PoR demo

.gitignore

@@ -3,3 +3,4 @@
 3dparty
 .vscode
 .env
+config.yaml

config-example.yaml

@@ -0,0 +1,2 @@
+demo:
+  public-key: "0x..."

demo/README.md

@@ -0,0 +1,30 @@
+# Demo
+
+This demo shows how to derive a deposit addresses from an address' deposit metadata and the base deposit public key. 
+
+## Derive the deposit address
+
+You will need the following to derive the deposit addresses:
+- The deposit address metadata from the Lombard public API. For mainnet, all the paginated deposit addresses are availalbe at https://mainnet.prod.lombard.finance/api/v1/address. To get a specific address, like that in our example, you can go to https://mainnet.prod.lombard.finance/api/v1/address?to_address=0x57F9672bA603251C9C03B36cabdBBcA7Ca8Cfcf4&to_blockchain=DESTINATION_BLOCKCHAIN_ETHEREUM&limit=1&offset=0&asc=false&referralId=lombard.
+- The Lombard base deposit public key. Lombard's base deposit key is stored on Cubist on and for each environment, we can provide you its public key. You must configure this in `config.yaml` by following the instructions below.
+
+### 1. Configure
+
+Set the following values in your `config.yaml`
+
+| Config          | Description                                                | Example            |
+|-----------------|------------------------------------------------------------|--------------------|
+| demo.public-key | The public key of Lombard's base deposit key on Cubist.  | `0x...`     |
+
+
+### 2. Derive the address
+```bash
+go run demo/cmd/derive/main.go
+```
+
+
+If the derivation is successful, the outpu will look like
+```shell
+Address: bc1q29nrqh3cj5q5r0n7yjea6hezkrxhf6nyfv3afz
+Addresses match
+```

demo/address.go

@@ -0,0 +1,19 @@
+package demo
+
+type Address struct {
+	BTCAddress      string          `json:"btc_address"`
+	Type            string          `json:"type"`
+	DepositMetadata DepositMetadata `json:"deposit_metadata"`
+	CreatedAt       string          `json:"created_at"`
+}
+
+type DepositMetadata struct {
+	ToAddress    string `json:"to_address"`
+	ToBlockchain string `json:"to_blockchain"`
+	Referral     string `json:"referral"`
+	Nonce        uint32 `json:"nonce"`
+}
+
+type AddressList struct {
+	Addresses []Address `json:"addresses"`
+}

demo/cmd/derive/example.json

@@ -0,0 +1,14 @@
+{
+    "addresses": [
+        {
+        "btc_address": "bc1q29nrqh3cj5q5r0n7yjea6hezkrxhf6nyfv3afz",
+        "type": "ADDRESS_TYPE_DEPOSIT",
+        "deposit_metadata": {
+            "to_address": "0x57f9672ba603251c9c03b36cabdbbca7ca8cfcf4",
+            "to_blockchain": "DESTINATION_BLOCKCHAIN_ETHEREUM",
+            "referral": "lombard"
+        },
+        "created_at": "1729794078"
+        }
+    ]
+}

demo/cmd/derive/main.go

@@ -0,0 +1,98 @@
+package main
+
+import (
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4"
+	"github.com/ethereum/go-ethereum/common"
+	deposit_address "github.com/lombard-finance/deposit-address"
+	utils "github.com/lombard-finance/deposit-address/demo"
+	"github.com/spf13/viper"
+)
+
+// In top level project folder, run `go run demo/cmd/derive/main.go`.
+func main() {
+	// Initialize configuration
+	utils.InitConfig()
+
+	// Read value from config.yaml file
+	// This is the public key for the base deposit key on Cubist
+	basePubKey := viper.GetString("demo.public-key")
+	if basePubKey == "" {
+		fmt.Println("Missing `demo.public-key`")
+		return
+	}
+
+	// Get this from the API instead of this example file, e.g.
+	// https://mainnet.prod.lombard.finance/api/v1/address?to_address=0x57F9672bA603251C9C03B36cabdBBcA7Ca8Cfcf4&to_blockchain=DESTINATION_BLOCKCHAIN_ETHEREUM&limit=1&offset=0&asc=false&referralId=lombard
+	data, err := os.ReadFile("./demo/cmd/derive/example.json")
+	if err != nil {
+		fmt.Println("Error reading file:", err)
+		return
+	}
+
+	var addressList utils.AddressList
+	err = json.Unmarshal(data, &addressList)
+	if err != nil {
+		fmt.Println("Error parsing JSON:", err)
+		return
+	}
+
+	for _, addr := range addressList.Addresses {
+		// get this from config
+		params := &chaincfg.MainNetParams
+
+		// wallet address on destination chain
+		walletAddr := common.HexToAddress(addr.DepositMetadata.ToAddress)
+
+		auxData, err := deposit_address.ComputeAuxDataV0(addr.DepositMetadata.Nonce, []byte(addr.DepositMetadata.Referral))
+		if err != nil {
+			fmt.Println("Error computing aux data:", err)
+			return
+		}
+
+		// parse public key of base deposit key
+		pkBytes, err := hex.DecodeString(strings.TrimPrefix(basePubKey, "0x"))
+		if err != nil {
+			fmt.Println("Decoding public key hex:", err)
+			return
+		}
+
+		pk, err := secp256k1.ParsePubKey(pkBytes)
+		if err != nil {
+			fmt.Println("Error decoding SEC1 encoded pubkey:", err)
+			return
+		}
+
+		if addr.DepositMetadata.ToBlockchain == "DESTINATION_BLOCKCHAIN_ETHEREUM" {
+			// for ethereum mainnet, LBTC contract address is 0x8236a87084f8B84306f72007F36F2618A5634494. get this from config.
+			lbtcContractAddrEthMainnet := [20]byte{0x82, 0x36, 0xa8, 0x70, 0x84, 0xf8, 0xB8, 0x43, 0x06, 0xf7, 0x20, 0x07, 0xF3, 0x6F, 0x26, 0x18, 0xA5, 0x63, 0x44, 0x94}
+			lbtcContractAddr := common.BytesToAddress(lbtcContractAddrEthMainnet[:20])
+
+			// for ethereum mainnet, chain id is 1. get this from config.
+			chainId := [32]byte{}
+			chainId[31] = 1
+
+			// derive the address
+			derivedAddr, err := deposit_address.EvmDepositSegwitAddr(pk, lbtcContractAddr, walletAddr, chainId[:], auxData[:], params)
+			if err != nil {
+				fmt.Println("Error tweaking address:", err)
+				return
+			}
+
+			fmt.Println("Address:", derivedAddr)
+
+			if addr.BTCAddress != derivedAddr {
+				fmt.Printf("Derived address (%s) doesn't match expected (%s)", derivedAddr, addr.BTCAddress)
+			} else {
+				fmt.Println("Addresses match")
+			}
+		}
+	}
+
+}

demo/utils.go

@@ -0,0 +1,136 @@
+package demo
+
+import (
+	"fmt"
+	"log"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/pkg/errors"
+	"github.com/spf13/viper"
+)
+
+type AddressType string
+
+const (
+	Unknown AddressType = "Unknown"
+	Taproot AddressType = "Taproot"
+	SegWit  AddressType = "Segwit"
+)
+
+func InitConfig() {
+	// Get the directory of the current file
+	_, filename, _, ok := runtime.Caller(0)
+	if !ok {
+		log.Fatal("No caller information")
+	}
+
+	// Go up two directories from the current file location
+	currentDir := filepath.Dir(filename)
+	projectRoot := filepath.Join(currentDir, "..")
+	configPath := filepath.Join(projectRoot, "config.yaml")
+
+	// For debugging
+	fmt.Printf("Looking for config at: %s\n", configPath)
+
+	viper.SetConfigFile(configPath)
+
+	// Set default values before reading the config file
+	viper.SetDefault("demo.challenge", "LOMBARD PROOF OF OWNERSHIP")
+
+	if err := viper.ReadInConfig(); err != nil {
+		log.Fatalf("Error reading config file: %v", err)
+	}
+
+	// Print which config file was used (for debugging)
+	fmt.Printf("Using config file: %s\n", viper.ConfigFileUsed())
+}
+
+func CheckAddressTypes(addresses []string) (AddressType, error) {
+	if len(addresses) == 0 {
+		return Unknown, fmt.Errorf("empty address list")
+	}
+
+	// Get type of first address as reference
+	expectedType := GetAddressType(addresses[0])
+	if expectedType == Unknown {
+		return Unknown, fmt.Errorf("invalid address format: %s", addresses[0])
+	}
+
+	// Check all other addresses match the same type
+	for i, addr := range addresses[1:] {
+		currentType := GetAddressType(addr)
+		if currentType == Unknown {
+			return Unknown, fmt.Errorf("invalid address format at index %d: %s", i+1, addr)
+		}
+		if currentType != expectedType {
+			return Unknown, fmt.Errorf("address type mismatch: expected %s, got %s at index %d: %s",
+				expectedType, currentType, i+1, addr)
+		}
+	}
+
+	return expectedType, nil
+}
+
+func GetAddressType(address string) AddressType {
+	if isTaproot(address) {
+		return Taproot
+	}
+
+	if isSegWit(address) {
+		return SegWit
+	}
+
+	return Unknown
+}
+
+func isTaproot(address string) bool {
+	return strings.HasPrefix(address, "bc1p") || strings.HasPrefix(address, "tb1p")
+}
+
+func isSegWit(address string) bool {
+	return (strings.HasPrefix(address, "bc1") || strings.HasPrefix(address, "tb1")) &&
+		!strings.HasPrefix(address, "bc1p") && !strings.HasPrefix(address, "tb1p")
+}
+
+func CheckNetworkParams(addresses []string) (*chaincfg.Params, error) {
+	if len(addresses) == 0 {
+		return nil, fmt.Errorf("empty address list")
+	}
+
+	// Get network of first address as reference
+	expectedNet, err := GetNetworkParams(addresses[0])
+	if err != nil || expectedNet == nil {
+		return nil, fmt.Errorf("invalid address network: %s", addresses[0])
+	}
+
+	// Check all other addresses match the same network
+	for i, addr := range addresses[1:] {
+		currentNet, err := GetNetworkParams(addr)
+		if err == nil || currentNet == nil {
+			return nil, fmt.Errorf("invalid address network at index %d: %s", i+1, addr)
+		}
+		if currentNet != expectedNet {
+			return nil, fmt.Errorf("address network mismatch: expected %v, got %v at index %d: %s",
+				expectedNet, currentNet, i+1, addr)
+		}
+	}
+
+	return expectedNet, nil
+}
+
+func GetNetworkParams(address string) (*chaincfg.Params, error) {
+	// Check for mainnet prefix (bc1)
+	if strings.HasPrefix(address, "bc1") {
+		return &chaincfg.MainNetParams, nil
+	}
+
+	// Check for testnet/signet prefix (tb1)
+	if strings.HasPrefix(address, "tb1") {
+		return &chaincfg.SigNetParams, nil
+	}
+
+	return nil, errors.Errorf("unsupported address format: %s", address)
+}

go.mod

@@ -5,19 +5,40 @@ go 1.22
 require (
 	github.com/btcsuite/btcd v0.24.0
 	github.com/btcsuite/btcd/btcutil v1.1.5
+	github.com/btcsuite/btcd/btcutil/psbt v1.1.9
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.2.0
 	github.com/ethereum/go-ethereum v1.14.5
 	github.com/pkg/errors v0.9.1
+	github.com/spf13/viper v1.19.0
 	github.com/stretchr/testify v1.9.0
 )
 
 require (
 	github.com/btcsuite/btcd/btcec/v2 v2.2.0 // indirect
 	github.com/btcsuite/btcd/chaincfg/chainhash v1.1.0 // indirect
-	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f // indirect
+	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
+	github.com/decred/dcrd/crypto/blake256 v1.0.1 // indirect
+	github.com/fsnotify/fsnotify v1.7.0 // indirect
+	github.com/hashicorp/hcl v1.0.0 // indirect
 	github.com/holiman/uint256 v1.2.4 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/magiconair/properties v1.8.7 // indirect
+	github.com/mitchellh/mapstructure v1.5.0 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.2 // indirect
+	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
+	github.com/sagikazarmark/locafero v0.4.0 // indirect
+	github.com/sagikazarmark/slog-shim v0.1.0 // indirect
+	github.com/sourcegraph/conc v0.3.0 // indirect
+	github.com/spf13/afero v1.11.0 // indirect
+	github.com/spf13/cast v1.6.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/subosito/gotenv v1.6.0 // indirect
+	go.uber.org/atomic v1.9.0 // indirect
+	go.uber.org/multierr v1.9.0 // indirect
 	golang.org/x/crypto v0.22.0 // indirect
+	golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa // indirect
 	golang.org/x/sys v0.20.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )