crypto: akcipher - add PKE API

Add Public Key Encryption API.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>

Made CRYPTO_AKCIPHER invisible like other type config options.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/internal/akcipher.h

@@ -0,0 +1,60 @@
+/*
+ * Public Key Encryption
+ *
+ * Copyright (c) 2015, Intel Corporation
+ * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+#ifndef _CRYPTO_AKCIPHER_INT_H
+#define _CRYPTO_AKCIPHER_INT_H
+#include <crypto/akcipher.h>
+
+/*
+ * Transform internal helpers.
+ */
+static inline void *akcipher_request_ctx(struct akcipher_request *req)
+{
+	return req->__ctx;
+}
+
+static inline void *akcipher_tfm_ctx(struct crypto_akcipher *tfm)
+{
+	return tfm->base.__crt_ctx;
+}
+
+static inline void akcipher_request_complete(struct akcipher_request *req,
+					     int err)
+{
+	req->base.complete(&req->base, err);
+}
+
+static inline const char *akcipher_alg_name(struct crypto_akcipher *tfm)
+{
+	return crypto_akcipher_tfm(tfm)->__crt_alg->cra_name;
+}
+
+/**
+ * crypto_register_akcipher() -- Register public key algorithm
+ *
+ * Function registers an implementation of a public key verify algorithm
+ *
+ * @alg:	algorithm definition
+ *
+ * Return: zero on success; error code in case of error
+ */
+int crypto_register_akcipher(struct akcipher_alg *alg);
+
+/**
+ * crypto_unregister_akcipher() -- Unregister public key algorithm
+ *
+ * Function unregisters an implementation of a public key verify algorithm
+ *
+ * @alg:	algorithm definition
+ */
+void crypto_unregister_akcipher(struct akcipher_alg *alg);
+#endif