=pod

=head1 NAME

EVP_PKEY_print_public, EVP_PKEY_print_private, EVP_PKEY_print_params,
EVP_PKEY_print_public_fp, EVP_PKEY_print_private_fp,
EVP_PKEY_print_params_fp - public key algorithm printing routines

=head1 SYNOPSIS

 #include <openssl/evp.h>

 int EVP_PKEY_print_public(BIO *out, const EVP_PKEY *pkey,
                           int indent, ASN1_PCTX *pctx);
 int EVP_PKEY_print_public_fp(FILE *fp, const EVP_PKEY *pkey,
                              int indent, ASN1_PCTX *pctx);
 int EVP_PKEY_print_private(BIO *out, const EVP_PKEY *pkey,
                            int indent, ASN1_PCTX *pctx);
 int EVP_PKEY_print_private_fp(FILE *fp, const EVP_PKEY *pkey,
                               int indent, ASN1_PCTX *pctx);
 int EVP_PKEY_print_params(BIO *out, const EVP_PKEY *pkey,
                           int indent, ASN1_PCTX *pctx);
 int EVP_PKEY_print_params_fp(FILE *fp, const EVP_PKEY *pkey,
                              int indent, ASN1_PCTX *pctx);

=head1 DESCRIPTION

The functions EVP_PKEY_print_public(), EVP_PKEY_print_private() and
EVP_PKEY_print_params() print out the public, private or parameter components
of key I<pkey> respectively. The key is sent to B<BIO> I<out> in human readable
form. The parameter I<indent> indicates how far the printout should be indented.

The I<pctx> parameter allows the print output to be finely tuned by using
ASN1 printing options. If I<pctx> is set to NULL then default values will
be used.

The functions EVP_PKEY_print_public_fp(), EVP_PKEY_print_private_fp() and
EVP_PKEY_print_params_fp() do the same as the B<BIO> based functions
but use B<FILE> I<fp> instead.

=head1 NOTES

Currently no public key algorithms include any options in the I<pctx> parameter.

If the key does not include all the components indicated by the function then
only those contained in the key will be printed. For example passing a public
key to EVP_PKEY_print_private() will only print the public components.

=head1 RETURN VALUES

These functions all return 1 for success and 0 or a negative value for failure.
In particular a return value of -2 indicates the operation is not supported by
the public key algorithm.

=head1 SEE ALSO

L<EVP_PKEY_CTX_new(3)>,
L<EVP_PKEY_keygen(3)>

=head1 HISTORY

The functions EVP_PKEY_print_public(), EVP_PKEY_print_private(),
and EVP_PKEY_print_params() were added in OpenSSL 1.0.0.

The functions EVP_PKEY_print_public_fp(), EVP_PKEY_print_private_fp(),
and EVP_PKEY_print_params_fp() were added in OpenSSL 3.0.

=head1 COPYRIGHT

Copyright 2006-2021 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>.

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