// This example demonstrates decrypting a message using a private key that is
// first parsed from raw bytes.
func Example_decryptMessage() {
// Decode the hex-encoded private key.
pkBytes, err := hex.DecodeString("a11b0a4e1a132305652ee7a8eb7848f6ad" +
"5ea381e3ce20a2c086a2e388230811")
if err != nil {
fmt.Println(err)
return
}
privKey, _ := secp256k1.PrivKeyFromBytes(secp256k1.S256(), pkBytes)
ciphertext, err := hex.DecodeString("35f644fbfb208bc71e57684c3c8b437402ca" +
"002047a2f1b38aa1a8f1d5121778378414f708fe13ebf7b4a7bb74407288c1958969" +
"00207cf4ac6057406e40f79961c973309a892732ae7a74ee96cd89823913b8b8d650" +
"a44166dc61ea1c419d47077b748a9c06b8d57af72deb2819d98a9d503efc59fc8307" +
"d14174f8b83354fac3ff56075162")
// Try decrypting the message.
plaintext, err := secp256k1.Decrypt(privKey, ciphertext)
if err != nil {
fmt.Println(err)
return
}
fmt.Println(string(plaintext))
// Output:
// test message
}
// This example demonstrates signing a message with a secp256k1 private key that
// is first parsed form raw bytes and serializing the generated signature.
func Example_signMessage() {
// Decode a hex-encoded private key.
pkBytes, err := hex.DecodeString("22a47fa09a223f2aa079edf85a7c2d4f87" +
"20ee63e502ee2869afab7de234b80c")
if err != nil {
fmt.Println(err)
return
}
privKey, pubKey := secp256k1.PrivKeyFromBytes(secp256k1.S256(), pkBytes)
// Sign a message using the private key.
message := "test message"
messageHash := chainhash.HashFuncB([]byte(message))
signature, err := privKey.Sign(messageHash)
if err != nil {
fmt.Println(err)
return
}
// Serialize and display the signature.
fmt.Printf("Serialized Signature: %x\n", signature.Serialize())
// Verify the signature for the message using the public key.
verified := signature.Verify(messageHash, pubKey)
fmt.Printf("Signature Verified? %v\n", verified)
// Output:
// Serialized Signature: 3045022100fcc0a8768cfbcefcf2cadd7cfb0fb18ed08dd2e2ae84bef1a474a3d351b26f0302200fc1a350b45f46fa00101391302818d748c2b22615511a3ffd5bb638bd777207
// Signature Verified? true
}
func randPrivKeyList(curve *secp256k1.KoblitzCurve,
i int) []*secp256k1.PrivateKey {
r := rand.New(rand.NewSource(54321))
privKeyList := make([]*secp256k1.PrivateKey, i, i)
for j := 0; j < i; j++ {
for {
bIn := new([32]byte)
for k := 0; k < scalarSize; k++ {
randByte := r.Intn(255)
bIn[k] = uint8(randByte)
}
pks, _ := secp256k1.PrivKeyFromBytes(curve, bIn[:])
if pks == nil {
continue
}
// No duplicates allowed.
if j > 0 &&
(bytes.Equal(pks.Serialize(), privKeyList[j-1].Serialize())) {
r.Seed(int64(j) + r.Int63n(12345))
continue
}
privKeyList[j] = pks
r.Seed(int64(j) + 54321)
break
}
}
return privKeyList
}
func randSigList(curve *secp256k1.KoblitzCurve, i int) []*SignatureVerParams {
r := rand.New(rand.NewSource(54321))
privKeyList := make([]*secp256k1.PrivateKey, i, i)
for j := 0; j < i; j++ {
for {
bIn := new([32]byte)
for k := 0; k < scalarSize; k++ {
randByte := r.Intn(255)
bIn[k] = uint8(randByte)
}
pks, _ := secp256k1.PrivKeyFromBytes(curve, bIn[:])
if pks == nil {
continue
}
privKeyList[j] = pks
r.Seed(int64(j) + 54321)
break
}
}
msgList := make([][]byte, i, i)
for j := 0; j < i; j++ {
m := make([]byte, 32, 32)
for k := 0; k < scalarSize; k++ {
randByte := r.Intn(255)
m[k] = uint8(randByte)
}
msgList[j] = m
r.Seed(int64(j) + 54321)
}
sigsList := make([]*Signature, i, i)
for j := 0; j < i; j++ {
r, s, err := Sign(curve, privKeyList[j], msgList[j])
if err != nil {
panic("sign failure")
}
sig := &Signature{r, s}
sigsList[j] = sig
}
sigStructList := make([]*SignatureVerParams, i, i)
for j := 0; j < i; j++ {
ss := new(SignatureVerParams)
pkx, pky := privKeyList[j].Public()
ss.pubkey = secp256k1.NewPublicKey(curve, pkx, pky)
ss.msg = msgList[j]
ss.sig = sigsList[j]
sigStructList[j] = ss
}
return sigStructList
}
func GetThresholdTestVectors() []*ThresholdTestVector {
curve := secp256k1.S256()
var tvs []*ThresholdTestVector
for _, v := range thresholdTestVectorsHex {
msg, _ := hex.DecodeString(v.msg)
combSig, _ := hex.DecodeString(v.combinedSignature)
signers := make([]signer, len(v.signersHex), len(v.signersHex))
for i, signerHex := range v.signersHex {
privkeyB, _ := hex.DecodeString(signerHex.privkey)
_, pubkey := secp256k1.PrivKeyFromBytes(curve, privkeyB)
privateNonceB, _ := hex.DecodeString(signerHex.privateNonce)
_, noncePub := secp256k1.PrivKeyFromBytes(curve, privateNonceB)
pubKeySumLocalB, _ := hex.DecodeString(signerHex.pubKeySumLocal)
pubKeySumLocal, _ := secp256k1.ParsePubKey(pubKeySumLocalB, curve)
partialSignature, _ := hex.DecodeString(signerHex.partialSignature)
signers[i].privkey = privkeyB
signers[i].pubkey = pubkey
signers[i].privateNonce = privateNonceB
signers[i].publicNonce = noncePub
signers[i].pubKeySumLocal = pubKeySumLocal
signers[i].partialSignature = partialSignature
}
lv := ThresholdTestVector{
msg: msg,
signers: signers,
combinedSignature: combSig,
}
tvs = append(tvs, &lv)
}
return tvs
}
func TestSchnorrSigning(t *testing.T) {
tRand := rand.New(rand.NewSource(54321))
curve := secp256k1.S256()
tvs := GetSigningTestVectors()
for _, tv := range tvs {
_, pubkey := secp256k1.PrivKeyFromBytes(curve, tv.priv)
sig, err :=
schnorrSign(curve, tv.msg, tv.priv, tv.nonce, nil, nil,
testSchnorrHash)
assert.NoError(t, err)
assert.Equal(t, sig.Serialize(), tv.sig)
// Make sure they verify too while we're at it.
_, err = schnorrVerify(curve, sig.Serialize(), pubkey, tv.msg,
testSchnorrHash)
assert.NoError(t, err)
// See if we can recover the public keys OK.
var pkRecover *secp256k1.PublicKey
pkRecover, _, err = schnorrRecover(curve, sig.Serialize(), tv.msg,
testSchnorrHash)
assert.NoError(t, err)
if err == nil {
assert.Equal(t, pubkey.Serialize(), pkRecover.Serialize())
}
// Screw up the signature at a random bit and make sure that breaks it.
sigBad := sig.Serialize()
pos := tRand.Intn(63)
bitPos := tRand.Intn(7)
sigBad[pos] ^= 1 << uint8(bitPos)
_, err = schnorrVerify(curve, sigBad, pubkey, tv.msg,
testSchnorrHash)
assert.Error(t, err)
// Make sure it breaks pubkey recovery too.
valid := false
pkRecover, valid, err = schnorrRecover(curve, sigBad, tv.msg,
testSchnorrHash)
if valid {
assert.NotEqual(t, pubkey.Serialize(), pkRecover.Serialize())
} else {
assert.Error(t, err)
}
}
}
// This example demonstrates encrypting a message for a public key that is first
// parsed from raw bytes, then decrypting it using the corresponding private key.
func Example_encryptMessage() {
// Decode the hex-encoded pubkey of the recipient.
pubKeyBytes, err := hex.DecodeString("04115c42e757b2efb7671c578530ec191a1" +
"359381e6a71127a9d37c486fd30dae57e76dc58f693bd7e7010358ce6b165e483a29" +
"21010db67ac11b1b51b651953d2") // uncompressed pubkey
if err != nil {
fmt.Println(err)
return
}
pubKey, err := secp256k1.ParsePubKey(pubKeyBytes, secp256k1.S256())
if err != nil {
fmt.Println(err)
return
}
// Encrypt a message decryptable by the private key corresponding to pubKey
message := "test message"
ciphertext, err := secp256k1.Encrypt(pubKey, []byte(message))
if err != nil {
fmt.Println(err)
return
}
// Decode the hex-encoded private key.
pkBytes, err := hex.DecodeString("a11b0a4e1a132305652ee7a8eb7848f6ad" +
"5ea381e3ce20a2c086a2e388230811")
if err != nil {
fmt.Println(err)
return
}
// note that we already have corresponding pubKey
privKey, _ := secp256k1.PrivKeyFromBytes(secp256k1.S256(), pkBytes)
// Try decrypting and verify if it's the same message.
plaintext, err := secp256k1.Decrypt(privKey, ciphertext)
if err != nil {
fmt.Println(err)
return
}
fmt.Println(string(plaintext))
// Output:
// test message
}
func TestPrivKeys(t *testing.T) {
tests := []struct {
name string
key []byte
}{
{
name: "check curve",
key: []byte{
0xea, 0xf0, 0x2c, 0xa3, 0x48, 0xc5, 0x24, 0xe6,
0x39, 0x26, 0x55, 0xba, 0x4d, 0x29, 0x60, 0x3c,
0xd1, 0xa7, 0x34, 0x7d, 0x9d, 0x65, 0xcf, 0xe9,
0x3c, 0xe1, 0xeb, 0xff, 0xdc, 0xa2, 0x26, 0x94,
},
},
}
for _, test := range tests {
priv, pub := secp256k1.PrivKeyFromBytes(secp256k1.S256(), test.key)
_, err := secp256k1.ParsePubKey(
pub.SerializeUncompressed(), secp256k1.S256())
if err != nil {
t.Errorf("%s privkey: %v", test.name, err)
continue
}
hash := []byte{0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9}
sig, err := priv.Sign(hash)
if err != nil {
t.Errorf("%s could not sign: %v", test.name, err)
continue
}
if !sig.Verify(hash, pub) {
t.Errorf("%s could not verify: %v", test.name, err)
continue
}
serializedKey := priv.Serialize()
if !bytes.Equal(serializedKey, test.key) {
t.Errorf("%s unexpected serialized bytes - got: %x, "+
"want: %x", test.name, serializedKey, test.key)
}
}
}
// Test 2: Byte compatibility with Pyelliptic
func TestCiphering(t *testing.T) {
pb, _ := hex.DecodeString("fe38240982f313ae5afb3e904fb8215fb11af1200592b" +
"fca26c96c4738e4bf8f")
privkey, _ := secp256k1.PrivKeyFromBytes(secp256k1.S256(), pb)
in := []byte("This is just a test.")
out, _ := hex.DecodeString("b0d66e5adaa5ed4e2f0ca68e17b8f2fc02ca002009e3" +
"3487e7fa4ab505cf34d98f131be7bd258391588ca7804acb30251e71a04e0020ecf" +
"df0f84608f8add82d7353af780fbb28868c713b7813eb4d4e61f7b75d7534dd9856" +
"9b0ba77cf14348fcff80fee10e11981f1b4be372d93923e9178972f69937ec850ed" +
"6c3f11ff572ddd5b2bedf9f9c0b327c54da02a28fcdce1f8369ffec")
dec, err := secp256k1.Decrypt(privkey, out)
if err != nil {
t.Fatal("failed to decrypt:", err)
}
if !bytes.Equal(in, dec) {
t.Error("decrypted data doesn't match original")
}
}
func TestSchnorrThreshold(t *testing.T) {
tRand := rand.New(rand.NewSource(54321))
maxSignatories := 10
numTests := 100
numSignatories := maxSignatories * numTests
curve := secp256k1.S256()
msg, _ := hex.DecodeString(
"07BE073995BF78D440B660AF7B06DC0E9BA120A8D686201989BA99AA384ADF12")
privkeys := randPrivKeyList(curve, numSignatories)
for i := 0; i < numTests; i++ {
numKeysForTest := tRand.Intn(maxSignatories-2) + 2
keyIndex := i * maxSignatories
keysToUse := make([]*secp256k1.PrivateKey, numKeysForTest, numKeysForTest)
for j := 0; j < numKeysForTest; j++ {
keysToUse[j] = privkeys[j+keyIndex]
}
pubKeysToUse := make([]*secp256k1.PublicKey, numKeysForTest,
numKeysForTest)
for j := 0; j < numKeysForTest; j++ {
_, pubkey := secp256k1.PrivKeyFromBytes(curve,
keysToUse[j].Serialize())
pubKeysToUse[j] = pubkey
}
privNoncesToUse := make([]*secp256k1.PrivateKey, numKeysForTest,
numKeysForTest)
pubNoncesToUse := make([]*secp256k1.PublicKey, numKeysForTest,
numKeysForTest)
for j := 0; j < numKeysForTest; j++ {
nonce := nonceRFC6979(keysToUse[j].Serialize(), msg, nil,
BlakeVersionStringRFC6979)
privNonce, pubNonce := secp256k1.PrivKeyFromBytes(curve,
nonce)
privNoncesToUse[j] = privNonce
pubNoncesToUse[j] = pubNonce
}
partialSignatures := make([]*Signature, numKeysForTest, numKeysForTest)
// Partial signature generation.
for j := range keysToUse {
thisPubNonce := pubNoncesToUse[j]
localPubNonces := make([]*secp256k1.PublicKey, numKeysForTest-1,
numKeysForTest-1)
itr := 0
for _, pubNonce := range pubNoncesToUse {
if bytes.Equal(thisPubNonce.Serialize(), pubNonce.Serialize()) {
continue
}
localPubNonces[itr] = pubNonce
itr++
}
publicNonceSum := CombinePubkeys(curve, localPubNonces)
sig, err := schnorrPartialSign(curve, msg, keysToUse[j].Serialize(),
privNoncesToUse[j].Serialize(), publicNonceSum,
chainhash.HashFuncB)
assert.NoError(t, err)
partialSignatures[j] = sig
}
// Combine signatures.
combinedSignature, err := CombineSigs(curve, partialSignatures)
assert.NoError(t, err)
// Combine pubkeys.
allPubkeys := make([]*secp256k1.PublicKey, numKeysForTest,
numKeysForTest)
for j, pubkey := range pubKeysToUse {
allPubkeys[j] = pubkey
}
allPksSum := CombinePubkeys(curve, allPubkeys)
// Verify the combined signature and public keys.
ok, err := schnorrVerify(curve, combinedSignature.Serialize(),
allPksSum, msg, chainhash.HashFuncB)
assert.NoError(t, err)
assert.Equal(t, true, ok)
// Corrupt some memory and make sure it breaks something.
corruptWhat := tRand.Intn(3)
randItem := tRand.Intn(numKeysForTest - 1)
// Corrupt private key.
if corruptWhat == 0 {
privSerCorrupt := keysToUse[randItem].Serialize()
pos := tRand.Intn(31)
bitPos := tRand.Intn(7)
privSerCorrupt[pos] ^= 1 << uint8(bitPos)
keysToUse[randItem].D.SetBytes(privSerCorrupt)
}
// Corrupt public key.
if corruptWhat == 1 {
pubXCorrupt := BigIntToEncodedBytes(pubKeysToUse[randItem].GetX())
pos := tRand.Intn(31)
bitPos := tRand.Intn(7)
pubXCorrupt[pos] ^= 1 << uint8(bitPos)
pubKeysToUse[randItem].GetX().SetBytes(pubXCorrupt[:])
}
// Corrupt private nonce.
if corruptWhat == 2 {
privSerCorrupt := privNoncesToUse[randItem].Serialize()
pos := tRand.Intn(31)
bitPos := tRand.Intn(7)
privSerCorrupt[pos] ^= 1 << uint8(bitPos)
privNoncesToUse[randItem].D.SetBytes(privSerCorrupt)
}
// Corrupt public nonce.
if corruptWhat == 3 {
pubXCorrupt := BigIntToEncodedBytes(pubNoncesToUse[randItem].GetX())
pos := tRand.Intn(31)
bitPos := tRand.Intn(7)
pubXCorrupt[pos] ^= 1 << uint8(bitPos)
pubNoncesToUse[randItem].GetX().SetBytes(pubXCorrupt[:])
}
for j := range keysToUse {
thisPubNonce := pubNoncesToUse[j]
localPubNonces := make([]*secp256k1.PublicKey, numKeysForTest-1,
numKeysForTest-1)
itr := 0
for _, pubNonce := range pubNoncesToUse {
if bytes.Equal(thisPubNonce.Serialize(), pubNonce.Serialize()) {
continue
}
localPubNonces[itr] = pubNonce
itr++
}
publicNonceSum := CombinePubkeys(curve, localPubNonces)
sig, _ := schnorrPartialSign(curve, msg, keysToUse[j].Serialize(),
privNoncesToUse[j].Serialize(), publicNonceSum,
chainhash.HashFuncB)
partialSignatures[j] = sig
}
// Combine signatures.
combinedSignature, _ = CombineSigs(curve, partialSignatures)
// Combine pubkeys.
allPubkeys = make([]*secp256k1.PublicKey, numKeysForTest,
numKeysForTest)
for j, pubkey := range pubKeysToUse {
allPubkeys[j] = pubkey
}
allPksSum = CombinePubkeys(curve, allPubkeys)
// Nothing that makes it here should be valid.
if allPksSum != nil && combinedSignature != nil {
ok, _ = schnorrVerify(curve, combinedSignature.Serialize(),
allPksSum, msg, chainhash.HashFuncB)
assert.Equal(t, false, ok)
}
}
}
func TestSchnorrThresholdRef(t *testing.T) {
curve := secp256k1.S256()
tvs := GetThresholdTestVectors()
for _, tv := range tvs {
partialSignatures := make([]*Signature, len(tv.signers), len(tv.signers))
// Ensure all the pubkey and nonce derivation is correct.
for i, signer := range tv.signers {
nonce := nonceRFC6979(signer.privkey, tv.msg, nil,
Sha256VersionStringRFC6979)
assert.Equal(t, nonce, signer.privateNonce)
_, pubkey := secp256k1.PrivKeyFromBytes(curve, signer.privkey)
assert.Equal(t, pubkey.Serialize(), signer.pubkey.Serialize())
_, pubNonce := secp256k1.PrivKeyFromBytes(curve, nonce)
assert.Equal(t, pubNonce.Serialize(), signer.publicNonce.Serialize())
// Calculate the public nonce sum.
pubKeys := make([]*secp256k1.PublicKey, len(tv.signers)-1,
len(tv.signers)-1)
itr := 0
for _, signer := range tv.signers {
if bytes.Equal(signer.publicNonce.Serialize(),
tv.signers[i].publicNonce.Serialize()) {
continue
}
pubKeys[itr] = signer.publicNonce
itr++
}
publicNonceSum := CombinePubkeys(curve, pubKeys)
assert.Equal(t, publicNonceSum, signer.pubKeySumLocal)
sig, err := schnorrPartialSign(curve, tv.msg, signer.privkey, nonce,
publicNonceSum, testSchnorrSha256Hash)
assert.NoError(t, err)
assert.Equal(t, sig.Serialize(), signer.partialSignature)
partialSignatures[i] = sig
}
// Combine signatures.
combinedSignature, err := CombineSigs(curve, partialSignatures)
assert.NoError(t, err)
assert.Equal(t, combinedSignature.Serialize(), tv.combinedSignature)
// Combine pubkeys.
allPubkeys := make([]*secp256k1.PublicKey, len(tv.signers),
len(tv.signers))
for i, signer := range tv.signers {
allPubkeys[i] = signer.pubkey
}
allPksSum := CombinePubkeys(curve, allPubkeys)
// Verify the combined signature and public keys.
ok, err := schnorrVerify(curve, combinedSignature.Serialize(),
allPksSum, tv.msg, testSchnorrSha256Hash)
assert.NoError(t, err)
assert.Equal(t, true, ok)
}
}
// newSecSchnorrDSA instatiates a function DSA subsystem over the secp256k1
// curve. A caveat for the functions below is that they're all routed through
// interfaces, and nil returns from the library itself for interfaces must
// ALWAYS be checked by checking the return value by attempted dereference
// (== nil).
func newSecSchnorrDSA() DSA {
var secp DSA = &secSchnorrDSA{
// Constants
getP: func() *big.Int {
return secp256k1Curve.P
},
getN: func() *big.Int {
return secp256k1Curve.N
},
// EC Math
add: func(x1, y1, x2, y2 *big.Int) (*big.Int, *big.Int) {
return secp256k1Curve.Add(x1, y1, x2, y2)
},
isOnCurve: func(x, y *big.Int) bool {
return secp256k1Curve.IsOnCurve(x, y)
},
scalarMult: func(x, y *big.Int, k []byte) (*big.Int, *big.Int) {
return secp256k1Curve.ScalarMult(x, y, k)
},
scalarBaseMult: func(k []byte) (*big.Int, *big.Int) {
return secp256k1Curve.ScalarBaseMult(k)
},
// Private keys
newPrivateKey: func(d *big.Int) PrivateKey {
pk := secp256k1.NewPrivateKey(secp256k1Curve, d)
if pk != nil {
return PrivateKey(pk)
}
return nil
},
privKeyFromBytes: func(pk []byte) (PrivateKey, PublicKey) {
priv, pub := secp256k1.PrivKeyFromBytes(secp256k1Curve, pk)
if priv == nil {
return nil, nil
}
if pub == nil {
return nil, nil
}
tpriv := PrivateKey(priv)
tpub := PublicKey(pub)
return tpriv, tpub
},
privKeyFromScalar: func(pk []byte) (PrivateKey, PublicKey) {
priv, pub := secp256k1.PrivKeyFromScalar(secp256k1Curve, pk)
if priv == nil {
return nil, nil
}
if pub == nil {
return nil, nil
}
tpriv := PrivateKey(priv)
tpub := PublicKey(pub)
return tpriv, tpub
},
privKeyBytesLen: func() int {
return secp256k1.PrivKeyBytesLen
},
// Public keys
// Note that Schnorr only allows 33 byte public keys, however
// as they are secp256k1 you still have access to the other
// serialization types.
newPublicKey: func(x *big.Int, y *big.Int) PublicKey {
pk := secp256k1.NewPublicKey(secp256k1Curve, x, y)
tpk := PublicKey(pk)
return tpk
},
parsePubKey: func(pubKeyStr []byte) (PublicKey, error) {
pk, err := schnorr.ParsePubKey(secp256k1Curve, pubKeyStr)
if err != nil {
return nil, err
}
tpk := PublicKey(pk)
return tpk, err
},
pubKeyBytesLen: func() int {
return schnorr.PubKeyBytesLen
},
pubKeyBytesLenUncompressed: func() int {
return schnorr.PubKeyBytesLen
},
pubKeyBytesLenCompressed: func() int {
return schnorr.PubKeyBytesLen
},
pubKeyBytesLenHybrid: func() int {
return schnorr.PubKeyBytesLen
},
// Signatures
newSignature: func(r *big.Int, s *big.Int) Signature {
sig := schnorr.NewSignature(r, s)
ts := Signature(sig)
return ts
},
parseDERSignature: func(sigStr []byte) (Signature, error) {
sig, err := schnorr.ParseSignature(sigStr)
ts := Signature(sig)
return ts, err
},
parseSignature: func(sigStr []byte) (Signature, error) {
sig, err := schnorr.ParseSignature(sigStr)
ts := Signature(sig)
return ts, err
},
recoverCompact: func(signature, hash []byte) (PublicKey, bool, error) {
pk, bl, err := schnorr.RecoverPubkey(secp256k1Curve, signature,
hash)
tpk := PublicKey(pk)
return tpk, bl, err
},
// ECDSA
generateKey: func(rand io.Reader) ([]byte, *big.Int, *big.Int, error) {
return secp256k1.GenerateKey(secp256k1Curve, rand)
},
sign: func(priv PrivateKey, hash []byte) (r, s *big.Int, err error) {
spriv := secp256k1.NewPrivateKey(secp256k1Curve, priv.GetD())
return schnorr.Sign(secp256k1Curve, spriv, hash)
},
verify: func(pub PublicKey, hash []byte, r, s *big.Int) bool {
spub := secp256k1.NewPublicKey(secp256k1Curve, pub.GetX(), pub.GetY())
return schnorr.Verify(secp256k1Curve, spub, hash, r, s)
},
// Symmetric cipher encryption
generateSharedSecret: func(privkey []byte, x, y *big.Int) []byte {
sprivkey, _ := secp256k1.PrivKeyFromBytes(secp256k1Curve, privkey)
if sprivkey == nil {
return nil
}
spubkey := secp256k1.NewPublicKey(secp256k1Curve, x, y)
return secp256k1.GenerateSharedSecret(sprivkey, spubkey)
},
encrypt: func(x, y *big.Int, in []byte) ([]byte, error) {
spubkey := secp256k1.NewPublicKey(secp256k1Curve, x, y)
return secp256k1.Encrypt(spubkey, in)
},
decrypt: func(privkey []byte, in []byte) ([]byte, error) {
sprivkey, _ := secp256k1.PrivKeyFromBytes(secp256k1Curve, privkey)
if sprivkey == nil {
return nil, fmt.Errorf("failure deserializing privkey")
}
return secp256k1.Decrypt(sprivkey, in)
},
}
return secp.(DSA)
}
func TestRFC6979(t *testing.T) {
// Test vectors matching Trezor and CoreBitcoin implementations.
// - https://github.com/trezor/trezor-crypto/blob/9fea8f8ab377dc514e40c6fd1f7c89a74c1d8dc6/tests.c#L432-L453
// - https://github.com/oleganza/CoreBitcoin/blob/e93dd71207861b5bf044415db5fa72405e7d8fbc/CoreBitcoin/BTCKey%2BTests.m#L23-L49
tests := []struct {
key string
msg string
nonce string
signature string
}{
{
"cca9fbcc1b41e5a95d369eaa6ddcff73b61a4efaa279cfc6567e8daa39cbaf50",
"sample",
"2df40ca70e639d89528a6b670d9d48d9165fdc0febc0974056bdce192b8e16a3",
"3045022100af340daf02cc15c8d5d08d7735dfe6b98a474ed373bdb5fbecf7571be52b384202205009fb27f37034a9b24b707b7c6b79ca23ddef9e25f7282e8a797efe53a8f124",
},
{
// This signature hits the case when S is higher than halforder.
// If S is not canonicalized (lowered by halforder), this test will fail.
"0000000000000000000000000000000000000000000000000000000000000001",
"Satoshi Nakamoto",
"8f8a276c19f4149656b280621e358cce24f5f52542772691ee69063b74f15d15",
"3045022100934b1ea10a4b3c1757e2b0c017d0b6143ce3c9a7e6a4a49860d7a6ab210ee3d802202442ce9d2b916064108014783e923ec36b49743e2ffa1c4496f01a512aafd9e5",
},
{
"fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140",
"Satoshi Nakamoto",
"33a19b60e25fb6f4435af53a3d42d493644827367e6453928554f43e49aa6f90",
"3045022100fd567d121db66e382991534ada77a6bd3106f0a1098c231e47993447cd6af2d002206b39cd0eb1bc8603e159ef5c20a5c8ad685a45b06ce9bebed3f153d10d93bed5",
},
{
"f8b8af8ce3c7cca5e300d33939540c10d45ce001b8f252bfbc57ba0342904181",
"Alan Turing",
"525a82b70e67874398067543fd84c83d30c175fdc45fdeee082fe13b1d7cfdf1",
"304402207063ae83e7f62bbb171798131b4a0564b956930092b33b07b395615d9ec7e15c022058dfcc1e00a35e1572f366ffe34ba0fc47db1e7189759b9fb233c5b05ab388ea",
},
{
"0000000000000000000000000000000000000000000000000000000000000001",
"All those moments will be lost in time, like tears in rain. Time to die...",
"38aa22d72376b4dbc472e06c3ba403ee0a394da63fc58d88686c611aba98d6b3",
"30450221008600dbd41e348fe5c9465ab92d23e3db8b98b873beecd930736488696438cb6b0220547fe64427496db33bf66019dacbf0039c04199abb0122918601db38a72cfc21",
},
{
"e91671c46231f833a6406ccbea0e3e392c76c167bac1cb013f6f1013980455c2",
"There is a computer disease that anybody who works with computers knows about. It's a very serious disease and it interferes completely with the work. The trouble with computers is that you 'play' with them!",
"1f4b84c23a86a221d233f2521be018d9318639d5b8bbd6374a8a59232d16ad3d",
"3045022100b552edd27580141f3b2a5463048cb7cd3e047b97c9f98076c32dbdf85a68718b0220279fa72dd19bfae05577e06c7c0c1900c371fcd5893f7e1d56a37d30174671f6",
},
}
for i, test := range tests {
privKey, _ := secp256k1.PrivKeyFromBytes(secp256k1.S256(), decodeHex(test.key))
hash := sha256.Sum256([]byte(test.msg))
// Ensure deterministically generated nonce is the expected value.
gotNonce := secp256k1.TstNonceRFC6979(privKey.D, hash[:]).Bytes()
wantNonce := decodeHex(test.nonce)
if !bytes.Equal(gotNonce, wantNonce) {
t.Errorf("NonceRFC6979 #%d (%s): Nonce is incorrect: "+
"%x (expected %x)", i, test.msg, gotNonce,
wantNonce)
continue
}
// Ensure deterministically generated signature is the expected value.
gotSig, err := privKey.Sign(hash[:])
if err != nil {
t.Errorf("Sign #%d (%s): unexpected error: %v", i,
test.msg, err)
continue
}
gotSigBytes := gotSig.Serialize()
wantSigBytes := decodeHex(test.signature)
if !bytes.Equal(gotSigBytes, wantSigBytes) {
t.Errorf("Sign #%d (%s): mismatched signature: %x "+
"(expected %x)", i, test.msg, gotSigBytes,
wantSigBytes)
continue
}
}
}
// newSecp256k1DSA instatiates a function DSA subsystem over the secp256k1
// curve. A caveat for the functions below is that they're all routed through
// interfaces, and nil returns from the library itself for interfaces must
// ALWAYS be checked by checking the return value by attempted dereference
// (== nil).
func newSecp256k1DSA() DSA {
var secp DSA = &secp256k1DSA{
// Constants
getP: func() *big.Int {
return secp256k1Curve.P
},
getN: func() *big.Int {
return secp256k1Curve.N
},
// EC Math
add: func(x1, y1, x2, y2 *big.Int) (*big.Int, *big.Int) {
return secp256k1Curve.Add(x1, y1, x2, y2)
},
isOnCurve: func(x, y *big.Int) bool {
return secp256k1Curve.IsOnCurve(x, y)
},
scalarMult: func(x, y *big.Int, k []byte) (*big.Int, *big.Int) {
return secp256k1Curve.ScalarMult(x, y, k)
},
scalarBaseMult: func(k []byte) (*big.Int, *big.Int) {
return secp256k1Curve.ScalarBaseMult(k)
},
// Private keys
newPrivateKey: func(d *big.Int) PrivateKey {
if d == nil {
return nil
}
pk := secp256k1.NewPrivateKey(secp256k1Curve, d)
if pk != nil {
return PrivateKey(pk)
}
return nil
},
privKeyFromBytes: func(pk []byte) (PrivateKey, PublicKey) {
priv, pub := secp256k1.PrivKeyFromBytes(secp256k1Curve, pk)
if priv == nil {
return nil, nil
}
if pub == nil {
return nil, nil
}
tpriv := PrivateKey(priv)
tpub := PublicKey(pub)
return tpriv, tpub
},
privKeyFromScalar: func(pk []byte) (PrivateKey, PublicKey) {
priv, pub := secp256k1.PrivKeyFromScalar(secp256k1Curve, pk)
if priv == nil {
return nil, nil
}
if pub == nil {
return nil, nil
}
tpriv := PrivateKey(priv)
tpub := PublicKey(pub)
return tpriv, tpub
},
privKeyBytesLen: func() int {
return secp256k1.PrivKeyBytesLen
},
// Public keys
newPublicKey: func(x *big.Int, y *big.Int) PublicKey {
pk := secp256k1.NewPublicKey(secp256k1Curve, x, y)
tpk := PublicKey(pk)
return tpk
},
parsePubKey: func(pubKeyStr []byte) (PublicKey, error) {
pk, err := secp256k1.ParsePubKey(pubKeyStr, secp256k1Curve)
if err != nil {
return nil, err
}
tpk := PublicKey(pk)
return tpk, err
},
pubKeyBytesLen: func() int {
return secp256k1.PubKeyBytesLenCompressed
},
pubKeyBytesLenUncompressed: func() int {
return secp256k1.PubKeyBytesLenUncompressed
},
pubKeyBytesLenCompressed: func() int {
return secp256k1.PubKeyBytesLenCompressed
},
pubKeyBytesLenHybrid: func() int {
return secp256k1.PubKeyBytesLenHybrid
},
// Signatures
newSignature: func(r *big.Int, s *big.Int) Signature {
sig := secp256k1.NewSignature(r, s)
ts := Signature(sig)
return ts
},
parseDERSignature: func(sigStr []byte) (Signature, error) {
sig, err := secp256k1.ParseDERSignature(sigStr, secp256k1Curve)
if err != nil {
return nil, err
}
ts := Signature(sig)
return ts, err
},
parseSignature: func(sigStr []byte) (Signature, error) {
sig, err := secp256k1.ParseSignature(sigStr, secp256k1Curve)
if err != nil {
return nil, err
}
ts := Signature(sig)
return ts, err
},
recoverCompact: func(signature, hash []byte) (PublicKey, bool, error) {
pk, bl, err := secp256k1.RecoverCompact(secp256k1Curve, signature,
hash)
tpk := PublicKey(pk)
return tpk, bl, err
},
// ECDSA
generateKey: func(rand io.Reader) ([]byte, *big.Int, *big.Int, error) {
return secp256k1.GenerateKey(secp256k1Curve, rand)
},
sign: func(priv PrivateKey, hash []byte) (r, s *big.Int, err error) {
if priv.GetType() != ECTypeSecp256k1 {
return nil, nil, errors.New("wrong type")
}
spriv, ok := priv.(*secp256k1.PrivateKey)
if !ok {
return nil, nil, errors.New("wrong type")
}
sig, err := spriv.Sign(hash)
if sig != nil {
r = sig.GetR()
s = sig.GetS()
}
return
},
verify: func(pub PublicKey, hash []byte, r, s *big.Int) bool {
spub := secp256k1.NewPublicKey(secp256k1Curve, pub.GetX(), pub.GetY())
ssig := secp256k1.NewSignature(r, s)
return ssig.Verify(hash, spub)
},
// Symmetric cipher encryption
generateSharedSecret: func(privkey []byte, x, y *big.Int) []byte {
sprivkey, _ := secp256k1.PrivKeyFromBytes(secp256k1Curve, privkey)
if sprivkey == nil {
return nil
}
spubkey := secp256k1.NewPublicKey(secp256k1Curve, x, y)
return secp256k1.GenerateSharedSecret(sprivkey, spubkey)
},
encrypt: func(x, y *big.Int, in []byte) ([]byte, error) {
spubkey := secp256k1.NewPublicKey(secp256k1Curve, x, y)
return secp256k1.Encrypt(spubkey, in)
},
decrypt: func(privkey []byte, in []byte) ([]byte, error) {
sprivkey, _ := secp256k1.PrivKeyFromBytes(secp256k1Curve, privkey)
if sprivkey == nil {
return nil, fmt.Errorf("failure deserializing privkey")
}
return secp256k1.Decrypt(sprivkey, in)
},
}
return secp.(DSA)
}