---
name: "gnutls_x509_crt_verify_data2"
section: "3"
platform: "linux"
package: "gnutls"
version: "3.8.13-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/gnutls_x509_crt_verify_data2"
---

# gnutls\_x509\_crt\_verify\_data2(3)

API function

## NAME

gnutls\_x509\_crt\_verify\_data2 - API function

## SYNOPSIS

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

**int gnutls\_x509\_crt\_verify\_data2(gnutls\_x509\_crt\_t** *crt***, gnutls\_sign\_algorithm\_t** *algo***, unsigned int** *flags***, const gnutls\_datum\_t \*** *data***, const gnutls\_datum\_t \*** *signature***);**

## ARGUMENTS

- gnutls\_x509\_crt\_t crt

  Holds the certificate to verify with

- gnutls\_sign\_algorithm\_t algo

  The signature algorithm used

- unsigned int flags

  Zero or an OR list of **gnutls\_certificate\_verify\_flags**

- const gnutls\_datum\_t \* data

  holds the signed data

- const gnutls\_datum\_t \* signature

  contains the signature

## DESCRIPTION

This function will verify the given signed data, using the parameters from the certificate.

## RETURNS

In case of a verification failure **GNUTLS\_E\_PK\_SIG\_VERIFY\_FAILED** is returned, **GNUTLS\_E\_EXPIRED** or **GNUTLS\_E\_NOT\_YET\_ACTIVATED** on expired or not yet activated certificate and zero or positive code on success.

Note that since GnuTLS 3.5.6 this function introduces checks in the end certificate ( *crt* ), including time checks and key usage checks.

## SINCE

3\.4.0

## REPORTING BUGS

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

## 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

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/