# gnutls_certificate_verify_peers

## NAME



           gnutls_certificate_verify_peers - API function
    


## SYNOPSIS



           **#include <gnutls/gnutls.h>**
    
           **int gnutls_certificate_verify_peers(gnutls_session_t** _session_**,**
           **gnutls_typed_vdata_st ***_data_**, unsigned int** _elements_**, unsigned int**
           *****_status_**);**
    


## ARGUMENTS



           gnutls_session_t session
                       is a gnutls session
    
           gnutls_typed_vdata_st * data
                       an array of typed data
    
           unsigned int elements
                       the number of data elements
    
           unsigned int * status
                       is the output of the verification
    


## DESCRIPTION



           This function will verify the peer's certificate and store the the
           status in the  _status_ variable as a bitwise OR of
           gnutls_certificate_status_t values or zero if the certificate is
           trusted. Note that value in  _status_ is set only when the return
           value of this function is success (i.e, failure to trust a
           certificate does not imply a negative return value).  The default
           verification flags used by this function can be overridden using
           **gnutls_certificate_set_verify_flags()**. See the documentation of
           **gnutls_certificate_verify_peers2()** for details in the verification
           process.
    
           This function will take into account the stapled OCSP responses
           sent by the server, as well as the following X.509 certificate
           extensions: Name Constraints, Key Usage, and Basic Constraints
           (pathlen).
    
           The acceptable  _data_ types are **GNUTLS_DT_DNS_HOSTNAME** ,
           **GNUTLS_DT_RFC822NAME** and **GNUTLS_DT_KEY_PURPOSE_OID**.  The former
           two accept as data a null-terminated hostname or email address,
           and the latter a null-terminated object identifier (e.g.,
           **GNUTLS_KP_TLS_WWW_SERVER**).
    
           If a DNS hostname is provided then this function will compare the
           hostname in the certificate against the given. If names do not
           match the **GNUTLS_CERT_UNEXPECTED_OWNER** status flag will be set.
           If a key purpose OID is provided and the end-certificate contains
           the extended key usage PKIX extension, it will be required to be
           have the provided key purpose or be marked for any purpose,
           otherwise verification status will have the
           **GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE** flag set.
    
           To avoid denial of service attacks some default upper limits
           regarding the certificate key size and chain size are set. To
           override them use **gnutls_certificate_set_verify_limits()**.
    
           Note that when using raw public-keys verification will not work
           because there is no corresponding certificate body belonging to
           the raw key that can be verified. In that case this function will
           return **GNUTLS_E_INVALID_REQUEST**.
    


## RETURNS



           **GNUTLS_E_SUCCESS**(0) when the validation is performed, or a
           negative error code otherwise.  A successful error code means that
           the  _status_ parameter must be checked to obtain the validation
           status.
    


## SINCE



           3.3.0
    


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