Virgil Core SDK Objective-C/Swift
Introduction | SDK Features | Installation | Configure SDK | Usage Examples | Docs | Support
Introduction
The Virgil Core SDK is a low-level library that allows developers to get up and running with Virgil Cards Service API quickly and add end-to-end security to their new or existing digital solutions.
In case you need additional security functionality for multi-device support, group chats and more, try our high-level Virgil E3Kit framework.
SDK Features
- Communicate with Virgil Cards Service
- Manage users' public keys
- Encrypt, sign, decrypt and verify data
- Store private keys in secure local storage
- Use Virgil Crypto Library
Installation
Virgil Core SDK is provided as a set of frameworks. These frameworks are distributed via Carthage and CocoaPods. In this guide you'll also find one more package - Virgil Crypto Library, that is used by the SDK to perform cryptographic operations.
All frameworks are available for:
- iOS 9.0+
- macOS 10.11+
- tvOS 9.0+
- watchOS 2.0+
COCOAPODS
CocoaPods is a dependency manager for Cocoa projects. You can install it with the following command:
$ gem install cocoapods
To integrate VirgilSDK into your Xcode project using CocoaPods, specify it in your Podfile:
target '<Your Target Name>' do
use_frameworks!
pod 'VirgilSDK', '~> 8.0'
end
Then, run the following command:
$ pod install
Carthage
Carthage is a decentralized dependency manager that builds your dependencies and provides you with binary frameworks.
You can install Carthage with Homebrew using the following command:
$ brew update
$ brew install carthage
To integrate VirgilSDK into your Xcode project using Carthage, create an empty file with name Cartfile in your project's root folder and add following lines to your Cartfile
github "VirgilSecurity/virgil-sdk-x" ~> 8.0
Linking against prebuilt binaries
To link prebuilt frameworks to your app, run following command:
$ carthage update --use-xcframeworks --no-use-binaries
This will build each dependency or download a pre-compiled framework from github Releases.
Building for iOS/tvOS/watchOS
On your application targets’ “General” settings tab, in the “Linked Frameworks and Libraries” section, add following frameworks from the Carthage/Build folder inside your project's folder:
- VirgilSDK
- VirgilCrypto
- VirgilCryptoFoundation
- VSCCommon
- VSCFoundation
Check Embed & sign for each.
Building for macOS
On your application target's “General” settings tab, in the “Embedded Binaries” section, drag and drop following frameworks from the Carthage/Build folder on disk:
- VirgilSDK
- VirgilCrypto
- VirgilCryptoFoundation
- VSCCommon
- VSCFoundation
Additionally, you'll need to copy debug symbols for debugging and crash reporting on macOS.
On your application target’s “Build Phases” settings tab, click the “+” icon and choose “New Copy Files Phase”. Click the “Destination” drop-down menu and select “Products Directory”. For each framework, drag and drop corresponding dSYM file.
Configure SDK
This section contains guides on how to set up Virgil Core SDK modules for authenticating users, managing Virgil Cards and storing private keys.
Set up authentication
Set up user authentication with tokens that are based on the JSON Web Token standard with some Virgil modifications.
In order to make calls to Virgil Services (for example, to publish user's Card on Virgil Cards Service), you need to have a JSON Web Token ("JWT") that contains the user's identity, which is a string that uniquely identifies each user in your application.
Credentials that you'll need:
| Parameter | Description |
|---|---|
| App ID | ID of your Application at Virgil Dashboard |
| App Key ID | A unique string value that identifies your account at the Virgil developer portal |
| App Key | A Private Key that is used to sign API calls to Virgil Services. For security, you will only be shown the App Key when the key is created. Don't forget to save it in a secure location for the next step |
Set up JWT provider on Client side
Use these lines of code to specify which JWT generation source you prefer to use in your project:
import VirgilSDK
// Get generated token from server-side
let authenticatedQueryToServerSide: ((String) -> Void) -> Void = { completion in
completion("eyJraWQiOiI3MGI0NDdlMzIxZj....MK7p7Ak")
}
// Setup AccessTokenProvider
let accessTokenProvider = CallbackJwtProvider { tokenContext, completion in
authenticatedQueryToServerSide { jwtString in
completion(jwtString, nil)
}
}
Generate JWT on Server side
For this subsection we've created a sample backend that demonstrates how you can set up your backend to generate the JWTs. To set up and run the sample backend locally, head over to your GitHub repo of choice:
Node.js | Golang | PHP | Java | Python and follow the instructions in README.
Set up Card Verifier
Virgil Card Verifier helps you automatically verify signatures of a user's Card, for example when you get a Card from Virgil Cards Service.
By default, VirgilCardVerifier verifies only two signatures - those of a Card owner and Virgil Cards Service.
Set up VirgilCardVerifier with the following lines of code:
import VirgilSDK
import VirgilCrypto
// initialize Crypto library
let cardCrypto = VirgilCardCrypto()
let yourBackendVerifierCredentials =
VerifierCredentials(signer: "YOUR_BACKEND",
publicKey: Data(base64Encoded: publicKeyStr)!)
let yourBackendWhitelist =
try! Whitelist(verifiersCredentials: [yourBackendVerifierCredentials])
let cardVerifier = VirgilCardVerifier(cardCrypto: cardCrypto,
whitelists: [yourBackendWhitelist])
Set up Card Manager
This subsection shows how to set up a Card Manager module to help you manage users' public keys.
With Card Manager you can:
- specify an access Token (JWT) Provider.
- specify a Card Verifier used to verify signatures of your users, your App Server, Virgil Services (optional).
Use the following lines of code to set up the Card Manager:
// initialize cardManager and specify accessTokenProvider, cardVerifier
let cardManagerParams = CardManagerParams(cardCrypto: cardCrypto,
accessTokenProvider: accessTokenProvider,
cardVerifier: cardVerifier)
let cardManager = CardManager(params: cardManagerParams)
Usage Examples
Before you start practicing with the usage examples, make sure that the SDK is configured. See the Configure SDK section for more information.
Generate and publish Virgil Cards at Cards Service
Use the following lines of code to create a user's Card with a public key inside and publish it at Virgil Cards Service:
import VirgilSDK
import VirgilCrypto
// save a private key into key storage
let data = try! crypto.exportPrivateKey(keyPair.privateKey)
let entry = try! keychainStorage.store(data: data, withName: "Alice", meta: nil)
// publish user's card on the Cards Service
cardManager.publishCard(privateKey: keyPair.privateKey, publicKey: keyPair.publicKey).start { result in
switch result {
// Card is created
case .success(let card): break
// Error occured
case .failure(let error): break
}
}
Sign then encrypt data
Virgil Core SDK allows you to use a user's private key and their Virgil Cards to sign and encrypt any kind of data.
In the following example, we load a private key from a customized key storage and get recipient's Card from the Virgil Cards Service. Recipient's Card contains a public key which we will use to encrypt the data and verify a signature.
import VirgilSDK
import VirgilCrypto
// prepare a message
let messageToEncrypt = "Hello, Bob!"
let dataToEncrypt = messageToEncrypt.data(using: .utf8)!
// prepare a user's private key
let alicePrivateKeyEntry = try! keychainStorage.retrieveEntry(withName: "Alice")
let alicePrivateKey = try! crypto.importPrivateKey(from: alicePrivateKeyEntry.data)
// using cardManager search for user's cards on Cards Service
cardManager.searchCards(identities: ["Bob"]).start { result in
switch result {
// Cards are obtained
case .success(let cards):
let bobRelevantCardsPublicKeys = cards
.map { $0.publicKey }
// sign a message with a private key then encrypt on a public key
let encryptedData = try! crypto.signAndEncrypt(dataToEncrypt,
with: alicePrivateKey,
for: bobRelevantCardsPublicKeys)
// Error occured
case .failure(let error): break
}
}
Decrypt data and verify signature
Once the user receives the signed and encrypted message, they can decrypt it with their own private key and verify the signature with the sender's Card:
import VirgilSDK
import VirgilCrypto
// prepare a user's private key
let bobPrivateKeyEntry = try! keychainStorage.retrieveEntry(withName: "Bob")
let bobPrivateKey = try! exporter.importPrivateKey(from: bobPrivateKeyEntry.data)
// using cardManager search for user's cards on Cards Service
cardManager.searchCards(identities: ["Alice"]).start { result in
switch result {
// Cards are obtained
case .success(let cards):
let aliceRelevantCardsPublicKeys = cards.map { $0.publicKey }
// decrypt with a private key and verify using a public key
let decryptedData = try! crypto.decryptAndVerify(encryptedData,
with: bobPrivateKey,
usingOneOf: aliceRelevantCardsPublicKeys)
// Error occured
case .failure(let error): break
}
}
Get Card by its ID
Use the following lines of code to get a user's card from Virgil Cloud by its ID:
import VirgilSDK
// using cardManager get a user's card from the Cards Service
cardManager.getCard(withId: "f4bf9f7fcbedaba0392f108c59d8f4a38b3838efb64877380171b54475c2ade8").start { result in
switch result {
// Card is obtained
case .success(let card): break
// Error occurred
case .failure(let error): break
}
}
Get Card by user's identity
For a single user, use the following lines of code to get a user's Card by a user's identity:
import VirgilSDK
// using cardManager search for user's cards on Cards Service
cardManager.searchCards(identity: "Bob").start { result in
switch result {
// Cards are obtained
case .success(let cards): break
// Error occurred
case .failure(let error): break
}
}
Revoke Card
You can revoke user's Card in case they don't need it anymore. Revoked Card can still be obtained using its identifier, but this card won't appear during search query.
import VirgilSDK
let result = cardManager.revokeCard(withId: card.identifier).start { result in
switch result {
// Card is revoked
case .success: break
// Error occured
case .failure(let error): break
}
}
Generate key pair using VirgilCrypto
You can generate a key pair and save it in a secure key storage with the following code:
import VirgilCrypto
let crypto = try! VirgilCrypto()
let keyPair = try! crypto.generateKeyPair()
Save and retrieve key using keychain storage
import VirgilSDK
import VirgilCrypto
let storageParams = try! KeychainStorageParams.makeKeychainStorageParams()
let keychainStorage = KeychainStorage(storageParams: storageParams)
// export key to Data
let data = try! crypto.exportPrivateKey(keyPair.privateKey)
let identity = "Alice"
// save key data
let entry = try! keychainStorage.store(data: data, withName: identity, meta: nil)
// retrieve key data
let retrievedEntry = try! keychainStorage.retrieveEntry(withName: identity)
// import key from Data
let privateKey = try! exporter.importPrivateKey(from: retrievedEntry.data)
Docs
Virgil Security has a powerful set of APIs, and the Developer Documentation can get you started today.
License
This library is released under the 3-clause BSD License.
Support
Our developer support team is here to help you. Find out more information on our Help Center.
You can find us on Twitter or send us email [email protected].
Also, get extra help from our support team on Slack.
![VSSSearchCardsHTTPRequest: response body: []](https://avatars.githubusercontent.com/u/5261045?v=4)
Podfile.lock:
3 Mar 16, 2021
135 Dec 15, 2022
229 Jan 6, 2023
20 Dec 4, 2022
8 Feb 16, 2022
5 Jul 31, 2022
13 Sep 2, 2022
4 Sep 3, 2021
0 Jan 3, 2022
122 Dec 16, 2022
483 Jan 5, 2023
432 Jan 7, 2023
2.1k Jan 8, 2023
250 Jan 4, 2023
2 Mar 29, 2022
3 Nov 9, 2022
9.4k Jan 5, 2023
162 Dec 15, 2022