=pod

=head1 NAME

EVP_sha224,
EVP_sha256,
EVP_sha512_224,
EVP_sha512_256,
EVP_sha384,
EVP_sha512
- SHA-2 For EVP

=head1 SYNOPSIS

 #include <openssl/evp.h>

 const EVP_MD *EVP_sha224(void);
 const EVP_MD *EVP_sha256(void);
 const EVP_MD *EVP_sha512_224(void);
 const EVP_MD *EVP_sha512_256(void);
 const EVP_MD *EVP_sha384(void);
 const EVP_MD *EVP_sha512(void);

=head1 DESCRIPTION

SHA-2 (Secure Hash Algorithm 2) is a family of cryptographic hash functions
standardized in NIST FIPS 180-4, first published in 2001.

=over 4

=item EVP_sha224(),
EVP_sha256(),
EVP_sha512_224,
EVP_sha512_256,
EVP_sha384(),
EVP_sha512()

The SHA-2 SHA-224, SHA-256, SHA-512/224, SHA512/256, SHA-384 and SHA-512
algorithms, which generate 224, 256, 224, 256, 384 and 512 bits
respectively of output from a given input.

The two algorithms: SHA-512/224 and SHA512/256 are truncated forms of the
SHA-512 algorithm. They are distinct from SHA-224 and SHA-256 even though
their outputs are of the same size.

=back


=head1 RETURN VALUES

These functions return a B<EVP_MD> structure that contains the
implementation of the symmetric cipher. See L<EVP_MD_meth_new(3)> for
details of the B<EVP_MD> structure.

=head1 CONFORMING TO

NIST FIPS 180-4.

=head1 SEE ALSO

L<evp(7)>,
L<EVP_DigestInit(3)>

=head1 COPYRIGHT

Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (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