.\"	$OpenBSD: X509_digest.3,v 1.1 2017/03/25 22:21:21 schwarze Exp $
.\"	OpenSSL X509_digest.pod 3ba4dac6 Mar 23 13:04:52 2017 -0400
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.\" This file was written by Rich Salz <rsalz@openssl.org>
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.Dd $Mdocdate: March 25 2017 $
.Dt X509_DIGEST 3
.Os
.Sh NAME
.Nm X509_digest ,
.Nm X509_CRL_digest ,
.Nm X509_pubkey_digest ,
.Nm X509_NAME_digest ,
.Nm X509_REQ_digest ,
.Nm PKCS7_ISSUER_AND_SERIAL_digest
.Nd get digests of various objects
.Sh SYNOPSIS
.In openssl/x509.h
.Ft int
.Fo X509_digest
.Fa "const X509 *data"
.Fa "const EVP_MD *type"
.Fa "unsigned char *md"
.Fa "unsigned int *len"
.Fc
.Ft int
.Fo X509_CRL_digest
.Fa "const X509_CRL *data"
.Fa "const EVP_MD *type"
.Fa "unsigned char *md"
.Fa "unsigned int *len"
.Fc
.Ft int
.Fo X509_pubkey_digest
.Fa "const X509 *data"
.Fa "const EVP_MD *type"
.Fa "unsigned char *md"
.Fa "unsigned int *len"
.Fc
.Ft int
.Fo X509_REQ_digest
.Fa "const X509_REQ *data"
.Fa "const EVP_MD *type"
.Fa "unsigned char *md"
.Fa "unsigned int *len"
.Fc
.Ft int
.Fo X509_NAME_digest
.Fa "const X509_NAME *data"
.Fa "const EVP_MD *type"
.Fa "unsigned char *md"
.Fa "unsigned int *len"
.Fc
.In openssl/pkcs7.h
.Ft int
.Fo PKCS7_ISSUER_AND_SERIAL_digest
.Fa "PKCS7_ISSUER_AND_SERIAL *data"
.Fa "const EVP_MD *type"
.Fa "unsigned char *md"
.Fa "unsigned int *len"
.Fc
.Sh DESCRIPTION
.Fn X509_pubkey_digest
returns a digest of the DER representation of the public key contained in
.Fa data .
All other functions described here return a digest of the DER
representation of their entire
.Fa data
object.
.Pp
The
.Fa type
parameter specifies the digest to be used, such as
.Xr EVP_sha1 3 .
.Fa 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
.Dv EVP_MAX_MD_SIZE
bytes is suggested.
The
.Fa len
parameter, if not
.Dv NULL ,
points to a place where the digest size will be stored.
.Sh RETURN VALUES
These functions return 1 for success or 0 for failure.
.Sh SEE ALSO
.Xr EVP_get_digestbyname 3