Ethernaut Hacks Level 0: Hello Ethernaut

This is the level 0 of Ethernaut game.

Pre-requisites

• Basics of web3js

Hack

I assume you've read instructions of the level 0 and acquired test ether. The level contract methods are injected right into our browser console, so we can start calling methods.

Let's start.
The instructions asks to call this method in console:

await contract.info()

// Output: 'You will find what you need in info1().'

We follow the output and call:

await contract.info1()

// Output: 'Try info2(), but with "hello" as a parameter.'

Following...

await contract.info2("hello")

// Output: 'The property infoNum holds the number of the next info method to call.'

To get infoNum we call it's public getter:

await contract.infoNum().then(v => v.toString())

// Output: 42

Note that infoNum() returns a BigNumber object so we convert it to string to see actual number.

Proceeding with info42:

await contract.info42()

// Output: 'theMethodName is the name of the next method.'

Again, following output:

await contract.theMethodName()

// Output: 'The method name is method7123949.'

And so:

await contract.method7123949()

// Output: 'If you know the password, submit it to authenticate().'

Ok...but what's the password? Let's inspect the contracts ABI:

contract

// Output: { abi: ..., address: ..., ...., password: f () }

Upon inspecting we see there's a password method for contract. Let's call it:

await contract.password()

// Output: 'ethernaut0`

We got the password. Finally:

await contract.authenticate('ethernaut0')

and confirm the transaction on metamask. Submit instance.

Level completed!

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