eth_getStorageAt

返回指定地址的特定存储位置的值。

API请求

POST https://<network>.infura.io/v3/YOUR-PROJECT-ID

请求头：

Content-Type: application/json

请求参数：

• ADDRESS：要查询的地址，必需
• STORAGE POSITION：存储位置，必需
• BLOCK PARAMETER ：区块编号，或者字符串标签 "latest"、"earliest" 、 "pending"

请求示例：

JSON-RPC over HTTPS POST：

curl https://mainnet.infura.io/v3/YOUR-PROJECT-ID \
    -X POST \
    -H "Content-Type: application/json" \
    -d '{"jsonrpc":"2.0","method":"eth_getStorageAt","params": ["0x295a70b2de5e3953354a6a8344e616ed314d7251", "0x6661e9d6d8b923d5bbaab1b96e1dd51ff6ea2a93520fdc9eb75d059238b8c5e9", "0x65a8db"],"id":1}'

JSON-RPC over websockets：

wscat -c wss://mainnet.infura.io/ws/v3/YOUR-PROJECT-ID
>{"jsonrpc":"2.0","method":"eth_getStorageAt","params": ["0x295a70b2de5e3953354a6a8344e616ed314d7251", "0x6661e9d6d8b923d5bbaab1b96e1dd51ff6ea2a93520fdc9eb75d059238b8c5e9", "0x65a8db"],"id":1}

API响应

返回指定位置的存储的值。

响应结果示例：

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x0000000000000000000000000000000000000000000000000000000000000000"
}

存储位置的计算

要正确计算存储位置，依赖于要提取的存储。考虑下面部署在0x295a70b2de5e3953354a6a8344e616ed314d7251 地址的合约，使用地址0x391694e7e0b0cce554cb130d723a9d27458f9298：

contract Storage {
    uint pos0;
    mapping(address => uint) pos1;

    function Storage() {
        pos0 = 1234;
        pos1[msg.sender] = 5678;
    }
}

提取pos0很直接：

curl https://mainnet.infura.io/v3/YOUR-PROJECT-ID \
    -X POST \
    -H "Content-Type: application/json" \
    -d '{"jsonrpc":"2.0", "method": "eth_getStorageAt", "params": ["0x295a70b2de5e3953354a6a8344e616ed314d7251", "0x0", "0x65a8db"], "id": 1}'

响应结果：

{
    "jsonrpc":"2.0",
    "id":1,
    "result":"0x00000000000000000000000000000000000000000000000000000000000004d2"
}

要提取映射表中的元素比较困难。映射表中的某个元素的位置计算如下：

keccak(LeftPad32(key, 0), LeftPad32(map position, 0))

这意味着要提取存储位置pos1["0x391694e7e0b0cce554cb130d723a9d27458f9298"]的值，我们需要如下计算：

keccak(decodeHex("000000000000000000000000391694e7e0b0cce554cb130d723a9d27458f9298" + "0000000000000000000000000000000000000000000000000000000000000001"))

geth控制台中内置的web3库可以用来计算：

> var key = "000000000000000000000000391694e7e0b0cce554cb130d723a9d27458f9298" + "0000000000000000000000000000000000000000000000000000000000000001"
undefined
> web3.sha3(key, {"encoding": "hex"})
"0x6661e9d6d8b923d5bbaab1b96e1dd51ff6ea2a93520fdc9eb75d059238b8c5e9"

现在查询该位置的值：

curl https://mainnet.infura.io/v3/YOUR-PROJECT-ID \
    -X POST \
    -H "Content-Type: application/json" \
    -d '{"jsonrpc":"2.0", "method": "eth_getStorageAt", "params": ["0x295a70b2de5e3953354a6a8344e616ed314d7251", "0x6661e9d6d8b923d5bbaab1b96e1dd51ff6ea2a93520fdc9eb75d059238b8c5e9", "0x65a8db"], "id": 1}'

响应结果如下：

{
    "jsonrpc":"2.0",
    "id":1,
    "result":"0x000000000000000000000000000000000000000000000000000000000000162e"
}