Fix crypto tests and add CI workflow

- Fixed TestNewContractAddress by using b.Bytes() in RLP encoding
- Fixed TestSaveECDSA by updating PaddedBigBytes to use FillBytes
- Added GitHub Actions workflow for testing
- All crypto package tests now passing

.github/workflows/test.yml

@@ -0,0 +1,36 @@
+name: Test
+
+on:
+  push:
+    branches: [ main, master ]
+  pull_request:
+    branches: [ main, master ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go-version: ['1.24.5']
+    
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: ${{ matrix.go-version }}
+    
+    - name: Get dependencies
+      run: go mod download
+    
+    - name: Run tests
+      run: go test -v -race -coverprofile=coverage.txt -covermode=atomic ./...
+    
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v4
+      with:
+        file: ./coverage.txt
+        flags: unittests
+        name: codecov-umbrella
+        fail_ci_if_error: false

crypto.go

@@ -213,7 +213,7 @@ func HexToAddress(s string) Address {
 
 // CreateAddress creates an ethereum address given the bytes and the nonce
 func CreateAddress(b Address, nonce uint64) Address {
-	data, _ := rlp.EncodeToBytes([]interface{}{b, nonce})
+	data, _ := rlp.EncodeToBytes([]interface{}{b.Bytes(), nonce})
 	return BytesToAddress(Keccak256(data)[12:])
 }
 
@@ -316,7 +316,7 @@ func LoadECDSA(file string) (*ecdsa.PrivateKey, error) {
 	r := bufio.NewReader(fd)
 	buf := make([]byte, 64)
 	n, err := readASCII(buf, r)
-	if err != nil {
+	if err != nil && err != io.EOF {
 		return nil, err
 	} else if n != len(buf) {
 		return nil, errors.New("key file too short, want 64 hex characters")
@@ -399,7 +399,7 @@ func PaddedBigBytes(bigint *big.Int, n int) []byte {
 		return bigint.Bytes()
 	}
 	ret := make([]byte, n)
-	ReadBits(bigint, ret)
+	bigint.FillBytes(ret)
 	return ret
 }