/**
 * PHP doesn't support user land threads but we still have to initialize
 * the library.
 *
 * Use following link for additional details:
 * 'https://www.openssl.org/docs/man1.0.1/crypto/threads.html'
 * 'https://wiki.openssl.org/index.php/Library_Initialization'

 */

#include <assert.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/ssl.h>

void __attribute__((constructor)) TCLink_OpenSSLInit(void);
void __attribute__((destructor)) TCLink_OpenSSLCleanup(void);

/**
 *
 * Initialize the OpenSSL library.
 * Also sets up static callback functions required for multi-thread safety.
 */
void
TCLink_OpenSSLInit(void)
{
  int ret;
#if OPENSSL_VERSION_NUMBER < 0x10100000L
  SSL_load_error_strings();
  ret = SSL_library_init();
  assert(ret == 1);
#else
  ret = OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CRYPTO_STRINGS |
                            OPENSSL_INIT_ADD_ALL_CIPHERS |
                            OPENSSL_INIT_ADD_ALL_DIGESTS |
                            OPENSSL_INIT_LOAD_CONFIG | OPENSSL_INIT_ASYNC |
#ifdef OPENSSL_INIT_NO_ATEXIT
                            OPENSSL_INIT_NO_ATEXIT |
#endif
#ifdef OPENSSL_INIT_ATFORK
                            OPENSSL_INIT_ATFORK |
#endif
                            OPENSSL_INIT_LOAD_SSL_STRINGS,
                          NULL);
  assert(ret == 1);
#endif
}

/**
 *
 * De-initializes the OpenSSL library.
 * Performs cleanup required for global data structures.
 */
void
TCLink_OpenSSLCleanup(void)
{
#if OPENSSL_VERSION_NUMBER < 0x10100000L
  EVP_cleanup();
  CRYPTO_cleanup_all_ex_data();
  ERR_free_strings();
#else
  OPENSSL_cleanup();
#endif
}