encrypt a string using Des64 and Des192 encryption algorithm in iPhone sdk?

I want to encrypt a string using des64 and des192 in iPhone . I ha开发者_运维知识库ve searched the internet and found some code but the thing is I am not that aware of cryptography . I heard that in iPhone we can make use of security framework which has got cryptography functions. But they are totally c based and really hard to understand .

Can anybody please direct me to some helpful resource or explain the code which is used to encrypt in iPhone ???

Thanks in advance !!

Bharat

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Sorry, Crypto isn't usually simple. The iPhone Developer Library has an example project including some symmetric crypto using Objective-C.

Essentially though, you follow these kinds of steps (not specific to any particular crypto API).

init_crypto_library();

key k = crypto_load_key("my/key.dat");
cipher c = crypto_init_cipher(k, CBCMODE);

while ( char* buf == get_plaintext() ){
  crypto_encrypt( c, buf );
}
char* encrypted = crypto_finalize_cipher( c );
crypto_unload_key( k );

You should always try to consider how safe the secret key is in your system. You can't really trust keeping it safe forever.