X509_DIGEST(3)             Library Functions Manual             X509_DIGEST(3)

NAME
     X509_digest, X509_CRL_digest, X509_pubkey_digest, X509_NAME_digest,
     X509_REQ_digest, PKCS7_ISSUER_AND_SERIAL_digest - get digests 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 contained in data.  All other functions described here return
     a digest of the DER representation of their entire data object.

     The type parameter specifies the digest to be used, such as EVP_sha1(3).
     md is a pointer to the buffer where the digest will be copied and is
     assumed to be large enough; a size of at least EVP_MAX_MD_SIZE bytes is
     suggested.  The len parameter, if not NULL, points to a place where the
     digest size will be stored.

RETURN VALUES
     These functions return 1 for success or 0 for failure.

SEE ALSO
     EVP_get_digestbyname(3), X509_cmp(3), X509_CRL_new(3), X509_NAME_new(3),
     X509_new(3), X509_REQ_new(3)

HISTORY
     X509_digest(), X509_NAME_digest(), and PKCS7_ISSUER_AND_SERIAL_digest()
     first appeared in SSLeay 0.6.5 and have been available since OpenBSD 2.4.

     X509_CRL_digest() and X509_REQ_digest() first appeared in OpenSSL 0.9.6
     and have been available since OpenBSD 2.9.

     X509_pubkey_digest() first appeared in OpenSSL 0.9.7 and has been
     available since OpenBSD 3.2.

Linux 6.8.7-arch1-1             August 20, 2019            Linux 6.8.7-arch1-1