+#define RAND_bytes(_dst_, _size_) do { urandom_bytes(NULL, _dst_, _size_); } while (0)
+int urandom_bytes(void *ctx, unsigned char *dest, size_t len);
+#endif
+
+#define SSLI_ERROR_WANT_READ -0x0F300 /* mbedTLS v0.x.x uses -0x0f00 -> --0x0f90, v1.x.x uses -0x7080 -> -0x7e80 */
+#define SSLI_ERROR_WANT_WRITE -0x0F310
+
+#define SSLI_ERROR_ZERO_RETURN 0
+#define SSLI_ERROR_CONNRESET MBEDTLS_ERR_NET_CONN_RESET
+#define SSLI_ERROR_SYSCALL MBEDTLS_ERR_NET_RECV_FAILED
+
+typedef mbedtls_ssl_context SSL_handle_t;
+
+#elif defined(USE_GNUTLS)
+
+#include <gnutls/gnutls.h>
+
+#define SSLI_ERROR_WANT_READ GNUTLS_E_AGAIN
+#define SSLI_ERROR_WANT_WRITE GNUTLS_E_AGAIN
+#define SSLI_ERROR_ZERO_RETURN GNUTLS_E_PREMATURE_TERMINATION
+#define SSLI_ERROR_CONNRESET GNUTLS_E_PREMATURE_TERMINATION
+#define SSLI_ERROR_SYSCALL GNUTLS_E_PREMATURE_TERMINATION
+
+typedef gnutls_session_t SSL_handle_t;
+
+#else /* OpenSSL */
+#include <openssl/x509v3.h>
+#include <openssl/ssl.h>