961e38b2b0
To enable more efficient buffer reuse for HMAC operations three new
functions have been introduced. This change prevents the need to
reallocate memory for each HMAC operation:
- grub_crypto_hmac_reset(): reinitializes the hash contexts in the HMAC handle,
- grub_crypto_hmac_final(): provides the final HMAC result without freeing the
handle allowing it to be reused immediately,
- grub_crypto_hmac_free(): deallocates the HMAC handle and its associated memory.
To further facilitate buffer reuse ctx2 is now included within the HMAC handle
struct and the initialization of ctx2 is moved to grub_crypto_hmac_init().
The intermediate hash states, ctx and ctx2, for the inner and outer padded
keys are now cached. The grub_crypto_hmac_reset() restores these cached
states for new operations which avoids redundant hashing of the keys.
Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This is GRUB 2, the second version of the GRand Unified Bootloader. GRUB 2 is rewritten from scratch to make GNU GRUB cleaner, safer, more robust, more powerful, and more portable. See the file NEWS for a description of recent changes to GRUB 2. See the file INSTALL for instructions on how to build and install the GRUB 2 data and program files. See the file MAINTAINERS for information about the GRUB maintainers, etc. If you found a security vulnerability in the GRUB please check the SECURITY file to get more information how to properly report this kind of bugs to the maintainers. Please visit the official web page of GRUB 2, for more information. The URL is <http://www.gnu.org/software/grub/grub.html>. More extensive documentation is available in the Info manual, accessible using 'info grub' after building and installing GRUB 2. There are a number of important user-visible differences from the first version of GRUB, now known as GRUB Legacy. For a summary, please see: info grub Introduction 'Changes from GRUB Legacy'