Security: Keys: Big keys stored encrypted

Solved TODO task: big keys saved to shmem file are now stored encrypted.
The encryption key is randomly generated and saved to payload[big_key_data].

Signed-off-by: Kirill Marinushkin <k.marinushkin@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/security/keys/Kconfig b/security/keys/Kconfig
index fe4d74e..4582809 100644
--- a/security/keys/Kconfig
+++ b/security/keys/Kconfig
@@ -41,6 +41,10 @@
 	bool "Large payload keys"
 	depends on KEYS
 	depends on TMPFS
+	select CRYPTO
+	select CRYPTO_AES
+	select CRYPTO_ECB
+	select CRYPTO_RNG
 	help
 	  This option provides support for holding large keys within the kernel
 	  (for example Kerberos ticket caches).  The data may be stored out to