gnutls\_x509\_privkey\_sign\_data(3) gnutls gnutls\_x509\_privkey\_sign\_data(3)

# [NAME](#NAME)

gnutls\_x509\_privkey\_sign\_data - API function

# [SYNOPSIS](#SYNOPSIS)

**#include <gnutls/x509.h>**

**int gnutls\_x509\_privkey\_sign\_data(gnutls\_x509\_privkey\_t key, gnutls\_digest\_algorithm\_t digest, unsigned int flags, const gnutls\_datum\_t * data, void * signature, size\_t * signature\_size);**

# [ARGUMENTS](#ARGUMENTS)

[gnutls\_x509\_privkey\_t key](#gnutls_x509_privkey_t)

a key

[gnutls\_digest\_algorithm\_t digest](#gnutls_digest_algorithm_t)

should be a digest algorithm

[unsigned int flags](#unsigned)

should be 0 for now

[const gnutls\_datum\_t * data](#const)

holds the data to be signed

[void * signature](#void)

will contain the signature

[size\_t * signature\_size](#size_t)

holds the size of signature (and will be replaced by the new size)

# [DESCRIPTION](#DESCRIPTION)

This function will sign the given 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-1 for the DSA keys.

If the buffer provided is not long enough to hold the output, then * *signature\_size* is updated and **GNUTLS\_E\_SHORT\_MEMORY\_BUFFER** will be returned.

Use **gnutls\_x509\_crt\_get\_preferred\_hash\_algorithm()** to determine the hash algorithm.

# [RETURNS](#RETURNS)

On success, **GNUTLS\_E\_SUCCESS** (0) is returned, otherwise a negative error value.

# [REPORTING BUGS](#REPORTING_BUGS)

Report bugs to <bugs@gnutls.org>.  
Home page: https://www.gnutls.org

# [COPYRIGHT](#COPYRIGHT)

Copyright © 2001-2023 Free Software Foundation, Inc., and others.  
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.

# [SEE ALSO](#SEE_ALSO)

The full documentation for **gnutls** is maintained as a Texinfo manual. If the /usr/share/doc/gnutls/ directory does not contain the HTML form visit

[https://www.gnutls.org/manual/](https://www.gnutls.org/manual/)

3.8.13 gnutls

---

Document: gnutls_x509_privkey_sign_data(3) from gnutls 3.8.13-r3 (Chainguard OS)
Source: https://gitlab.com/gnutls/gnutls