AES/CCM Implementation in Objective-C with Streaming Support

Features:

• AES/128 - ECB Mode
• Streaming support for large files
• Data to Data Encryption/Decryption
• File to File Encryption/Decryption
• Stream Encryption/Decryption which allows you to upload each chunk of data to server
• It uses only 16kb of memory for all operations

Initialization:

NSData *key = ...
NSData *iv = ...
NSData *adata = ...
NSInteger tagLength = ...

VPCCMCrypt *ccm = [[VPCCMCrypt alloc] initWithKey:key
                                               iv:iv
                                            adata:adata
                                        tagLength:tagLength];

How to use:

Data to Data Encryption:

NSData *plainData = ...

[ccm encryptDataWithData:plainData finishedBlock:^(NSData *data) {
        //Do something with data
} errorBlock:^(NSError *error) {
        NSLog(@"Encryption Error: %@", error);
}];

Data to Data Decryption:

NSData *encryptedData = ...

[ccm decryptDataWithData:encryptedData finishedBlock:^(NSData *data) {
        //Do something with data
} errorBlock:^(NSError *error) {
        NSLog(@"Decryption Error: %@", error);
}];

File to File Encryption:

NSURL *sourceURL = ...
NSURL *destinationURL = ...

[ccm encryptFileToFileWithSourceURL:sourceURL
                            destUrl:destinationURL
                      finishedBlock:^{
                          //Encryption finished
                      } errorBlock:^(NSError *error) {
                          NSLog(@"Encryption Error: %@", error);
                      }];

File to File Decryption:

NSURL *sourceURL = ...
NSURL *destinationURL = ...

[ccm decryptFileToFileWithSourceURL:sourceURL
                            destUrl:destinationURL
                      finishedBlock:^{
                          //Decryption finished
                      } errorBlock:^(NSError *error) {
                          NSLog(@"Encryption Error: %@", error);
                      }];

Stream Encryption

NSURL *fileUrl = ...
[ccm encryptStreamWithUrl:fileUrl
                dataBlock:^(NSData *data, BOOL isLastBlock) {
                    if (isLastBlock) {
                        //data = TAG
                    }
                    //Upload data to server

                } errorBlock:^(NSError *error) {
                    NSLog(@"Encryption Error: %@", error);
                }];

Stream Decryption

NSURL *fileUrl = ...
[ccm decryptStreamWithUrl:fileUrl
                dataBlock:^(NSData *data, BOOL isLastBlock) {
                    //Do something with the decrypted data

                } errorBlock:^(NSError *error) {
                    NSLog(@"Decryption Error: %@", error);
                }];

Special thanks to Thanos Chatziathanasiou ([email protected]) for his help