This is placed as CORE because the core of libcrypto is the authority
for what is possible to do and what's required to make these abstract
objects work.

In essence, an abstract object is an OSSL_PARAM array with well
defined parameter keys and values:

-   an object type, which is a number indicating what kind of
    libcrypto structure the object in question can be used with.  The
    currently possible numbers are defined in <openssl/core_object.h>.
-   an object data type, which is a string that indicates more closely
    what the contents of the object are.
-   the object data, an octet string.  The exact encoding used depends
    on the context in which it's used.  For example, the decoder
    sub-system accepts any encoding, as long as there is a decoder
    implementation that takes that as input.  If central code is to
    handle the data directly, DER encoding is assumed. (*)
-   an object reference, also an octet string.  This octet string is
    not the object contents, just a mere reference to a provider-native
    object. (**)
-   an object description, which is a human readable text string that
    can be displayed if some software desires to do so.

The intent is that certain provider-native operations (called X
here) are able to return any sort of object that belong with other
operations, or an object that has no provider support otherwise.

(*) A future extension might be to be able to specify encoding.

(**) The possible mechanisms for dealing with object references are:

-   An object loading function in the target operation.  The exact
    target operation is determined by the object type (for example,
    OSSL_OBJECT_PKEY implies that the target operation is a KEYMGMT)
    and the implementation to be fetched by its object data type (for
    an OSSL_OBJECT_PKEY, that's the KEYMGMT keytype to be fetched).
    This loading function is only useful for this if the implementations
    that are involved (X and KEYMGMT, for example) are from the same
    provider.

-   An object exporter function in the operation X implementation.
    That exporter function can be used to export the object data in
    OSSL_PARAM form that can be imported by a target operation's
    import function.  This can be used when it's not possible to fetch
    the target operation implementation from the same provider.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from #12512)

The pass phrase prompter that's part of OSSL_ENCODER and OSSL_DECODER
is really a passphrase callback bridge between the diverse forms of
prompters that exist within OpenSSL: pem_password_cb, ui_method and
OSSL_PASSPHRASE_CALLBACK.

This can be generalised, to be re-used by other parts of OpenSSL, and
to thereby allow the users to specify whatever form of pass phrase
callback they need, while being able to pass that on to other APIs
that are called internally, in the form that those APIs demand.

Additionally, we throw in the possibility to cache pass phrases during
a "session" (we leave it to each API to define what a "session" is).
This is useful for any API that implements discovery and therefore may
need to get the same password more than once, such as OSSL_DECODER and
OSSL_STORE.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from #12512)

Reviewed-by: Shane Lontis <[email protected]>
(Merged from #12512)

Reviewed-by: Shane Lontis <[email protected]>
(Merged from #12512)

This includes fixing a bug that could only be discovered when no
loaders were registered.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from #12512)

When some function receives an OSSL_PARAM array to pilfer for data,
and there is a string of some sort, and all the code needs is to get
the pointer to the data, rather than a copy, there is currently no
other way than to use |param->data| directly.  This is of course a
valid method, but lacks any safety check (is |param->data_type|
correct, for example?).

OSSL_PARAM_get_utf8_string_ptr() and OSSL_PARAM_get_octet_string_ptr()
helps the programmer with such things, by setting the argument pointer
to |param->data|.
Additionally, the handle the data types OSSL_PARAM_UTF8_PTR and
OSSL_PARAM_OCTET_PTR as well.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from #12512)

This makes it possible to use OSSL_DECODER in functions that are passed
a OSSL_PASSPHRASE_CALLBACK already.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from #12512)

This adds the needed code to make the OSSL_STORE API functions handle
provided STORE implementations.

This also modifies OSSL_STORE_attach() for have the URI, the
library context and the properties in the same order as
OSSL_STORE_open_with_libctx().

The most notable change, though, is how this creates a division of
labor between libcrypto and any storemgmt implementation that wants to
pass X.509, X.509 CRL, etc structures back to libcrypto.  Since those
structures aren't directly supported in the libcrypto <-> provider
interface (asymmetric keys being the only exception so far), we resort
to a libcrypto object callback that can handle passed data in DER form
and does its part of figuring out what the DER content actually is.

This also adds the internal x509_crl_set0_libctx(), which works just
like x509_set0_libctx(), but for X509_CRL.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from #12512)

Reviewed-by: Shane Lontis <[email protected]>
(Merged from #12512)

This is placed as CORE because the core of libcrypto is the authority
for what is possible to do and what's required to make these abstract
objects work.

In essence, an abstract object is an OSSL_PARAM array with well
defined parameter keys and values:

-   an object type, which is a number indicating what kind of
    libcrypto structure the object in question can be used with.  The
    currently possible numbers are defined in <openssl/core_object.h>.
-   an object data type, which is a string that indicates more closely
    what the contents of the object are.
-   the object data, an octet string.  The exact encoding used depends
    on the context in which it's used.  For example, the decoder
    sub-system accepts any encoding, as long as there is a decoder
    implementation that takes that as input.  If central code is to
    handle the data directly, DER encoding is assumed. (*)
-   an object reference, also an octet string.  This octet string is
    not the object contents, just a mere reference to a provider-native
    object. (**)
-   an object description, which is a human readable text string that
    can be displayed if some software desires to do so.

The intent is that certain provider-native operations (called X
here) are able to return any sort of object that belong with other
operations, or an object that has no provider support otherwise.

(*) A future extension might be to be able to specify encoding.

(**) The possible mechanisms for dealing with object references are:

-   An object loading function in the target operation.  The exact
    target operation is determined by the object type (for example,
    OSSL_OBJECT_PKEY implies that the target operation is a KEYMGMT)
    and the implementation to be fetched by its object data type (for
    an OSSL_OBJECT_PKEY, that's the KEYMGMT keytype to be fetched).
    This loading function is only useful for this if the implementations
    that are involved (X and KEYMGMT, for example) are from the same
    provider.

-   An object exporter function in the operation X implementation.
    That exporter function can be used to export the object data in
    OSSL_PARAM form that can be imported by a target operation's
    import function.  This can be used when it's not possible to fetch
    the target operation implementation from the same provider.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from openssl#12512)

The pass phrase prompter that's part of OSSL_ENCODER and OSSL_DECODER
is really a passphrase callback bridge between the diverse forms of
prompters that exist within OpenSSL: pem_password_cb, ui_method and
OSSL_PASSPHRASE_CALLBACK.

This can be generalised, to be re-used by other parts of OpenSSL, and
to thereby allow the users to specify whatever form of pass phrase
callback they need, while being able to pass that on to other APIs
that are called internally, in the form that those APIs demand.

Additionally, we throw in the possibility to cache pass phrases during
a "session" (we leave it to each API to define what a "session" is).
This is useful for any API that implements discovery and therefore may
need to get the same password more than once, such as OSSL_DECODER and
OSSL_STORE.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from openssl#12512)

Reviewed-by: Shane Lontis <[email protected]>
(Merged from openssl#12512)

Reviewed-by: Shane Lontis <[email protected]>
(Merged from openssl#12512)

This includes fixing a bug that could only be discovered when no
loaders were registered.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from openssl#12512)

When some function receives an OSSL_PARAM array to pilfer for data,
and there is a string of some sort, and all the code needs is to get
the pointer to the data, rather than a copy, there is currently no
other way than to use |param->data| directly.  This is of course a
valid method, but lacks any safety check (is |param->data_type|
correct, for example?).

OSSL_PARAM_get_utf8_string_ptr() and OSSL_PARAM_get_octet_string_ptr()
helps the programmer with such things, by setting the argument pointer
to |param->data|.
Additionally, the handle the data types OSSL_PARAM_UTF8_PTR and
OSSL_PARAM_OCTET_PTR as well.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from openssl#12512)

This makes it possible to use OSSL_DECODER in functions that are passed
a OSSL_PASSPHRASE_CALLBACK already.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from openssl#12512)

This adds the needed code to make the OSSL_STORE API functions handle
provided STORE implementations.

This also modifies OSSL_STORE_attach() for have the URI, the
library context and the properties in the same order as
OSSL_STORE_open_with_libctx().

The most notable change, though, is how this creates a division of
labor between libcrypto and any storemgmt implementation that wants to
pass X.509, X.509 CRL, etc structures back to libcrypto.  Since those
structures aren't directly supported in the libcrypto <-> provider
interface (asymmetric keys being the only exception so far), we resort
to a libcrypto object callback that can handle passed data in DER form
and does its part of figuring out what the DER content actually is.

This also adds the internal x509_crl_set0_libctx(), which works just
like x509_set0_libctx(), but for X509_CRL.

Reviewed-by: Shane Lontis <[email protected]>
(Merged from openssl#12512)

Reviewed-by: Shane Lontis <[email protected]>
(Merged from openssl#12512)