“Crypto for Humans”
The aim of the project is to provide useful and easy to use API interfaces for performing advanced cryptographic techniques in the iOS platform. Anyone who has tried to use the underlying crypto functionality APIs provided by the iOS, or to integrate with external crypto libraries like OpenSSL, can understand how frustrated the experience can be. The reasons for this are twofold. Firstly, all crypto libraries offer a variety of cryptographic primitives and you need to make a lot of decisions about which specific pieces to use. And if your decisions are wrong, the end-result will be an insecure system. Secondly, most libraries are written using the C language (and for a good reason), but this results in cumbersome usage for an obj-c developer (with potentially adverse and dangerous consequences for the unfamiliar).
By leveraging the state-of-the-art NaCl encryption library, which provides extremely powerful cryptographic primitives so the developer doesn’t need to worry on choosing the “right” one and offering an easy-to-use interfaces around the platform’s build-in Security and CommonCrypto services, we believe Crypto can be transformed from a frustrating experience to an enjoyable one.
We understand that applying good cryptographic techniques is not an easy task and requires deep knowledge of the underlying concepts. But we strongly believe a “friendlier” developer interface can ease that pain.
The project shares the same vision with our sibling AeroGear project AeroGear-Crypto-Java. If you are a Java developer, we strongly recommend to look at the project.
The project is also the base for providing cryptographic services to AeroGear-IOS library project.
- iOS 7 or higher
Installation with CocoaPods
CocoaPods is a dependency manager for Objective-C, which eases the pain of installing third-party libraries in your programs. The project is already published in the Cocoapods repository, so just add the following line in your ‘Podfile’ :
pod "AeroGear-Crypto", '0.2.3'
The following services are currently provided:
- A Symmetric encryption interface
- An Asymmetric encryption interface
- Password based key generation using PBKDF2
- Generation of Cryptographically secure random numbers.
- Digital signatures support interface
- Hashing functions interface
Password based key derivation
AGPBKDF2 *pbkdf2 = [[AGPBKDF2 alloc] init]; NSData *rawKey = [pbkdf2 deriveKey:@"passphrase"];
//Generate the key AGPBKDF2 *pbkdf2 = [[AGPBKDF2 alloc] init]; NSData *privateKey = [pbkdf2 deriveKey:@"passphrase"]; //Initializes the secret box AGSecretBox *secretBox = [[AGSecretBox alloc] initWithKey:privateKey]; //Encryption NSData *nonce = [AGRandomGenerator randomBytes:32]; NSData *dataToEncrypt = [@"My bonnie lies over the ocean" dataUsingEncoding:NSUTF8StringEncoding]; NSData *cipherData = [secretBox encrypt:dataToEncrypt nonce:nonce]; //Decryption AGSecretBox *pandora = [[AGSecretBox alloc] initWithKey:privateKey]; NSData *message = [secretBox decrypt:cipherData nonce:nonce];
//Create a new key pair AGKeyPair *keyPairBob = [[AGKeyPair alloc] init]; AGKeyPair *keyPairAlice = [[AGKeyPair alloc] init]; //Initializes the crypto box AGCryptoBox *cryptoBox = [[AGCryptoBox alloc] initWithKey:keyPairAlice.publicKey privateKey:keyPairBob.privateKey]; NSData *nonce = [AGRandomGenerator randomBytes:32]; NSData *dataToEncrypt = [@"My bonnie lies over the ocean" dataUsingEncoding:NSUTF8StringEncoding]; NSData *cipherData = [cryptoBox encrypt:dataToEncrypt nonce:nonce]; //Create a new box to test end to end asymmetric encryption AGCryptoBox *pandora = [[AGCryptoBox alloc] initWithKey:keyPairBob.publicKey privateKey:keyPairAlice.privateKey]; NSData *message = [pandora decrypt:cipherData nonce:nonce];
// create an SHA256 hash AGHash *agHash = [[AGHash alloc] init:CC_SHA256_DIGEST_LENGTH]; NSData *rawPassword = [agHash digest:@"My bonnie lies over the ocean"]; // create an SHA512 hash AGHash *agHash = [[AGHash alloc] init:CC_SHA512_DIGEST_LENGTH]; NSData *rawPassword = [agHash digest:@"My bonnie lies over the ocean"];
NSData *message = [@"My bonnie lies over the ocean" dataUsingEncoding:NSUTF8StringEncoding]; AGSigningKey *signingKey = [[AGSigningKey alloc] init]; AGVerifyKey *verifyKey = [[AGVerifyKey alloc] initWithKey:signingKey.publicKey]; // sign the message NSData *signedMessage = [signingKey sign:message]; // should detect corrupted signature NSMutableData *corruptedSignature = [NSMutableData dataWithLength:64]; BOOL isValid = [verifyKey verify:message signature:signedMessage]; // isValid should be YES BOOL isValid = [verifyKey verify:message signature:corruptedSignature]; // isValid should be NO
Generation of Cryptographically secure Random Numbers
NSData *random = [AGRandomGenerator randomBytes: