Implemented block encoding according to Whitepaper 0.8.2.

Blocks aren't yet shared.
This commit is contained in:
Kleissner
2021-05-30 15:28:11 +02:00
parent 1a44b9c5e7
commit 594c06e276
3 changed files with 499 additions and 0 deletions

336
Block Encoding.go Normal file
View File

@@ -0,0 +1,336 @@
/*
File Name: Block Encoding.go
Copyright: 2021 Peernet s.r.o.
Author: Peter Kleissner
Block encoding in messages.
*/
package core
import (
"bytes"
"encoding/binary"
"errors"
"io"
"path"
"strings"
"unicode/utf8"
"github.com/btcsuite/btcd/btcec"
)
// Block is a single block containing a set of records (metadata).
// It has no upper size limit, although a soft limit of 64 KB - overhead is encouraged for efficiency.
type Block struct {
OwnerPublicKey *btcec.PublicKey // Owner Public Key, ECDSA (secp256k1) 257-bit
LastBlockHash []byte // Hash of the last block. Blake3.
BlockchainVersion uint64 // Blockchain version
Number uint32 // Block number
RecordsRaw []BlockRecordRaw // Block records raw
Files []BlockRecordFile // Files
User BlockRecordUser // User details
directories []BlockRecordDirectory // Internal list of directories for decoding files.
}
// BlockRecordRaw is a single block record (not decoded)
type BlockRecordRaw struct {
Type uint8 // Record Type. See RecordTypeX.
Data []byte // Data according to the type
}
const (
RecordTypeUsername = 0 // Username. Arbitrary name defined by the user.
RecordTypeDirectory = 1 // Directory. Only valid in the context of the current block.
RecordTypeFile = 2 // File
RecordTypeContentRating = 3 // Content rating (positive).
RecordTypeContentReport = 4 // Content report (negative).
RecordTypeDelete = 5 // Delete previous record.
)
// block record structures
// BlockRecordUser specifies user information
type BlockRecordUser struct {
Valid bool // Whether the username is supplied
Name string // Arbitrary name of the user.
NameS string // Sanitized version of the name.
}
// BlockRecordDirectory is a directory, only valid within the same block.
type BlockRecordDirectory struct {
ID uint16 // ID, only valid within the same block
Name string // Name of the directory. Slashes (both backward and forward) mark subdirectories.
}
// BlockRecordFile is the metadata of a file published on the blockchain
type BlockRecordFile struct {
Hash []byte // Hash of the file data
Type uint8 // Type (low-level)
Format uint16 // Format (high-level)
Size uint64 // Size of the file
Directory string // Directory
Name string // File name
directoryID uint16 // Internal directory ID
// Tags todo
}
// Tag structure to be defined
const blockHeaderSize = 115
const blockRecordHeaderSize = 5
// decodeBlock decodes a single block
func decodeBlock(raw []byte) (block *Block, err error) {
if len(raw) < blockHeaderSize {
return nil, errors.New("decodeBlock invalid block size")
}
block = &Block{}
signature := raw[0 : 0+65]
block.OwnerPublicKey, _, err = btcec.RecoverCompact(btcec.S256(), signature, hashData(raw[65:]))
if err != nil {
return nil, err
}
block.LastBlockHash = make([]byte, hashSize)
copy(block.LastBlockHash, raw[65:65+hashSize])
block.BlockchainVersion = binary.LittleEndian.Uint64(raw[97 : 97+8])
block.Number = binary.LittleEndian.Uint32(raw[105 : 105+4])
blockSize := binary.LittleEndian.Uint32(raw[109 : 109+4])
if blockSize != uint32(len(raw)) {
return nil, errors.New("decodeBlock invalid block size")
}
countRecords := binary.LittleEndian.Uint16(raw[113 : 113+2])
index := 115
for n := uint16(0); n < countRecords; n++ {
if index+blockRecordHeaderSize > len(raw) {
return nil, errors.New("decodeBlock block record exceeds block size")
}
recordType := raw[index]
recordSize := binary.LittleEndian.Uint32(raw[index+1 : index+5])
index += blockRecordHeaderSize
if index+int(recordSize) > len(raw) {
return nil, errors.New("decodeBlock block record exceeds block size")
}
block.RecordsRaw = append(block.RecordsRaw, BlockRecordRaw{Type: recordType, Data: raw[index : index+int(recordSize)]})
if err := decodeBlockRecord(raw[index:index+int(recordSize)], block, recordType); err != nil {
return nil, err
}
index += int(recordSize)
}
return block, nil
}
// decodeBlockRecord decodes a single block and fills it into the provided block structure
func decodeBlockRecord(data []byte, block *Block, recordType uint8) (err error) {
switch recordType {
case RecordTypeUsername:
block.User.Name = string(data)
block.User.NameS = sanitizeUsername(block.User.Name)
block.User.Valid = true
case RecordTypeDirectory:
if len(data) < 3 {
return errors.New("decodeBlockRecord directory record invalid size")
}
directory := &BlockRecordDirectory{}
directory.ID = binary.LittleEndian.Uint16(data[0 : 0+2])
directory.Name = string(data[2:])
block.directories = append(block.directories, *directory)
case RecordTypeFile:
if len(data) < 49 {
return errors.New("decodeBlockRecord file record invalid size")
}
file := BlockRecordFile{}
file.Hash = make([]byte, hashSize)
copy(file.Hash, data[0:0+hashSize])
file.Type = data[32]
file.Format = binary.LittleEndian.Uint16(data[33 : 33+2])
file.Size = binary.LittleEndian.Uint64(data[35 : 35+8])
directoryID := binary.LittleEndian.Uint16(data[43 : 43+2])
filenameSize := binary.LittleEndian.Uint16(data[45 : 45+2])
//countTags := binary.LittleEndian.Uint16(data[47 : 47+2]) // future implementation of tags
if len(data) < 49+int(filenameSize) {
return errors.New("decodeBlockRecord file record invalid filename size")
}
file.Name = string(data[49 : 49+filenameSize])
for n := range block.directories {
if block.directories[n].ID == directoryID {
file.Directory = block.directories[n].Name
break
}
}
block.Files = append(block.Files, file)
}
return nil
}
// sanitizeUsername returns the sanitized version of the username.
func sanitizeUsername(input string) string {
if !utf8.ValidString(input) {
return "<invalid encoding>"
}
input = strings.TrimSpace(input)
input = strings.ReplaceAll(input, "\n", " ")
input = strings.ReplaceAll(input, "\r", "")
// Max length for sanitized version is 36, resembling the limit from StackOverflow.
if len(input) > 36 {
input = input[:36]
}
return input
}
func encodeBlock(block *Block, ownerPrivateKey *btcec.PrivateKey) (raw []byte, err error) {
var buffer bytes.Buffer
buffer.Write(make([]byte, 65)) // Signature, filled at the end
if block.Number > 0 && len(block.LastBlockHash) != hashSize {
return nil, errors.New("encodeBlock invalid last block hash")
} else if block.Number == 0 { // Block 0: Empty last hash
block.LastBlockHash = make([]byte, 32)
}
buffer.Write(block.LastBlockHash)
var temp [8]byte
binary.LittleEndian.PutUint64(temp[0:8], block.BlockchainVersion)
buffer.Write(temp[:])
binary.LittleEndian.PutUint32(temp[0:4], block.Number)
buffer.Write(temp[:4])
buffer.Write(make([]byte, 4)) // Size of block, filled later
buffer.Write(make([]byte, 2)) // Count of records, filled later
// write all records
countRecords, err := encodeBlockRecords(&buffer, block)
if err != nil {
return nil, err
}
// finalize the block
raw = buffer.Bytes()
if len(raw) < blockHeaderSize {
return nil, errors.New("encodeBlock invalid block size")
}
binary.LittleEndian.PutUint32(raw[109:109+4], uint32(len(raw))) // Size of block
binary.LittleEndian.PutUint16(raw[113:113+2], countRecords) // Count of records
// signature is last
signature, err := btcec.SignCompact(btcec.S256(), ownerPrivateKey, hashData(raw[65:]), true)
if err != nil {
return nil, err
}
copy(raw[0:0+65], signature)
return raw, nil
}
// encodeBlockRecords writes all records of the block into the writer
func encodeBlockRecords(writer io.Writer, block *Block) (count uint16, err error) {
nextDirectoryID := uint16(1) // start as 1 to prevent collision with files without explicit directory
writeBlockRecord := func(recordType uint8, data []byte) {
var temp [8]byte
binary.LittleEndian.PutUint32(temp[0:4], uint32(len(data)))
writer.Write([]byte{recordType}) // Record Type
writer.Write(temp[:4]) // Size of data
writer.Write(data) // Data
count++
}
// Username
if block.User.Valid {
writeBlockRecord(RecordTypeUsername, []byte(block.User.Name))
}
// First the directory records must be declared for any references by files
directoryCreateLoop:
for n := range block.Files {
block.Files[n].sanitizePath()
if block.Files[n].Directory == "" {
continue
}
// already known directory ID?
for m := range block.directories {
if block.directories[m].Name == block.Files[n].Directory {
block.Files[n].directoryID = block.directories[m].ID
continue directoryCreateLoop
}
}
// Create the new directory record
var directoryID [2]byte
binary.LittleEndian.PutUint16(directoryID[0:2], nextDirectoryID)
block.Files[n].directoryID = nextDirectoryID
nextDirectoryID++
writeBlockRecord(RecordTypeDirectory, append(directoryID[:], []byte(block.Files[n].Directory)...))
}
for n := range block.Files {
var data [49]byte
if len(block.Files[n].Hash) != hashSize {
return 0, errors.New("encodeBlockRecords invalid file hash")
}
copy(data[0:32], block.Files[n].Hash[0:32])
data[32] = block.Files[n].Type
binary.LittleEndian.PutUint16(data[33:33+2], block.Files[n].Format)
binary.LittleEndian.PutUint64(data[35:35+8], block.Files[n].Size)
binary.LittleEndian.PutUint16(data[43:43+2], block.Files[n].directoryID)
filenameB := []byte(block.Files[n].Name)
binary.LittleEndian.PutUint16(data[45:45+2], uint16(len(filenameB)))
binary.LittleEndian.PutUint16(data[47:47+2], uint16(0)) // Count of Tags (future use)
writeBlockRecord(RecordTypeFile, append(data[:], filenameB...))
}
return count, nil
}
const PATH_MAX_LENGTH = 32767 // Windows Maximum Path Length for UNC paths
func (record *BlockRecordFile) sanitizePath() {
// Enforced forward slashes as directory separator and clean the path.
record.Directory = strings.ReplaceAll(record.Directory, "\\", "/")
record.Directory = path.Clean(record.Directory)
// No slash at the beginning and end to save space.
record.Directory = strings.Trim(record.Directory, "/")
// Slashes in filenames are not encouraged, but not removed.
// Enforce max filename length.
if len(record.Name) > PATH_MAX_LENGTH {
record.Name = record.Name[:PATH_MAX_LENGTH]
}
}

44
File Formats.go Normal file
View File

@@ -0,0 +1,44 @@
/*
File Name: File Formats.go
Copyright: 2021 Peernet s.r.o.
Author: Peter Kleissner
Definition of all recognized file formats. This file is likely being updated more frequently than regular code.
*/
package core
// Low-level content types of file data. This is a copy from Intelligence X.
const (
TypeBinary = iota // Binary/unspecified
TypeText // Plain text
TypePicture // Picture of any format
TypeVideo // Video
TypeAudio // Audio
TypeDocument // Any document file, including office documents, PDFs, power point, spreadsheets
TypeExecutable // Any executable file, OS independent
TypeContainer // Container files like ZIP, RAR, TAR
TypeCompressed // Compressed files like GZ, BZ
)
// High-level file types. New ones may be added as required.
const (
FormatUnspecified = iota // Unspecified
FormatPDF // PDF document
FormatWord // Word document
FormatExcel // Excel
FormatPowerpoint // Powerpoint
FormatPicture // Pictures (including GIF, excluding icons)
FormatAudio // Audio files
FormatVideo // Video files
FormatContainer // Compressed files including ZIP, RAR, TAR and others
FormatHTML // HTML file
FormatText // Text file
FormatEbook // Ebook file
FormatCompressed // Compressed file.
FormatDatabase // Database file
FormatEmail // Single email
FormatCSV // CSV file
)
// Future tags to be defined for audio/video: Artist, Album, Title, Length, Bitrate, Codec

119
Test_test.go Normal file
View File

@@ -0,0 +1,119 @@
// Functions to manually debug encoding/decoding. No actual automated unit tests.
package core
import (
"encoding/hex"
"fmt"
"testing"
)
func TestMessageEncodingAnnouncement(t *testing.T) {
_, publicKey, err := Secp256k1NewPrivateKey()
if err != nil {
fmt.Printf("Error: %s\n", err.Error())
return
}
// encode and decode announcement
packetR := PacketRaw{Protocol: 0, Command: CommandAnnouncement, Sequence: 123}
var findPeer []KeyHash
var findValue []KeyHash
var files []InfoStore
hash1 := hashData([]byte("test"))
hash2 := hashData([]byte("test3"))
findPeer = append(findPeer, KeyHash{Hash: hash1})
findValue = append(findValue, KeyHash{Hash: hash2})
packets := msgEncodeAnnouncement(true, true, findPeer, findValue, files)
msg := &MessageRaw{PacketRaw: packetR, SenderPublicKey: publicKey}
msg.Payload = packets[0].raw
result, err := msgDecodeAnnouncement(msg)
if err != nil {
fmt.Printf("Error msgDecodeAnnouncement: %s\n", err.Error())
return
}
fmt.Printf("Decode:\nUser Agent: %s\nFind Peer: %v\nFind Data: %v\n", result.UserAgent, result.FindPeerKeys, result.FindDataKeys)
}
func TestMessageEncodingResponse(t *testing.T) {
_, publicKey, err := Secp256k1NewPrivateKey()
if err != nil {
fmt.Printf("Error: %s\n", err.Error())
return
}
// encode and decode response
packetR := PacketRaw{Protocol: 0, Command: CommandResponse}
var hash2Peers []Hash2Peer
var filesEmbed []EmbeddedFileData
var hashesNotFound [][]byte
file1Data := []byte("test")
file2Data := []byte("test3")
file1 := EmbeddedFileData{ID: KeyHash{hashData(file1Data)}, Data: file1Data}
file2 := EmbeddedFileData{ID: KeyHash{hashData(file2Data)}, Data: file2Data}
filesEmbed = append(filesEmbed, file1)
filesEmbed = append(filesEmbed, file2)
hashesNotFound = append(hashesNotFound, hashData([]byte("NA")))
packetsRaw, err := msgEncodeResponse(true, hash2Peers, filesEmbed, hashesNotFound)
if err != nil {
fmt.Printf("Error msgEncodeAnnouncement: %s\n", err.Error())
return
}
msg := &MessageRaw{PacketRaw: packetR, SenderPublicKey: publicKey}
msg.Payload = packetsRaw[0]
result, err := msgDecodeResponse(msg)
if err != nil {
fmt.Printf("Error msgDecodeAnnouncement: %s\n", err.Error())
return
}
fmt.Printf("Decode:\nUser Agent: %s\nHash2Peers: %v\nHashesNotFound: %v\nFiles embedded: %v\n", result.UserAgent, result.Hash2Peers, result.HashesNotFound, result.FilesEmbed)
}
func TestBlockEncoding(t *testing.T) {
privateKey, _, err := Secp256k1NewPrivateKey()
if err != nil {
fmt.Printf("Error: %s\n", err.Error())
return
}
file1 := BlockRecordFile{Hash: hashData([]byte("Test data")), Type: TypeText, Format: FormatText, Size: 9, Name: "Filename 1.txt", Directory: "documents\\sub folder"}
block := &Block{BlockchainVersion: 42, Number: 0, User: BlockRecordUser{Valid: true, Name: "Test User 1"}, Files: []BlockRecordFile{file1}}
raw, err := encodeBlock(block, privateKey)
if err != nil {
fmt.Printf("Error: %s\n", err.Error())
return
}
block, err = decodeBlock(raw)
if err != nil {
fmt.Printf("Error: %s\n", err.Error())
return
}
// output the block details
fmt.Printf("Block details:\n----------------\nNumber: %d\nVersion: %d\nLast Hash: %s\nPublic Key: %s\n", block.Number, block.BlockchainVersion, hex.EncodeToString(block.LastBlockHash), hex.EncodeToString(block.OwnerPublicKey.SerializeCompressed()))
for _, file := range block.Files {
fmt.Printf("* File %s\n", file.Name)
fmt.Printf(" Directory %s\n", file.Directory)
fmt.Printf(" Size %d\n", file.Size)
fmt.Printf(" Type %d\n", file.Type)
fmt.Printf(" Format %d\n", file.Format)
fmt.Printf(" Hash %s\n", hex.EncodeToString(file.Hash))
fmt.Printf(" Directory ID %d\n\n", file.directoryID)
}
}