forked from cerc-io/plugeth
536 lines
14 KiB
Go
536 lines
14 KiB
Go
package api
|
|
|
|
import (
|
|
"context"
|
|
"crypto/ecdsa"
|
|
"crypto/rand"
|
|
"encoding/hex"
|
|
"encoding/json"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/crypto"
|
|
"github.com/ethereum/go-ethereum/crypto/ecies"
|
|
"github.com/ethereum/go-ethereum/crypto/sha3"
|
|
"github.com/ethereum/go-ethereum/swarm/log"
|
|
"github.com/ethereum/go-ethereum/swarm/sctx"
|
|
"github.com/ethereum/go-ethereum/swarm/storage"
|
|
"golang.org/x/crypto/scrypt"
|
|
cli "gopkg.in/urfave/cli.v1"
|
|
)
|
|
|
|
var (
|
|
ErrDecrypt = errors.New("cant decrypt - forbidden")
|
|
ErrUnknownAccessType = errors.New("unknown access type (or not implemented)")
|
|
ErrDecryptDomainForbidden = errors.New("decryption request domain forbidden - can only decrypt on localhost")
|
|
AllowedDecryptDomains = []string{
|
|
"localhost",
|
|
"127.0.0.1",
|
|
}
|
|
)
|
|
|
|
const EMPTY_CREDENTIALS = ""
|
|
|
|
type AccessEntry struct {
|
|
Type AccessType
|
|
Publisher string
|
|
Salt []byte
|
|
Act string
|
|
KdfParams *KdfParams
|
|
}
|
|
|
|
type DecryptFunc func(*ManifestEntry) error
|
|
|
|
func (a *AccessEntry) MarshalJSON() (out []byte, err error) {
|
|
|
|
return json.Marshal(struct {
|
|
Type AccessType `json:"type,omitempty"`
|
|
Publisher string `json:"publisher,omitempty"`
|
|
Salt string `json:"salt,omitempty"`
|
|
Act string `json:"act,omitempty"`
|
|
KdfParams *KdfParams `json:"kdf_params,omitempty"`
|
|
}{
|
|
Type: a.Type,
|
|
Publisher: a.Publisher,
|
|
Salt: hex.EncodeToString(a.Salt),
|
|
Act: a.Act,
|
|
KdfParams: a.KdfParams,
|
|
})
|
|
|
|
}
|
|
|
|
func (a *AccessEntry) UnmarshalJSON(value []byte) error {
|
|
v := struct {
|
|
Type AccessType `json:"type,omitempty"`
|
|
Publisher string `json:"publisher,omitempty"`
|
|
Salt string `json:"salt,omitempty"`
|
|
Act string `json:"act,omitempty"`
|
|
KdfParams *KdfParams `json:"kdf_params,omitempty"`
|
|
}{}
|
|
|
|
err := json.Unmarshal(value, &v)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
a.Act = v.Act
|
|
a.KdfParams = v.KdfParams
|
|
a.Publisher = v.Publisher
|
|
a.Salt, err = hex.DecodeString(v.Salt)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if len(a.Salt) != 32 {
|
|
return errors.New("salt should be 32 bytes long")
|
|
}
|
|
a.Type = v.Type
|
|
return nil
|
|
}
|
|
|
|
type KdfParams struct {
|
|
N int `json:"n"`
|
|
P int `json:"p"`
|
|
R int `json:"r"`
|
|
}
|
|
|
|
type AccessType string
|
|
|
|
const AccessTypePass = AccessType("pass")
|
|
const AccessTypePK = AccessType("pk")
|
|
const AccessTypeACT = AccessType("act")
|
|
|
|
// NewAccessEntryPassword creates a manifest AccessEntry in order to create an ACT protected by a password
|
|
func NewAccessEntryPassword(salt []byte, kdfParams *KdfParams) (*AccessEntry, error) {
|
|
if len(salt) != 32 {
|
|
return nil, fmt.Errorf("salt should be 32 bytes long")
|
|
}
|
|
return &AccessEntry{
|
|
Type: AccessTypePass,
|
|
Salt: salt,
|
|
KdfParams: kdfParams,
|
|
}, nil
|
|
}
|
|
|
|
// NewAccessEntryPK creates a manifest AccessEntry in order to create an ACT protected by a pair of Elliptic Curve keys
|
|
func NewAccessEntryPK(publisher string, salt []byte) (*AccessEntry, error) {
|
|
if len(publisher) != 66 {
|
|
return nil, fmt.Errorf("publisher should be 66 characters long, got %d", len(publisher))
|
|
}
|
|
if len(salt) != 32 {
|
|
return nil, fmt.Errorf("salt should be 32 bytes long")
|
|
}
|
|
return &AccessEntry{
|
|
Type: AccessTypePK,
|
|
Publisher: publisher,
|
|
Salt: salt,
|
|
}, nil
|
|
}
|
|
|
|
// NewAccessEntryACT creates a manifest AccessEntry in order to create an ACT protected by a combination of EC keys and passwords
|
|
func NewAccessEntryACT(publisher string, salt []byte, act string) (*AccessEntry, error) {
|
|
if len(salt) != 32 {
|
|
return nil, fmt.Errorf("salt should be 32 bytes long")
|
|
}
|
|
if len(publisher) != 66 {
|
|
return nil, fmt.Errorf("publisher should be 66 characters long")
|
|
}
|
|
|
|
return &AccessEntry{
|
|
Type: AccessTypeACT,
|
|
Publisher: publisher,
|
|
Salt: salt,
|
|
Act: act,
|
|
KdfParams: DefaultKdfParams,
|
|
}, nil
|
|
}
|
|
|
|
// NOOPDecrypt is a generic decrypt function that is passed into the API in places where real ACT decryption capabilities are
|
|
// either unwanted, or alternatively, cannot be implemented in the immediate scope
|
|
func NOOPDecrypt(*ManifestEntry) error {
|
|
return nil
|
|
}
|
|
|
|
var DefaultKdfParams = NewKdfParams(262144, 1, 8)
|
|
|
|
// NewKdfParams returns a KdfParams struct with the given scrypt params
|
|
func NewKdfParams(n, p, r int) *KdfParams {
|
|
|
|
return &KdfParams{
|
|
N: n,
|
|
P: p,
|
|
R: r,
|
|
}
|
|
}
|
|
|
|
// NewSessionKeyPassword creates a session key based on a shared secret (password) and the given salt
|
|
// and kdf parameters in the access entry
|
|
func NewSessionKeyPassword(password string, accessEntry *AccessEntry) ([]byte, error) {
|
|
if accessEntry.Type != AccessTypePass && accessEntry.Type != AccessTypeACT {
|
|
return nil, errors.New("incorrect access entry type")
|
|
|
|
}
|
|
return sessionKeyPassword(password, accessEntry.Salt, accessEntry.KdfParams)
|
|
}
|
|
|
|
func sessionKeyPassword(password string, salt []byte, kdfParams *KdfParams) ([]byte, error) {
|
|
return scrypt.Key(
|
|
[]byte(password),
|
|
salt,
|
|
kdfParams.N,
|
|
kdfParams.R,
|
|
kdfParams.P,
|
|
32,
|
|
)
|
|
}
|
|
|
|
// NewSessionKeyPK creates a new ACT Session Key using an ECDH shared secret for the given key pair and the given salt value
|
|
func NewSessionKeyPK(private *ecdsa.PrivateKey, public *ecdsa.PublicKey, salt []byte) ([]byte, error) {
|
|
granteePubEcies := ecies.ImportECDSAPublic(public)
|
|
privateKey := ecies.ImportECDSA(private)
|
|
|
|
bytes, err := privateKey.GenerateShared(granteePubEcies, 16, 16)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
bytes = append(salt, bytes...)
|
|
sessionKey := crypto.Keccak256(bytes)
|
|
return sessionKey, nil
|
|
}
|
|
|
|
func (a *API) doDecrypt(ctx context.Context, credentials string, pk *ecdsa.PrivateKey) DecryptFunc {
|
|
return func(m *ManifestEntry) error {
|
|
if m.Access == nil {
|
|
return nil
|
|
}
|
|
|
|
allowed := false
|
|
requestDomain := sctx.GetHost(ctx)
|
|
for _, v := range AllowedDecryptDomains {
|
|
if strings.Contains(requestDomain, v) {
|
|
allowed = true
|
|
}
|
|
}
|
|
|
|
if !allowed {
|
|
return ErrDecryptDomainForbidden
|
|
}
|
|
|
|
switch m.Access.Type {
|
|
case "pass":
|
|
if credentials != "" {
|
|
key, err := NewSessionKeyPassword(credentials, m.Access)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
ref, err := hex.DecodeString(m.Hash)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
enc := NewRefEncryption(len(ref) - 8)
|
|
decodedRef, err := enc.Decrypt(ref, key)
|
|
if err != nil {
|
|
return ErrDecrypt
|
|
}
|
|
|
|
m.Hash = hex.EncodeToString(decodedRef)
|
|
m.Access = nil
|
|
return nil
|
|
}
|
|
return ErrDecrypt
|
|
case "pk":
|
|
publisherBytes, err := hex.DecodeString(m.Access.Publisher)
|
|
if err != nil {
|
|
return ErrDecrypt
|
|
}
|
|
publisher, err := crypto.DecompressPubkey(publisherBytes)
|
|
if err != nil {
|
|
return ErrDecrypt
|
|
}
|
|
key, err := NewSessionKeyPK(pk, publisher, m.Access.Salt)
|
|
if err != nil {
|
|
return ErrDecrypt
|
|
}
|
|
ref, err := hex.DecodeString(m.Hash)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
enc := NewRefEncryption(len(ref) - 8)
|
|
decodedRef, err := enc.Decrypt(ref, key)
|
|
if err != nil {
|
|
return ErrDecrypt
|
|
}
|
|
|
|
m.Hash = hex.EncodeToString(decodedRef)
|
|
m.Access = nil
|
|
return nil
|
|
case "act":
|
|
var (
|
|
sessionKey []byte
|
|
err error
|
|
)
|
|
|
|
publisherBytes, err := hex.DecodeString(m.Access.Publisher)
|
|
if err != nil {
|
|
return ErrDecrypt
|
|
}
|
|
publisher, err := crypto.DecompressPubkey(publisherBytes)
|
|
if err != nil {
|
|
return ErrDecrypt
|
|
}
|
|
|
|
sessionKey, err = NewSessionKeyPK(pk, publisher, m.Access.Salt)
|
|
if err != nil {
|
|
return ErrDecrypt
|
|
}
|
|
|
|
found, ciphertext, decryptionKey, err := a.getACTDecryptionKey(ctx, storage.Address(common.Hex2Bytes(m.Access.Act)), sessionKey)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if !found {
|
|
// try to fall back to password
|
|
if credentials != "" {
|
|
sessionKey, err = NewSessionKeyPassword(credentials, m.Access)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
found, ciphertext, decryptionKey, err = a.getACTDecryptionKey(ctx, storage.Address(common.Hex2Bytes(m.Access.Act)), sessionKey)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if !found {
|
|
return ErrDecrypt
|
|
}
|
|
} else {
|
|
return ErrDecrypt
|
|
}
|
|
}
|
|
enc := NewRefEncryption(len(ciphertext) - 8)
|
|
decodedRef, err := enc.Decrypt(ciphertext, decryptionKey)
|
|
if err != nil {
|
|
return ErrDecrypt
|
|
}
|
|
|
|
ref, err := hex.DecodeString(m.Hash)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
enc = NewRefEncryption(len(ref) - 8)
|
|
decodedMainRef, err := enc.Decrypt(ref, decodedRef)
|
|
if err != nil {
|
|
return ErrDecrypt
|
|
}
|
|
m.Hash = hex.EncodeToString(decodedMainRef)
|
|
m.Access = nil
|
|
return nil
|
|
}
|
|
return ErrUnknownAccessType
|
|
}
|
|
}
|
|
|
|
func (a *API) getACTDecryptionKey(ctx context.Context, actManifestAddress storage.Address, sessionKey []byte) (found bool, ciphertext, decryptionKey []byte, err error) {
|
|
hasher := sha3.NewKeccak256()
|
|
hasher.Write(append(sessionKey, 0))
|
|
lookupKey := hasher.Sum(nil)
|
|
hasher.Reset()
|
|
|
|
hasher.Write(append(sessionKey, 1))
|
|
accessKeyDecryptionKey := hasher.Sum(nil)
|
|
hasher.Reset()
|
|
|
|
lk := hex.EncodeToString(lookupKey)
|
|
list, err := a.GetManifestList(ctx, NOOPDecrypt, actManifestAddress, lk)
|
|
if err != nil {
|
|
return false, nil, nil, err
|
|
}
|
|
for _, v := range list.Entries {
|
|
if v.Path == lk {
|
|
cipherTextBytes, err := hex.DecodeString(v.Hash)
|
|
if err != nil {
|
|
return false, nil, nil, err
|
|
}
|
|
return true, cipherTextBytes, accessKeyDecryptionKey, nil
|
|
}
|
|
}
|
|
return false, nil, nil, nil
|
|
}
|
|
|
|
func GenerateAccessControlManifest(ctx *cli.Context, ref string, accessKey []byte, ae *AccessEntry) (*Manifest, error) {
|
|
refBytes, err := hex.DecodeString(ref)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// encrypt ref with accessKey
|
|
enc := NewRefEncryption(len(refBytes))
|
|
encrypted, err := enc.Encrypt(refBytes, accessKey)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
m := &Manifest{
|
|
Entries: []ManifestEntry{
|
|
{
|
|
Hash: hex.EncodeToString(encrypted),
|
|
ContentType: ManifestType,
|
|
ModTime: time.Now(),
|
|
Access: ae,
|
|
},
|
|
},
|
|
}
|
|
|
|
return m, nil
|
|
}
|
|
|
|
// DoPK is a helper function to the CLI API that handles the entire business logic for
|
|
// creating a session key and access entry given the cli context, ec keys and salt
|
|
func DoPK(ctx *cli.Context, privateKey *ecdsa.PrivateKey, granteePublicKey string, salt []byte) (sessionKey []byte, ae *AccessEntry, err error) {
|
|
if granteePublicKey == "" {
|
|
return nil, nil, errors.New("need a grantee Public Key")
|
|
}
|
|
b, err := hex.DecodeString(granteePublicKey)
|
|
if err != nil {
|
|
log.Error("error decoding grantee public key", "err", err)
|
|
return nil, nil, err
|
|
}
|
|
|
|
granteePub, err := crypto.DecompressPubkey(b)
|
|
if err != nil {
|
|
log.Error("error decompressing grantee public key", "err", err)
|
|
return nil, nil, err
|
|
}
|
|
|
|
sessionKey, err = NewSessionKeyPK(privateKey, granteePub, salt)
|
|
if err != nil {
|
|
log.Error("error getting session key", "err", err)
|
|
return nil, nil, err
|
|
}
|
|
|
|
ae, err = NewAccessEntryPK(hex.EncodeToString(crypto.CompressPubkey(&privateKey.PublicKey)), salt)
|
|
if err != nil {
|
|
log.Error("error generating access entry", "err", err)
|
|
return nil, nil, err
|
|
}
|
|
|
|
return sessionKey, ae, nil
|
|
}
|
|
|
|
// DoACT is a helper function to the CLI API that handles the entire business logic for
|
|
// creating a access key, access entry and ACT manifest (including uploading it) given the cli context, ec keys, password grantees and salt
|
|
func DoACT(ctx *cli.Context, privateKey *ecdsa.PrivateKey, salt []byte, grantees []string, encryptPasswords []string) (accessKey []byte, ae *AccessEntry, actManifest *Manifest, err error) {
|
|
if len(grantees) == 0 && len(encryptPasswords) == 0 {
|
|
return nil, nil, nil, errors.New("did not get any grantee public keys or any encryption passwords")
|
|
}
|
|
|
|
publisherPub := hex.EncodeToString(crypto.CompressPubkey(&privateKey.PublicKey))
|
|
grantees = append(grantees, publisherPub)
|
|
|
|
accessKey = make([]byte, 32)
|
|
if _, err := io.ReadFull(rand.Reader, salt); err != nil {
|
|
panic("reading from crypto/rand failed: " + err.Error())
|
|
}
|
|
if _, err := io.ReadFull(rand.Reader, accessKey); err != nil {
|
|
panic("reading from crypto/rand failed: " + err.Error())
|
|
}
|
|
|
|
lookupPathEncryptedAccessKeyMap := make(map[string]string)
|
|
i := 0
|
|
for _, v := range grantees {
|
|
i++
|
|
if v == "" {
|
|
return nil, nil, nil, errors.New("need a grantee Public Key")
|
|
}
|
|
b, err := hex.DecodeString(v)
|
|
if err != nil {
|
|
log.Error("error decoding grantee public key", "err", err)
|
|
return nil, nil, nil, err
|
|
}
|
|
|
|
granteePub, err := crypto.DecompressPubkey(b)
|
|
if err != nil {
|
|
log.Error("error decompressing grantee public key", "err", err)
|
|
return nil, nil, nil, err
|
|
}
|
|
sessionKey, err := NewSessionKeyPK(privateKey, granteePub, salt)
|
|
|
|
hasher := sha3.NewKeccak256()
|
|
hasher.Write(append(sessionKey, 0))
|
|
lookupKey := hasher.Sum(nil)
|
|
|
|
hasher.Reset()
|
|
hasher.Write(append(sessionKey, 1))
|
|
|
|
accessKeyEncryptionKey := hasher.Sum(nil)
|
|
|
|
enc := NewRefEncryption(len(accessKey))
|
|
encryptedAccessKey, err := enc.Encrypt(accessKey, accessKeyEncryptionKey)
|
|
if err != nil {
|
|
return nil, nil, nil, err
|
|
}
|
|
lookupPathEncryptedAccessKeyMap[hex.EncodeToString(lookupKey)] = hex.EncodeToString(encryptedAccessKey)
|
|
}
|
|
|
|
for _, pass := range encryptPasswords {
|
|
sessionKey, err := sessionKeyPassword(pass, salt, DefaultKdfParams)
|
|
if err != nil {
|
|
return nil, nil, nil, err
|
|
}
|
|
hasher := sha3.NewKeccak256()
|
|
hasher.Write(append(sessionKey, 0))
|
|
lookupKey := hasher.Sum(nil)
|
|
|
|
hasher.Reset()
|
|
hasher.Write(append(sessionKey, 1))
|
|
|
|
accessKeyEncryptionKey := hasher.Sum(nil)
|
|
|
|
enc := NewRefEncryption(len(accessKey))
|
|
encryptedAccessKey, err := enc.Encrypt(accessKey, accessKeyEncryptionKey)
|
|
if err != nil {
|
|
return nil, nil, nil, err
|
|
}
|
|
lookupPathEncryptedAccessKeyMap[hex.EncodeToString(lookupKey)] = hex.EncodeToString(encryptedAccessKey)
|
|
}
|
|
|
|
m := &Manifest{
|
|
Entries: []ManifestEntry{},
|
|
}
|
|
|
|
for k, v := range lookupPathEncryptedAccessKeyMap {
|
|
m.Entries = append(m.Entries, ManifestEntry{
|
|
Path: k,
|
|
Hash: v,
|
|
ContentType: "text/plain",
|
|
})
|
|
}
|
|
|
|
ae, err = NewAccessEntryACT(hex.EncodeToString(crypto.CompressPubkey(&privateKey.PublicKey)), salt, "")
|
|
if err != nil {
|
|
return nil, nil, nil, err
|
|
}
|
|
|
|
return accessKey, ae, m, nil
|
|
}
|
|
|
|
// DoPassword is a helper function to the CLI API that handles the entire business logic for
|
|
// creating a session key and an access entry given the cli context, password and salt.
|
|
// By default - DefaultKdfParams are used as the scrypt params
|
|
func DoPassword(ctx *cli.Context, password string, salt []byte) (sessionKey []byte, ae *AccessEntry, err error) {
|
|
ae, err = NewAccessEntryPassword(salt, DefaultKdfParams)
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
|
|
sessionKey, err = NewSessionKeyPassword(password, ae)
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
return sessionKey, ae, nil
|
|
}
|