SwiftyEOS

SwiftyEOS is an open-source framework for interacting with EOS, written in Swift.

Features

• EOS key pairs generation
• Private key import
• Signature hash
• Basic RPC API(chain/history) query client
• Transaction(EOS token transfer)
• Helper class for handling offline wallet on iOS
• Encrypt/decrypt importing private key on iOS

How to use it

1. Copy the Libraries and Sources folders into your project, without main.swift.
2. Delete Sources/Utils/iOS if not targeted to iOS platform.
3. Add Libraries/include into Header Search Path.
4. Set Libraries/include/Bridging-Header.h as Objective-C Bridging Header. If you've got your own bridging header , copy all the import content in that file and paste into your own one.
5. Compile and pray.

Key Pairs Generation

SwiftyEOS now support secp256k1 key pairs.

There are bugs around secp256r1 key pairs generation but I cannot figure out why. Unit tests created from cleos create key --r1 wouldn't pass. You may not consider secp256r1 as an option since the cleos wallet command cannot import those keys, either.

Generate a random key pair:

let (pk, pub) = generateRandomKeyPair(enclave: .Secp256k1)

Easy, right?

print("private key: \(pk!.wif())")
print("public key : \(pub!.wif())")

// private key: PVT_K1_5HxrYTdZX89zodtJhTzCk87MfNZAkiBRfFvSX8kacYjtwaDpTkL
// public key : PUB_K1_4yDYdmcVcXxAxeNsUWRG7x9FKQE4HbJZdzgZFv1AYxk6oSVcLd

The PVT_K1_ and the PUB_K1_ prefixes are the parts of standard key presentations. But old styles are also supported in EOS system and SwiftyEOS:

print("private key: \(pk!.rawPrivateKey())")
print("public key : \(pub!.rawPublicKey())")

// private key: 5HxrYTdZX89zodtJhTzCk87MfNZAkiBRfFvSX8kacYjtwaDpTkL
// public key : EOS4yDYdmcVcXxAxeNsUWRG7x9FKQE4HbJZdzgZFv1AYxk6oSVcLd

Import existing key:

let importedPk = try PrivateKey(keyString: "5HxrYTdZX89zodtJhTzCk87MfNZAkiBRfFvSX8kacYjtwaDpTkL")
let importedPub = PublicKey(privateKey: importedPk!)

With delimiter and prefix:

let importedPk = try PrivateKey(keyString: "PVT_K1_5HxrYTdZX89zodtJhTzCk87MfNZAkiBRfFvSX8kacYjtwaDpTkL")
let importedPub = PublicKey(privateKey: importedPk!)

RPC API

EOSRPC.sharedInstance.chainInfo { (chainInfo, error) in
    if error == nil {
        print("Success: \(chainInfo!)")
    } else {
        print("Error: \(error!.localizedDescription)")
    }
}

Currently we have some basic rpc endpoints, you can find it at Sources/SwiftyEOS/Network

iOS Key Store

We have helpers for iOS offline wallet management at SEWallet.swift.

With SEWallet.swift you can easily store AES encrypted key info into file system. The default location is app's sandbox Library.

Multiple wallets management is not supported yet.

Create new wallet on iOS

In Objective-C:

[SEKeystoreService.sharedInstance newAccountWithPasscode:passcode succeed:^(SELocalAccount *account) {
} failed:^(NSError *error) {
        
}];

Retrieve saved wallet

[SELocalAccount currentAccount];

It will return nil if there's no saved wallet.

Transactions

Transaction behaviors are not fully supported yet, but you still can have a try with sample code at main.swift.

The related documents will be provided once the whole function is done.

1. Currency transfer (2018.08.15)
2. Push general transactions (2018.08.16)
3. On-device(offline) wallet lock & unlock on iOS (2018.08.17)
4. Stake/unstake cpu/net (2018.08.28)
5. Buy/sell ram (2018.08.28)
6. Create account (2018.10)
7. Push transaction with params list (2018.11.05)
8. Create/import key pairs with mnemonic

Transfer Currency

var transfer = Transfer()
transfer.from = "agoodaccount"
transfer.to = "gq3dinztgage"
transfer.quantity = "1.0000 EOS"
transfer.memo = "eureka"

Currency.transferCurrency(transfer: transfer, code: "eosio.token", privateKey: importedPk!, completion: { (result, error) in
    if error != nil {
        if error is RPCErrorResponse {
            print("\((error as! RPCErrorResponse).errorDescription())")
        } else {
            print("other error: \(String(describing: error?.localizedDescription))")
        }
    } else {
        print("done.")
    }
})

Push General Transactions

In Swift:

let account = "raoji"
let asset = "1.0000 EPRA"

let data = "{\"hey\": {\"account\":\"" + account  + "\", \"quantity\":\"" + asset + "\"}}"
let abi = try! AbiJson(code: "prabox1", action: "withdraw", json: data)

TransactionUtil.pushTransaction(abi: abi, account: account, privateKey: importedPk!, completion: { (result, error) in
    if error != nil {
        if (error! as NSError).code == RPCErrorResponse.ErrorCode {
            print("\(((error! as NSError).userInfo[RPCErrorResponse.ErrorKey] as! RPCErrorResponse).errorDescription())")
        } else {
            print("other error: \(String(describing: error?.localizedDescription))")
        }
    } else {
        print("Ok. Txid: \(result!.transactionId)")
    }
})

And also in Objective-C:

AbiJson *your_abi;
[TransactionUtil pushTransactionWithAbi:your_abi
                                account:@"your_account"
                               pkString:@"your_private_key"
                             completion:^(TransactionResult *result, NSError *error) {
        
}];

On-device(offline) Wallet Lock & Unlock on iOS

We added lock and timedUnlock functions to SELocalAccount.

Cpu/net/ram operations

There's a ResourceUtil.swift file with ResourceUtil class including, within which are several methods:

• stakeResource
• unstakeResource
• buyRam
• sellRam

Stake resource:

ResourceUtil.stakeResource(account: "raoji", net: 1.0, cpu: 1.0, pkString: "5HsaHvRCPrjU3yhapB5rLRyuKHuFTsziidA13Uw6WnQTeJAG3t4", completion: { (result, error) in
})

Mnemonic

Create a new key pair:

let (pk, pub, mn) = generateRandomKeyPair(enclave: .Secp256k1)

Import existing mnemonic:

let (pk, mn) = PrivateKey(enclave: .Secp256k1, mnemonicString: "your words here")

And we do have iOS helper API with mnemonic for key manangement in SEWallet.swift. Creating and importing mnemonic is possible now, with SEKeystoreService class(or SEKeystore deep level API if you're store it on yourself):

SEKeystoreService.sharedInstance.newAccountAndMnemonic(passcode: "your pass here", succeed: { (account, mnemonic) in

}) { (error) in

}

We're using NSObject inhereiting class for all top level API, so calling in Objective-C is the same way without providing additional bridging files.

And in SEWallet.swift file there are helper methods for iOS, too.

Thanks

Inspired by:

• https://github.com/EOSIO/eos
• https://github.com/EOSIO/fc
• https://github.com/bitcoin/bitcoin
• https://github.com/bitcoin/libbase58
• https://github.com/OracleChain/chainkit
• https://github.com/OracleChain/PocketEOS-IOS

Built with:

• https://github.com/kmackay/micro-ecc
• https://github.com/Flight-School/AnyCodable

Contributers:

• https://github.com/croath