Is there a support for zip with encryption on the iPad? Also, looks like there are security flaws in using zip with encryption. Could you someone give some information on this?
Thanks,
Praveen
ZIP's default encryption indeed has security problems (weak encryption used). WinZIP and PKZip independently offered their own stronger encryption mechanisms. WinZIP offered only symmetric (AES-based) encryption, while PKZip also offers certificate-based encryption (but only within their own products - third-parties are allowed to only decrypt files encrypted with certificates).
Zip old-style decryption is definitely weak, however new implementations (WinZIP and others) can use AES for encryption. And, as well there is a lot of open source implementations (InfoZIP for instance) which can be used on iPhone, and support that encryption type.
Related
I need to implement jcryption in IOS. I have gone through the library it uses Rijndael encryption internally to encrypt the data.
I have tried AES256EncryptWithKey but it is not giving me expected encryption key.
Any help on this would be nice. Thanks
Rijndael with a 128-bit block size is AES. Use Common Crypto on iOS, it uses the hardware encryption engine. There are several ObjC AES answers here on SO, see iOS AES Encryption.
For a detailed answer you will need to provide your usage information on jCryption.
Also notice that jCryption has been discontinued. If you are trying to use jCryption in place of HTTPS the correct solution is to use HTTPS, see jCryption.
I am developing an app that stores PDF files. These files should be stored secure, i. e. encrypted. I also found some libraries that extend NSData with AES en/decryption. But then I read, that iOS supports hardware encryption via AES. Is the NSData library really necessary if they both provide AES256 encryption?
If there are differences, which way is more secure? Also.. how do I activate the hardware encryption? Or is this a global setting that applies to all apps? I guess that the files become decrypted after the device is unlocked? So if someone cracks my phone he has also access to the decrypted files? But if I do the encryption by myself and connect the decryption with a SHA hashed password that is stored in the keychain the files might still be inaccessible?
Edit:
Did I get it all wrong and my library (AQToolkit) is just some kind of API for the built-in hardware encryption and I am basically talking about the same thing?
I heartily recommend RNCryptor, which uses Apple's own Security.framework guaranteeing hardware encryption/decryption if possible. It's incredibly easy to use in the default case (AES-256 with 10k iterations of PBKDF2). It's not an encryption library per se, but rather an Obj-C packaging of the open source Common Crypto C library. Check it out.
I've worked with Java cryptography for many years. Now, we have a requirement to write an iOS application that will send encrypted payloads from the mobile device to a Java service. I've begun working with the iOS crypto support (CommonCrypto, etc.) and have found it a bit more difficult. The JCE has a very clean, concise API, so I've clearly gotten spoiled. In contrast, iOS cryptography is a far more difficult API to work with.
Are there any simplified crypto libraries or wrappers around CommonCrypto that provide a more concise API? In particular, we need:
Key generation (both symmetric and asymmetric)
Encryption/decryption of data
Digital signatures (SHA1withRSA, for example)
Hashing
RSA, 3DES, and AES support
I know I've seen a sample class or two that wraps AES encryption, for example. I'm looking for something a bit richer and more full-featured. Anyone have any suggestions?
You can use openSSL inside your iOS app, for ease of use you can use the SSCrypto library by septicus.
From the septicus site:
SSCrypto.framework provides a simple wrapper around OpenSSL library
functions for encryption, decryption (both symmetric and RSA) and
checksums. It also encodes and decodes base64 data and can generate
both private and public RSA keys. A test tool is included in the
project. Click here to see the main.m file that comes with SSCrypto
for examples of it's use.
I want to encrypt a parameter(which consist of sensitive data) while sending to server(WCF Service) using SHA1 algorithm, On server end I'll decrypt the string and use it.
This way i can ensure any third party won't read my sensitive data so easily.
How do I encrypt the string in windows phone 7 using SHA1 algorithm and decrypt the same in my WCF service.
Encrypted string may come to server from iPhone, android or WP7; How do I ensure that every client will produce the same result in server.
Update:
Can I use AES algorithm for above requirement?
How do I encrypt the string in windows phone 7 using SHA1 algorithm and decrypt the same
You don't. SHA-1 is a hashing algorithm. It's one way - you can't "decrypt" it. You should choose a symmetric or public/private key algorithm based on your requirements. Read the .NET cryptographic services documentation as a starting point - I'd expect pretty much any of the algorithms supported by .NET to also be supported on other platforms.
Alternatively, just use HTTPS instead of HTTP... that would satisfy your initial highlighted requirement without you having to do much work at all (beyond the server-side deployment of appropriate HTTPS certs).
Agree with Jon's post but with additional thoughts.
I cannot comment yet (need more street cred) so I will post it here.
Your question does not state if you are transmitting this from a native app, or a browser (using an Ajaxian mechanism). But I will presume native. Really though the answer is the same with the difference being implementation.
The easiest approach IMO would be to use the tools and APIs to be a HTTPS (SSL/TLS) client which will give you over the wire confidentiality. The details of what quality of service the SSL connection provides is for you to configure from the "cipher suites") available. AES is available.
I'm looking for a Delphi implementation of an asymmetric encryption algorithm without any dependencies on external DLLs. Is there any available?
My goal is to encrypt/decrypt a string (or array of bytes) using a public/private key pair.
SecureBlackBox from Eldos offers a native, comprehensive solution - including certificate management and access to external crypto devices (i.e. USB tokens)
LockBox is now improved. It allows long keys for RSA, AES cipher and is in active development.
It is free, Open Source and 100% native code with no DLLs.
You can try Lockbox - http://sourceforge.net/projects/tplockbox/. It's free and includes RSA among others (Blowfish, MD5, SHA-1, DES, triple-DES, Rijndael, & digital signing of messages).
It comes complete with a good RSA example that demonstrates how to generate your public/private keys and how to actually encrypt and decrypt data using the keys.
I'm currently using it with Delphi 2010.
I realize that the original question stated "no external DLLs" but in the absence of an acceptable answer maybe you should take a look at the OpenSSL DLLs along with this Delphi link which contains an import unit for the library and some good examples on how to use it, including RSA encryption.
I have tinkered with this and got it working pretty well. There are some changes required to make it work with unicode Delphi - but these are mostly to do with changing PChar to PAnsiChar or PBytes.
Simple Delphi wrappers now allow me to sign/verify/encrypt sym or asym and use SSL. And let's be honest - the distribution of the OpenSSL DLLs is a lot more straightforward than some of the Microsoft offerings. Plus it's free and well maintained.
Take a look at the FGInt package on this site: http://submanifold.be/
If you can stomach using Windows services, there is the Crypto API: http://msdn.microsoft.com/en-us/library/aa380255(v=VS.85).aspx
If you are targeting Vista and up, there is the new Cryptography API: Next Generation. This also supports Elliptic Curve crypto: http://msdn.microsoft.com/en-us/library/aa376210(VS.85).aspx
Another very good fairly complete package is the Delphi Encryption Compendium (DEC) 5.2. You can download (Free with source) from http://www.torry.net/pages.php?id=519#939342.