The 'rand_generate' method is not well suited for being used with
weak entropy sources in the 'get_entropy' callback, because the
caller needs to provide a preallocated buffer without knowing
how much bytes are actually needed to collect the required entropy.
Instead we use the 'rand_get_seed' and 'rand_clear_seed' methods
which were exactly designed for this purpose: it's the callee who
allocates and fills the buffer, and finally cleans it up again.
The 'rand_get_seed' and 'rand_clear_seed' methods are currently
optional for a provided random generator. We could fall back to
using 'rand_generate' if those methods are not implemented.
However, imo it would be better to simply make them an officially
documented requirement for seed sources.
Fixes#22332
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22394)
(cherry picked from commit 7998e7dc07)
The `get_user_{entropy,nonce}` callbacks were add recently to the
dispatch table in commit 4cde7585ce. Instead of adding corresponding
`cleanup_user_{entropy,nonce}` callbacks, the `cleanup_{entropy,nonce}`
callbacks were reused. This can cause a problem in the case where the
seed source is replaced by a provider: the buffer gets allocated by
the provider but cleared by the core.
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22423)
(cherry picked from commit 5516d20226)
When assigning pointers to functions in an OSSL_DISPATCH table, we try
to ensure that those functions are properly defined or declared with
an extra declaration using the corresponding function typedefs that
are defined by include/openssl/core_dispatch.h.
For the core dispatch table, found in crypto/provider_core.c, it seems
we forgot this habit, and thus didn't ensure well enough that the
function pointers that are assigned in the table can actually be used
for those dispatch table indexes.
This change adds all the missing declarations, and compensates for
differences with functions that do the necessary casting, making those
explicit rather than implicit, thereby trying to assure that we know
what we're doing.
One function is not fixed in this change, because there's a controversy,
a clash between the signature of BIO_ctrl() and OSSL_FUNC_BIO_ctrl_fn.
They have different return types.
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18198)
(cherry picked from commit 9574842e90)
Matt Caswell
Matthias St. Pierre
Pauli
Richard Levitte
Shane Lontis
Pauli