fetching the logic contracts of the icon-bridge proxy contracts (BTSCore) on ethereum-like chains

[FidelVe]

How to fetch the logic contract address of the icon-bridge proxy contracts on the ethereum-type chains.

According to the eip-1967 standard for proxy contracts the address of the logic contract is to be stored in the storage slot "0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc" which is the result of the following hash bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1)

Following this standard if a developers wants to fetch the logic contract using web3.js they should do the following:

// BTSCore proxy contract on bsc testnet
const proxyContract = "0x1a2aDf985D6c2700fdAf72A9c1e2b39e3B647F7e"
const dataInMemorySlot = await web3.eth.getStorageAt( proxyContract, "0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc");

The result of this query is the following:

0x000000000000000000000000e020d4ad483c7ec90a24d9db502e66564ef9c236

Undo the 0 padding to obtain the contract address 0xe020d4ad483c7ec90a24d9db502e66564ef9c236

References:

• https://ethereum.stackexchange.com/questions/103143/how-do-i-get-the-implementation-contract-address-from-the-proxy-contract-address
• https://eips.ethereum.org/EIPS/eip-1967