frostfs-s3-gw/creds/accessbox/accessbox.go

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package accessbox
import (
"bytes"
"crypto/cipher"
"crypto/elliptic"
"crypto/rand"
"crypto/sha256"
"encoding/hex"
"fmt"
"io"
"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/session"
"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
"golang.org/x/crypto/chacha20poly1305"
"golang.org/x/crypto/hkdf"
"google.golang.org/protobuf/proto"
)
// Box represents friendly AccessBox.
type Box struct {
Gate *GateData
Policies []*ContainerPolicy
}
// ContainerPolicy represents friendly AccessBox_ContainerPolicy.
type ContainerPolicy struct {
LocationConstraint string
Policy netmap.PlacementPolicy
}
// GateData represents gate tokens in AccessBox.
type GateData struct {
AccessKey string
BearerToken *bearer.Token
SessionTokens []*session.Container
GateKey *keys.PublicKey
}
// NewGateData returns GateData from the provided bearer token and the public gate key.
func NewGateData(gateKey *keys.PublicKey, bearerTkn *bearer.Token) *GateData {
return &GateData{GateKey: gateKey, BearerToken: bearerTkn}
}
// SessionTokenForPut returns the first suitable container session context for PUT operation.
func (g *GateData) SessionTokenForPut() *session.Container {
return g.containerSessionToken(session.VerbContainerPut)
}
// SessionTokenForDelete returns the first suitable container session context for DELETE operation.
func (g *GateData) SessionTokenForDelete() *session.Container {
return g.containerSessionToken(session.VerbContainerDelete)
}
// SessionTokenForSetEACL returns the first suitable container session context for SetEACL operation.
func (g *GateData) SessionTokenForSetEACL() *session.Container {
return g.containerSessionToken(session.VerbContainerSetEACL)
}
func (g *GateData) containerSessionToken(verb session.ContainerVerb) *session.Container {
for _, sessionToken := range g.SessionTokens {
if isAppropriateContainerContext(sessionToken, verb) {
return sessionToken
}
}
return nil
}
func isAppropriateContainerContext(tok *session.Container, verb session.ContainerVerb) bool {
switch verb {
case session.VerbContainerSetEACL, session.VerbContainerDelete, session.VerbContainerPut:
return tok.AssertVerb(verb)
default:
return false
}
}
// Secrets represents AccessKey and the key to encrypt gate tokens.
type Secrets struct {
AccessKey string
EphemeralKey *keys.PrivateKey
}
// Marshal returns the wire-format of AccessBox.
func (x *AccessBox) Marshal() ([]byte, error) {
return proto.Marshal(x)
}
// Unmarshal parses the wire-format message and put data to x.
func (x *AccessBox) Unmarshal(data []byte) error {
return proto.Unmarshal(data, x)
}
// PackTokens adds bearer and session tokens to BearerTokens and SessionToken lists respectively.
// Session token can be nil.
func PackTokens(gatesData []*GateData) (*AccessBox, *Secrets, error) {
box := &AccessBox{}
ephemeralKey, err := keys.NewPrivateKey()
if err != nil {
return nil, nil, fmt.Errorf("create ephemeral key: %w", err)
}
box.OwnerPublicKey = ephemeralKey.PublicKey().Bytes()
secret, err := generateSecret()
if err != nil {
return nil, nil, fmt.Errorf("failed to generate accessKey as hex: %w", err)
}
if err := box.addTokens(gatesData, ephemeralKey, secret); err != nil {
return nil, nil, fmt.Errorf("failed to add tokens to accessbox: %w", err)
}
return box, &Secrets{hex.EncodeToString(secret), ephemeralKey}, err
}
// GetTokens returns gate tokens from AccessBox.
func (x *AccessBox) GetTokens(owner *keys.PrivateKey) (*GateData, error) {
sender, err := keys.NewPublicKeyFromBytes(x.OwnerPublicKey, elliptic.P256())
if err != nil {
return nil, fmt.Errorf("couldn't unmarshal OwnerPublicKey: %w", err)
}
ownerKey := owner.PublicKey().Bytes()
for _, gate := range x.Gates {
if !bytes.Equal(gate.GatePublicKey, ownerKey) {
continue
}
gateData, err := decodeGate(gate, owner, sender)
if err != nil {
return nil, fmt.Errorf("failed to decode gate: %w", err)
}
return gateData, nil
}
return nil, fmt.Errorf("no gate data for key %x was found", ownerKey)
}
// GetPlacementPolicy returns ContainerPolicy from AccessBox.
func (x *AccessBox) GetPlacementPolicy() ([]*ContainerPolicy, error) {
var result []*ContainerPolicy
for _, policy := range x.ContainerPolicy {
var cnrPolicy ContainerPolicy
if err := cnrPolicy.Policy.Unmarshal(policy.Policy); err != nil {
return nil, fmt.Errorf("unmarshal placement policy: %w", err)
}
cnrPolicy.LocationConstraint = policy.LocationConstraint
result = append(result, &cnrPolicy)
}
return result, nil
}
// GetBox parses AccessBox to Box.
func (x *AccessBox) GetBox(owner *keys.PrivateKey) (*Box, error) {
tokens, err := x.GetTokens(owner)
if err != nil {
return nil, fmt.Errorf("get tokens: %w", err)
}
policy, err := x.GetPlacementPolicy()
if err != nil {
return nil, fmt.Errorf("get policy: %w", err)
}
return &Box{
Gate: tokens,
Policies: policy,
}, nil
}
func (x *AccessBox) addTokens(gatesData []*GateData, ephemeralKey *keys.PrivateKey, secret []byte) error {
for _, gate := range gatesData {
encBearer := gate.BearerToken.Marshal()
encSessions := make([][]byte, len(gate.SessionTokens))
for i, sessionToken := range gate.SessionTokens {
encSessions[i] = sessionToken.Marshal()
}
tokens := new(Tokens)
tokens.AccessKey = secret
tokens.BearerToken = encBearer
tokens.SessionTokens = encSessions
boxGate, err := encodeGate(ephemeralKey, gate.GateKey, tokens)
if err != nil {
return fmt.Errorf("encode gate: %w", err)
}
x.Gates = append(x.Gates, boxGate)
}
return nil
}
func encodeGate(ephemeralKey *keys.PrivateKey, ownerKey *keys.PublicKey, tokens *Tokens) (*AccessBox_Gate, error) {
data, err := proto.Marshal(tokens)
if err != nil {
return nil, fmt.Errorf("encode tokens: %w", err)
}
encrypted, err := encrypt(ephemeralKey, ownerKey, data)
if err != nil {
return nil, fmt.Errorf("ecrypt tokens: %w", err)
}
gate := new(AccessBox_Gate)
gate.GatePublicKey = ownerKey.Bytes()
gate.Tokens = encrypted
return gate, nil
}
func decodeGate(gate *AccessBox_Gate, owner *keys.PrivateKey, sender *keys.PublicKey) (*GateData, error) {
data, err := decrypt(owner, sender, gate.Tokens)
if err != nil {
return nil, fmt.Errorf("decrypt tokens: %w", err)
}
tokens := new(Tokens)
if err = proto.Unmarshal(data, tokens); err != nil {
return nil, fmt.Errorf("unmarshal tokens: %w", err)
}
var bearerTkn bearer.Token
if err = bearerTkn.Unmarshal(tokens.BearerToken); err != nil {
return nil, fmt.Errorf("unmarshal bearer token: %w", err)
}
sessionTkns := make([]*session.Container, len(tokens.SessionTokens))
for i, encSessionToken := range tokens.SessionTokens {
sessionTkn := new(session.Container)
if err = sessionTkn.Unmarshal(encSessionToken); err != nil {
return nil, fmt.Errorf("unmarshal session token: %w", err)
}
sessionTkns[i] = sessionTkn
}
gateData := NewGateData(owner.PublicKey(), &bearerTkn)
gateData.SessionTokens = sessionTkns
gateData.AccessKey = hex.EncodeToString(tokens.AccessKey)
return gateData, nil
}
func generateShared256(prv *keys.PrivateKey, pub *keys.PublicKey) (sk []byte, err error) {
if prv.PublicKey().Curve != pub.Curve {
return nil, fmt.Errorf("not equal curves")
}
x, _ := pub.Curve.ScalarMult(pub.X, pub.Y, prv.D.Bytes())
if x == nil {
return nil, fmt.Errorf("shared key is point at infinity")
}
sk = make([]byte, 32)
skBytes := x.Bytes()
copy(sk[len(sk)-len(skBytes):], skBytes)
return sk, nil
}
func deriveKey(secret []byte) ([]byte, error) {
hash := sha256.New
kdf := hkdf.New(hash, secret, nil, nil)
key := make([]byte, 32)
_, err := io.ReadFull(kdf, key)
return key, err
}
func encrypt(owner *keys.PrivateKey, sender *keys.PublicKey, data []byte) ([]byte, error) {
enc, err := getCipher(owner, sender)
if err != nil {
return nil, fmt.Errorf("get chiper: %w", err)
}
nonce := make([]byte, enc.NonceSize())
if _, err = rand.Read(nonce); err != nil {
return nil, fmt.Errorf("generate random nonce: %w", err)
}
return enc.Seal(nonce, nonce, data, nil), nil
}
func decrypt(owner *keys.PrivateKey, sender *keys.PublicKey, data []byte) ([]byte, error) {
dec, err := getCipher(owner, sender)
if err != nil {
return nil, fmt.Errorf("get chiper: %w", err)
}
if ld, ns := len(data), dec.NonceSize(); ld < ns {
return nil, fmt.Errorf("wrong data size (%d), should be greater than %d", ld, ns)
}
nonce, cypher := data[:dec.NonceSize()], data[dec.NonceSize():]
return dec.Open(nil, nonce, cypher, nil)
}
func getCipher(owner *keys.PrivateKey, sender *keys.PublicKey) (cipher.AEAD, error) {
secret, err := generateShared256(owner, sender)
if err != nil {
return nil, fmt.Errorf("generate shared key: %w", err)
}
key, err := deriveKey(secret)
if err != nil {
return nil, fmt.Errorf("derive key: %w", err)
}
return chacha20poly1305.NewX(key)
}
func generateSecret() ([]byte, error) {
b := make([]byte, 32)
_, err := io.ReadFull(rand.Reader, b)
return b, err
}