
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// )
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// if err == nil {
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// _, _, current, err := r.decodeHeader(header)
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// if err != nil {
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// return nil, errors.Wrap(err, "malformed header")
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// }
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// messageKey := skippedKeys[current][:32]
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// aeadKey := skippedKeys[current][32:]
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// plaintext, err := r.decrypt(
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// envelope.MessageBody,
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// messageKey,
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// append(
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// append([]byte{}, aeadKey...),
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// envelope.MessageHeader.Ciphertext[:]...,
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// ),
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// )
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// if err != nil {
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// return nil, errors.Wrap(err, "could not decrypt from skipped key")
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// }
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// delete(r.skippedKeysMap[receivingHeaderKey], current)
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// if len(r.skippedKeysMap[receivingHeaderKey]) == 0 {
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// delete(r.skippedKeysMap, receivingHeaderKey)
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// }
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// return plaintext, nil
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// }
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// }
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// return nil, nil
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// }
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// func (r *DoubleRatchetParticipant) skipMessageKeys(until uint32) error {
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// if r.currentReceivingChainLength+100 < until {
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// return errors.New("skip limit exceeded")
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// }
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// if r.receivingChainKey != nil {
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// for r.currentReceivingChainLength < until {
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// newChainKey, messageKey, aeadKey := ratchetKeys(r.receivingChainKey)
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// skippedKeys := r.skippedKeysMap[string(r.currentReceivingHeaderKey)]
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// if skippedKeys == nil {
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// r.skippedKeysMap[string(r.currentReceivingHeaderKey)] =
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// make(map[uint32][]byte)
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// }
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// skippedKeys[r.currentReceivingChainLength] = append(
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// append([]byte{}, messageKey...),
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// aeadKey...,
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// )
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// r.receivingChainKey = newChainKey
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// r.currentReceivingChainLength++
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// }
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// }
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// return nil
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// }
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// func (r *DoubleRatchetParticipant) encodeHeader() []byte {
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// header := []byte{}
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// header = append(
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// header,
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// r.curve.NewGeneratorPoint().Mul(
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// r.sendingEphemeralPrivateKey,
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// ).ToAffineCompressed()[:]...,
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// )
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// header = binary.BigEndian.AppendUint32(header, r.previousSendingChainLength)
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// header = binary.BigEndian.AppendUint32(header, r.currentSendingChainLength)
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// return header
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// }
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// func (r *DoubleRatchetParticipant) decryptHeader(
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// ciphertext *protobufs.MessageCiphertext,
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// receivingHeaderKey []byte,
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// ) ([]byte, bool, error) {
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// header, err := r.decrypt(
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// ciphertext,
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// receivingHeaderKey,
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// nil,
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// )
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// if err != nil && subtle.ConstantTimeCompare(
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// r.currentReceivingHeaderKey,
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// receivingHeaderKey,
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// ) == 1 {
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// if header, err = r.decrypt(
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// ciphertext,
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// r.nextReceivingHeaderKey,
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// nil,
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// ); err != nil {
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// return nil, false, errors.Wrap(err, "could not decrypt header")
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// }
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// return header, true, nil
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// }
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// return header, false, errors.Wrap(err, "could not decrypt header")
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// }
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// func (r *DoubleRatchetParticipant) decodeHeader(
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// header []byte,
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// ) (curves.Point, uint32, uint32, error) {
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// if len(header) < 9 {
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// return nil, 0, 0, errors.New("malformed header")
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// }
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// currentReceivingChainLength := binary.BigEndian.Uint32(header[len(header)-4:])
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// previousReceivingChainLength := binary.BigEndian.Uint32(
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// header[len(header)-8 : len(header)-4],
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// )
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// receivingEphemeralKeyBytes := header[:len(header)-8]
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// receivingEphemeralKey, err := r.curve.Point.FromAffineCompressed(
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// receivingEphemeralKeyBytes,
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// )
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// return receivingEphemeralKey,
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// previousReceivingChainLength,
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// currentReceivingChainLength,
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// errors.Wrap(err, "could not decode receiving dh key")
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// }
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// func (r *DoubleRatchetParticipant) encrypt(
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// plaintext []byte,
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// key []byte,
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// associatedData []byte,
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// ) (*protobufs.MessageCiphertext, error) {
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// iv := [12]byte{}
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// rand.Read(iv[:])
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// aesCipher, err := aes.NewCipher(key)
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// if err != nil {
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// return nil, errors.Wrap(err, "could not construct cipher")
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// }
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// gcm, err := cipher.NewGCM(aesCipher)
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// if err != nil {
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// return nil, errors.Wrap(err, "could not construct block")
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// }
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// ciphertext := &protobufs.MessageCiphertext{}
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// if associatedData == nil {
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// associatedData = make([]byte, 32)
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// if _, err := rand.Read(associatedData); err != nil {
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// return nil, errors.Wrap(err, "could not obtain entropy")
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// }
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// ciphertext.AssociatedData = associatedData
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// }
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// ciphertext.Ciphertext = gcm.Seal(nil, iv[:], plaintext, associatedData)
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// ciphertext.InitializationVector = iv[:]
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// return ciphertext, nil
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// }
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// func (r *DoubleRatchetParticipant) decrypt(
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// ciphertext *protobufs.MessageCiphertext,
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// key []byte,
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// associatedData []byte,
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// ) ([]byte, error) {
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// if associatedData == nil {
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// associatedData = ciphertext.AssociatedData
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// }
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// aesCipher, err := aes.NewCipher(key)
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// if err != nil {
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// return nil, errors.Wrap(err, "could not construct cipher")
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// }
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// gcm, err := cipher.NewGCM(aesCipher)
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// if err != nil {
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// return nil, errors.Wrap(err, "could not construct block")
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// }
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// plaintext, err := gcm.Open(
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// nil,
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// ciphertext.InitializationVector,
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// ciphertext.Ciphertext,
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// associatedData,
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// )
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// return plaintext, errors.Wrap(err, "could not decrypt ciphertext")
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// }
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// func ratchetKeys(inputKey []byte) ([]byte, []byte, []byte) {
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// buf := hmac.New(sha512.New, inputKey)
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// buf.Write([]byte{AEAD_KEY})
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// aeadKey := buf.Sum(nil)
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// buf.Reset()
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// buf.Write([]byte{MESSAGE_KEY})
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// messageKey := buf.Sum(nil)
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// buf.Reset()
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// buf.Write([]byte{CHAIN_KEY})
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// chainKey := buf.Sum(nil)
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// return chainKey[:32], messageKey[:32], aeadKey[:32]
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// }
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