getStorageAt() rejects properly padded storage addresses starting with zeros

[cameel]

Og Hardhat 2.9.5 this code causes an error despite the storage address being correctly padded to 66 characters

await ethers.provider.getStorageAt(
    address,
    "0x0000000000000000000000000000000000000000000000000000000000000006"
)

InvalidArgumentsError: Errors encountered in param 1: Storage slot argument must have a length of 66 ("0x" + 32 bytes), but '0x6' has a length of 3

As I understand it something like "0x6" should be rejected but a number with all the leading zeros should not cause this error. Currently both are rejected.

How to reproduce

Run this in the shell:

mkdir test/ contracts/

cat <<EOF > hardhat.config.js
require("@nomiclabs/hardhat-waffle");

module.exports = {
    solidity: {
        compilers: [{
            version: "0.8.13",
            settings: {
                viaIR: true,
                optimizer: { enabled: true },
            },
        }]
    }
};
EOF

cat <<EOF > test/GetStorageAtTest.js
const { ethers } = require("hardhat");

const address = "0x1111111111222222222233333333334444444444";

it("getStorageAt() without leading zeros", async () => {
    await ethers.provider.getStorageAt(address, "0x12");
});

it("getStorageAt() with leading zeros", async () => {
    await ethers.provider.getStorageAt(address, "0x00" + "".padEnd(60, "0") + "12");
});

it("getStorageAt() with leading non-zeros", async () => {
    await ethers.provider.getStorageAt(address, "0x12" + "".padEnd(60, "0") + "12");;
});
EOF

cat <<EOF > contracts/C.sol
contract C {}
EOF

npm install hardhat @nomiclabs/hardhat-waffle chai
npx hardhat test

Output:

  1) getStorageAt() without leading zeros
  2) getStorageAt() with leading zeros
  ✔ getStorageAt() with leading non-zeros

  1 passing (537ms)
  2 failing

  1) getStorageAt() without leading zeros:
     InvalidArgumentsError: Errors encountered in param 1: Storage slot argument must have a length of 66 ("0x" + 32 bytes), but '0x12' has a length of 4
      at validateParams (node_modules/hardhat/src/internal/core/jsonrpc/types/input/validation.ts:64:13)
      at EthModule._getStorageAtParams (node_modules/hardhat/src/internal/hardhat-network/provider/modules/eth.ts:695:26)
      at EthModule.processRequest (node_modules/hardhat/src/internal/hardhat-network/provider/modules/eth.ts:185:49)
      at HardhatNetworkProvider._send (node_modules/hardhat/src/internal/hardhat-network/provider/provider.ts:195:31)
      at processTicksAndRejections (node:internal/process/task_queues:96:5)
      at runNextTicks (node:internal/process/task_queues:65:3)
      at listOnTimeout (node:internal/timers:528:9)
      at processTimers (node:internal/timers:502:7)
      at HardhatNetworkProvider.request (node_modules/hardhat/src/internal/hardhat-network/provider/provider.ts:118:18)
      at EthersProviderWrapper.send (node_modules/@nomiclabs/hardhat-ethers/src/internal/ethers-provider-wrapper.ts:13:20)

  2) getStorageAt() with leading zeros:
     InvalidArgumentsError: Errors encountered in param 1: Storage slot argument must have a length of 66 ("0x" + 32 bytes), but '0x12' has a length of 4
      at validateParams (node_modules/hardhat/src/internal/core/jsonrpc/types/input/validation.ts:64:13)
      at EthModule._getStorageAtParams (node_modules/hardhat/src/internal/hardhat-network/provider/modules/eth.ts:695:26)
      at EthModule.processRequest (node_modules/hardhat/src/internal/hardhat-network/provider/modules/eth.ts:185:49)
      at HardhatNetworkProvider._send (node_modules/hardhat/src/internal/hardhat-network/provider/provider.ts:195:31)
      at processTicksAndRejections (node:internal/process/task_queues:96:5)
      at runNextTicks (node:internal/process/task_queues:65:3)
      at listOnTimeout (node:internal/timers:528:9)
      at processTimers (node:internal/timers:502:7)
      at HardhatNetworkProvider.request (node_modules/hardhat/src/internal/hardhat-network/provider/provider.ts:118:18)
      at EthersProviderWrapper.send (node_modules/@nomiclabs/hardhat-ethers/src/internal/ethers-provider-wrapper.ts:13:20)

[github-actions]

This issue is also being tracked on Linear.

We use Linear to manage our development process, but we keep the conversations on Github.

LINEAR-ID: 90203a2a-e723-4825-a069-2ee3a443d523

[haardikk21]

Facing the same issue, looks like ethers.js is actually trimming zeroes from the padded string.

[stobiewan]

hardhat-ethers 2.0.6 strips the zeros in index.ts:hexValue(), and hardhat 2.9.5 changed the type of slot from quantity to Storageslot. The Storageslot validation function requires all the leading zeros so getStorageAt() always fails.

[fvictorio]

I think this comes from ethers. See this issue. This was working before because both us and ethers were going together against the spec 😅

By the way, we recently released a new package (in beta) to help with things like these. If anyone is interested in trying it, check this doc.

I'm going to close this issue now since there's not much we can do on our side.