X509_digest(feed) - phpMan

X509_DIGEST(3)                      OpenSSL                     X509_DIGEST(3)
NAME
       X509_digest, X509_CRL_digest, X509_pubkey_digest, X509_NAME_digest,
       X509_REQ_digest, PKCS7_ISSUER_AND_SERIAL_digest - get digest of various
       objects
SYNOPSIS
        #include <openssl/x509.h>
        int X509_digest(const X509 *data, const EVP_MD *type, unsigned char *md,
                        unsigned int *len);
        int X509_CRL_digest(const X509_CRL *data, const EVP_MD *type, unsigned char *md,
                            unsigned int *len);
        int X509_pubkey_digest(const X509 *data, const EVP_MD *type,
                               unsigned char *md, unsigned int *len);
        int X509_REQ_digest(const X509_REQ *data, const EVP_MD *type,
                            unsigned char *md, unsigned int *len);
        int X509_NAME_digest(const X509_NAME *data, const EVP_MD *type,
                             unsigned char *md, unsigned int *len);
        #include <openssl/pkcs7.h>
        int PKCS7_ISSUER_AND_SERIAL_digest(PKCS7_ISSUER_AND_SERIAL *data,
                                           const EVP_MD *type, unsigned char *md,
                                           unsigned int *len);
DESCRIPTION
       X509_pubkey_digest() returns a digest of the DER representation of the
       public key in the specified X509 data object.  All other functions
       described here return a digest of the DER representation of their
       entire data objects.
       The type parameter specifies the digest to be used, such as EVP_sha1().
       The md is a pointer to the buffer where the digest will be copied and
       is assumed to be large enough; the constant EVP_MAX_MD_SIZE is
       suggested. The len parameter, if not NULL, points to a place where the
       digest size will be stored.
RETURN VALUES
       All functions described here return 1 for success and 0 for failure.
SEE ALSO
       EVP_sha1(3)
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
       <https://www.openssl.org/source/license.html>;.
1.1.1k                            2021-03-25                    X509_DIGEST(3)