adds RNG wrappers

setup.py

@@ -28,6 +28,7 @@ setup(
     install_requires=["cffi>=1.5.2"],
     cffi_modules=[
         "./wolfcrypt/build_hashes.py:ffi",
-        "./wolfcrypt/build_ciphers.py:ffi"
+        "./wolfcrypt/build_ciphers.py:ffi",
+        "./wolfcrypt/build_random.py:ffi"
     ],
 )

wolfcrypt/build_random.py

@@ -0,0 +1,53 @@
+# build_random.py
+#
+# Copyright (C) 2006-2016 wolfSSL Inc.
+#
+# This file is part of wolfSSL. (formerly known as CyaSSL)
+#
+# wolfSSL 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.
+#
+# wolfSSL is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+import os
+
+from cffi import FFI
+
+ffi = FFI()
+
+ffi.set_source("wolfcrypt._random",
+    """
+        #include <wolfssl/options.h>
+        #include <wolfssl/wolfcrypt/random.h>
+    """,
+    include_dirs=["/usr/local/include"],
+    library_dirs=["/usr/local/lib"],
+    libraries=["wolfssl"],
+)
+
+ffi.cdef(
+"""
+
+    typedef unsigned char byte;
+    typedef unsigned int  word32;
+
+    typedef struct { ...; } WC_RNG;
+
+    int wc_InitRng(WC_RNG*);
+    int wc_RNG_GenerateBlock(WC_RNG*, byte*, word32);
+    int wc_RNG_GenerateByte(WC_RNG*, byte*);
+    int wc_FreeRng(WC_RNG*);
+
+"""
+)
+
+if __name__ == "__main__":
+    ffi.compile(verbose=1)

wolfcrypt/random.py

@@ -0,0 +1,49 @@
+# random.py
+#
+# Copyright (C) 2006-2016 wolfSSL Inc.
+#
+# This file is part of wolfSSL. (formerly known as CyaSSL)
+#
+# wolfSSL 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.
+#
+# wolfSSL is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+from wolfcrypt._random import ffi
+from wolfcrypt._random import lib
+
+
+class Random(object):
+    def __init__(self):
+        self.native_object = ffi.new("WC_RNG *")
+        if lib.wc_InitRng(self.native_object) != 0:
+            self.native_object = None
+
+
+    def __del__(self):
+        if self.native_object:
+            lib.wc_FreeRng(self.native_object)
+
+
+    def byte(self):
+        ret = "\0"
+
+        lib.wc_RNG_GenerateByte(self.native_object, ret)
+
+        return ret
+
+
+    def bytes(self, length):
+        ret = "\0" * length
+
+        lib.wc_RNG_GenerateBlock(self.native_object, ret, length)
+
+        return ret