Name
crypto_hash_digest — 
  calculate message digest for a buffer
 
Synopsis
| int crypto_hash_digest ( | struct hash_desc * desc, | 
|  | struct scatterlist * sg, | 
|  | unsigned int nbytes, | 
|  | u8 * out ); | 
 
Description
   This function is a “short-hand” for the function calls of crypto_hash_init,
   crypto_hash_update and crypto_hash_final. The parameters have the same
   meaning as discussed for those separate three functions.
Return
   0 if the message digest creation was successful; < 0 if an error
   occurred