.\" DO NOT MODIFY THIS FILE!  It was generated by gdoc.
.TH "gnutls_privkey_sign_hash" 3 "3.8.8" "gnutls" "gnutls"
.SH NAME
gnutls_privkey_sign_hash \- API function
.SH SYNOPSIS
.B #include <gnutls/abstract.h>
.sp
.BI "int gnutls_privkey_sign_hash(gnutls_privkey_t " signer ", gnutls_digest_algorithm_t " hash_algo ", unsigned int " flags ", const gnutls_datum_t * " hash_data ", gnutls_datum_t * " signature ");"
.SH ARGUMENTS
.IP "gnutls_privkey_t signer" 12
Holds the signer's key
.IP "gnutls_digest_algorithm_t hash_algo" 12
The hash algorithm used
.IP "unsigned int flags" 12
Zero or one of \fBgnutls_privkey_flags_t\fP
.IP "const gnutls_datum_t * hash_data" 12
holds the data to be signed
.IP "gnutls_datum_t * signature" 12
will contain newly allocated signature
.SH "DESCRIPTION"
This function will sign the given hashed data using a signature algorithm
supported by the private key. Signature algorithms are always used
together with a hash functions.  Different hash functions may be
used for the RSA algorithm, but only SHA\-XXX for the DSA keys.

You may use \fBgnutls_pubkey_get_preferred_hash_algorithm()\fP to determine
the hash algorithm.

The flags may be \fBGNUTLS_PRIVKEY_SIGN_FLAG_TLS1_RSA\fP or \fBGNUTLS_PRIVKEY_SIGN_FLAG_RSA_PSS\fP.
In the former case this function will ignore  \fIhash_algo\fP and perform a raw PKCS1 signature,
and in the latter an RSA\-PSS signature will be generated.

Note that, not all algorithm support signing already hashed data. When
signing with Ed25519, \fBgnutls_privkey_sign_data()\fP should be used.
.SH "RETURNS"
On success, \fBGNUTLS_E_SUCCESS\fP (0) is returned, otherwise a
negative error value.
.SH "SINCE"
2.12.0
.SH "REPORTING BUGS"
Report bugs to <bugs@gnutls.org>.
.br
Home page: https://www.gnutls.org

.SH COPYRIGHT
Copyright \(co 2001-2023 Free Software Foundation, Inc., and others.
.br
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.
.SH "SEE ALSO"
The full documentation for
.B gnutls
is maintained as a Texinfo manual.
If the /usr/share/doc/gnutls/
directory does not contain the HTML form visit
.B
.IP https://www.gnutls.org/manual/
.PP