• Ability to do AES CCM encryption (no auth data)
• Ability to use Modulus and Exponent in RSA encryption
• Native iOS code without dependancies, no need in OpenSSL

Usage

// generate a unique AES key and (later) encrypt it with the public RSA key of the merchant
NSMutableData *key = [NSMutableData dataWithLength:kCCKeySizeAES256];
SecRandomCopyBytes(NULL, kCCKeySizeAES256, key.mutableBytes);

// generate a nonce
NSMutableData *iv = [NSMutableData dataWithLength:12];
SecRandomCopyBytes(NULL, 12, iv.mutableBytes);

NSData *cipherText = [TKAESCCMCryptor encrypt:data withKey:key iv:iv];
NSData *encryptedKey = [TKRSACryptor encrypt:key withKeyInHex:keyInHex];

Or use the wrapper class TKCryptor and it's method

+ (NSString *)encrypt:(NSData *)data publicKeyInHex:(NSString *)keyInHex;

wich does:

• Encrypts the data with AES-CBC using generated AES256 session key and IV (12)
• Encrypts the session key with RSA using public key (using Keychain)
• Returns fully composed message in format:
  • a prefix ("")
  • a separator ($)
  • RSA encrypted AES key, base64 encoded
  • a separator ($)
  • a Payload of iv and cipherText, base64 encoded

Note:

• AES 256 key
• no additional auth data
• tagLength = 8
• ivLength = 12
• L = 3
• RSA stores certificate to Keychain by fingerprint (SHA1)
• keyInHex format is Exponent|Modulus

Installation

TKCryptor is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod "TKCryptor", :git => "https://github.com/xslim/TKCryptor.git"

Author

• Taras Kalapun, [email protected]
• Some code from tinydtls
• Some code from iphonelib

License

TKCryptor is available under the MIT license. See the LICENSE file for more info.