int gnutls_x509_trust_list_verify_crt2(gnutls_x509_trust_list_t list, gnutls_x509_crt_t * cert_list, unsigned int cert_list_size, gnutls_typed_vdata_st * data, unsigned int elements, unsigned int flags, unsigned int * voutput, gnutls_verify_output_function func);
When a certificate chain of cert_list_size with more than one certificates is provided, the verification status will apply to the first certificate in the chain that failed verification. The verification process starts from the end of the chain (from CA to end certificate). The first certificate in the chain must be the end-certificate while the rest of the members may be sorted or not.
Additionally a certificate verification profile can be specified from the ones in gnutls_certificate_verification_profiles_t by ORing the result of GNUTLS_PROFILE_TO_VFLAGS() to the verification flags.
Additional verification parameters are possible via the data types; the acceptable types are GNUTLS_DT_DNS_HOSTNAME, GNUTLS_DT_IP_ADDRESS and GNUTLS_DT_KEY_PURPOSE_OID. The former accepts as data a null-terminated hostname, 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 end certificate against the given. If names do not match the GNUTLS_CERT_UNEXPECTED_OWNER status flag will be set. In addition it will consider certificates provided with gnutls_x509_trust_list_add_named_crt().
If a key purpose OID is provided and the end-certificate contains the extended key usage PKIX extension, it will be required to match the provided OID or be marked for any purpose, otherwise verification will fail with GNUTLS_CERT_PURPOSE_MISMATCH status.