lbcwallet/votingpool/db.go
Guilherme Salgado 2181f4859d votingpool: implement Pool.StartWithdrawal()
<http://opentransactions.org/wiki/index.php/Voting_Pool_Withdrawal_Process>

Also includes some refactorings and other improvements, including better docs
and a new error type (votingpool.Error) used for all votingpool-specific
errors.
2015-04-01 15:55:42 +01:00

354 lines
12 KiB
Go

/*
* Copyright (c) 2014 Conformal Systems LLC <info@conformal.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package votingpool
import (
"bytes"
"encoding/binary"
"fmt"
"github.com/btcsuite/btcwallet/snacl"
"github.com/btcsuite/btcwallet/walletdb"
)
// These constants define the serialized length for a given encrypted extended
// public or private key.
const (
// We can calculate the encrypted extended key length this way:
// snacl.Overhead == overhead for encrypting (16)
// actual base58 extended key length = (111)
// snacl.NonceSize == nonce size used for encryption (24)
seriesKeyLength = snacl.Overhead + 111 + snacl.NonceSize
// 4 bytes version + 1 byte active + 4 bytes nKeys + 4 bytes reqSigs
seriesMinSerial = 4 + 1 + 4 + 4
// 15 is the max number of keys in a voting pool, 1 each for
// pubkey and privkey
seriesMaxSerial = seriesMinSerial + 15*seriesKeyLength*2
// version of serialized Series that we support
seriesMaxVersion = 1
)
var (
usedAddrsBucketName = []byte("usedaddrs")
seriesBucketName = []byte("series")
// string representing a non-existent private key
seriesNullPrivKey = [seriesKeyLength]byte{}
)
type dbSeriesRow struct {
version uint32
active bool
reqSigs uint32
pubKeysEncrypted [][]byte
privKeysEncrypted [][]byte
}
// getUsedAddrBucketID returns the used addresses bucket ID for the given series
// and branch. It has the form seriesID:branch.
func getUsedAddrBucketID(seriesID uint32, branch Branch) []byte {
var bucketID [9]byte
binary.LittleEndian.PutUint32(bucketID[0:4], seriesID)
bucketID[4] = ':'
binary.LittleEndian.PutUint32(bucketID[5:9], uint32(branch))
return bucketID[:]
}
// putUsedAddrHash adds an entry (key==index, value==encryptedHash) to the used
// addresses bucket of the given pool, series and branch.
func putUsedAddrHash(tx walletdb.Tx, poolID []byte, seriesID uint32, branch Branch,
index Index, encryptedHash []byte) error {
usedAddrs := tx.RootBucket().Bucket(poolID).Bucket(usedAddrsBucketName)
bucket, err := usedAddrs.CreateBucketIfNotExists(getUsedAddrBucketID(seriesID, branch))
if err != nil {
return newError(ErrDatabase, "failed to store used address hash", err)
}
return bucket.Put(uint32ToBytes(uint32(index)), encryptedHash)
}
// getUsedAddrHash returns the addr hash with the given index from the used
// addresses bucket of the given pool, series and branch.
func getUsedAddrHash(tx walletdb.Tx, poolID []byte, seriesID uint32, branch Branch,
index Index) []byte {
usedAddrs := tx.RootBucket().Bucket(poolID).Bucket(usedAddrsBucketName)
bucket := usedAddrs.Bucket(getUsedAddrBucketID(seriesID, branch))
if bucket == nil {
return nil
}
return bucket.Get(uint32ToBytes(uint32(index)))
}
// getMaxUsedIdx returns the highest used index from the used addresses bucket
// of the given pool, series and branch.
func getMaxUsedIdx(tx walletdb.Tx, poolID []byte, seriesID uint32, branch Branch) (Index, error) {
maxIdx := Index(0)
usedAddrs := tx.RootBucket().Bucket(poolID).Bucket(usedAddrsBucketName)
bucket := usedAddrs.Bucket(getUsedAddrBucketID(seriesID, branch))
if bucket == nil {
return maxIdx, nil
}
// FIXME: This is far from optimal and should be optimized either by storing
// a separate key in the DB with the highest used idx for every
// series/branch or perhaps by doing a large gap linear forward search +
// binary backwards search (e.g. check for 1000000, 2000000, .... until it
// doesn't exist, and then use a binary search to find the max using the
// discovered bounds).
err := bucket.ForEach(
func(k, v []byte) error {
idx := Index(bytesToUint32(k))
if idx > maxIdx {
maxIdx = idx
}
return nil
})
if err != nil {
return Index(0), newError(ErrDatabase, "failed to get highest idx of used addresses", err)
}
return maxIdx, nil
}
// putPool stores a voting pool in the database, creating a bucket named
// after the voting pool id and two other buckets inside it to store series and
// used addresses for that pool.
func putPool(tx walletdb.Tx, poolID []byte) error {
poolBucket, err := tx.RootBucket().CreateBucket(poolID)
if err != nil {
return newError(ErrDatabase, fmt.Sprintf("cannot create pool %v", poolID), err)
}
_, err = poolBucket.CreateBucket(seriesBucketName)
if err != nil {
return newError(ErrDatabase, fmt.Sprintf("cannot create series bucket for pool %v",
poolID), err)
}
_, err = poolBucket.CreateBucket(usedAddrsBucketName)
if err != nil {
return newError(ErrDatabase, fmt.Sprintf("cannot create used addrs bucket for pool %v",
poolID), err)
}
return nil
}
// loadAllSeries returns a map of all the series stored inside a voting pool
// bucket, keyed by id.
func loadAllSeries(tx walletdb.Tx, poolID []byte) (map[uint32]*dbSeriesRow, error) {
bucket := tx.RootBucket().Bucket(poolID).Bucket(seriesBucketName)
allSeries := make(map[uint32]*dbSeriesRow)
err := bucket.ForEach(
func(k, v []byte) error {
seriesID := bytesToUint32(k)
series, err := deserializeSeriesRow(v)
if err != nil {
return err
}
allSeries[seriesID] = series
return nil
})
if err != nil {
return nil, err
}
return allSeries, nil
}
// existsPool checks the existence of a bucket named after the given
// voting pool id.
func existsPool(tx walletdb.Tx, poolID []byte) bool {
bucket := tx.RootBucket().Bucket(poolID)
return bucket != nil
}
// putSeries stores the given series inside a voting pool bucket named after
// poolID. The voting pool bucket does not need to be created beforehand.
func putSeries(tx walletdb.Tx, poolID []byte, version, ID uint32, active bool, reqSigs uint32, pubKeysEncrypted, privKeysEncrypted [][]byte) error {
row := &dbSeriesRow{
version: version,
active: active,
reqSigs: reqSigs,
pubKeysEncrypted: pubKeysEncrypted,
privKeysEncrypted: privKeysEncrypted,
}
return putSeriesRow(tx, poolID, ID, row)
}
// putSeriesRow stores the given series row inside a voting pool bucket named
// after poolID. The voting pool bucket does not need to be created
// beforehand.
func putSeriesRow(tx walletdb.Tx, poolID []byte, ID uint32, row *dbSeriesRow) error {
bucket, err := tx.RootBucket().CreateBucketIfNotExists(poolID)
if err != nil {
str := fmt.Sprintf("cannot create bucket %v", poolID)
return newError(ErrDatabase, str, err)
}
bucket = bucket.Bucket(seriesBucketName)
serialized, err := serializeSeriesRow(row)
if err != nil {
return err
}
err = bucket.Put(uint32ToBytes(ID), serialized)
if err != nil {
str := fmt.Sprintf("cannot put series %v into bucket %v", serialized, poolID)
return newError(ErrDatabase, str, err)
}
return nil
}
// deserializeSeriesRow deserializes a series storage into a dbSeriesRow struct.
func deserializeSeriesRow(serializedSeries []byte) (*dbSeriesRow, error) {
// The serialized series format is:
// <version><active><reqSigs><nKeys><pubKey1><privKey1>...<pubkeyN><privKeyN>
//
// 4 bytes version + 1 byte active + 4 bytes reqSigs + 4 bytes nKeys
// + seriesKeyLength * 2 * nKeys (1 for priv, 1 for pub)
// Given the above, the length of the serialized series should be
// at minimum the length of the constants.
if len(serializedSeries) < seriesMinSerial {
str := fmt.Sprintf("serialized series is too short: %v", serializedSeries)
return nil, newError(ErrSeriesSerialization, str, nil)
}
// Maximum number of public keys is 15 and the same for public keys
// this gives us an upper bound.
if len(serializedSeries) > seriesMaxSerial {
str := fmt.Sprintf("serialized series is too long: %v", serializedSeries)
return nil, newError(ErrSeriesSerialization, str, nil)
}
// Keeps track of the position of the next set of bytes to deserialize.
current := 0
row := dbSeriesRow{}
row.version = bytesToUint32(serializedSeries[current : current+4])
if row.version > seriesMaxVersion {
str := fmt.Sprintf("deserialization supports up to version %v not %v",
seriesMaxVersion, row.version)
return nil, newError(ErrSeriesVersion, str, nil)
}
current += 4
row.active = serializedSeries[current] == 0x01
current++
row.reqSigs = bytesToUint32(serializedSeries[current : current+4])
current += 4
nKeys := bytesToUint32(serializedSeries[current : current+4])
current += 4
// Check to see if we have the right number of bytes to consume.
if len(serializedSeries) < current+int(nKeys)*seriesKeyLength*2 {
str := fmt.Sprintf("serialized series has not enough data: %v", serializedSeries)
return nil, newError(ErrSeriesSerialization, str, nil)
} else if len(serializedSeries) > current+int(nKeys)*seriesKeyLength*2 {
str := fmt.Sprintf("serialized series has too much data: %v", serializedSeries)
return nil, newError(ErrSeriesSerialization, str, nil)
}
// Deserialize the pubkey/privkey pairs.
row.pubKeysEncrypted = make([][]byte, nKeys)
row.privKeysEncrypted = make([][]byte, nKeys)
for i := 0; i < int(nKeys); i++ {
pubKeyStart := current + seriesKeyLength*i*2
pubKeyEnd := current + seriesKeyLength*i*2 + seriesKeyLength
privKeyEnd := current + seriesKeyLength*(i+1)*2
row.pubKeysEncrypted[i] = serializedSeries[pubKeyStart:pubKeyEnd]
privKeyEncrypted := serializedSeries[pubKeyEnd:privKeyEnd]
if bytes.Equal(privKeyEncrypted, seriesNullPrivKey[:]) {
row.privKeysEncrypted[i] = nil
} else {
row.privKeysEncrypted[i] = privKeyEncrypted
}
}
return &row, nil
}
// serializeSeriesRow serializes a dbSeriesRow struct into storage format.
func serializeSeriesRow(row *dbSeriesRow) ([]byte, error) {
// The serialized series format is:
// <version><active><reqSigs><nKeys><pubKey1><privKey1>...<pubkeyN><privKeyN>
//
// 4 bytes version + 1 byte active + 4 bytes reqSigs + 4 bytes nKeys
// + seriesKeyLength * 2 * nKeys (1 for priv, 1 for pub)
serializedLen := 4 + 1 + 4 + 4 + (seriesKeyLength * 2 * len(row.pubKeysEncrypted))
if len(row.privKeysEncrypted) != 0 &&
len(row.pubKeysEncrypted) != len(row.privKeysEncrypted) {
str := fmt.Sprintf("different # of pub (%v) and priv (%v) keys",
len(row.pubKeysEncrypted), len(row.privKeysEncrypted))
return nil, newError(ErrSeriesSerialization, str, nil)
}
if row.version > seriesMaxVersion {
str := fmt.Sprintf("serialization supports up to version %v, not %v",
seriesMaxVersion, row.version)
return nil, newError(ErrSeriesVersion, str, nil)
}
serialized := make([]byte, 0, serializedLen)
serialized = append(serialized, uint32ToBytes(row.version)...)
if row.active {
serialized = append(serialized, 0x01)
} else {
serialized = append(serialized, 0x00)
}
serialized = append(serialized, uint32ToBytes(row.reqSigs)...)
nKeys := uint32(len(row.pubKeysEncrypted))
serialized = append(serialized, uint32ToBytes(nKeys)...)
var privKeyEncrypted []byte
for i, pubKeyEncrypted := range row.pubKeysEncrypted {
// check that the encrypted length is correct
if len(pubKeyEncrypted) != seriesKeyLength {
str := fmt.Sprintf("wrong length of Encrypted Public Key: %v",
pubKeyEncrypted)
return nil, newError(ErrSeriesSerialization, str, nil)
}
serialized = append(serialized, pubKeyEncrypted...)
if len(row.privKeysEncrypted) == 0 {
privKeyEncrypted = seriesNullPrivKey[:]
} else {
privKeyEncrypted = row.privKeysEncrypted[i]
}
if privKeyEncrypted == nil {
serialized = append(serialized, seriesNullPrivKey[:]...)
} else if len(privKeyEncrypted) != seriesKeyLength {
str := fmt.Sprintf("wrong length of Encrypted Private Key: %v",
len(privKeyEncrypted))
return nil, newError(ErrSeriesSerialization, str, nil)
} else {
serialized = append(serialized, privKeyEncrypted...)
}
}
return serialized, nil
}
// uint32ToBytes converts a 32 bit unsigned integer into a 4-byte slice in
// little-endian order: 1 -> [1 0 0 0].
func uint32ToBytes(number uint32) []byte {
buf := make([]byte, 4)
binary.LittleEndian.PutUint32(buf, number)
return buf
}
// bytesToUint32 converts a 4-byte slice in little-endian order into a 32 bit
// unsigned integer: [1 0 0 0] -> 1.
func bytesToUint32(encoded []byte) uint32 {
return binary.LittleEndian.Uint32(encoded)
}