| =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 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 | 
 |  |