# man > EVP_MD-common(7)

[_EVP_MD-COMMON_(7SSL)](https://www.chedong.com/phpMan.php/man/EVPMD-COMMON/7SSL/markdown)                            OpenSSL                           [_EVP_MD-COMMON_(7SSL)](https://www.chedong.com/phpMan.php/man/EVPMD-COMMON/7SSL/markdown)

## NAME
       EVP_MD-common - The OpenSSL EVP_MD implementations, common things

## DESCRIPTION
       All the OpenSSL EVP_MD implementations understand the following [**OSSL_PARAM**(3)](https://www.chedong.com/phpMan.php/man/OSSLPARAM/3/markdown) entries that
       are gettable with [**EVP_MD_get_params**(3)](https://www.chedong.com/phpMan.php/man/EVPMDgetparams/3/markdown), as well as these:

       "blocksize" (**OSSL_DIGEST_PARAM_BLOCK_SIZE**) <unsigned integer>
           The digest block size.  The length of the "blocksize" parameter should not exceed that of
           a **size_t**.

           This value can also be retrieved with [**EVP_MD_get_block_size**(3)](https://www.chedong.com/phpMan.php/man/EVPMDgetblocksize/3/markdown).

       "size" (**OSSL_DIGEST_PARAM_SIZE**) <unsigned integer>
           The  digest  output size.  The length of the "size" parameter should not exceed that of a
           **size_t**.

           This value can also be retrieved with [**EVP_MD_get_size**(3)](https://www.chedong.com/phpMan.php/man/EVPMDgetsize/3/markdown).

       "flags" (**OSSL_DIGEST_PARAM_FLAGS**) <unsigned integer>
           Diverse flags that describe exceptional  behaviour  for  the  digest.   These  flags  are
           described in "DESCRIPTION" in [**EVP_MD_meth_set_flags**(3)](https://www.chedong.com/phpMan.php/man/EVPMDmethsetflags/3/markdown).

           The length of the "flags" parameter should equal that of an **unsigned long int**.

           This value can also be retrieved with [**EVP_MD_get_flags**(3)](https://www.chedong.com/phpMan.php/man/EVPMDgetflags/3/markdown).

## SEE ALSO
       [**EVP_MD_get_params**(3)](https://www.chedong.com/phpMan.php/man/EVPMDgetparams/3/markdown), [**provider-digest**(7)](https://www.chedong.com/phpMan.php/man/provider-digest/7/markdown)

## COPYRIGHT
       Copyright 2020-2021 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 <<https://www.openssl.org/source/license.html>>.

3.0.13                                       2026-07-29                          [_EVP_MD-COMMON_(7SSL)](https://www.chedong.com/phpMan.php/man/EVPMD-COMMON/7SSL/markdown)