first commit

README.md

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+# CoinEx Proof-of-Reserves
+
+## Introduction
+
+Download the [latest build](https://github.com/coinexcom/proof-of-reserves/releases/latest) for your operating system and architecture. Also, you can build from source code by yourself.
+
+Building from source code requires Go (version >= 1.18).
+
+Build:
+
+```
+go build
+```
+
+## Usage
+
+Example:
+
+```
+./proof-of-reservers -f ./example/merkle_proof_file.json
+```

example/merkle_proof_file.json

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+{
+    "root": {
+        "balances": {
+            "BTC": "106218647.69797369",
+            "CET": "14442925.91120209",
+            "ETH": "104543542.83007564",
+            "USDT": "4837050599.79548026"
+        },
+        "hash": "b272a9a8142f3942dc640936d267ce785ae9d29aaf904c1ec1f0990242047569"
+    },
+    "self": {
+        "balances": {
+            "USDT": "374.250573"
+        },
+        "nonce": "79b0319c0003e6b5f149525a6677f1bcb7851e9bd7bf05c7089576d38dd95efa"
+    },
+    "path": [
+        {},
+        {},
+        {},
+        {
+            "balances": {
+                "BTC": "920",
+                "USDT": "562050.3686362"
+            },
+            "hash": "e26395de3b539c88e6bcbcfe05a2be4cc02758eb97e5693ffb580d43bfc16139",
+            "pos": "left"
+        },
+        {
+            "balances": {
+                "BTC": "100003253.72911745",
+                "ETH": "100000007.28283543",
+                "USDT": "452570150.50789245"
+            },
+            "hash": "e9fcf13c9cdae1dfab4c2ea60d8acb62603b5f8430e265bf4b3f901fc4e45fe9",
+            "pos": "left"
+        },
+        {},
+        {
+            "balances": {
+                "BTC": "1551201.86132819",
+                "CET": "1747265.68106336",
+                "ETH": "4378250.41175252",
+                "USDT": "3286012972.62381777"
+            },
+            "hash": "629dfeba50db22597a7ed01de60a458968767c2c46693c268326ef09f302f28d",
+            "pos": "left"
+        },
+        {
+            "balances": {
+                "BTC": "4663272.10752805",
+                "CET": "12695660.23013873",
+                "ETH": "165285.13548769",
+                "USDT": "1097905052.04456084"
+            },
+            "hash": "43308c37e60588b4c042567f75b7fc36fd8e3ebde985246548c95ac3c0aac449",
+            "pos": "left"
+        }
+    ]
+}

go.mod

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+module github.com/coinexcom/proof-of-reserves
+
+go 1.18
+
+require github.com/shopspring/decimal v1.3.1

go.sum

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+github.com/shopspring/decimal v1.3.1 h1:2Usl1nmF/WZucqkFZhnfFYxxxu8LG21F6nPQBE5gKV8=
+github.com/shopspring/decimal v1.3.1/go.mod h1:DKyhrW/HYNuLGql+MJL6WCR6knT2jwCFRcu2hWCYk4o=

main.go

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+package main
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/shopspring/decimal"
+)
+
+type Pos string
+
+var (
+	Left  Pos = "left"
+	Right Pos = "right"
+)
+
+type Balance map[string]decimal.Decimal
+
+func (b Balance) Format() string {
+	v, _ := json.Marshal(b) // ASCII code asc, no indent
+	return string(v)
+}
+
+func (b Balance) Add(other Balance) Balance {
+	r := make(Balance)
+	for k, v := range b {
+		r[k] = v
+	}
+	for k, v := range other {
+		vv, ok := r[k]
+		if ok {
+			r[k] = v.Add(vv)
+		} else {
+			r[k] = v
+		}
+	}
+	return r
+}
+
+func (b Balance) Equal(other Balance) bool {
+	if len(b) != len(other) {
+		return false
+	}
+	for k, v := range b {
+		vv, ok := other[k]
+		if !ok {
+			return false
+		}
+		if !v.Equal(vv) {
+			return false
+		}
+	}
+	return true
+}
+
+func hash(v string) string {
+	h := sha256.New()
+	h.Write([]byte(v))
+	b := h.Sum(nil)
+	return hex.EncodeToString(b)
+}
+
+type MarkelProof struct {
+	Root struct {
+		Balances Balance
+		Hash     string
+	}
+	Self struct {
+		Balances Balance
+		Nonce    string
+	}
+	Path []struct {
+		Balances Balance
+		Hash     string
+		Pos      Pos
+	}
+}
+
+func (m *MarkelProof) Validate() bool {
+	h := hash(m.Self.Nonce + m.Self.Balances.Format())
+	b := m.Self.Balances
+	for _, path := range m.Path {
+		if path.Hash == "" { // no right node
+			h = hash(h + h + b.Format())
+		} else {
+			b = b.Add(path.Balances)
+			if path.Pos == Left {
+				h = hash(path.Hash + h + b.Format())
+			} else {
+				h = hash(h + path.Hash + b.Format())
+			}
+		}
+	}
+
+	fmt.Printf("proofed hash: %s\n", h)
+	fmt.Printf("root hash: %s\n", m.Root.Hash)
+	if h != m.Root.Hash {
+		return false
+	}
+	fmt.Printf("proofed balances: %s\n", b.Format())
+	fmt.Printf("root balances: %s\n", m.Root.Balances.Format())
+	if !b.Equal(m.Root.Balances) {
+		return false
+	}
+	return true
+}
+
+func main() {
+	var f string
+	flag.StringVar(&f, "f", "", "merkle proof file")
+	flag.Parse()
+	if f == "" {
+		flag.Usage()
+		return
+	}
+
+	b, err := os.ReadFile(f)
+	if err != nil {
+		fmt.Println("invalid merkle proof file", err)
+		return
+	}
+	var m MarkelProof
+	if err := json.Unmarshal(b, &m); err != nil {
+		fmt.Println("invalid merkle proof file", err)
+		return
+	}
+	if m.Root.Hash == "" || len(m.Path) == 0 {
+		fmt.Println("empty merkle proof file")
+		return
+	}
+	if m.Validate() {
+		fmt.Println("Merkle tree path validation passed")
+	} else {
+		fmt.Println("Merkle tree path validation failed.")
+	}
+}