开发指南

DMC 安全指南

該指南旨在幫助業務方瞭解在對接 DMC 時需要注意的安全問題，以及如何防範這些安全問題。

交易所充提接入方案

基本邏輯

充值：用戶需要向交易所的賬戶充值，為此，交易所會生成一個在平臺內唯一可識別的標識。當用戶充值到交易所賬戶時，需要在轉賬操作的”memo”字段中填入交易所為該用戶生成的唯一標識。

提現：用戶在進行提現時，需要填寫自己的 DMC 賬戶。交易所通過轉賬方式將用戶提現的 DMC 數量轉給用戶填寫的賬戶名，從而完成提幣操作。在此過程中，”memo”字段可能也有必要的，因為用戶有可能從一個交易所提現至另一個交易所。

注意事項

DMC 支持兩種轉賬方式，分別是 transfer 和 extransfer

其區別在於，transfer 操作只能轉移官方發行的通證，即 contract 為 @datamall 的通證，而 extransfer 則可以轉移任意通證。

目前，DMC 中官方發行的通證有 DMC@datamall，PST@datamall，僅支持 DMC@datamall 進行轉賬操作

DMC@datamall 是四位精度，最小單位為 0.0001 DMC

示例

extransfer

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{
    account: 'dmc.token',
    name: 'extransfer',
    authorization: [{
        actor: account,
        permission: 'active',
    }],
    data: {
        from: account,
        to: to,
        quantity: {
            quantity: `${amount} DMC`,
            contract: 'datamall'
        }
        memo: memo
    }
}

鏈上返回結果：

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{
  "transaction_id": "2b0e27e0b9c9d6c6ada6b09be5c267c7e2ce1926e6fa4bc7d3fae369d22175ca",
  "processed": {
    "id": "2b0e27e0b9c9d6c6ada6b09be5c267c7e2ce1926e6fa4bc7d3fae369d22175ca",
    "block_num": 13111072,
    "block_time": "2023-06-19T04:20:50.500",
    "producer_block_id": null,
    "receipt": {
      "status": "executed",
      "cpu_usage_us": 421,
      "net_usage_words": 18
    },
    "elapsed": 421,
    "net_usage": 144,
    "scheduled": false,
    "action_traces": [
      {
        "action_ordinal": 1,
        "creator_action_ordinal": 0,
        "closest_unnotified_ancestor_action_ordinal": 0,
        "receipt": {
          "receiver": "dmc.token",
          "act_digest": "b238dc7fc3dd05f45fde4ecc48bb66fad2c1669f1f81af51fd3384866e881c6f",
          "global_sequence": 13486942,
          "recv_sequence": 390918,
          "auth_sequence": [
            [
              "speakfool123",
              211
            ]
          ],
          "code_sequence": 37,
          "abi_sequence": 37
        },
        "receiver": "dmc.token",
        "act": {
          "account": "dmc.token",
          "name": "extransfer",
          "authorization": [
            {
              "actor": "speakfool123",
              "permission": "active"
            }
          ],
          "data": {
            "from": "speakfool123",
            "to": "asdasdqwdqwd",
            "quantity": {
              "quantity": "0.0001 DMC",
              "contract": "datamall"
            },
            "memo": "test"
          },
          "hex_data": "304488942e6854c590b84ddc266c1236010000000000000004444d4300000000000000311a69b2490474657374"
        },
        "context_free": false,
        "elapsed": 131,
        "console": "",
        "trx_id": "2b0e27e0b9c9d6c6ada6b09be5c267c7e2ce1926e6fa4bc7d3fae369d22175ca",
        "block_num": 13111072,
        "block_time": "2023-06-19T04:20:50.500",
        "producer_block_id": null,
        "account_ram_deltas": [],
        "except": null,
        "error_code": null,
        "return_value_hex_data": "",
        "inline_traces": []
      }
    ],
    "account_ram_delta": null,
    "except": null,
    "error_code": null
  }
}

transfer

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{
    "account": "dmc.token",
    "name": 'transfer',
    "authorization": [{
        actor: from,
        permission: 'active',
    }],
    "data": {
        "from": from,
        "to": to,
        "quantity": `${amount} DMC`,
        "memo": memo
    }
}

鏈上返回結果：

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{
  "transaction_id": "eeaa563d937e26dafa39cbe306faf47fa7a55d75ea558aa34148d206eecd0a86",
  "processed": {
    "id": "eeaa563d937e26dafa39cbe306faf47fa7a55d75ea558aa34148d206eecd0a86",
    "block_num": 13110171,
    "block_time": "2023-06-19T04:13:20.000",
    "producer_block_id": null,
    "receipt": {
      "status": "executed",
      "cpu_usage_us": 356,
      "net_usage_words": 17
    },
    "elapsed": 356,
    "net_usage": 136,
    "scheduled": false,
    "action_traces": [
      {
        "action_ordinal": 1,
        "creator_action_ordinal": 0,
        "closest_unnotified_ancestor_action_ordinal": 0,
        "receipt": {
          "receiver": "dmc.token",
          "act_digest": "75efa22efa51fc67e8379ca04d92b2dbdc4fef20652ad21995e4cd34226d2a36",
          "global_sequence": 13486018,
          "recv_sequence": 390897,
          "auth_sequence": [
            [
              "speakfool123",
              208
            ]
          ],
          "code_sequence": 37,
          "abi_sequence": 37
        },
        "receiver": "dmc.token",
        "act": {
          "account": "dmc.token",
          "name": "transfer",
          "authorization": [
            {
              "actor": "speakfool123",
              "permission": "active"
            }
          ],
          "data": {
            "from": "speakfool123",
            "to": "asdasdqwdqwd",
            "quantity": "0.0001 DMC",
            "memo": "test"
          },
          "hex_data": "304488942e6854c590b84ddc266c1236010000000000000004444d43000000000474657374"
        },
        "context_free": false,
        "elapsed": 152,
        "console": "",
        "trx_id": "eeaa563d937e26dafa39cbe306faf47fa7a55d75ea558aa34148d206eecd0a86",
        "block_num": 13110171,
        "block_time": "2023-06-19T04:13:20.000",
        "producer_block_id": null,
        "account_ram_deltas": [],
        "except": null,
        "error_code": null,
        "return_value_hex_data": "",
        "inline_traces": []
      }
    ],
    "account_ram_delta": null,
    "except": null,
    "error_code": null
  }
}

參數說明詳見 接口文檔

“假幣”充值

需要甄別，僅支持接受 DMC@datamall 的轉賬，其他通證的轉賬均視為無效交易。

對於transfer,

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"act": {
  "account": "dmc.token",
    "name": "transfer",
      "authorization": [
        {
          "actor": "speakfool123",
          "permission": "active"
        }
      ],
        "data": {
        "from": "speakfool123",
        "to": "asdasdqwdqwd",
        "quantity": "0.0001 DMC",
        "memo": "test"
      },
  "hex_data": "304488942e6854c590b84ddc266c1236010000000000000004444d43000000000474657374" 
}

需要注意：

對於extransfer,

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"act": {
  "account": "dmc.token",
  "name": "extransfer",
  "authorization": [
    {
      "actor": "speakfool123",
      "permission": "active"
    }
  ],
  "data": {
    "from": "speakfool123",
    "to": "asdasdqwdqwd",
    "quantity": {
      "quantity": "0.0001 DMC",
      "contract": "datamall"
    },
    "memo": "test"
  },
  "hex_data": "304488942e6854c590b84ddc266c1236010000000000000004444d4300000000000000311a69b2490474657374"
}

需要注意：

交易狀態確認

不可逆高度判斷

由於 DMC 使用了 PoSS的共識機制,在判斷一筆交易時，需要確保該交易已經被確認幷包含在不可逆的區塊中。不可逆高度是指在當前 DMC 節點網絡中已經達到共識的高度，低於這個高度的區塊不可被回滾。這意味著該高度以內的交易已經得到足夠的確認，不會被篡改或逆轉。

對於 DMC 網絡，如果一筆交易所在的區塊高度大於不可逆高度，那麼該交易仍處於可逆狀態，可能會受到區塊鏈的重組或其他攻擊的影響。但如果一筆交易所在的區塊高度小於或等於不可逆高度，我們可以確定該交易已經被足 夠多的 BP 節點確認，進入了不可逆狀態，不會再被回滾。

Hard - failed 狀態攻擊

DMC 鏈上交易的執行狀態存在多種，其中有一種狀態為 hard-failed，處於這種狀態下的交易的特點是，沒有被成功執行，但是依舊在鏈上留下了記錄，攻擊者可以利用 DMC 的這一交易特性對業務方造成威脅，從而進行無效交易。對這一安全威脅的防範辦法是，在不可逆高度的基礎上，對交易的狀態進行判斷，如果發現交易的狀態是 hard-failed 則認定為是非法交易。

chain/get_transaction_status

以下操作需要對應請求節點已經配置了transaction-finality-status-max-storage-size-gb的配置項，如果涉及資金問題，推薦維護自有同步節點。

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curl --location '${RPC_ENDPOINT}/v1/chain/get_transaction_status' \
--header 'Content-Type: application/json' \
--data '{
    "id": "TRX_ID"
}'

如果請求正確，會返回以下結果

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{
    "state": "IRREVERSIBLE",
    "block_number": 14899444,
    "block_id": "00e358f4f8906b140aff2db43ed991aea50255223eb0660e87e6c84861c2dbbc",
    "block_timestamp": "2023-07-06T09:27:05.000",
    "expiration": "2023-07-06T09:27:29.000",
    "head_number": 14899540,
    "head_id": "00e3595421070003362eb53f66808cfc9a1dd84e66c6fd63f23faa35493b8b31",
    "head_timestamp": "2023-07-06T09:27:53.000",
    "irreversible_number": 14899493,
    "irreversible_id": "00e35925187869c08d4fba75234066fd4e203ada79b0d923adab4ecfcd116806",
    "irreversible_timestamp": "2023-07-06T09:27:29.500",
    "earliest_tracked_block_id": "00e35341164012efb8685db89045bd88164adf21d8a7386c399437b8d644cd26",
    "earliest_tracked_block_number": 14897985
}

注意事項：

  1. state 為 IRREVERSIBLE 表示該交易已經被不可逆區塊確認，不會被回滾。
  2. 記錄默認保留 3 分鐘，超過時間則變為 UNKNOWN 狀態，如果有額外需要可以修改參數項 transaction-finality-status-success-duration-sec，默認值為 180 秒。

trace_api/get_block

以下操作需要對應請求節點已經加載了trace_api_plugin，如果涉及資金問題，推薦維護自有同步節點。

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curl --location '${RPC_ENDPOINT}/v1/trace_api/get_block' \
--header 'Content-Type: application/json' \
--data '{
    "block_num": ${block_num}
}'

如果請求正確，會返回以下結果

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{
    "id": "00f433cc28f34dc4a80e0bcfb6d935d0bf06f1d57210c76485bef6126b6de87e",
    "number": 16004044,
    "previous_id": "00f433cb0997beac31ea8977415b62fd0ac565aa4eba8a1959fbf7bd7e897e98",
    "status": "irreversible",
    "timestamp": "2023-05-17T02:47:36.000Z",
    "producer": "dmcrc1bppa11",
    "transaction_mroot": "0000000000000000000000000000000000000000000000000000000000000000",
    "action_mroot": "ea58ff5ff979f865869ebc38606017291950aeb9d67181e884e6722d048cce04",
    "schedule_version": 4,
    "transactions": [
        {
            "id": "a2d14ce284e5b3ad6ac708a5744cc8a771a643a0d69cbbf96d4223e40a879a39",
            "block_num": 16004044,
            "block_time": "2023-05-17T02:47:36.000",
            "producer_block_id": "00f433cc28f34dc4a80e0bcfb6d935d0bf06f1d57210c76485bef6126b6de87e",
            "actions": [
                ..
            ],
            "status": "executed",
            "cpu_usage_us": 100,
            "net_usage_words": 0,
            "signatures": [],
            "transaction_header": {
                "expiration": "2023-05-17T02:47:36",
                "ref_block_num": 13259,
                "ref_block_prefix": 2005527089,
                "max_net_usage_words": 0,
                "max_cpu_usage_ms": 0,
                "delay_sec": 0
            }
        }
    ]
}

注意事項：

  1. 確認 status為 irreversible，證明該區塊已經不可逆
  2. 遍歷transactions[]，確認所檢索交易在該區塊內
  3. 確認transactions[i].status 為 executed狀態

節點安全

對於交易所自己的 API 節點建議禁用外網 RPC，如果節點需要 RPC 訪問，建議使用內網 HTTP，對應配置示例代碼如下：

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chain.load("http", {
	"http-server-address": "127.0.0.1:8870",
});