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
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.
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.
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.
dsa_mod_exp() and bn_mod_exp() handlers from dsa_do_verify() and
dsa_sign_setup(). When another DSA_METHOD implementation does not define
these lower-level handlers, it becomes impossible to do a fallback to
software on errors using a simple DSA_OpenSSL()->fn(key).
This change allows the default DSA_METHOD to function in such circumstances
by only using dsa_mod_exp() and bn_mod_exp() handlers if they exist,
otherwise using BIGNUM implementations directly (which is what those
handlers did before this change). There should be no noticable difference
for the software case, or indeed any custom case that didn't already
segfault, except perhaps that there is now one less level of indirection in
all cases.
PR: 507
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.
override key-generation implementations by placing handlers in the methods
for DSA and DH. Also, parameter generation for DSA and DH is possible by
another new handler for each method.
- a patch to fix a memory leak in rsa_gen.c
- a note about compiler warnings with unions
- a note about improving structure element names
This applies his patch and implements a solution to the notes.
key-generation and prime-checking functions. Rather than explicitly passing
callback functions and caller-defined context data for the callbacks, a new
structure BN_GENCB is defined that encapsulates this; a pointer to the
structure is passed to all such functions instead.
This wrapper structure allows the encapsulation of "old" and "new" style
callbacks - "new" callbacks return a boolean result on the understanding
that returning FALSE should terminate keygen/primality processing. The
BN_GENCB abstraction will allow future callback modifications without
needing to break binary compatibility nor change the API function
prototypes. The new API functions have been given names ending in "_ex" and
the old functions are implemented as wrappers to the new ones. The
OPENSSL_NO_DEPRECATED symbol has been introduced so that, if defined,
declaration of the older functions will be skipped. NB: Some
openssl-internal code will stick with the older callbacks for now, so
appropriate "#undef" logic will be put in place - this is in case the user
is *building* openssl (rather than *including* its headers) with this
symbol defined.
There is another change in the new _ex functions; the key-generation
functions do not return key structures but operate on structures passed by
the caller, the return value is a boolean. This will allow for a smoother
transition to having key-generation as "virtual function" in the various
***_METHOD tables.
