md: Add Whirlpool bug emulation feature.
* src/gcrypt.h.in (GCRY_MD_FLAG_BUGEMU1): New. * src/cipher-proto.h (gcry_md_init_t): Add arg FLAGS. Change all code to implement that flag. * cipher/md.c (gcry_md_context): Replace SECURE and FINALIZED by bit field FLAGS. Add flag BUGEMU1. Change all users. (md_open): Replace args SECURE and HMAC by FLAGS. Init flags.bugemu1. (_gcry_md_open): Add for GCRY_MD_FLAG_BUGEMU1. (md_enable): Pass bugemu1 flag to the hash init function. (_gcry_md_reset): Ditto.
This problem is for example exhibited in the Linux cryptsetup tool.
See https://bbs.archlinux.org/viewtopic.php?id=175737 . It has be
been tracked down by Milan Broz.
The suggested way of using the flag is:
if (whirlpool_bug_assumed)
{#if GCRYPT_VERSION_NUMBER >= 0x010601
err = gcry_md_open (&hd, GCRY_MD_WHIRLPOOL, GCRY_MD_FLAG_BUGEMU1)
if (gpg_err_code (err) == GPG_ERR_INV_ARG)
error ("Need at least Libggcrypt 1.6.1 for the fix");
else
{
do_hash (hd);
gcry_md_close (hd);
}#endif
}
- Signed-off-by: Werner Koch <wk@gnupg.org>