Where to specify key and IV value when doing AES encryption/decryption in Android? -

i working on aes encryption , decryption in android. have audio file encrypted using aes/cbc. have key , iv (initialization vector).

i have read links. this

secretkeyspec skeyspec = new secretkeyspec(raw, "aes");

the secretkeyspec class used. should use key , iv values?

and need decrypt first 256 bytes data only. how can achieve this?

in code snippet, raw key (as byte array):

secretkeyspec skeyspec = new secretkeyspec(raw, "aes"); //                                         ^^^ key

of course, if have key hex string, you'll need convert bytes.

when encrypting, can either specify iv or let random 1 generated. if want specify yourself, use:

cipher cipher = cipher.getinstance("aes/cbc/pkcs5padding"); // adjust padding cipher.init(cipher.encrypt_mode, skeyspec, new ivparameterspec(...));

if want use automatic one, sure record 1 chosen calling

cipher.getiv();

for decryption, must specify iv , using ivparameterspec, encryption.

and need decrypt first 256 bytes data only. how can achieve this?

consider using cipherinputstream , read 256 bytes it.

Deter