i have encrypted file during their creation using AES-256 algorithm in linux kernel (read_write.c) using the following sequence of functions:-
crypto_alloc_cipher()
crypto_cipher_setkey()
crypto_cipher_encrypt_one()
crypto_free_cipher()
the above sequence encrypts the file successfully, but the same sequence with decrypt function (crypto_cipher_decrypt_one()) does not decrypts the file, can anyone help me plz. thanks in advance.

There are a couple of places in the kernel which use the crypto module: the eCryptfs file system (linux/fs/ecryptfs/) and the 802.11 wireless stack (linux/drivers/staging/rtl8187se/ieee80211/). Both of these use AES.

Be certain that we are really talking about the kernel's implementation of these ciphers, which are necessarily used for things like VPN, versus the user space implementation of many of these same ciphers.

The bottom line for you, though, Aliasgar, is simply that ... ummm... "you have a bug in your code."

The easiest solution is ... grep the kernel source-tree to find other examples where these routines are used successfully, and very faithfully and very precisely imitate them. Crypto debugging always sux ... ... because you can only see that your code is wrong, but not why.

thanks sundialsvcs! can u tell me wat d bug could be, bcoz i tried many things n i saw dat wen i decrypt d file while encrypting only it does it successfully but decrypting separately while reading d file does not work, i think prblm could be in crypto_alloc_cipher(), while encryption i m passing parameters to dis routine as crypto_alloc_cipher("aes",4,32), whether it is correct, while decryption wat values should b passed to dis function, plz reply.thank you.