Finish crypto wrapping. Also provide wrappers for OpenSSL.

Disable libgcrypt by default. Since it doesn't support the OFB cipher mode,
we can't use it in a backwards compatible way.

src/tincd.c

@@ -31,18 +31,13 @@
 #include <sys/mman.h>
 #endif
 
-#include <openssl/rand.h>
-#include <openssl/rsa.h>
-#include <openssl/pem.h>
-#include <openssl/evp.h>
-#include <openssl/engine.h>
-
 #include LZO1X_H
 
 #include <getopt.h>
 
 #include "conf.h"
 #include "control.h"
+#include "crypto.h"
 #include "device.h"
 #include "logger.h"
 #include "net.h"
@@ -294,12 +289,7 @@ int main(int argc, char **argv)
 	/* Slllluuuuuuurrrrp! */
 
 	srand(time(NULL));
-	RAND_load_file("/dev/urandom", 1024);
-
-	ENGINE_load_builtin_engines();
-	ENGINE_register_all_complete();
-
-	OpenSSL_add_all_algorithms();
+	crypto_init();
 
 	if(!read_server_config())
 		return 1;
@@ -352,7 +342,7 @@ end:
 	exit_control();
 #endif
 
-	EVP_cleanup();
-	
+	crypto_exit();
+
 	return status;
 }