timing attacks.
BN_FLG_EXP_CONSTTIME requests this algorithm, and this done by default for
RSA/DSA/DH private key computations unless
RSA_FLAG_NO_EXP_CONSTTIME/DSA_FLAG_NO_EXP_CONSTTIME/
DH_FLAG_NO_EXP_CONSTTIME is set.
Submitted by: Matthew D Wood
Reviewed by: Bodo Moeller
- possibility of re-creation of the blinding parameters after a
fixed number of uses (suggested by Bodo)
- calculatition of the rsa::e in case it's absent and p and q
are present (see bug report #785)
- improve the performance when if one rsa structure is shared by
more than a thread (see bug report #555)
- fix the problem described in bug report #827
- hide the definition ot the BN_BLINDING structure in bn_blind.c
COFF and a.out targets [similar to ELF targets]. You might notice some
rudementary support for shared mingw builds under cygwin. It works (it
produces cryptoeay32.dll and ssleay32.dll with everything exported by
name), but it's primarily for testing/debugging purposes, at least for
now...
- Remove unused and unuseful debug cruft.
- Remove unnecessary 'top' fudging from BN_copy().
- Fix a potential memory leak and simplify the expansion logic in
BN_bin2bn().
Submitted by: Nils Larsch
Reviewed by: Geoff Thorpe
Yet another question: some time ago you changed BN_set_word.
Why didn't you change BN_get_word as well?
Quite. I'm also removing the older commented-out implementations to improve
readability. This complex stuff seems to date from a time when the types
didn't match up well.
Submitted by: Nils Larsch, Geoff Thorpe
the only function that uses it) because it would trip up an assertion in
bn_div_words() when first invoked. This also adds BN_div_word() testing to
bntest.
Submitted by: Nils Larsch
Reviewed by: Geoff Thorpe
corresponding headers are only required for API functions or structure
details. This now includes the bignum types and BUF_MEM. Subsequent commits
will remove various dependencies on bn.h and buffer.h and update the
makefile dependencies.
especially for AIX. But most important BIGNUM assembler implementation
submitted by IBM.
Submitted by: Peter Waltenberg <pwalten@au1.ibm.com>
Reviewed by: appro
locally initialising their own.
NB: I've removed the "BN_clear_free()" loops for the exit-paths in some of
these functions, and that may be a major part of the performance
improvements we're seeing. The "free" part can be removed because we're
using BN_CTX. The "clear" part OTOH can be removed because BN_CTX
destruction automatically performs this task, so performing it inside
functions that may be called repeatedly is wasteful. This is currently safe
within openssl due to the fact that BN_CTX objects are never created for
longer than a single high-level operation. However, that is only because
there's currently no mechanism in openssl for thread-local storage. Beyond
that, this might be an issue for applications using the bignum API directly
and caching their own BN_CTX objects. The solution is to introduce a flag
to BN_CTX_start() that allows its variables to be automatically sanitised
on release during BN_CTX_end(). This way any higher-level function (and
perhaps the application) can specify this flag in its own
BN_CTX_start()/BN_CTX_end() pair, and this will cause inner-loop functions
specifying the flag to be ignored so that sanitisation is handled only once
back out at the higher level. I will be implementing this in the near
future.
