Introduce new files rsa_internal.[ch] for RSA helper functions
This commit splits off the RSA helper functions into separate headers and
compilation units to have a clearer separation of the public RSA interface,
intended to be used by end-users, and the helper functions which are publicly
provided only for the benefit of designers of alternative RSA implementations.
diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index 7a9f185..49f037c 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -48,6 +48,7 @@
platform.c
ripemd160.c
rsa.c
+ rsa_internal.c
sha1.c
sha256.c
sha512.c