Move the description of the core types into their own pages

This expands on some of the core type descriptions, and also makes it
easier to find the documentation for each type, at least on Unix, with
a simple call like "man OSSL_ALGORITHM".

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19842)

1 files changed, 6 insertions, 84 deletions

diff --git a/doc/man7/openssl-core.h.pod b/doc/man7/openssl-core.h.pod
index 3d1eca3e64..568bf397b4 100644
--- a/doc/man7/openssl-core.h.pod
+++ b/doc/man7/openssl-core.h.pod
@@ -20,95 +20,17 @@ The types are:
 
 =over 4
 
-=item B<OSSL_DISPATCH>
+=item L<OSSL_DISPATCH(3)>
 
-This type is a tuple of function identity and function pointer.
-Arrays of this type are passed between the OpenSSL libraries and the
-providers to describe what functionality one side provides to the
-other.
-Arrays of this type must be terminated with a tuple having function
-identity zero and function pointer NULL.
+=item L<OSSL_ITEM(3)>
 
-The available function identities and corresponding function
-signatures are defined in L<openssl-core_dispatch.h(7)>.
+=item L<OSSL_ALGORITHM(3)>
 
-Any function identity not recognised by the recipient of this type
-will be ignored.
-This ensures that providers built with one OpenSSL version in mind
-will work together with any other OpenSSL version that supports this
-mechanism.
+=item L<OSSL_PARAM(3)>
 
-=item B<OSSL_ITEM>
+=item L<OSSL_CALLBACK(3)>
 
-This type is a tuple of integer and pointer.
-It's a generic type used as a generic descriptor, its exact meaning
-being defined by how it's used.
-Arrays of this type are passed between the OpenSSL libraries and the
-providers, and must be terminated with a tuple where the integer is
-zero and the pointer NULL.
-
-=item B<OSSL_ALGORITHM>
-
-This type is a tuple of an algorithm name (string), a property
-definition (string) and a dispatch table (array of B<OSSL_DISPATCH>).
-Arrays of this type are passed on demand from the providers to the
-OpenSSL libraries to describe what algorithms the providers provide
-implementations of, and with what properties.
-Arrays of this type must be terminated with a tuple having function
-identity zero and function pointer NULL.
-
-The algorithm names and property definitions are defined by the
-providers.
-
-The OpenSSL libraries use the first of the algorithm names as the main
-or canonical name, on a per algorithm implementation basis.
-
-=item B<OSSL_PARAM>
-
-This type is a structure that allows passing arbitrary object data
-between two parties that have no or very little shared knowledge about
-their respective internal structures for that object.
-It's normally passed in arrays, where the array is terminated with an
-element where all fields are zero (for non-pointers) or NULL (for
-pointers).
-
-These arrays can be used to set parameters for some object, to request
-parameters, and to describe parameters.
-
-B<OSSL_PARAM> is further described in L<OSSL_PARAM(3)>
-
-=item B<OSSL_CALLBACK>
-
-This is a function type for a generic feedback callback function:
-
-    typedef int (OSSL_CALLBACK)(const OSSL_PARAM params[], void *arg);
-
-A function that takes a pointer of this type should also take a
-pointer to caller data.  When calling this callback, the function is
-expected to build an B<OSSL_PARAM> array of data it wants or is
-expected to pass back, and pass that as I<params>, as well as
-the caller data pointer it received, as I<arg>.
-
-=item B<OSSL_PASSPHRASE_CALLBACK>
-
-This is a function type for a generic pass phrase callback function:
-
-    typedef int (OSSL_PASSPHRASE_CALLBACK)(char *pass, size_t pass_size,
-                                           size_t *pass_len,
-                                           const OSSL_PARAM params[],
-                                           void *arg);
-
-This callback can be used to prompt the user for a passphrase.  When
-calling it, a buffer to store the pass phrase needs to be given with
-I<pass>, and its size with I<pass_size>.  The length of the prompted
-pass phrase will be given back in I<*pass_len>.
-
-Additional parameters can be passed with the B<OSSL_PARAM> array
-I<params>.
-
-A function that takes a pointer of this type should also take a
-pointer to caller data, which should be passed as I<arg> to this
-callback.
+=item L<OSSL_PASSPHRASE_CALLBACK(3)>
 
 =back