Uniswap V2 Router - Casper Blockchain

Router uses other contracts (factory, pair, library, etc) and add, remove, swap tokens from liquidity pools.

Security Review Status

Quantstamp - commit 237cf3fa15ee95843603ab3857789cf2b53d58b7

Halborn

Contents

There are 2 contracts in this repo

1. uniswap-v2-library
2. uniswap-v2-router

Table of contents

• Interacting with the contract
  • Install the prerequisites
  • All Test Cases
  • Known contract hashes
  • Deploying Router contract manually
    • Manual Deployment
      • Factory
      • Wcspr
      • Library
      • Pair
    • Entry Point methods
      • add_liquidity
      • add_liquidity_cspr
      • remove_liquidity
      • remove_liquidity_cspr
      • swap_exact_tokens_for_tokens
      • swap_tokens_for_exact_tokens
      • swap_exact_cspr_for_tokens
      • swap_tokens_for_exact_cspr
      • swap_exact_tokens_for_cspr
      • swap_cspr_for_exact_tokens
      • quote
      • get_amount_out
      • get_amount_in
      • get_amounts_out
      • get_amounts_in
      • receive
      • change_owner
      • add_to_whitelist
      • remove_from_whitelist
  • Deploying Library contract manually
    • Entry Point methods
      • sort_tokens
      • get_reserves
      • quote
      • get_amount_out
      • get_amount_in
      • get_amounts_out
      • get_amounts_in
      • pair_for

Interacting with the contract

You need to have casper-client and jq installed on your system to run the examples. The instructions have been tested on Ubuntu 20.04.0 LTS.

Install the prerequisites

You can install the required software by issuing the following commands. If you are on an up-to-date Casper node, you probably already have all of the prerequisites installed so you can skip this step.

Note: If any command fails try again by restarting the terminal to reset the enviornment variable.

Update package repositories

sudo apt update

Install the command-line JSON processor

sudo apt install jq -y

Install rust

Choose cutomize intallation to install nightly version Install the nightly version (by default stable toolchain is installed)

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

rustup install nightly-2022-08-29

Check that nightly toolchain version is installed(this will list stable and nightly versions)

rustup toolchain list

Set rust nightly as default

rustup default nightly-2022-08-29-x86_64-unknown-linux-gnu

Install wasm32-unknown-unknown

rustup target add wasm32-unknown-unknown

Rust Version

rustup --version

Install Cmake

sudo apt-get -y install cmake

Note:https://cgold.readthedocs.io/en/latest/first-step/installation.html

Check if cmake is installed properly

cmake --version

Install the Casper Crates

cargo install cargo-casper

Add Casper repository

echo "deb https://repo.casperlabs.io/releases" bionic main | sudo tee -a /etc/apt/sources.list.d/casper.list

curl -O https://repo.casperlabs.io/casper-repo-pubkey.asc

sudo apt-key add casper-repo-pubkey.asc

sudo apt update

sudo apt install libssl-dev

sudo apt install pkg-config

Install the Casper client software

cargo +nightly-2022-08-29-x86_64-unknown-linux-gnu install casper-client

To check Casper Client Version

casper-client --version

Additonal commands for help

casper-client --help
casper-client <command> --help

Generate the keys

casper-client keygen keys

Fund the key

The keys can be funded from casper live website testnet faucet. Requires chrome browser and the casper signer extension. You should import the keys that were generated in the previous step

Install

Make sure wasm32-unknown-unknown is installed.

  make prepare

It's also recommended to have wasm-strip available in your PATH to reduce the size of compiled Wasm.

Build Dependencies

Run this command to build specific smart contract.

  make build-dependencies

Build Smart Contract

Run this command to build specific smart contract.

  make build-contract-uniswap-v2-library
  make build-contract-uniswap-v2-router

Build All Smart Contracts

Run this command in main folder to build all Smart Contract.

  make build-all

All Test Cases

Tests require that the CasperLabs-UniswapV2-core repository to be checked out into a sibling directory (one up from the current directory).

cd ..

git clone git@github.com:Rengo-Labs/uniswap-v2-core-casper.git

To build the contracts and run the tests, first navigate back to this directory and run:

make all

To run all the tests:

make test-all

Clean Command

To Clean up

make clean

Known contract hashes

Router contract has already being deployed. Inorder to interact with it you need to call it by its hash. The table below contains the contract hash (without the hash- prefix) for Router contract on public Casper networks:

Network	Account info contract hash	Contract owner
Testnet	hash-d52d2e98554c1854fd8a9ce541a9d52dab73fd2841655513a9c8295898803ce0	Casper Association

Deploying Router contract manually

If you need to deploy the router contract manually you need to pass the hashes of the other contracts as parameter. Following is the command to deploy the Router contract.

sudo casper-client put-deploy \
    --chain-name chain_name \
    --node-address http://$NODE_ADDRESS:7777/ \
    --secret-key path_to_secret_key.pem \
    --session-path path_to_wasm_file \
    --payment-amount 250000000000 \
    --session-arg="public_key:public_key='Public Key In Hex'" \
    --session-arg="factory:Key='Hash of factory Contract'" \
    --session-arg="wcspr:Key='Hash of WCSPR Contract'" \
    --session-arg="library:Key='Hash of Library Contract'" \
    --session-arg="contract_name:string='contract_name'"

Before deploying Router Contract, you would need to deploy other contracts first and pass hashes of these contracts to the respective parameters above. We have already deployed these contracts and the tables belows displays the hashes of the contracts.

Name	Network	Account info contract hash	Contract owner
Factory	Testnet	hash-5028190b8a5b6addbf3d51ee2c6ae5b913f09223d65eff9bcf5985f74ae976ec	Casper Association
Wcspr	Testnet	hash-083756dee38a7e3a8a7190a17623cfbc8bc107511de206f03c3dbd1af5463a45	Casper Association
Library	Testnet	hash-fa073d1a95a606871983689633dab9464fb5fbe5f723b0855e025ea01b9bf308	Casper Association
Pair	Testnet	hash-8e6fbaae9f5ff3bb3cca7cb15723b2a47917d074922575187cb136e8d4b169a7	Casper Association

Manual Deployment

For manual deployments of these contracts, following are the commands.

Factory

sudo casper-client put-deploy \
    --chain-name chain_name \
    --node-address http://$NODE_ADDRESS:7777/ \
    --secret-key path_to_secret_key.pem \
    --session-path path_to_wasm_file \
    --payment-amount 150000000000 \
    --session-arg="public_key:public_key='Public Key In Hex'" \
    --session-arg="fee_to_setter:Key='Hash of fee-to-setter Contract'" \
    --session-arg="contract_name:string='contract_name'"

Wcspr

sudo casper-client put-deploy \
    --chain-name chain_name \
    --node-address http://$NODE_ADDRESS:7777/ \
    --secret-key path_to_secret_key.pem \
    --session-path path_to_wasm_file \
    --payment-amount 345000000000 \
    --session-arg="public_key:public_key='Public Key In Hex'" \
    --session-arg="name:string='token-name'" \
    --session-arg="symbol:string='token-symbol'" \
    --session-arg="decimals:u8='unsigned integer value'" \
    --session-arg="initial_supply:u256='unsigned integer value'" \
    --session-arg="contract_name:string='contract_name'"

Library

sudo casper-client put-deploy \
    --chain-name chain_name \
    --node-address http://$NODE_ADDRESS:7777/ \
    --secret-key path_to_secret_key.pem \
    --session-path path_to_wasm_file \
    --payment-amount 120000000000 \
    --session-arg="public_key:public_key='Public Key In Hex'" \
    --session-arg="contract_name:string='contract_name'"

Pair

sudo casper-client put-deploy \
    --chain-name chain_name \
    --node-address http://$NODE_ADDRESS:7777/ \
    --secret-key path_to_secret_key.pem \
    --session-path path_to_wasm_file \
    --payment-amount 440000000000 \
    --session-arg="public_key:public_key='Public Key In Hex'" \
    --session-arg="name:string='token-name'" \
    --session-arg="symbol:string='token-symbol'" \
    --session-arg="decimals:u8='unsigned integer value'" \
    --session-arg="initial_supply:u256='unsigned integer value'" \
    --session-arg="factory_hash:Key='Hash of factory Contract'" \
    --session-arg="callee_contract_hash:Key='Callee Contract Hash'" \
    --session-arg="contract_name:string='contract_name'"

Entry Point methods

Following are the Router's entry point methods.

• add_liquidity

  This method adds liquidity to ERC-20⇄ERC-20 pool.
  To cover all possible scenarios, msg.sender should have already given the router an allowance of at least amount_a_desired/amount_b_desired on token_a/token_b.
  Always adds assets at the ideal ratio, according to the price when the transaction is executed.

  Following is the table of parameters.

  Parameter Name	Type
  token_a	Key
  token_b	Key
  amount_a_desired	U256
  amount_b_desired	U256
  amount_a_min	U256
  amount_b_min	U256
  to	KEY
  deadline	U256
  pair	Option<Key>

  This method returns Tuple3(U256,U256,U256)

• add_liquidity_cspr

  This method adds liquidity to ERC-20⇄CSPR pool with CSPR.
  To cover all possible scenarios, msg.sender should have already given the router an allowance of at least amount_token_desired on token.
  Always adds assets at the ideal ratio, according to the price when the transaction is executed.
  Left over cspr if any is returned to msg.sender

  Following is the table of parameters.

  Parameter Name	Type
  token	Key
  amount_token_desired	U256
  amount_cspr_desired	U256
  amount_token_min	U256
  amount_cspr_min	U256
  to	KEY
  deadline	U256
  pair	Option<Key>
  purse	URef

  This method returns Tuple3(U256,U256,U256)

• remove_liquidity

  This method Removes liquidity from an ERC-20⇄ERC-20 pool.
  msg.sender should have already given the router an allowance of at least liquidity on the pool.

  Following is the table of parameters.

  Parameter Name	Type
  token_a	Key
  token_b	Key
  liquidity	U256
  amount_a_min	U256
  amount_b_min	U256
  to	Key
  deadline	U256

  This method returns Tuple2(U256,U256)

• remove_liquidity_cspr

  This method Removes liquidity from an ERC-20⇄ERC-20 pool.
  msg.sender should have already given the router an allowance of at least liquidity on the pool.

  Following is the table of parameters.

  Parameter Name	Type
  token	Key
  liquidity	U256
  amount_token_min	U256
  amount_cspr_min	U256
  to	Key
  deadline	U256
  to_purse	URef

  This method returns Tuple2(U256,U256)

• swap_exact_tokens_for_tokens

  Swaps an exact amount of input tokens for as many output tokens as possible, along the route determined by the path. The first element of path is the input token, the last is the output token, and any intermediate elements represent intermediate pairs to trade through (if, for example, a direct pair does not exist).
  msg.sender should have already given the router an allowance of at least amount_in on the input token.

  Following is the table of parameters.

  Parameter Name	Type
  amount_in	U256
  amount_out_min	U256
  path	Vec<String>
  to	Key
  deadline	U256

  This method returns Vec<U256>

• swap_tokens_for_exact_tokens

  Receive an exact amount of output tokens for as few input tokens as possible, along the route determined by the path. The first element of path is the input token, the last is the output token, and any intermediate elements represent intermediate tokens to trade through (if, for example, a direct pair does not exist).
  msg.sender should have already given the router an allowance of at least amount_in_max on the input token.

  Following is the table of parameters.

  Parameter Name	Type
  amount_out	U256
  amount_in_max	U256
  path	Vec<String>
  to	Key
  deadline	U256

  This method returns Vec<String>

• swap_exact_cspr_for_tokens

  Swaps an exact amount of cspr for as many output tokens as possible, along the route determined by the path. The first element of path must be WCSPR, the last is the output token, and any intermediate elements represent intermediate pairs to trade through (if, for example, a direct pair does not exist).

  Following is the table of parameters.

  Parameter Name	Type
  amount_out_min	U256
  amount_in	U256
  path	Vec<String>
  to	Key
  deadline	U256
  purse	URef

  This method returns Vec<U256>

• swap_tokens_for_exact_cspr

  Receive an exact amount of CSPR for as few input tokens as possible, along the route determined by the path. The first element of path is the input token, the last must be WCSPR, and any intermediate elements represent intermediate pairs to trade through (if, for example, a direct pair does not exist).
  msg.sender should have already given the router an allowance of at least amount_in_max on the input token.
  If the to address is a smart contract, it must have the ability to receive cspr.

  Following is the table of parameters.

  Parameter Name	Type
  amount_out	U256
  amount_in_max	U256
  path	Vec<String>
  to	URef
  deadline	U256

  This method returns Vec<U256>

• swap_exact_tokens_for_cspr

  Swaps an exact amount of tokens for as much cspr as possible, along the route determined by the path. The first element of path is the input token, the last must be WCSPR, and any intermediate elements represent intermediate pairs to trade through (if, for example, a direct pair does not exist).
  If the to address is a smart contract, it must have the ability to receive cspr.

  Following is the table of parameters.

  Parameter Name	Type
  amount_in	U256
  amount_out_min	U256
  path	Vec<String>
  to	URef
  deadline	U256

  This method returns Vec<U256>

• swap_cspr_for_exact_tokens

  Receive an exact amount of tokens for as little CSPR as possible, along the route determined by the path. The first element of path must be WCSPR, the last is the output token and any intermediate elements represent intermediate pairs to trade through (if, for example, a direct pair does not exist).
  Leftover CSPR, if any, is returned to msg.sender.

  Following is the table of parameters.

  Parameter Name	Type
  amount_out	U256
  amount_in_max	U256
  path	Vec<String>
  to	Key
  deadline	U256
  purse	URef

  This method returns Vec<U256>

• quote

  Given some amount of an asset and pair reserves, returns an equivalent amount of the other asset.

  Following is the table of parameters.

  Parameter Name	Type
  amount_a	U256
  reserve_a	U256
  reserve_b	U256

  This method returns U256

• get_amount_out

  Given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset.

  Following is the table of parameters.

  Parameter Name	Type
  amount_in	U256
  reserve_in	U256
  reserve_out	U256

  This method returns U256

• get_amount_in

  Given an output amount of an asset and pair reserves, returns a required input amount of the other asset.

  Following is the table of parameters.

  Parameter Name	Type
  amount_out	U256
  reserve_in	U256
  reserve_out	U256

  This method returns U256

• get_amounts_out

  Performs chained getAmountOut calculations on any number of pairs.

  Following is the table of parameters.

  Parameter Name	Type
  amount_in	U256
  path	Vec<Key>

  This method returns Vec<U256>

• get_amounts_in

  Performs chained getAmountIn calculations on any number of pairs.

  Following is the table of parameters.

  Parameter Name	Type
  amount_out	U256
  path	Vec<Key>

  This method returns Vec<U256>

• receive

  Only accept CSPR via from the WCSPR contract.

  Following is the table of parameters.

  Parameter Name	Type
  amount	U512
  purse	URef

  This method returns nothing.

• change_owner

  Change the owner for whitelisting.

  Following is the table of parameters.

  Parameter Name	Type
  owner	Key

  This method returns nothing.

• add_to_whitelist

  Add a user to whitelist.

  Following is the table of parameters.

  Parameter Name	Type
  user	Key

  This method returns nothing.

• remove_from_whitelist

  Remove a user from whitelist.

  Following is the table of parameters.

  Parameter Name	Type
  user	Key

  This method returns nothing.

Deploying Library contract manually

If you need to deploy the Library contract manually you need to pass the some parameters. Following is the command to deploy the Library contract.

sudo casper-client put-deploy \
    --chain-name chain_name \
    --node-address http://$NODE_ADDRESS:7777/ \
    --secret-key path_to_secret_key.pem \
    --session-path path_to_wasm_file \
    --payment-amount 120000000000 \
    --session-arg="public_key:public_key='Public Key In Hex'" \
    --session-arg="contract_name:string='contract_name'"

Entry Point methods

Following are the WCSPR's entry point methods.

• sort_tokens

  Return the tokens Contract Package Hash.

  Following is the table of parameters.

  Parameter Name	Type
  token_a	Key
  token_b	Key

  This method returns Tuple2(ContractPackageHash,ContractPackageHash)

• get_reserves

  Return the reserves.

  Following is the table of parameters.

  Parameter Name	Type
  factory	Key
  token_a	Key
  token_b	Key

  This method returns Tuple2(U128,U128)

• quote

  Given some amount of an asset and pair reserves, returns an equivalent amount of the other asset.

  Following is the table of parameters.

  Parameter Name	Type
  amount_a	U256
  reserve_a	U256
  reserve_b	U256

  This method returns U256

• get_amount_out

  Given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset.

  Following is the table of parameters.

  Parameter Name	Type
  amount_in	U256
  reserve_in	U256
  reserve_out	U256

  This method returns U256

• get_amount_in

  Given an output amount of an asset and pair reserves, returns a required input amount of the other asset.

  Following is the table of parameters.

  Parameter Name	Type
  amount_out	U256
  reserve_in	U256
  reserve_out	U256

  This method returns U256

• get_amounts_out

  Performs chained getAmountOut calculations on any number of pairs.

  Following is the table of parameters.

  Parameter Name	Type
  factory	Key
  amount_in	U256
  path	Vec<Key>

  This method returns Vec<U256>

• get_amounts_in

  Performs chained getAmountIn calculations on any number of pairs.

  Following is the table of parameters.

  Parameter Name	Type
  factory	Key
  amount_out	U256
  path	Vec<Key>

  This method returns Vec<U256>

• pair_for

  Returns the pair on the following addresses.

  Following is the table of parameters.

  Parameter Name	Type
  factory	Key
  token_a	Key
  token_b	Key

  This method returns Key