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
dh.h, dsa.h, ec.h, ecdh.h, ecdsa.h, rsa.h), as the opaque bignum types are
already declared in ossl_typ.h. Add explicit includes for bn.h in those C
files that need access to structure internals or API functions+macros.
small key sizes seems to result from the code continually regenerating the
same prime value once the range is small enough. From my tests, this change
fixes the problem by setting an escape velocity of 3 repeats for the second
of the two primes.
PR: 874
proposed the change and submitted the patch, I jiggled it slightly and
adjusted the other parts of openssl that were affected.
PR: 867
Submitted by: Jelte Jansen
Reviewed by: Geoff Thorpe
changes are the fallout). As this could break source code that doesn't
directly include headers for interfaces it uses, changes to recursive
includes are covered by the OPENSSL_NO_DEPRECATED symbol. It's better to
define this when building and using openssl, and then adapt code where
necessary - this is how to stay current. However the mechanism exists for
the lethargic.
operations no longer require two distinct BN_CTX structures. This may put
more "strain" on the current BN_CTX implementation (which has a fixed limit
to the number of variables it will hold), but so far this limit is not
triggered by any of the tests pass and I will be changing BN_CTX in the
near future to avoid this problem anyway.
This also changes the default RSA implementation code to use the BN_CTX in
favour of initialising some of its variables locally in each function.
functions and macros.
This change has associated tags: LEVITTE_before_const and
LEVITTE_after_const. Those will be removed when this change has been
properly reviewed.
I have tried to convert 'len' type variable declarations to unsigned as a
means to address these warnings when appropriate, but when in doubt I have
used casts in the comparisons instead. The better solution (that would get
us all lynched by API users) would be to go through and convert all the
function prototypes and structure definitions to use unsigned variables
except when signed is necessary. The proliferation of (signed) "int" for
strictly non-negative uses is unfortunate.
be) precompiled out in the API headers. This change is to ensure that if
it is defined when compiling openssl, the deprecated functions aren't
implemented either.
called downstream that need it to be non-const. The fact that the RSA_METHOD
functions take the RSA* as a const doesn't matter, it just expresses that
*they* won't touch it.
PR: 602
Memory leak fix: RSA_blinding_on() would leave a dangling pointer in
rsa->blinding under certain circumstances.
Double definition fix: RSA_FLAG_NO_BLINDING was defined twice.
Also, I've added handling for other mod_exp calls that were not using any
cached montgomery forms. These cases matter only for special RSA keys (eg.
ones that are missing information) so are unlikely to be used in normal
circumstances.
verification step of CRT private key operations in the RSA code -
previously no montgomery form was checked or used for 'n', and so it would
be generated on the fly each time. As a result, private key operations are
now a percent or two faster.
Rather than adding this as another repetition of the nearly-identical
montgomery "check for first-use" initialisation code blocks, I've taken
this chance to create a helper function and macro-wrapper to replace them.
PR: 475
bad, so let's not check OPENSSL_NO_ENGINE in those places. Fortunately, all
the header files where the problem existed include ossl_typ.h, which makes
a 'forward declaration' of the ENGINE type.
