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README.md Normal file
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# opentimestamps
Go port of https://github.com/opentimestamps/python-opentimestamps.
Copied from https://github.com/BlockchainSource/go-opentimestamps.
# Done
* Byte-level serialization format
* Timestamp parsing
* Creating pending timestamps
* Upgrading pending timestamps
* Bitcoin Timestamp verification
# To do
* Support for multiple timestamp servers
* Proper timestamp merging (on upgrade)
* More conformant serialization (sorting)
# License
Apache 2.0

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attestations.go Normal file
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package opentimestamps
import (
"bytes"
"fmt"
)
const (
attestationTagSize = 8
attestationMaxPayloadSize = 8192
pendingAttestationMaxUriLength = 1000
)
var (
bitcoinAttestationTag = mustDecodeHex("0588960d73d71901")
pendingAttestationTag = mustDecodeHex("83dfe30d2ef90c8e")
)
type Attestation interface {
tag() []byte
decode(*deserializationContext) (Attestation, error)
encode(*serializationContext) error
}
type baseAttestation struct {
fixedTag []byte
}
func (b *baseAttestation) tag() []byte {
return b.fixedTag
}
type pendingAttestation struct {
baseAttestation
uri string
}
func newPendingAttestation() *pendingAttestation {
return &pendingAttestation{
baseAttestation: baseAttestation{
fixedTag: pendingAttestationTag,
},
}
}
func (p *pendingAttestation) decode(
ctx *deserializationContext,
) (Attestation, error) {
uri, err := ctx.readVarBytes(0, pendingAttestationMaxUriLength)
if err != nil {
return nil, err
}
// TODO utf8 checks
ret := *p
ret.uri = string(uri)
return &ret, nil
}
func (p *pendingAttestation) encode(ctx *serializationContext) error {
return ctx.writeVarBytes([]byte(p.uri))
}
func (p *pendingAttestation) String() string {
return fmt.Sprintf("VERIFY PendingAttestation(url=%s)", p.uri)
}
type BitcoinAttestation struct {
baseAttestation
Height uint64
}
func newBitcoinAttestation() *BitcoinAttestation {
return &BitcoinAttestation{
baseAttestation: baseAttestation{bitcoinAttestationTag},
}
}
func (b *BitcoinAttestation) String() string {
return fmt.Sprintf("VERIFY BitcoinAttestation(height=%d)", b.Height)
}
func (b *BitcoinAttestation) decode(
ctx *deserializationContext,
) (Attestation, error) {
height, err := ctx.readVarUint()
if err != nil {
return nil, err
}
ret := *b
ret.Height = height
return &ret, nil
}
func (b *BitcoinAttestation) encode(ctx *serializationContext) error {
return ctx.writeVarUint(uint64(b.Height))
}
const hashMerkleRootSize = 32
//
func (b *BitcoinAttestation) VerifyAgainstBlockHash(
digest, blockHash []byte,
) error {
if len(digest) != hashMerkleRootSize {
return fmt.Errorf("invalid digest size %d", len(digest))
}
if !bytes.Equal(digest, blockHash) {
return fmt.Errorf(
"hash mismatch digest=%x blockHash=%x",
digest, blockHash,
)
}
return nil
}
// This is a catch-all for when we don't know how to parse it
type unknownAttestation struct {
tagBytes []byte
bytes []byte
}
func (u unknownAttestation) tag() []byte {
return u.tagBytes
}
func (unknownAttestation) decode(*deserializationContext) (Attestation, error) {
panic("not implemented")
}
func (unknownAttestation) encode(*serializationContext) error {
panic("not implemented")
}
func (u unknownAttestation) String() string {
return fmt.Sprintf("UnknownAttestation(bytes=%q)", u.bytes)
}
var attestations []Attestation = []Attestation{
newPendingAttestation(),
newBitcoinAttestation(),
}
func encodeAttestation(ctx *serializationContext, att Attestation) error {
if err := ctx.writeBytes(att.tag()); err != nil {
return err
}
buf := &bytes.Buffer{}
if err := att.encode(&serializationContext{buf}); err != nil {
return err
}
return ctx.writeVarBytes(buf.Bytes())
}
func ParseAttestation(ctx *deserializationContext) (Attestation, error) {
tag, err := ctx.readBytes(attestationTagSize)
if err != nil {
return nil, err
}
attBytes, err := ctx.readVarBytes(
0, attestationMaxPayloadSize,
)
if err != nil {
return nil, err
}
attCtx := newDeserializationContext(
bytes.NewBuffer(attBytes),
)
for _, a := range attestations {
if bytes.Equal(tag, a.tag()) {
att, err := a.decode(attCtx)
if err != nil {
return nil, err
}
if !attCtx.assertEOF() {
return nil, fmt.Errorf("expected EOF in attCtx")
}
return att, nil
}
}
return unknownAttestation{tag, attBytes}, nil
}

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client/bitcoin.go Normal file
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package client
import (
"fmt"
"math"
"time"
"github.com/fiatjaf/opentimestamps"
"github.com/btcsuite/btcd/rpcclient"
)
// A BitcoinAttestationVerifier uses a bitcoin RPC connection to verify bitcoin
// headers.
type BitcoinAttestationVerifier struct {
btcrpcClient *rpcclient.Client
}
func NewBitcoinAttestationVerifier(
c *rpcclient.Client,
) *BitcoinAttestationVerifier {
return &BitcoinAttestationVerifier{c}
}
// VerifyAttestation checks a BitcoinAttestation using a given hash digest. It
// returns the time of the block if the verification succeeds, an error
// otherwise.
func (v *BitcoinAttestationVerifier) VerifyAttestation(
digest []byte, a *opentimestamps.BitcoinAttestation,
) (*time.Time, error) {
if a.Height > math.MaxInt64 {
return nil, fmt.Errorf("illegal block height")
}
blockHash, err := v.btcrpcClient.GetBlockHash(int64(a.Height))
if err != nil {
return nil, err
}
h, err := v.btcrpcClient.GetBlockHeader(blockHash)
if err != nil {
return nil, err
}
merkleRootBytes := h.MerkleRoot[:]
err = a.VerifyAgainstBlockHash(digest, merkleRootBytes)
if err != nil {
return nil, err
}
utc := h.Timestamp.UTC()
return &utc, nil
}
// A BitcoinVerification is the result of verifying a BitcoinAttestation
type BitcoinVerification struct {
Timestamp *opentimestamps.Timestamp
Attestation *opentimestamps.BitcoinAttestation
AttestationTime *time.Time
Error error
}
// BitcoinVerifications returns the all bitcoin attestation results for the
// timestamp.
func (v *BitcoinAttestationVerifier) BitcoinVerifications(
t *opentimestamps.Timestamp,
) (res []BitcoinVerification) {
t.Walk(func(ts *opentimestamps.Timestamp) {
for _, att := range ts.Attestations {
btcAtt, ok := att.(*opentimestamps.BitcoinAttestation)
if !ok {
continue
}
attTime, err := v.VerifyAttestation(ts.Message, btcAtt)
res = append(res, BitcoinVerification{
Timestamp: ts,
Attestation: btcAtt,
AttestationTime: attTime,
Error: err,
})
}
})
return res
}
// Verify returns the earliest bitcoin-attested time, or nil if none can be
// found or verified successfully.
func (v *BitcoinAttestationVerifier) Verify(
t *opentimestamps.Timestamp,
) (ret *time.Time, err error) {
res := v.BitcoinVerifications(t)
for _, r := range res {
if r.Error != nil {
err = r.Error
continue
}
if ret == nil || r.AttestationTime.Before(*ret) {
ret = r.AttestationTime
}
}
return
}

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client/bitcoin_test.go Normal file
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package client
import (
"fmt"
"net/url"
"os"
"testing"
"time"
"github.com/fiatjaf/opentimestamps"
"github.com/btcsuite/btcd/rpcclient"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
const envvarRPCURL = "GOTS_TEST_BITCOIN_RPC"
func newTestBTCConn() (*rpcclient.Client, error) {
val := os.Getenv(envvarRPCURL)
if val == "" {
return nil, fmt.Errorf("envvar %q unset", envvarRPCURL)
}
connData, err := url.Parse(val)
if err != nil {
return nil, fmt.Errorf(
"could not parse %q=%q: %v", envvarRPCURL, val, err,
)
}
host := connData.Host
if connData.User == nil {
return nil, fmt.Errorf("no Userinfo in parsed url")
}
username := connData.User.Username()
password, ok := connData.User.Password()
if !ok {
return nil, fmt.Errorf("no password given in RPC URL")
}
connCfg := &rpcclient.ConnConfig{
Host: host,
User: username,
Pass: password,
HTTPPostMode: true,
DisableTLS: true,
}
return rpcclient.New(connCfg, nil)
}
func TestVerifyHelloWorld(t *testing.T) {
if os.Getenv(envvarRPCURL) == "" {
t.Skipf("envvar %s unset, skipping", envvarRPCURL)
}
// Format RFC3339
expectedTime := "2015-05-28T15:41:18Z"
helloWorld, err := opentimestamps.NewDetachedTimestampFromPath(
"../../examples/hello-world.txt.ots",
)
require.NoError(t, err)
ts := helloWorld.Timestamp
btcConn, err := newTestBTCConn()
require.NoError(t, err)
verifier := BitcoinAttestationVerifier{btcConn}
// using BitcoinVerifications()
results := verifier.BitcoinVerifications(ts)
assert.Equal(t, 1, len(results))
result0 := results[0]
require.NoError(t, result0.Error)
assert.Equal(
t, expectedTime, result0.AttestationTime.Format(time.RFC3339),
)
// using Verify()
verifiedTime, err := verifier.Verify(ts)
require.NoError(t, err)
require.NotNil(t, verifiedTime)
assert.Equal(t, expectedTime, verifiedTime.Format(time.RFC3339))
}

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commands.go Normal file
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package opentimestamps
import (
"crypto/sha256"
"io"
"os"
)
func CreateDetachedTimestampForFile(
path string, cal *RemoteCalendar,
) (*DetachedTimestamp, error) {
f, err := os.Open(path)
if err != nil {
return nil, err
}
hasher := sha256.New()
if _, err := io.Copy(hasher, f); err != nil {
return nil, err
}
digest := hasher.Sum([]byte{})
ts, err := cal.Submit(digest)
if err != nil {
return nil, err
}
return NewDetachedTimestamp(*opSHA256, digest, ts)
}

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detached_timestamp.go Normal file
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package opentimestamps
import (
"bytes"
"fmt"
"io"
"os"
)
var fileHeaderMagic = []byte(
"\x00OpenTimestamps\x00\x00Proof\x00\xbf\x89\xe2\xe8\x84\xe8\x92\x94",
)
const (
minFileDigestLength = 20
maxFileDigestLength = 32
fileMajorVersion = 1
)
type DetachedTimestamp struct {
HashOp cryptOp
FileHash []byte
Timestamp *Timestamp
}
func (d *DetachedTimestamp) Dump() string {
w := &bytes.Buffer{}
fmt.Fprintf(
w, "File %s hash: %x\n", d.HashOp.name, d.Timestamp.Message,
)
fmt.Fprint(w, d.Timestamp.Dump())
return w.String()
}
func (d *DetachedTimestamp) encode(ctx *serializationContext) error {
if err := ctx.writeBytes(fileHeaderMagic); err != nil {
return err
}
if err := ctx.writeVarUint(fileMajorVersion); err != nil {
return err
}
if err := d.HashOp.encode(ctx); err != nil {
return err
}
if err := ctx.writeBytes(d.FileHash); err != nil {
return err
}
return d.Timestamp.encode(ctx)
}
func (d *DetachedTimestamp) WriteToStream(w io.Writer) error {
return d.encode(&serializationContext{w})
}
func NewDetachedTimestamp(
hashOp cryptOp, fileHash []byte, ts *Timestamp,
) (*DetachedTimestamp, error) {
if len(fileHash) != hashOp.digestLength {
return nil, fmt.Errorf(
"op %v expects %d byte digest, got %d",
hashOp, hashOp.digestLength, len(fileHash),
)
}
return &DetachedTimestamp{hashOp, fileHash, ts}, nil
}
func NewDetachedTimestampFromReader(r io.Reader) (*DetachedTimestamp, error) {
ctx := newDeserializationContext(r)
if err := ctx.assertMagic([]byte(fileHeaderMagic)); err != nil {
return nil, err
}
major, err := ctx.readVarUint()
if err != nil {
return nil, err
}
if major != uint64(fileMajorVersion) {
return nil, fmt.Errorf("unexpected major version %d", major)
}
fileHashOp, err := parseCryptOp(ctx)
if err != nil {
return nil, err
}
fileHash, err := ctx.readBytes(fileHashOp.digestLength)
if err != nil {
return nil, err
}
ts, err := newTimestampFromContext(ctx, fileHash)
if err != nil {
return nil, err
}
return &DetachedTimestamp{*fileHashOp, fileHash, ts}, nil
}
func NewDetachedTimestampFromPath(p string) (*DetachedTimestamp, error) {
f, err := os.Open(p)
if err != nil {
return nil, err
}
return NewDetachedTimestampFromReader(f)
}

110
detached_timestamp_test.go Normal file
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package opentimestamps
import (
"bytes"
"encoding/hex"
"io/ioutil"
"path/filepath"
"testing"
"github.com/stretchr/testify/assert"
)
func examplePaths() []string {
matches, err := filepath.Glob("../examples/*ots")
if err != nil {
panic(err)
}
return matches
}
func containsUnknownAttestation(ts *Timestamp) (res bool) {
ts.Walk(func(subTs *Timestamp) {
for _, att := range subTs.Attestations {
if _, ok := att.(unknownAttestation); ok {
res = true
}
}
})
return
}
func TestDecodeHelloWorld(t *testing.T) {
dts, err := NewDetachedTimestampFromPath(
"../examples/hello-world.txt.ots",
)
assert.NoError(t, err)
attCount := 0
checkAttestation := func(ts *Timestamp, att Attestation) {
assert.Equal(t, 0, attCount)
expectedAtt := newBitcoinAttestation()
expectedAtt.Height = 358391
assert.Equal(t, expectedAtt, att)
// If ts.Message is correct, opcode parsing and execution should
// have succeeded.
assert.Equal(t,
"007ee445d23ad061af4a36b809501fab1ac4f2d7e7a739817dd0cbb7ec661b8a",
hex.EncodeToString(ts.Message),
)
attCount += 1
}
dts.Timestamp.Walk(func(ts *Timestamp) {
for _, att := range ts.Attestations {
// this should be called exactly once
checkAttestation(ts, att)
}
})
assert.Equal(t, 1, attCount)
}
func TestDecodeEncodeAll(t *testing.T) {
for _, path := range examplePaths() {
t.Log(path)
dts, err := NewDetachedTimestampFromPath(path)
assert.NoError(t, err, path)
if containsUnknownAttestation(dts.Timestamp) {
t.Logf("skipping encode cycle: unknownAttestation")
continue
}
buf := &bytes.Buffer{}
err = dts.Timestamp.encode(&serializationContext{buf})
if !assert.NoError(t, err, path) {
continue
}
buf = bytes.NewBuffer(buf.Bytes())
ts1, err := NewTimestampFromReader(buf, dts.Timestamp.Message)
if !assert.NoError(t, err, path) {
continue
}
dts1, err := NewDetachedTimestamp(
dts.HashOp, dts.FileHash, ts1,
)
if !assert.NoError(t, err) {
continue
}
dts1Target := &bytes.Buffer{}
err = dts1.WriteToStream(dts1Target)
if !assert.NoError(t, err) {
continue
}
orgBytes, err := ioutil.ReadFile(path)
if !assert.NoError(t, err) {
continue
}
assert.Equal(t, orgBytes, dts1Target.Bytes())
t.Log("encode cycle success")
}
}

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go.mod Normal file
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module github.com/fiatjaf/opentimestamps
go 1.21
require (
github.com/btcsuite/btcd v0.23.4
github.com/sirupsen/logrus v1.9.3
github.com/stretchr/testify v1.8.4
golang.org/x/crypto v0.13.0
)
require (
github.com/btcsuite/btcd/btcec/v2 v2.1.3 // indirect
github.com/btcsuite/btcd/btcutil v1.1.0 // indirect
github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1 // indirect
github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f // indirect
github.com/btcsuite/go-socks v0.0.0-20170105172521-4720035b7bfd // indirect
github.com/btcsuite/websocket v0.0.0-20150119174127-31079b680792 // indirect
github.com/davecgh/go-spew v1.1.1 // indirect
github.com/decred/dcrd/crypto/blake256 v1.0.0 // indirect
github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
github.com/pmezard/go-difflib v1.0.0 // indirect
golang.org/x/sys v0.12.0 // indirect
gopkg.in/yaml.v3 v3.0.1 // indirect
)

113
go.sum Normal file
View File

@@ -0,0 +1,113 @@
github.com/aead/siphash v1.0.1/go.mod h1:Nywa3cDsYNNK3gaciGTWPwHt0wlpNV15vwmswBAUSII=
github.com/btcsuite/btcd v0.20.1-beta/go.mod h1:wVuoA8VJLEcwgqHBwHmzLRazpKxTv13Px/pDuV7OomQ=
github.com/btcsuite/btcd v0.22.0-beta.0.20220111032746-97732e52810c/go.mod h1:tjmYdS6MLJ5/s0Fj4DbLgSbDHbEqLJrtnHecBFkdz5M=
github.com/btcsuite/btcd v0.23.4 h1:IzV6qqkfwbItOS/sg/aDfPDsjPP8twrCOE2R93hxMlQ=
github.com/btcsuite/btcd v0.23.4/go.mod h1:0QJIIN1wwIXF/3G/m87gIwGniDMDQqjVn4SZgnFpsYY=
github.com/btcsuite/btcd/btcec/v2 v2.1.0/go.mod h1:2VzYrv4Gm4apmbVVsSq5bqf1Ec8v56E48Vt0Y/umPgA=
github.com/btcsuite/btcd/btcec/v2 v2.1.3 h1:xM/n3yIhHAhHy04z4i43C8p4ehixJZMsnrVJkgl+MTE=
github.com/btcsuite/btcd/btcec/v2 v2.1.3/go.mod h1:ctjw4H1kknNJmRN4iP1R7bTQ+v3GJkZBd6mui8ZsAZE=
github.com/btcsuite/btcd/btcutil v1.0.0/go.mod h1:Uoxwv0pqYWhD//tfTiipkxNfdhG9UrLwaeswfjfdF0A=
github.com/btcsuite/btcd/btcutil v1.1.0 h1:MO4klnGY+EWJdoWF12Wkuf4AWDBPMpZNeN/jRLrklUU=
github.com/btcsuite/btcd/btcutil v1.1.0/go.mod h1:5OapHB7A2hBBWLm48mmw4MOHNJCcUBTwmWH/0Jn8VHE=
github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1 h1:q0rUy8C/TYNBQS1+CGKw68tLOFYSNEs0TFnxxnS9+4U=
github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1/go.mod h1:7SFka0XMvUgj3hfZtydOrQY2mwhPclbT2snogU7SQQc=
github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f h1:bAs4lUbRJpnnkd9VhRV3jjAVU7DJVjMaK+IsvSeZvFo=
github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f/go.mod h1:TdznJufoqS23FtqVCzL0ZqgP5MqXbb4fg/WgDys70nA=
github.com/btcsuite/btcutil v0.0.0-20190425235716-9e5f4b9a998d/go.mod h1:+5NJ2+qvTyV9exUAL/rxXi3DcLg2Ts+ymUAY5y4NvMg=
github.com/btcsuite/go-socks v0.0.0-20170105172521-4720035b7bfd h1:R/opQEbFEy9JGkIguV40SvRY1uliPX8ifOvi6ICsFCw=
github.com/btcsuite/go-socks v0.0.0-20170105172521-4720035b7bfd/go.mod h1:HHNXQzUsZCxOoE+CPiyCTO6x34Zs86zZUiwtpXoGdtg=
github.com/btcsuite/goleveldb v0.0.0-20160330041536-7834afc9e8cd/go.mod h1:F+uVaaLLH7j4eDXPRvw78tMflu7Ie2bzYOH4Y8rRKBY=
github.com/btcsuite/goleveldb v1.0.0/go.mod h1:QiK9vBlgftBg6rWQIj6wFzbPfRjiykIEhBH4obrXJ/I=
github.com/btcsuite/snappy-go v0.0.0-20151229074030-0bdef8d06723/go.mod h1:8woku9dyThutzjeg+3xrA5iCpBRH8XEEg3lh6TiUghc=
github.com/btcsuite/snappy-go v1.0.0/go.mod h1:8woku9dyThutzjeg+3xrA5iCpBRH8XEEg3lh6TiUghc=
github.com/btcsuite/websocket v0.0.0-20150119174127-31079b680792 h1:R8vQdOQdZ9Y3SkEwmHoWBmX1DNXhXZqlTpq6s4tyJGc=
github.com/btcsuite/websocket v0.0.0-20150119174127-31079b680792/go.mod h1:ghJtEyQwv5/p4Mg4C0fgbePVuGr935/5ddU9Z3TmDRY=
github.com/btcsuite/winsvc v1.0.0/go.mod h1:jsenWakMcC0zFBFurPLEAyrnc/teJEM1O46fmI40EZs=
github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/decred/dcrd/crypto/blake256 v1.0.0 h1:/8DMNYp9SGi5f0w7uCm6d6M4OU2rGFK09Y2A4Xv7EE0=
github.com/decred/dcrd/crypto/blake256 v1.0.0/go.mod h1:sQl2p6Y26YV+ZOcSTP6thNdn47hh8kt6rqSlvmrXFAc=
github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 h1:YLtO71vCjJRCBcrPMtQ9nqBsqpA1m5sE92cU+pd5Mcc=
github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1/go.mod h1:hyedUtir6IdtD/7lIxGeCxkaw7y45JueMRL4DIyJDKs=
github.com/decred/dcrd/lru v1.0.0/go.mod h1:mxKOwFd7lFjN2GZYsiz/ecgqR6kkYAl+0pz0tEMk218=
github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
github.com/golang/protobuf v1.4.0-rc.1/go.mod h1:ceaxUfeHdC40wWswd/P6IGgMaK3YpKi5j83Wpe3EHw8=
github.com/golang/protobuf v1.4.0-rc.1.0.20200221234624-67d41d38c208/go.mod h1:xKAWHe0F5eneWXFV3EuXVDTCmh+JuBKY0li0aMyXATA=
github.com/golang/protobuf v1.4.0-rc.2/go.mod h1:LlEzMj4AhA7rCAGe4KMBDvJI+AwstrUpVNzEA03Pprs=
github.com/golang/protobuf v1.4.0-rc.4.0.20200313231945-b860323f09d0/go.mod h1:WU3c8KckQ9AFe+yFwt9sWVRKCVIyN9cPHBJSNnbL67w=
github.com/golang/protobuf v1.4.0/go.mod h1:jodUvKwWbYaEsadDk5Fwe5c77LiNKVO9IDvqG2KuDX0=
github.com/golang/protobuf v1.4.2/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
github.com/jessevdk/go-flags v0.0.0-20141203071132-1679536dcc89/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
github.com/jrick/logrotate v1.0.0/go.mod h1:LNinyqDIJnpAur+b8yyulnQw/wDuN1+BYKlTRt3OuAQ=
github.com/kkdai/bstream v0.0.0-20161212061736-f391b8402d23/go.mod h1:J+Gs4SYgM6CZQHDETBtE9HaSEkGmuNXF86RwHhHUvq4=
github.com/nxadm/tail v1.4.4/go.mod h1:kenIhsEOeOJmVchQTgglprH7qJGnHDVpk1VPCcaMI8A=
github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
github.com/onsi/ginkgo v1.12.1/go.mod h1:zj2OWP4+oCPe1qIXoGWkgMRwljMUYCdkwsT2108oapk=
github.com/onsi/ginkgo v1.14.0/go.mod h1:iSB4RoI2tjJc9BBv4NKIKWKya62Rps+oPG/Lv9klQyY=
github.com/onsi/gomega v1.4.1/go.mod h1:C1qb7wdrVGGVU+Z6iS04AVkA3Q65CEZX59MT0QO5uiA=
github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7JYyY=
github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1ybHNo=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
golang.org/x/crypto v0.13.0 h1:mvySKfSWJ+UKUii46M40LOvyWfN0s2U+46/jDd0e6Ck=
golang.org/x/crypto v0.13.0/go.mod h1:y6Z2r+Rw4iayiXXAIxJIDAJ1zMW4yaTpebo8fPOliYc=
golang.org/x/net v0.0.0-20180719180050-a680a1efc54d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/net v0.0.0-20200520004742-59133d7f0dd7/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
golang.org/x/net v0.0.0-20200813134508-3edf25e44fcc/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20190904154756-749cb33beabd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20200519105757-fe76b779f299/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20200814200057-3d37ad5750ed/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=
google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQJ+fmap5saPgwCLgHXTUD7jkjRqWcaiX5VyM=
google.golang.org/protobuf v1.20.1-0.20200309200217-e05f789c0967/go.mod h1:A+miEFZTKqfCUM6K7xSMQL9OKL/b6hQv+e19PK+JZNE=
google.golang.org/protobuf v1.21.0/go.mod h1:47Nbq4nVaFHyn7ilMalzfO3qCViNmqZ2kzikPIcrTAo=
google.golang.org/protobuf v1.23.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

220
operations.go Normal file
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@@ -0,0 +1,220 @@
package opentimestamps
import (
"crypto/sha1"
"crypto/sha256"
"encoding/hex"
"fmt"
"golang.org/x/crypto/ripemd160"
)
const maxResultLength = 4096
type (
unaryMsgOp func(message []byte) ([]byte, error)
binaryMsgOp func(message, argument []byte) ([]byte, error)
)
// msgAppend returns the concatenation of msg and arg
func msgAppend(msg, arg []byte) (res []byte, err error) {
res = append(res, msg...)
res = append(res, arg...)
return
}
// msgPrepend returns the concatenation of arg and msg
func msgPrepend(msg, arg []byte) (res []byte, err error) {
res = append(res, arg...)
res = append(res, msg...)
return
}
// msgReverse returns the reversed msg. Deprecated.
func msgReverse(msg []byte) ([]byte, error) {
if len(msg) == 0 {
return nil, fmt.Errorf("empty input invalid for msgReverse")
}
res := make([]byte, len(msg))
for i, b := range msg {
res[len(res)-i-1] = b
}
return res, nil
}
func msgHexlify(msg []byte) ([]byte, error) {
if len(msg) == 0 {
return nil, fmt.Errorf("empty input invalid for msgHexlify")
}
return []byte(hex.EncodeToString(msg)), nil
}
func msgSHA1(msg []byte) ([]byte, error) {
res := sha1.Sum(msg)
return res[:], nil
}
func msgRIPEMD160(msg []byte) ([]byte, error) {
h := ripemd160.New()
_, err := h.Write(msg)
if err != nil {
return nil, err
}
return h.Sum([]byte{}), nil
}
func msgSHA256(msg []byte) ([]byte, error) {
res := sha256.Sum256(msg)
return res[:], nil
}
type opCode interface {
match(byte) bool
decode(*deserializationContext) (opCode, error)
encode(*serializationContext) error
apply(message []byte) ([]byte, error)
}
type op struct {
tag byte
name string
}
func (o op) match(tag byte) bool {
return o.tag == tag
}
type unaryOp struct {
op
msgOp unaryMsgOp
}
func newUnaryOp(tag byte, name string, msgOp unaryMsgOp) *unaryOp {
return &unaryOp{op{tag: tag, name: name}, msgOp}
}
func (u *unaryOp) String() string {
return u.name
}
func (u *unaryOp) decode(ctx *deserializationContext) (opCode, error) {
ret := *u
return &ret, nil
}
func (u *unaryOp) encode(ctx *serializationContext) error {
return ctx.writeByte(u.tag)
}
func (u *unaryOp) apply(message []byte) ([]byte, error) {
return u.msgOp(message)
}
// Crypto operations
// These are hash ops that define a digest length
type cryptOp struct {
unaryOp
digestLength int
}
func newCryptOp(
tag byte, name string, msgOp unaryMsgOp, digestLength int,
) *cryptOp {
return &cryptOp{
unaryOp: *newUnaryOp(tag, name, msgOp),
digestLength: digestLength,
}
}
func (c *cryptOp) decode(ctx *deserializationContext) (opCode, error) {
u, err := c.unaryOp.decode(ctx)
if err != nil {
return nil, err
}
return &cryptOp{*u.(*unaryOp), c.digestLength}, nil
}
// Binary operations
// We decode an extra varbyte argument and use it in apply()
type binaryOp struct {
op
msgOp binaryMsgOp
argument []byte
}
func newBinaryOp(tag byte, name string, msgOp binaryMsgOp) *binaryOp {
return &binaryOp{
op: op{tag: tag, name: name},
msgOp: msgOp,
argument: nil,
}
}
func (b *binaryOp) decode(ctx *deserializationContext) (opCode, error) {
arg, err := ctx.readVarBytes(0, maxResultLength)
if err != nil {
return nil, err
}
if len(arg) == 0 {
return nil, fmt.Errorf("empty argument invalid for binaryOp")
}
ret := *b
ret.argument = arg
return &ret, nil
}
func (b *binaryOp) encode(ctx *serializationContext) error {
if err := ctx.writeByte(b.tag); err != nil {
return err
}
return ctx.writeVarBytes(b.argument)
}
func (b *binaryOp) apply(message []byte) ([]byte, error) {
return b.msgOp(message, b.argument)
}
func (b *binaryOp) String() string {
return fmt.Sprintf("%s %x", b.name, b.argument)
}
var (
opAppend = newBinaryOp(0xf0, "APPEND", msgAppend)
opPrepend = newBinaryOp(0xf1, "PREPEND", msgPrepend)
opReverse = newUnaryOp(0xf2, "REVERSE", msgReverse)
opHexlify = newUnaryOp(0xf3, "HEXLIFY", msgHexlify)
opSHA1 = newCryptOp(0x02, "SHA1", msgSHA1, 20)
opRIPEMD160 = newCryptOp(0x03, "RIPEMD160", msgRIPEMD160, 20)
opSHA256 = newCryptOp(0x08, "SHA256", msgSHA256, 32)
)
var opCodes []opCode = []opCode{
opAppend, opPrepend, opReverse, opHexlify, opSHA1, opRIPEMD160,
opSHA256,
}
func parseOp(ctx *deserializationContext, tag byte) (opCode, error) {
for _, op := range opCodes {
if op.match(tag) {
return op.decode(ctx)
}
}
return nil, fmt.Errorf("could not decode tag %02x", tag)
}
func parseCryptOp(ctx *deserializationContext) (*cryptOp, error) {
tag, err := ctx.readByte()
if err != nil {
return nil, err
}
op, err := parseOp(ctx, tag)
if err != nil {
return nil, err
}
if cryptOp, ok := op.(*cryptOp); ok {
return cryptOp, nil
} else {
return nil, fmt.Errorf("expected cryptOp, got %#v", op)
}
}

78
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package opentimestamps
import (
"encoding/hex"
"testing"
"github.com/stretchr/testify/assert"
)
func TestMsgAppend(t *testing.T) {
msg := []byte("123")
res, err := msgAppend(msg, []byte("456"))
assert.NoError(t, err)
assert.Equal(t, "123456", string(res))
// make sure changes to input msg don't affect output
msg[0] = byte('0')
assert.Equal(t, "123456", string(res))
}
func TestMsgPrepend(t *testing.T) {
msg := []byte("123")
res, err := msgPrepend(msg, []byte("abc"))
assert.NoError(t, err)
assert.Equal(t, "abc123", string(res))
// make sure changes to input msg don't affect output
msg[0] = byte('0')
assert.Equal(t, "abc123", string(res))
}
func TestMsgReverse(t *testing.T) {
_, err := msgReverse([]byte{})
assert.Error(t, err)
res, err := msgReverse([]byte{1, 2, 3})
assert.NoError(t, err)
assert.Equal(t, []byte{3, 2, 1}, res)
}
func TestMsgHexlify(t *testing.T) {
_, err := msgHexlify([]byte{})
assert.Error(t, err)
res, err := msgHexlify([]byte{1, 2, 3, 0xff})
assert.NoError(t, err)
assert.Equal(t, []byte("010203ff"), res)
}
func TestMsgSHA1(t *testing.T) {
out, err := msgSHA1([]byte{})
assert.NoError(t, err)
assert.Equal(t,
"da39a3ee5e6b4b0d3255bfef95601890afd80709",
hex.EncodeToString(out),
)
}
func TestMsgSHA256(t *testing.T) {
out, err := msgSHA256([]byte{})
assert.NoError(t, err)
assert.Equal(t,
"e3b0c44298fc1c149afbf4c8996fb924"+
"27ae41e4649b934ca495991b7852b855",
hex.EncodeToString(out),
)
}
func TestRIPEMD160(t *testing.T) {
out, err := msgRIPEMD160([]byte{})
assert.Equal(t,
"9c1185a5c5e9fc54612808977ee8f548b2258d31",
hex.EncodeToString(out),
)
out, err = msgRIPEMD160(out)
assert.NoError(t, err)
assert.Equal(t,
"38bbc57e4cbe8b6a1d2c999ef62503e0a6e58109",
hex.EncodeToString(out),
)
}

146
remote_calendar.go Normal file
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package opentimestamps
import (
"bytes"
"encoding/hex"
"fmt"
"io/ioutil"
"net/http"
"net/http/httputil"
"strings"
"github.com/sirupsen/logrus"
)
const userAgent = "go-opentimestamps"
const dumpResponse = false
type RemoteCalendar struct {
baseURL string
client *http.Client
log *logrus.Logger
}
func NewRemoteCalendar(baseURL string) (*RemoteCalendar, error) {
// FIXME remove this
if baseURL == "localhost" {
baseURL = "http://localhost:14788"
}
// TODO validate url
if !strings.HasSuffix(baseURL, "/") {
baseURL += "/"
}
return &RemoteCalendar{
baseURL,
http.DefaultClient,
logrus.New(),
}, nil
}
// Check response status, return informational error message if
// status is not `200 OK`.
func checkStatusOK(resp *http.Response) error {
if resp.StatusCode == http.StatusOK {
return nil
}
errMsg := fmt.Sprintf("unexpected response: %q", resp.Status)
if resp.Body == nil {
return fmt.Errorf("%s (body=nil)", errMsg)
}
defer resp.Body.Close()
bodyBytes, err := ioutil.ReadAll(resp.Body)
if err != nil {
return fmt.Errorf("%s (bodyErr=%v)", errMsg, err)
} else {
return fmt.Errorf("%s (body=%q)", errMsg, bodyBytes)
}
}
func (c *RemoteCalendar) do(r *http.Request) (*http.Response, error) {
r.Header.Add("Accept", "application/vnd.opentimestamps.v1")
r.Header.Add("User-Agent", userAgent)
c.log.Debugf("> %s %s", r.Method, r.URL)
resp, err := c.client.Do(r)
if err != nil {
c.log.Errorf("> %s %s error: %v", r.Method, r.URL, err)
return resp, err
}
c.log.Debugf("< %s %s - %v", r.Method, r.URL, resp.Status)
if dumpResponse {
bytes, err := httputil.DumpResponse(resp, true)
if err == nil {
c.log.Debugf("response dump:%s ", bytes)
}
}
return resp, err
}
func (c *RemoteCalendar) url(path string) string {
return c.baseURL + path
}
func (c *RemoteCalendar) Submit(digest []byte) (*Timestamp, error) {
body := bytes.NewBuffer(digest)
req, err := http.NewRequest("POST", c.url("digest"), body)
if err != nil {
return nil, err
}
resp, err := c.do(req)
if err != nil {
return nil, err
}
if resp.Body != nil {
defer resp.Body.Close()
}
if resp.StatusCode != http.StatusOK {
return nil, fmt.Errorf("expected 200, got %v", resp.Status)
}
return NewTimestampFromReader(resp.Body, digest)
}
func (c *RemoteCalendar) GetTimestamp(commitment []byte) (*Timestamp, error) {
url := c.url("timestamp/" + hex.EncodeToString(commitment))
req, err := http.NewRequest("GET", url, nil)
if err != nil {
return nil, err
}
resp, err := c.do(req)
if err != nil {
return nil, err
}
if err := checkStatusOK(resp); err != nil {
return nil, err
}
if resp.Body != nil {
defer resp.Body.Close()
}
return NewTimestampFromReader(resp.Body, commitment)
}
type PendingTimestamp struct {
Timestamp *Timestamp
PendingAttestation *pendingAttestation
}
func (p PendingTimestamp) Upgrade() (*Timestamp, error) {
cal, err := NewRemoteCalendar(p.PendingAttestation.uri)
if err != nil {
return nil, err
}
return cal.GetTimestamp(p.Timestamp.Message)
}
func PendingTimestamps(ts *Timestamp) (res []PendingTimestamp) {
ts.Walk(func(ts *Timestamp) {
for _, att := range ts.Attestations {
p, ok := att.(*pendingAttestation)
if !ok {
continue
}
attCopy := *p
res = append(res, PendingTimestamp{ts, &attCopy})
}
})
return
}

71
remote_calendar_test.go Normal file
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package opentimestamps
import (
"crypto/sha256"
"fmt"
"os"
"testing"
"time"
"github.com/sirupsen/logrus"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
const (
calendarServerEnvvar = "GOTS_TEST_CALENDAR_SERVER"
bitcoinRegtestEnvvar = "GOTS_TEST_BITCOIN_REGTEST_SERVER"
)
func newTestCalendar(url string) *RemoteCalendar {
logrus.SetLevel(logrus.DebugLevel)
cal, err := NewRemoteCalendar(url)
if err != nil {
panic("could not create test calendar")
}
cal.log.Level = logrus.DebugLevel
return cal
}
func newTestDigest(in string) []byte {
hash := sha256.Sum256([]byte(in))
return hash[:]
}
func TestRemoteCalendarExample(t *testing.T) {
dts, err := NewDetachedTimestampFromPath(
"../examples/two-calendars.txt.ots",
)
require.NoError(t, err)
pts := PendingTimestamps(dts.Timestamp)
assert.Equal(t, 2, len(pts))
for _, pt := range pts {
ts, err := pt.Upgrade()
assert.NoError(t, err)
fmt.Print(ts.Dump())
}
}
func TestRemoteCalendarRoundTrip(t *testing.T) {
calendarServer := os.Getenv(calendarServerEnvvar)
if calendarServer == "" {
t.Skipf("%q not set, skipping test", calendarServerEnvvar)
}
cal := newTestCalendar(calendarServer)
ts, err := cal.Submit(newTestDigest("Hello, World!"))
require.NoError(t, err)
require.NotNil(t, ts)
// TODO call rpcclient generateblock 100
// FIXME possible opentimestamps-server bug?
// wait until attestation has been aggregated
time.Sleep(2 * time.Second)
for _, pts := range PendingTimestamps(ts) {
ts, err := pts.Upgrade()
assert.NoError(t, err)
_ = ts
}
}

206
serialize.go Normal file
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package opentimestamps
import (
"bufio"
"bytes"
"fmt"
"io"
"math"
)
// serializationContext helps encoding values in the ots format
type serializationContext struct {
w io.Writer
}
// newSerializationContext returns a serializationContext for a writer
func newSerializationContext(w io.Writer) *serializationContext {
return &serializationContext{w}
}
// writeBytes writes the raw bytes to the underlying writer
func (s serializationContext) writeBytes(b []byte) error {
// number of bytes can be ignored
// if it is equal len(b) then err is nil
_, err := s.w.Write(b)
if err != nil {
return err
}
return nil
}
// writeByte writes a single byte
func (s serializationContext) writeByte(b byte) error {
return s.writeBytes([]byte{b})
}
// writeBool encodes and writes a boolean value
func (s serializationContext) writeBool(b bool) error {
if b {
return s.writeByte(0xff)
} else {
return s.writeByte(0x00)
}
}
// writeVarUint encodes and writes writes a variable-length integer
func (s serializationContext) writeVarUint(v uint64) error {
if v == 0 {
s.writeByte(0x00)
}
for v > 0 {
b := byte(v & 0x7f)
if v > uint64(0x7f) {
b |= 0x80
}
if err := s.writeByte(b); err != nil {
return err
}
if v <= 0x7f {
break
}
v >>= 7
}
return nil
}
// writeVarBytes encodes and writes a variable-length array
func (s serializationContext) writeVarBytes(arr []byte) error {
if err := s.writeVarUint(uint64(len(arr))); err != nil {
return err
}
return s.writeBytes(arr)
}
// deserializationContext helps decoding values from the ots format
type deserializationContext struct {
r io.Reader
}
// safety boundary for readBytes
// allocation limit for arrays
const maxReadSize = (1 << 12)
func (d deserializationContext) dump() string {
arr, _ := d.r.(*bufio.Reader).Peek(512)
return fmt.Sprintf("% x", arr)
}
// readBytes reads n bytes.
func (d deserializationContext) readBytes(n int) ([]byte, error) {
if n > maxReadSize {
return nil, fmt.Errorf("over maxReadSize: %d", maxReadSize)
}
b := make([]byte, n)
m, err := d.r.Read(b)
if err != nil {
return b, err
}
if n != m {
return b, fmt.Errorf("expected %d bytes, got %d", n, m)
}
return b[:], nil
}
// readByte reads a single byte.
func (d deserializationContext) readByte() (byte, error) {
arr, err := d.readBytes(1)
if err != nil {
return 0, err
}
return arr[0], nil
}
// readBool reads a boolean.
func (d deserializationContext) readBool() (bool, error) {
arr, err := d.readBytes(1)
if err != nil {
return false, err
}
switch v := arr[0]; v {
case 0x00:
return false, nil
case 0xff:
return true, nil
default:
return false, fmt.Errorf("unexpected value %x", v)
}
}
// readVarUint reads a variable-length uint64.
func (d deserializationContext) readVarUint() (uint64, error) {
// NOTE
// the original python implementation has no uint64 limit, but I
// don't think we'll ever need more that that.
val := uint64(0)
shift := uint(0)
for {
b, err := d.readByte()
if err != nil {
return 0, err
}
shifted := uint64(b&0x7f) << shift
// ghetto overflow check
if (shifted >> shift) != uint64(b&0x7f) {
return 0, fmt.Errorf("uint64 overflow")
}
val |= shifted
if b&0x80 == 0 {
return val, nil
}
shift += 7
}
}
// readVarBytes reads variable-length number of bytes.
func (d deserializationContext) readVarBytes(minLen, maxLen int) ([]byte, error) {
v, err := d.readVarUint()
if err != nil {
return nil, err
}
if v > math.MaxInt32 {
return nil, fmt.Errorf("int overflow")
}
vint := int(v)
if maxLen < vint || vint < minLen {
return nil, fmt.Errorf(
"varbytes length %d outside range (%d, %d)",
vint, minLen, maxLen,
)
}
return d.readBytes(vint)
}
// assertMagic removes reads the expected bytes from the stream. Returns an
// error if the bytes are unexpected.
func (d deserializationContext) assertMagic(expected []byte) error {
arr, err := d.readBytes(len(expected))
if err != nil {
return err
}
if !bytes.Equal(expected, arr) {
return fmt.Errorf(
"magic bytes mismatch, expected % x got % x",
expected, arr,
)
}
return nil
}
// assertEOF reads a byte and returns true if the end of the reader is reached.
// Careful: the read operation is a side-effect.
func (d deserializationContext) assertEOF() bool {
// Unfortunately we can't always do a zero-byte read here, since some
// reader implementations fail to return EOF. This means assertEOF
_, err := d.readByte()
return err == io.EOF
}
// newDeserializationContext returns a deserializationContext for a reader
func newDeserializationContext(r io.Reader) *deserializationContext {
// TODO
// bufio is used here to allow debugging via d.dump()
// once this code here is robust enough we can just pass r
return &deserializationContext{bufio.NewReader(r)}
}

153
serialize_test.go Normal file
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package opentimestamps
import (
"bytes"
"math"
"testing"
"github.com/stretchr/testify/assert"
)
func newDeserializationContextFromBytes(in []byte) *deserializationContext {
return newDeserializationContext(bytes.NewBuffer(in))
}
func TestReadWrite(t *testing.T) {
magic := []byte("magic")
buf := &bytes.Buffer{}
s := newSerializationContext(buf)
assert.NoError(t, s.writeBytes([]byte{0x00, 0x01}))
assert.NoError(t, s.writeByte(0x02))
assert.NoError(t, s.writeBool(true))
assert.NoError(t, s.writeBool(false))
assert.NoError(t, s.writeByte(0x03))
assert.NoError(t, s.writeVarUint(1))
assert.NoError(t, s.writeBytes([]byte{0x81, 0x00}))
assert.NoError(t, s.writeBytes([]byte{0x81, 0x01}))
assert.NoError(t, s.writeVarUint(0x100))
assert.NoError(t, s.writeVarUint(uint64(math.MaxUint32)+1))
assert.NoError(t, s.writeVarUint(math.MaxUint64))
assert.NoError(t, s.writeBytes([]byte{
// varunit excess MaxUint64
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0x01,
}))
assert.NoError(t, s.writeBytes(magic))
assert.NoError(t, s.writeByte(0))
assert.NoError(t, s.writeBytes(magic))
data := buf.Bytes()
expectedData := []byte{
0x00, 0x01, // bytes [0x00, 0x01]
0x02, // byte 0x02
0xff, // bool true
0x00, // bool false
0x03, // bool error
0x01, // varuint 1
0x81, 0x00, // varuint 1
0x81, 0x01, // varuint 1 (alternative)
0x80, 0x02, // varuint 0x100
// varunit math.MaxUint32 + 1
0x80, 0x80, 0x80, 0x80, 0x10,
// varunit math.MaxUint64
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
0xff, 0x01,
// varunit excess math.MaxUint64
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0x01,
// "magic"
0x6d, 0x61, 0x67, 0x69, 0x63,
// zero
0x00,
// "magic"
0x6d, 0x61, 0x67, 0x69, 0x63,
}
assert.Equal(t, expectedData, data)
d := newDeserializationContextFromBytes(data)
{
v, err := d.readBytes(2)
assert.NoError(t, err)
assert.Equal(t, []byte{0x00, 0x01}, v)
}
{
v, err := d.readByte()
assert.NoError(t, err)
assert.Equal(t, byte(0x02), v)
}
{
v, err := d.readBool()
assert.NoError(t, err)
assert.Equal(t, true, v)
}
{
v, err := d.readBool()
assert.NoError(t, err)
assert.Equal(t, false, v)
}
{
_, err := d.readBool()
assert.Error(t, err)
}
{
v, err := d.readVarUint()
assert.NoError(t, err)
assert.Equal(t, uint64(1), v)
}
{
v, err := d.readVarUint()
assert.NoError(t, err)
assert.Equal(t, uint64(1), v)
}
{
v, err := d.readVarUint()
assert.NoError(t, err)
assert.Equal(t, uint64(0x81), v)
}
{
v, err := d.readVarUint()
assert.NoError(t, err)
assert.Equal(t, uint64(0x100), v)
}
{
v, err := d.readVarUint()
assert.NoError(t, err)
assert.Equal(t, uint64(math.MaxUint32)+uint64(1), v)
}
{
v, err := d.readVarUint()
assert.NoError(t, err)
assert.Equal(t, uint64(math.MaxUint64), uint64(v))
}
{
_, err := d.readVarUint()
assert.Error(t, err)
// read leftover 0x02
b, err := d.readByte()
assert.NoError(t, err)
assert.Equal(t, byte(0x01), b)
}
{
assert.NoError(t, d.assertMagic(magic))
// fails because of in-between 0x00
assert.Error(t, d.assertMagic(magic))
}
{
// read leftover byte
_, err := d.readByte()
assert.NoError(t, err)
assert.True(t, d.assertEOF())
}
}

193
timestamp.go Normal file
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package opentimestamps
import (
"bytes"
"fmt"
"io"
"strings"
)
type dumpConfig struct {
showMessage bool
showFlat bool
}
var defaultDumpConfig dumpConfig = dumpConfig{
showMessage: true,
showFlat: false,
}
// A timestampLink with the opCode being the link edge. The reference
// implementation uses a map, but the implementation is a bit complex. A list
// should work as well.
type tsLink struct {
opCode opCode
timestamp *Timestamp
}
// A Timestamp can contain many attestations and operations.
type Timestamp struct {
Message []byte
Attestations []Attestation
ops []tsLink
}
// Walk calls the passed function f for this timestamp and all
// downstream timestamps that are chained via operations.
func (t *Timestamp) Walk(f func(t *Timestamp)) {
f(t)
for _, l := range t.ops {
l.timestamp.Walk(f)
}
}
func (t *Timestamp) encode(ctx *serializationContext) error {
n := len(t.Attestations) + len(t.ops)
if n == 0 {
return fmt.Errorf("cannot encode empty timestamp")
}
prefixAtt := []byte{0x00}
prefixOp := []byte{}
nextNode := func(prefix []byte) error {
n -= 1
if n > 0 {
return ctx.writeByte(0xff)
}
if len(prefix) > 0 {
return ctx.writeBytes(prefix)
}
return nil
}
// FIXME attestations should be sorted
for _, att := range t.Attestations {
if err := nextNode(prefixAtt); err != nil {
return err
}
if err := encodeAttestation(ctx, att); err != nil {
return err
}
}
// FIXME ops should be sorted
for _, op := range t.ops {
if err := nextNode(prefixOp); err != nil {
return err
}
if err := op.opCode.encode(ctx); err != nil {
return err
}
if err := op.timestamp.encode(ctx); err != nil {
return err
}
}
return nil
}
func (t *Timestamp) DumpIndent(w io.Writer, indent int, cfg dumpConfig) {
if cfg.showMessage {
fmt.Fprintf(w, strings.Repeat(" ", indent))
fmt.Fprintf(w, "message %x\n", t.Message)
}
for _, att := range t.Attestations {
fmt.Fprint(w, strings.Repeat(" ", indent))
fmt.Fprintln(w, att)
}
for _, tsLink := range t.ops {
fmt.Fprint(w, strings.Repeat(" ", indent))
fmt.Fprintln(w, tsLink.opCode)
// fmt.Fprint(w, strings.Repeat(" ", indent))
// if the timestamp is indeed tree-shaped, show it like that
if !cfg.showFlat || len(t.ops) > 1 {
indent += 1
}
tsLink.timestamp.DumpIndent(w, indent, cfg)
}
}
func (t *Timestamp) DumpWithConfig(cfg dumpConfig) string {
b := &bytes.Buffer{}
t.DumpIndent(b, 0, cfg)
return b.String()
}
func (t *Timestamp) Dump() string {
return t.DumpWithConfig(defaultDumpConfig)
}
func parseTagOrAttestation(
ts *Timestamp,
ctx *deserializationContext,
tag byte,
message []byte,
limit int,
) error {
if tag == 0x00 {
a, err := ParseAttestation(ctx)
if err != nil {
return err
}
ts.Attestations = append(ts.Attestations, a)
} else {
op, err := parseOp(ctx, tag)
if err != nil {
return err
}
newMessage, err := op.apply(message)
if err != nil {
return err
}
nextTs := &Timestamp{Message: newMessage}
err = parse(nextTs, ctx, newMessage, limit-1)
if err != nil {
return err
}
ts.ops = append(ts.ops, tsLink{op, nextTs})
}
return nil
}
func parse(
ts *Timestamp, ctx *deserializationContext, message []byte, limit int,
) error {
if limit == 0 {
return fmt.Errorf("recursion limit")
}
var tag byte
var err error
for {
tag, err = ctx.readByte()
if err != nil {
return err
}
if tag == 0xff {
tag, err = ctx.readByte()
if err != nil {
return err
}
err := parseTagOrAttestation(ts, ctx, tag, message, limit)
if err != nil {
return err
}
} else {
break
}
}
return parseTagOrAttestation(ts, ctx, tag, message, limit)
}
func newTimestampFromContext(
ctx *deserializationContext, message []byte,
) (*Timestamp, error) {
recursionLimit := 1000
ts := &Timestamp{Message: message}
err := parse(ts, ctx, message, recursionLimit)
if err != nil {
return nil, err
}
return ts, nil
}
func NewTimestampFromReader(r io.Reader, message []byte) (*Timestamp, error) {
return newTimestampFromContext(newDeserializationContext(r), message)
}

11
util.go Normal file
View File

@@ -0,0 +1,11 @@
package opentimestamps
import "encoding/hex"
func mustDecodeHex(in string) []byte {
out, err := hex.DecodeString(in)
if err != nil {
panic(err)
}
return out
}