c# - How to decrypt with WinRT without changing existing encryption code in .NET Desktop App? -

i have little problem whole encrypt/decrypt cr*p ;-)

is possible decrypt data in winrt (windows store app) encrypted in .net desktop application , vice versa? cannot change code of desktop app because in use.

i tried few tutorials cryptographicengine in winrt never results match ones desktop app.

maybe me? i'm new .net development , never did encryption have no idea i'm doing ;-)

here of code used in desktop app - can't change code!

    private string pwd = "password";     private string salt = "salt";      public byte[] encrypt(byte[] data)     {         passwordderivebytes derivedpassword = new passwordderivebytes(pwd, encoding.ascii.getbytes(salt));         byte[] key = derivedpassword.getbytes(16);         byte[] iv = encoding.ascii.getbytes("1234567891234567");          rijndaelmanaged symmetrickey = new rijndaelmanaged();         symmetrickey.mode = ciphermode.cbc;         byte[] cipherbytes = null;          using (icryptotransform encryptor = symmetrickey.createencryptor(key, iv))         {             using (memorystream ms = new memorystream())             {                 using (cryptostream cryptostream = new cryptostream(ms, encryptor, cryptostreammode.write))                 {                     cryptostream.write(data, 0, data.length);                     cryptostream.flushfinalblock();                     cryptostream.close();                     cipherbytes = ms.toarray();                     ms.close();                 }             }         }          symmetrickey.clear();         return cipherbytes;     } 

here example method tried in winrt - result different desktop app (most of code http://blog.lordinaire.fr/2012/12/winrt-encryption-and-decryption-with-aes-algorithm/ )

non functioning code removed - see edit

i apreciate help

greetings austria

edit tried few things, still not work right :( can't right key. test encryption nonetheless, hardcoded key - works.

like nate diamond suggested, used keyderivationalogrithm empty salt , salted password. 1 problem is, don't know how "to salt". tried putting salt in front, @ end, in middle , alternating every symbol - still not right key :( here code using:

    // password = 11112222333344445555  // salt = aaaabbbbccccddddeeee     private string password = "11112222333344445555aaaabbbbccccddddeeee";     private byte[] salt = new byte[20];     private uint iterationcount = 100;      private static byte[] keybytes = null;     public static byte[] keybytes     {                 {             //for (int = 0; < salt.length; i++)             //{             //    salt[i] = 0;             //}              // setup kdf parameters desired salt , iteration count             keyderivationparameters kdfparameters = keyderivationparameters.buildforpbkdf2(cryptographicbuffer.createfrombytearray(salt), iterationcount);              // kdf provider pbkdf2, , store source password in cryptographic key             keyderivationalgorithmprovider kdf = keyderivationalgorithmprovider.openalgorithm(keyderivationalgorithmnames.pbkdf2sha1);             ibuffer passwordbuffer = cryptographicbuffer.convertstringtobinary(password, binarystringencoding.utf8);             cryptographickey passwordsourcekey = kdf.createkey(passwordbuffer);              // generate key material source password, salt, , iteration count.  call derivekeymaterial once,             // since calling twice generate same data key , iv.             uint totaldataneeded = 16;             ibuffer keyandiv = cryptographicengine.derivekeymaterial(passwordsourcekey, kdfparameters, totaldataneeded);              // split derived bytes seperate key , iv             keybytes = keyandiv.toarray();               return keybytes;         }     } 

here code of encrypt method - yields same result 1 in .net desktop app :)

private byte[] btvector = encoding.utf8.getbytes("1234567891234567"); private byte[] keybytes = encoding.utf8.getbytes("123456789123456789123456");  public byte[] encrypt(byte[] data)     {         // key , iv , put ibuffers         ibuffer keybuffer = windowsruntimebuffer.create(keybytes, 0, 16, 16); ;         ibuffer iv = windowsruntimebuffer.create(initialvectorbytes, 0, 16, 16);         ibuffer plaintext = cryptographicbuffer.createfrombytearray(data);         byte[] encrypteddata;          // setup aes key, using aes in cbc mode , applying pkcs#7 padding on input         symmetrickeyalgorithmprovider aesprovider = symmetrickeyalgorithmprovider.openalgorithm(symmetricalgorithmnames.aescbcpkcs7);         cryptographickey aeskeysymm = aesprovider.createsymmetrickey(keybuffer);          // encrypt data , convert byte array         ibuffer encrypted = cryptographicengine.encrypt(aeskeysymm, plaintext, iv);         cryptographicbuffer.copytobytearray(encrypted, out encrypteddata);         return encrypteddata;     } 

pbkdf[1/2] this:

1. take password.   2. add salt.   3. hash combined password , salt.  store in `result` 4. (number of iterations)     1. hash `result`, store in `result`. 

the big difference between pbkdf1 , pbkdf2 first part of step 4. in pbkdf1, printed. in pbkdf2, changes this:

4. (number of iterations)     1. combine `result` , `salt`. store in `result`     2. hash `result`, store in `result`. 

so, have few options.

option 1:

create custom implementation of pbkdf1. hashalgorithmprovider makes easy repeatedly hash result.

option 2:

use pbkdf2 empty salt byte array , combined salt , password secret. should have same effect pbkdf1.

it should noted if @ possible, should switch using pbkdf2.

hope helps , happy coding!