#ifndef CERTHELP_H
#define CERTHELP_H

/* Polarssl mh.h contains a conversion which gcc warns about */
#pragma GCC diagnostic ignored "-Wsign-conversion"
#pragma GCC diagnostic ignored "-Wconversion"
#include <polarssl/oid.h>
#include <polarssl/x509_crt.h>
#pragma GCC diagnostic pop
#pragma GCC diagnostic pop

#define CERT_OID_CN     (unsigned char *)OID_AT_CN "\0"
#define CERT_OID_O      (unsigned char *)OID_AT_ORGANIZATION "\0"
#define CERT_OID_OU     (unsigned char *)OID_AT_ORG_UNIT "\0"
#define CERT_OID_SN     (unsigned char *)OID_AT_SERIAL_NUMBER "\0"
#ifdef __cplusplus
extern "C" {
#endif

/**
 * @file
 * @brief Helper functinos to handle and parse X.509 certificates.
 *
 * Simple helper functions based on PolarSSL.
 */

/**
 * @brief Extracts value of an gieb OID from an x509_name object.
 *
 * The value is copyed to an bull byte terminated c-string.
 * The caller should free it after use.
 * @param[in] namebuf ponter to the x509_name object.
 * @param[in] oid the oid to search for.
 * @returns the extracted String, or NULL in failure.
 */
char *get_oid_valstr(x509_name *namebuf, unsigned char *oid);

/**
 * @brief Parse x509 certificate and retrieve specified OID from Subject.
 *
 * The value is copyed to an bull byte terminated c-string.
 * The caller should free it after use.
 * @param[in] derdata pointer to certificate in DER format.
 * @param[in] derlen length of the DER data.
 * @param[in] oid the OID to search for.
 * @returns the extracted String, or NULL in failure.
 */
char *x509_parse_subject(unsigned char *derdata, size_t derlen,
                         unsigned char *oid);
#ifdef __cplusplus
}
#endif

#endif