aes_unwrap() function

aes_unwrap - Unwrap key with AES Key Wrap Algorithm (RFC3394) @kek: Key encryption key (KEK) @kek_len: Length of KEK in octets @n: Length of the plaintext key in 64-bit units; e.g., 2 = 128-bit = 16 bytes @cipher: Wrapped key to be unwrapped, (n + 1) * 64 bits @plain: Plaintext key, n * 64 bits Returns: 0 on success, -1 on failure (e.g., integrity verification failed)