Update core_names.h fields and document most fields.

Renamed some values in core_names i.e Some DH specific names were changed to use DH instead of FFC.
Added some strings values related to RSA keys.
Moved set_params related docs out of EVP_PKEY_CTX_ctrl.pod into its own file.
Updated Keyexchange and signature code and docs.
Moved some common DSA/DH docs into a shared EVP_PKEY-FFC.pod.
Moved Ed25519.pod into EVP_SIGNATURE-ED25519.pod and reworked it.

Added some usage examples. As a result of the usage examples the following change was also made:
ec allows OSSL_PKEY_PARAM_USE_COFACTOR_ECDH as a settable gen parameter.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11610)

1 files changed, 199 insertions, 0 deletions

diff --git a/doc/man7/EVP_PKEY-FFC.pod b/doc/man7/EVP_PKEY-FFC.pod
new file mode 100644
index 0000000000..e97a1c6bc4
--- /dev/null
+++ b/doc/man7/EVP_PKEY-FFC.pod
@@ -0,0 +1,199 @@
+=pod
+
+=head1 NAME
+
+EVP_PKEY-FFC - EVP_PKEY DSA and DH shared FFC parameters.
+
+=head1 DESCRIPTION
+
+Finite field cryptography (FFC) is a method of implementing discrete logarithm
+cryptography using finite field mathematics. DSA is an example of FFC and
+Diffie-Hellman key establishment algorithms specified in SP800-56A can also be
+implemented as FFC.
+
+The B<DSA> and B<DH> keytypes are implemented in OpenSSL's default and FIPS
+providers.
+The implementations support the basic DSA and DH keys, containing the public
+and private keys I<pub> and I<priv> as well as the three main domain parameters
+I<p>, I<q> and I<g>.
+
+For B<DSA> (and B<DH> that is not a named group) the FIPS186-4 standard
+specifies that the values used for FFC parameter generation are also required
+for parameter validation.
+This means that optional FFC domain parameter values for I<seed>, I<pcounter>
+and I<gindex> may need to be stored for validation purposes.
+For B<DH> the I<seed> and I<pcounter> can be stored in ASN1 data
+(but the I<gindex> is not). For B<DSA> however, these fields are not stored in
+the ASN1 data so they need to be stored externally if validation is required.
+
+=head2 FFC parameters
+
+In addition to the common parameters that all keytypes should support (see
+L<provider-keymgmt(7)/Common parameters>), the B<DSA> and B<DH> keytype
+implementations support the following.
+
+=over 4
+
+=item "pub" (B<OSSL_PKEY_PARAM_PUB_KEY>) <unsigned integer>
+
+The public key value.
+
+=item "priv" (B<OSSL_PKEY_PARAM_PRIV_KEY>) <unsigned integer>
+
+The private key value.
+
+=item "p" (B<OSSL_PKEY_PARAM_FFC_P>) <unsigned integer>
+
+A DSA or Diffie-Hellman prime "p" value.
+
+=item "q" (B<OSSL_PKEY_PARAM_FFC_Q>) <unsigned integer>
+
+A DSA or Diffie-Hellman prime "q" value.
+
+=item "g" (B<OSSL_PKEY_PARAM_FFC_G>) <unsigned integer>
+
+A DSA or Diffie-Hellman generator "g" value.
+
+=item "seed" (B<OSSL_PKEY_PARAM_FFC_SEED>) <octet string>
+
+An optional domain parameter I<seed> value used during generation and validation
+of I<p>, I<q> and canonical I<g>.
+For validation this needs to set the I<seed> that was produced during generation.
+
+=item "gindex" (B<OSSL_PKEY_PARAM_FFC_GINDEX>) <integer>
+
+Sets the index to use for canonical generation and verification of the generator
+I<g>.
+Set this to a positive value from 0..FF to use this mode. This I<gindex> can
+then be reused during key validation to verify the value of I<g>. If this value
+is not set or is -1 then unverifiable generation of the generator I<g> will be
+used.
+
+=item "pcounter" (B<OSSL_PKEY_PARAM_FFC_PCOUNTER>) <integer>
+
+An optional domain parameter I<counter> value that is output during generation
+of I<p>. This value must be saved if domain parameter validation is required.
+
+=item "hindex" (B<OSSL_PKEY_PARAM_FFC_H>) <integer>
+
+For unverifiable generation of the generator I<g> this value is output during 
+generation of I<g>. Its value is the first integer larger than one that
+satisfies g = h^j mod p (where g != 1 and "j" is the cofactor).
+
+=item "j" (B<OSSL_PKEY_PARAM_FFC_COFACTOR>) <unsigned integer>
+
+An optional informational cofactor parameter that should equal to (p - 1) / q.
+
+=back
+
+=head2 FFC key generation parameters
+
+The following key generation types are available for DSA and DH algorithms:
+
+=over 4
+
+=item "type" (B<OSSL_PKEY_PARAM_FFC_TYPE>) <utf8_string>
+
+Sets the type of parameter generation. The shared valid values are:
+
+=over 4
+
+=item "fips186_4"
+
+The current standard. This is the default value.
+
+=item "fips186_2"
+
+The old standard that should only be used for legacy purposes.
+
+=item "default"
+
+This is an alias to use the latest implemented standard.
+It is currently set to "fips186_4".
+
+=back
+
+=item "pbits" (B<OSSL_PKEY_PARAM_FFC_PBITS>) <unsigned integer>
+
+Sets the size (in bits) of the prime 'p'.
+
+=item "qbits" (B<OSSL_PKEY_PARAM_FFC_QBITS>) <unsigned integer>
+
+Sets the size (in bits) of the prime 'q'.
+
+For "fips186_4" this can be either 224 or 256.
+For "fips186_2" this has a size of 160.
+
+=item "digest" (B<OSSL_PKEY_PARAM_FFC_DIGEST>)  <utf8_string>
+
+Sets the Digest algorithm to be used as part of the Key Generation Function
+associated with the given Key Generation I<ctx>.
+This must also be set for key validation.
+
+=item "properties" (B<OSSL_PKEY_PARAM_FFC_DIGEST_PROPS>) <utf8_string>
+
+Sets properties to be used upon look up of the implementation for the selected
+Digest algorithm for the Key Generation Function associated with the given key
+generation I<ctx>. This may also be set for key validation.
+
+=item "seed" (B<OSSL_PKEY_PARAM_FFC_SEED>) <octet string>
+
+For "fips186_4" or "fips186_2" generation this sets the I<seed> data to use
+instead of generating a random seed internally. This should be used for
+testing purposes only. This will either produce fixed values for the generated
+parameters OR it will fail if the seed did not generate valid primes.
+
+=item "gindex" (B<OSSL_PKEY_PARAM_FFC_GINDEX>) <integer>
+
+=item "pcounter" (B<OSSL_PKEY_PARAM_FFC_PCOUNTER>) <integer>
+
+=item "hindex" (B<OSSL_PKEY_PARAM_FFC_H>) <integer>
+
+These types are described above.
+
+=back
+
+=head1 CONFORMING TO
+
+The following sections of SP800-56Ar3:
+
+=over 4
+
+=item 5.5.1.1 FFC Domain Parameter Selection/Generation
+
+=back
+
+The following sections of FIPS 186-4:
+
+=over 4
+
+=item A.1.1.2 Generation of Probable Primes p and q Using an Approved Hash Function.
+
+=item A.2.3 Generation of canonical generator g.
+
+=item A.2.1 Unverifiable Generation of the Generator g.
+
+=back
+
+=head1 SEE ALSO
+
+L<EVP_PKEY-DSA(7)>,
+L<EVP_PKEY-DH(7)>,
+L<EVP_SIGNATURE-DSA(7)>,
+L<EVP_KEYEXCH-DH(7)>
+L<EVP_KEYMGMT(3)>,
+L<EVP_PKEY(3)>,
+L<provider-keymgmt(7)>,
+L<OSSL_PROVIDER-default(7)>,
+L<OSSL_PROVIDER-FIPS(7)>,
+
+=head1 COPYRIGHT
+
+Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the Apache License 2.0 (the "License").  You may not use
+this file except in compliance with the License.  You can obtain a copy
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
+
+=cut