+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you must
+ not claim that you wrote the original software. If you use this
+ software in a product, an acknowledgment in the product documentation
+ would be appreciated but is not required.
+
+ 2. Altered source versions must be plainly marked as such, and must
+ not be misrepresented as being the original software.
+
+ 3. This notice may not be removed or altered from any source
+ distribution.
+*/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+#include <assert.h>
+#include "crypto.h"
+#include "crypto_if.h"
+
+extern struct crypto_interface ossl_crypto_if;
+extern struct crypto_interface tom_crypto_if;
+extern struct crypto_interface gnu_crypto_if;
+
+static struct crypto_interface *ifs[] = {
+#ifdef HAVE_OPENSSL
+ &ossl_crypto_if,
+#endif
+#ifdef HAVE_TOMCRYPT
+ &tom_crypto_if,
+#endif
+#ifdef HAVE_GCRYPT
+ &gnu_crypto_if,
+#endif
+ (struct crypto_interface *)0,
+};
+#define MAX_IF (sizeof(ifs)/sizeof(struct crypto_interface *)-2)
+
+static int which = 0;
+
+int select_crypto_if(const int ifno)