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core/secp256k1: update libsecp256k1 Go wrapper and tests

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pull/1853/head
Gustav Simonsson 9 years ago
parent 1d20b0247c
commit f32fa075f1
3 changed files with 256 additions and 249 deletions
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  1. 10
      crypto/crypto.go
  2. 190
      crypto/secp256k1/secp256.go
  3. 283
      crypto/secp256k1/secp256_test.go

10
crypto/crypto.go
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@ -198,7 +198,9 @@ func Sign(hash []byte, prv *ecdsa.PrivateKey) (sig []byte, err error) {
return nil, fmt.Errorf("hash is required to be exactly 32 bytes (%d)", len(hash))
}
sig, err = secp256k1.Sign(hash, common.LeftPadBytes(prv.D.Bytes(), prv.Params().BitSize/8))
seckey := common.LeftPadBytes(prv.D.Bytes(), prv.Params().BitSize/8)
defer zeroBytes(seckey)
sig, err = secp256k1.Sign(hash, seckey)
return
}
@ -337,3 +339,9 @@ func PubkeyToAddress(p ecdsa.PublicKey) common.Address {
pubBytes := FromECDSAPub(&p)
return common.BytesToAddress(Sha3(pubBytes[1:])[12:])
}
func zeroBytes(bytes []byte) {
for i := range bytes {
bytes[i] = 0
}
}

190
crypto/secp256k1/secp256.go
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@ -19,7 +19,7 @@ package secp256k1
// TODO: set USE_SCALAR_4X64 depending on platform?
/*
#cgo CFLAGS: -I./secp256k1
#cgo CFLAGS: -I./libsecp256k1
#cgo darwin CFLAGS: -I/usr/local/include
#cgo freebsd CFLAGS: -I/usr/local/include
#cgo linux,arm CFLAGS: -I/usr/local/arm/include
@ -33,7 +33,8 @@ package secp256k1
#define USE_SCALAR_8X32
#define USE_SCALAR_INV_BUILTIN
#define NDEBUG
#include "./secp256k1/src/secp256k1.c"
#include "./libsecp256k1/src/secp256k1.c"
#include "./libsecp256k1/src/modules/recovery/main_impl.h"
*/
import "C"
@ -48,48 +49,51 @@ import (
//#define USE_FIELD_5X64
/*
Todo:
> Centralize key management in module
> add pubkey/private key struct
> Dont let keys leave module; address keys as ints
TODO:
> store private keys in buffer and shuffle (deters persistance on swap disc)
> Byte permutation (changing)
> byte permutation (changing)
> xor with chaning random block (to deter scanning memory for 0x63) (stream cipher?)
On Disk
> Store keys in wallets
> use slow key derivation function for wallet encryption key (2 seconds)
> on disk: store keys in wallets
*/
func init() {
//takes 10ms to 100ms
C.secp256k1_start(3) // SECP256K1_START_SIGN | SECP256K1_START_VERIFY
}
// holds ptr to secp256k1_context_struct (see secp256k1/include/secp256k1.h)
var context *C.secp256k1_context
func Stop() {
C.secp256k1_stop()
func init() {
// around 20 ms on a modern CPU.
context = C.secp256k1_context_create(3) // SECP256K1_START_SIGN | SECP256K1_START_VERIFY
}
func GenerateKeyPair() ([]byte, []byte) {
pubkey_len := C.int(65)
const seckey_len = 32
var pubkey []byte = make([]byte, pubkey_len)
var seckey []byte = randentropy.GetEntropyCSPRNG(seckey_len)
var pubkey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&pubkey[0]))
var seckey []byte = randentropy.GetEntropyCSPRNG(32)
var seckey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&seckey[0]))
var pubkey64 []byte = make([]byte, 64) // secp256k1_pubkey
var pubkey65 []byte = make([]byte, 65) // 65 byte uncompressed pubkey
pubkey64_ptr := (*C.secp256k1_pubkey)(unsafe.Pointer(&pubkey64[0]))
pubkey65_ptr := (*C.uchar)(unsafe.Pointer(&pubkey65[0]))
ret := C.secp256k1_ec_pubkey_create(
pubkey_ptr, &pubkey_len,
seckey_ptr, 0)
context,
pubkey64_ptr,
seckey_ptr,
)
if ret != C.int(1) {
return GenerateKeyPair() // invalid secret, try again
}
return pubkey, seckey
var output_len C.size_t
C.secp256k1_ec_pubkey_serialize( // always returns 1
context,
pubkey65_ptr,
&output_len,
pubkey64_ptr,
0, // SECP256K1_EC_COMPRESSED
)
return pubkey65, seckey
}
func GeneratePubKey(seckey []byte) ([]byte, error) {
@ -97,17 +101,16 @@ func GeneratePubKey(seckey []byte) ([]byte, error) {
return nil, err
}
pubkey_len := C.int(65)
const seckey_len = 32
var pubkey []byte = make([]byte, pubkey_len)
var pubkey []byte = make([]byte, 64)
var pubkey_ptr *C.secp256k1_pubkey = (*C.secp256k1_pubkey)(unsafe.Pointer(&pubkey[0]))
var pubkey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&pubkey[0]))
var seckey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&seckey[0]))
ret := C.secp256k1_ec_pubkey_create(
pubkey_ptr, &pubkey_len,
seckey_ptr, 0)
context,
pubkey_ptr,
seckey_ptr,
)
if ret != C.int(1) {
return nil, errors.New("Unable to generate pubkey from seckey")
@ -117,38 +120,48 @@ func GeneratePubKey(seckey []byte) ([]byte, error) {
}
func Sign(msg []byte, seckey []byte) ([]byte, error) {
nonce := randentropy.GetEntropyCSPRNG(32)
msg_ptr := (*C.uchar)(unsafe.Pointer(&msg[0]))
seckey_ptr := (*C.uchar)(unsafe.Pointer(&seckey[0]))
var sig []byte = make([]byte, 65)
var recid C.int
sig := make([]byte, 65)
sig_ptr := (*C.secp256k1_ecdsa_recoverable_signature)(unsafe.Pointer(&sig[0]))
var msg_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&msg[0]))
var sig_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&sig[0]))
var seckey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&seckey[0]))
nonce := randentropy.GetEntropyCSPRNG(32)
ndata_ptr := unsafe.Pointer(&nonce[0])
var noncefp_ptr = &(*C.secp256k1_nonce_function_default)
var ndata_ptr = unsafe.Pointer(&nonce[0])
noncefp_ptr := &(*C.secp256k1_nonce_function_default)
if C.secp256k1_ec_seckey_verify(seckey_ptr) != C.int(1) {
if C.secp256k1_ec_seckey_verify(context, seckey_ptr) != C.int(1) {
return nil, errors.New("Invalid secret key")
}
ret := C.secp256k1_ecdsa_sign_compact(
msg_ptr,
ret := C.secp256k1_ecdsa_sign_recoverable(
context,
sig_ptr,
msg_ptr,
seckey_ptr,
noncefp_ptr,
ndata_ptr,
&recid)
sig[64] = byte(int(recid))
)
if ret != C.int(1) {
// nonce invalid, retry
return Sign(msg, seckey)
if ret == C.int(0) {
return Sign(msg, seckey) //invalid secret, try again
}
return sig, nil
sig_serialized := make([]byte, 65)
sig_serialized_ptr := (*C.uchar)(unsafe.Pointer(&sig_serialized[0]))
var recid C.int
C.secp256k1_ecdsa_recoverable_signature_serialize_compact(
context,
sig_serialized_ptr, // 64 byte compact signature
&recid,
sig_ptr, // 65 byte "recoverable" signature
)
sig_serialized[64] = byte(int(recid)) // add back recid to get 65 bytes sig
return sig_serialized, nil
}
@ -157,26 +170,13 @@ func VerifySeckeyValidity(seckey []byte) error {
return errors.New("priv key is not 32 bytes")
}
var seckey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&seckey[0]))
ret := C.secp256k1_ec_seckey_verify(seckey_ptr)
ret := C.secp256k1_ec_seckey_verify(context, seckey_ptr)
if int(ret) != 1 {
return errors.New("invalid seckey")
}
return nil
}
func VerifyPubkeyValidity(pubkey []byte) error {
if len(pubkey) != 65 {
return errors.New("pub key is not 65 bytes")
}
var pubkey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&pubkey[0]))
ret := C.secp256k1_ec_pubkey_verify(pubkey_ptr, 65)
if int(ret) != 1 {
return errors.New("invalid pubkey")
}
return nil
}
func VerifySignatureValidity(sig []byte) bool {
//64+1
if len(sig) != 65 {
@ -231,36 +231,58 @@ func VerifySignature(msg []byte, sig []byte, pubkey1 []byte) error {
return nil
}
//recovers the public key from the signature
//recovery of pubkey means correct signature
// recovers a public key from the signature
func RecoverPubkey(msg []byte, sig []byte) ([]byte, error) {
if len(sig) != 65 {
return nil, errors.New("Invalid signature length")
}
var pubkey []byte = make([]byte, 65)
msg_ptr := (*C.uchar)(unsafe.Pointer(&msg[0]))
sig_ptr := (*C.uchar)(unsafe.Pointer(&sig[0]))
var msg_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&msg[0]))
var sig_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&sig[0]))
var pubkey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&pubkey[0]))
pubkey := make([]byte, 64)
/*
this slice is used for both the recoverable signature and the
resulting serialized pubkey (both types in libsecp256k1 are 65
bytes). this saves one allocation of 65 bytes, which is nice as
pubkey recovery is one bottleneck during load in Ethereum
*/
bytes65 := make([]byte, 65)
var pubkeylen C.int
pubkey_ptr := (*C.secp256k1_pubkey)(unsafe.Pointer(&pubkey[0]))
recoverable_sig_ptr := (*C.secp256k1_ecdsa_recoverable_signature)(unsafe.Pointer(&bytes65[0]))
ret := C.secp256k1_ecdsa_recover_compact(
msg_ptr,
recid := C.int(sig[64])
ret := C.secp256k1_ecdsa_recoverable_signature_parse_compact(
context,
recoverable_sig_ptr,
sig_ptr,
recid)
if ret == C.int(0) {
return nil, errors.New("Failed to parse signature")
}
ret = C.secp256k1_ecdsa_recover(
context,
pubkey_ptr,
&pubkeylen,
C.int(0),
C.int(sig[64]),
recoverable_sig_ptr,
msg_ptr,
)
if ret == C.int(0) {
return nil, errors.New("Failed to recover public key")
} else if pubkeylen != C.int(65) {
return nil, errors.New("Impossible Error: Invalid recovered public key length")
} else {
return pubkey, nil
serialized_pubkey_ptr := (*C.uchar)(unsafe.Pointer(&bytes65[0]))
var output_len C.size_t
C.secp256k1_ec_pubkey_serialize( // always returns 1
context,
serialized_pubkey_ptr,
&output_len,
pubkey_ptr,
0, // SECP256K1_EC_COMPRESSED
)
return bytes65, nil
}
return nil, errors.New("Impossible Error: func RecoverPubkey has reached an unreachable state")
}

283
crypto/secp256k1/secp256_test.go
Unescape View File

@ -18,168 +18,129 @@ package secp256k1
import (
"bytes"
"fmt"
"log"
"encoding/hex"
"testing"
"github.com/ethereum/go-ethereum/crypto/randentropy"
)
const TESTS = 10000 // how many tests
const SigSize = 65 //64+1
const TestCount = 10000
func Test_Secp256_00(t *testing.T) {
var nonce []byte = randentropy.GetEntropyCSPRNG(32) //going to get bitcoins stolen!
if len(nonce) != 32 {
t.Fatal()
}
}
//tests for Malleability
//highest bit of S must be 0; 32nd byte
func CompactSigTest(sig []byte) {
var b int = int(sig[32])
if b < 0 {
log.Panic()
}
if ((b >> 7) == 1) != ((b & 0x80) == 0x80) {
log.Panic("b= %v b2= %v \n", b, b>>7)
}
if (b & 0x80) == 0x80 {
log.Panic("b= %v b2= %v \n", b, b&0x80)
}
}
//test pubkey/private generation
func Test_Secp256_01(t *testing.T) {
pubkey, seckey := GenerateKeyPair()
func TestPrivkeyGenerate(t *testing.T) {
_, seckey := GenerateKeyPair()
if err := VerifySeckeyValidity(seckey); err != nil {
t.Fatal()
}
if err := VerifyPubkeyValidity(pubkey); err != nil {
t.Fatal()
t.Errorf("seckey not valid: %s", err)
}
}
//test size of messages
func Test_Secp256_02s(t *testing.T) {
func TestSignatureValidity(t *testing.T) {
pubkey, seckey := GenerateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
sig, _ := Sign(msg, seckey)
CompactSigTest(sig)
if sig == nil {
t.Fatal("Signature nil")
sig, err := Sign(msg, seckey)
if err != nil {
t.Errorf("signature error: %s", err)
}
compactSigCheck(t, sig)
if len(pubkey) != 65 {
t.Fail()
t.Errorf("pubkey length mismatch: want: 65 have: %d", len(pubkey))
}
if len(seckey) != 32 {
t.Fail()
t.Errorf("seckey length mismatch: want: 32 have: %d", len(seckey))
}
if len(sig) != 65 {
t.Errorf("sig length mismatch: want: 65 have: %d", len(sig))
}
if len(sig) != 64+1 {
t.Fail()
recid := int(sig[64])
if recid > 4 || recid < 0 {
t.Errorf("sig recid mismatch: want: within 0 to 4 have: %d", int(sig[64]))
}
if int(sig[64]) > 4 {
t.Fail()
} //should be 0 to 4
}
//test signing message
func Test_Secp256_02(t *testing.T) {
func TestSignAndRecover(t *testing.T) {
pubkey1, seckey := GenerateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
sig, _ := Sign(msg, seckey)
if sig == nil {
t.Fatal("Signature nil")
sig, err := Sign(msg, seckey)
if err != nil {
t.Errorf("signature error: %s", err)
}
pubkey2, _ := RecoverPubkey(msg, sig)
if pubkey2 == nil {
t.Fatal("Recovered pubkey invalid")
pubkey2, err := RecoverPubkey(msg, sig)
if err != nil {
t.Errorf("recover error: %s", err)
}
if bytes.Equal(pubkey1, pubkey2) == false {
t.Fatal("Recovered pubkey does not match")
if !bytes.Equal(pubkey1, pubkey2) {
t.Errorf("pubkey mismatch: want: %x have: %x", pubkey1, pubkey2)
}
err := VerifySignature(msg, sig, pubkey1)
err = VerifySignature(msg, sig, pubkey1)
if err != nil {
t.Fatal("Signature invalid")
t.Errorf("signature verification error: %s", err)
}
}
//test pubkey recovery
func Test_Secp256_02a(t *testing.T) {
pubkey1, seckey1 := GenerateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
sig, _ := Sign(msg, seckey1)
if sig == nil {
t.Fatal("Signature nil")
func TestRandomMessagesWithSameKey(t *testing.T) {
pubkey, seckey := GenerateKeyPair()
keys := func() ([]byte, []byte) {
// Sign function zeroes the privkey so we need a new one in each call
newkey := make([]byte, len(seckey))
copy(newkey, seckey)
return pubkey, newkey
}
err := VerifySignature(msg, sig, pubkey1)
if err != nil {
t.Fatal("Signature invalid")
signAndRecoverWithRandomMessages(t, keys)
}
pubkey2, _ := RecoverPubkey(msg, sig)
if len(pubkey1) != len(pubkey2) {
t.Fatal()
}
for i, _ := range pubkey1 {
if pubkey1[i] != pubkey2[i] {
t.Fatal()
}
}
if bytes.Equal(pubkey1, pubkey2) == false {
t.Fatal()
func TestRandomMessagesWithRandomKeys(t *testing.T) {
keys := func() ([]byte, []byte) {
pubkey, seckey := GenerateKeyPair()
return pubkey, seckey
}
signAndRecoverWithRandomMessages(t, keys)
}
//test random messages for the same pub/private key
func Test_Secp256_03(t *testing.T) {
_, seckey := GenerateKeyPair()
for i := 0; i < TESTS; i++ {
func signAndRecoverWithRandomMessages(t *testing.T, keys func() ([]byte, []byte)) {
for i := 0; i < TestCount; i++ {
pubkey1, seckey := keys()
msg := randentropy.GetEntropyCSPRNG(32)
sig, _ := Sign(msg, seckey)
CompactSigTest(sig)
sig, err := Sign(msg, seckey)
if err != nil {
t.Fatalf("signature error: %s", err)
}
if sig == nil {
t.Fatal("signature is nil")
}
compactSigCheck(t, sig)
// TODO: why do we flip around the recovery id?
sig[len(sig)-1] %= 4
pubkey2, _ := RecoverPubkey(msg, sig)
pubkey2, err := RecoverPubkey(msg, sig)
if err != nil {
t.Fatalf("recover error: %s", err)
}
if pubkey2 == nil {
t.Fail()
t.Error("pubkey is nil")
}
if !bytes.Equal(pubkey1, pubkey2) {
t.Fatalf("pubkey mismatch: want: %x have: %x", pubkey1, pubkey2)
}
}
}
//test random messages for different pub/private keys
func Test_Secp256_04(t *testing.T) {
for i := 0; i < TESTS; i++ {
func TestRecoveryOfRandomSignature(t *testing.T) {
pubkey1, seckey := GenerateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
sig, _ := Sign(msg, seckey)
CompactSigTest(sig)
if sig[len(sig)-1] >= 4 {
t.Fail()
sig, err := Sign(msg, seckey)
if err != nil {
t.Errorf("signature error: %s", err)
}
for i := 0; i < TestCount; i++ {
sig = randSig()
pubkey2, _ := RecoverPubkey(msg, sig)
if pubkey2 == nil {
t.Fail()
// recovery can sometimes work, but if so should always give wrong pubkey
if bytes.Equal(pubkey1, pubkey2) {
t.Fatalf("iteration: %d: pubkey mismatch: do NOT want %x: ", i, pubkey2)
}
if bytes.Equal(pubkey1, pubkey2) == false {
t.Fail()
}
}
}
//test random signatures against fixed messages; should fail
//crashes:
// -SIPA look at this
func randSig() []byte {
sig := randentropy.GetEntropyCSPRNG(65)
@ -188,67 +149,83 @@ func randSig() []byte {
return sig
}
func Test_Secp256_06a_alt0(t *testing.T) {
func TestRandomMessagesAgainstValidSig(t *testing.T) {
pubkey1, seckey := GenerateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
sig, _ := Sign(msg, seckey)
if sig == nil {
t.Fail()
for i := 0; i < TestCount; i++ {
msg = randentropy.GetEntropyCSPRNG(32)
pubkey2, _ := RecoverPubkey(msg, sig)
// recovery can sometimes work, but if so should always give wrong pubkey
if bytes.Equal(pubkey1, pubkey2) {
t.Fatalf("iteration: %d: pubkey mismatch: do NOT want %x: ", i, pubkey2)
}
if len(sig) != 65 {
t.Fail()
}
for i := 0; i < TESTS; i++ {
sig = randSig()
pubkey2, _ := RecoverPubkey(msg, sig)
if bytes.Equal(pubkey1, pubkey2) == true {
t.Fail()
}
if pubkey2 != nil && VerifySignature(msg, sig, pubkey2) != nil {
t.Fail()
func TestZeroPrivkey(t *testing.T) {
zeroedBytes := make([]byte, 32)
err := VerifySeckeyValidity(zeroedBytes)
if err == nil {
t.Errorf("zeroed bytes should have returned error")
}
}
if VerifySignature(msg, sig, pubkey1) == nil {
t.Fail()
// Useful when the underlying libsecp256k1 API changes to quickly
// check only recover function without use of signature function
func TestRecoverSanity(t *testing.T) {
msg, _ := hex.DecodeString("ce0677bb30baa8cf067c88db9811f4333d131bf8bcf12fe7065d211dce971008")
sig, _ := hex.DecodeString("90f27b8b488db00b00606796d2987f6a5f59ae62ea05effe84fef5b8b0e549984a691139ad57a3f0b906637673aa2f63d1f55cb1a69199d4009eea23ceaddc9301")
pubkey1, _ := hex.DecodeString("04e32df42865e97135acfb65f3bae71bdc86f4d49150ad6a440b6f15878109880a0a2b2667f7e725ceea70c673093bf67663e0312623c8e091b13cf2c0f11ef652")
pubkey2, err := RecoverPubkey(msg, sig)
if err != nil {
t.Fatalf("recover error: %s", err)
}
if !bytes.Equal(pubkey1, pubkey2) {
t.Errorf("pubkey mismatch: want: %x have: %x", pubkey1, pubkey2)
}
}
//test random messages against valid signature: should fail
func Test_Secp256_06b(t *testing.T) {
pubkey1, seckey := GenerateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
sig, _ := Sign(msg, seckey)
fail_count := 0
for i := 0; i < TESTS; i++ {
msg = randentropy.GetEntropyCSPRNG(32)
pubkey2, _ := RecoverPubkey(msg, sig)
if bytes.Equal(pubkey1, pubkey2) == true {
t.Fail()
// tests for malleability
// highest bit of signature ECDSA s value must be 0, in the 33th byte
func compactSigCheck(t *testing.T, sig []byte) {
var b int = int(sig[32])
if b < 0 {
t.Errorf("highest bit is negative: %d", b)
}
if pubkey2 != nil && VerifySignature(msg, sig, pubkey2) != nil {
t.Fail()
if ((b >> 7) == 1) != ((b & 0x80) == 0x80) {
t.Errorf("highest bit: %d bit >> 7: %d", b, b>>7)
}
if (b & 0x80) == 0x80 {
t.Errorf("highest bit: %d bit & 0x80: %d", b, b&0x80)
}
if VerifySignature(msg, sig, pubkey1) == nil {
t.Fail()
}
// godep go test -v -run=XXX -bench=BenchmarkSignRandomInputEachRound
// add -benchtime=10s to benchmark longer for more accurate average
func BenchmarkSignRandomInputEachRound(b *testing.B) {
for i := 0; i < b.N; i++ {
b.StopTimer()
_, seckey := GenerateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
b.StartTimer()
if _, err := Sign(msg, seckey); err != nil {
b.Fatal(err)
}
if fail_count != 0 {
fmt.Printf("ERROR: Accepted signature for %v of %v random messages\n", fail_count, TESTS)
}
}
func TestInvalidKey(t *testing.T) {
p1 := make([]byte, 32)
err := VerifySeckeyValidity(p1)
if err == nil {
t.Errorf("pvk %x varify sec key should have returned error", p1)
//godep go test -v -run=XXX -bench=BenchmarkRecoverRandomInputEachRound
func BenchmarkRecoverRandomInputEachRound(b *testing.B) {
for i := 0; i < b.N; i++ {
b.StopTimer()
_, seckey := GenerateKeyPair()
msg := randentropy.GetEntropyCSPRNG(32)
sig, _ := Sign(msg, seckey)
b.StartTimer()
if _, err := RecoverPubkey(msg, sig); err != nil {
b.Fatal(err)
}
}
}

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