EVP_sha1 - SHA-1 For EVP

       NIST FIPS 180-4.

       Copyright 2017-2023 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>.

3.5.0                                              2025-06-04                                     EVP_SHA1(3SSL)

       SHA-1 (Secure Hash Algorithm 1) is a cryptographic hash function standardized in NIST FIPS 180-4. The
       algorithm was designed by the United States National Security Agency and initially published in 1995.

       EVP_sha1()
           The SHA-1 algorithm which produces a 160-bit output from a given input.

       EVP_sha1 - SHA-1 For EVP

       Developers  should  be  aware  of the negative performance implications of calling this function multiple
       times and should consider using  EVP_MD_fetch(3)  with  EVP_MD-SHA1(7)  instead.   See  "Performance"  in
       crypto(7) for further information.

       These  functions  return  a  EVP_MD structure that contains the implementation of the message digest. See
       EVP_MD_meth_new(3) for details of the EVP_MD structure.

evp(7), EVP_DigestInit(3)

        #include <openssl/evp.h>

        const EVP_MD *EVP_sha1(void);