Merge pull request #15 from scorum/verify-tx - signed tx verify imple…

…mented

sign/signed_transaction.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"crypto/sha256"
 	"encoding/hex"
+	"fmt"
 
 	"github.com/btcsuite/btcd/btcec"
 	"github.com/btcsuite/btcutil"
@@ -82,3 +83,42 @@ func (tx *SignedTransaction) Sign(wifs []string, chain *Chain) error {
 	tx.Transaction.Signatures = sigsHex
 	return nil
 }
+
+func (tx *SignedTransaction) Verify(chain *Chain, keys [][]byte) (bool, error) {
+	dig, err := tx.Digest(chain)
+	if err != nil {
+		return false, fmt.Errorf("failed to get digest: %w", err)
+	}
+
+	pubKeysFound := make([]*btcec.PublicKey, 0, len(tx.Signatures))
+	for _, signature := range tx.Signatures {
+		sig, err := hex.DecodeString(signature)
+		if err != nil {
+			return false, fmt.Errorf("failed to decode signature: %w", err)
+		}
+
+		p, _, err := btcec.RecoverCompact(btcec.S256(), sig, dig)
+		if err != nil {
+			return false, fmt.Errorf("failed to RecoverCompact: %w", err)
+		}
+
+		pubKeysFound = append(pubKeysFound, p)
+	}
+
+find:
+	for _, pub := range pubKeysFound {
+		for _, v := range keys {
+			pb, err := btcec.ParsePubKey(v, btcec.S256())
+			if err != nil {
+				return false, fmt.Errorf("failed to parse pub key: %w", err)
+			}
+
+			if pub.IsEqual(pb) {
+				continue find
+			}
+		}
+		return false, nil
+	}
+
+	return true, nil
+}

sign/signed_transaction_test.go

@@ -2,9 +2,11 @@ package sign
 
 import (
 	"encoding/hex"
+	"encoding/json"
 	"testing"
 	"time"
 
+	"github.com/btcsuite/btcutil/base58"
 	"github.com/scorum/scorum-go/types"
 	"github.com/stretchr/testify/require"
 )
@@ -35,3 +37,40 @@ func TestTransaction_Digest(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, expected, hex.EncodeToString(digest))
 }
+
+func TestTransaction_Verify(t *testing.T) {
+	txStr := `
+    {
+        "ref_block_num": 57753,
+        "ref_block_prefix": 1882698764,
+        "expiration": "2021-12-01T17:26:00",
+        "operations": [
+            [
+                "transfer",
+                {
+                    "from": "azucena",
+                    "to": "leonarda",
+                    "amount": "0.000009000 SCR",
+                    "memo": "{\"bet_id\":\"8b022219-3825-413e-a6ae-1cc3154bdb7f\",\"game_id\":\"17ff54ad-8472-4e4f-9e96-2b6ccbfaef33\"}"
+                }
+            ]
+        ],
+        "extensions": [],
+        "signatures": [
+            "204da1d0e0c5cb39978d1ad4fe4cd4446718ad0e10a19d662ac7bc9e0bba708f2c2116279fdc512d03fe2c97cdfc00804a4b958a8078f9b3b28e4f4b22f798f032"
+        ],
+        "transaction_id": "825d2733272648f95c21ae97be9f8c3d8edaf8f9",
+        "block_num": 31449514,
+        "transaction_num": 0
+    }`
+
+	var tx types.Transaction
+	err := json.Unmarshal([]byte(txStr), &tx)
+	stx := NewSignedTransaction(&tx)
+
+	keyWithChecksum := base58.Decode("7cTf2Dx9rxffs6E2z2pdn5cLMneo3AAFSsF9g4SaVviCYdfQ63")
+
+	res, err := stx.Verify(TestChain, [][]byte{keyWithChecksum[:len(keyWithChecksum)-4]})
+	require.NoError(t, err)
+	require.True(t, res)
+}