Sample application using RAND_event() to collect entropy from mouse

movements, keyboard etc. and write it to a seed file.

apps/winrand.c

+/* apps/winrand.c */
+/* ====================================================================
+ * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+
+/* Usage: winrand [filename]
+ *
+ * Collects entropy from mouse movements and other events and writes
+ * random data to filename or .rnd
+ */
+
+#include <windows.h>
+#include <openssl/opensslv.h>
+#include <openssl/rand.h>
+
+LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
+const char *filename;
+
+int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
+        PSTR cmdline, int iCmdShow)
+	{
+	static char appname[] = "OpenSSL";
+	HWND hwnd;
+	MSG msg;
+	WNDCLASSEX wndclass;
+        char buffer[200];
+
+        if (cmdline[0] == '\0')
+                filename = RAND_file_name(buffer, sizeof buffer);
+        else
+                filename = cmdline;
+
+        RAND_load_file(filename, -1);
+
+	wndclass.cbSize = sizeof(wndclass);
+	wndclass.style = CS_HREDRAW | CS_VREDRAW;
+	wndclass.lpfnWndProc = WndProc;
+	wndclass.cbClsExtra = 0;
+	wndclass.cbWndExtra = 0;
+	wndclass.hInstance = hInstance;
+	wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
+	wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
+	wndclass.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
+	wndclass.lpszMenuName = NULL;
+        wndclass.lpszClassName = appname;
+	wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
+	RegisterClassEx(&wndclass);
+
+        hwnd = CreateWindow(appname, OPENSSL_VERSION_TEXT,
+		WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT,
+		CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL);
+
+	ShowWindow(hwnd, iCmdShow);
+	UpdateWindow(hwnd);
+
+
+	while (GetMessage(&msg, NULL, 0, 0))
+		{
+		TranslateMessage(&msg);
+		DispatchMessage(&msg);
+		}
+
+	return msg.wParam;
+	}
+
+LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
+	{
+        HDC hdc;
+	PAINTSTRUCT ps;
+        RECT rect;
+        char buffer[200];
+        static int seeded = 0;
+
+	switch (iMsg)
+		{
+	case WM_PAINT:
+		hdc = BeginPaint(hwnd, &ps);
+		GetClientRect(hwnd, &rect);
+                DrawText(hdc, "Seeding the PRNG. Please move the mouse!", -1,
+			&rect, DT_SINGLELINE | DT_CENTER | DT_VCENTER);
+		EndPaint(hwnd, &ps);
+		return 0;
+		
+        case WM_DESTROY:
+                PostQuitMessage(0);
+                return 0;
+                }
+
+        if (RAND_event(iMsg, wParam, lParam) == 1 && seeded == 0)
+                {
+                seeded = 1;
+                if (RAND_write_file(filename) <= 0)
+                        MessageBox(hwnd, "Couldn't write random file!",
+				"OpenSSL", MB_OK | MB_ICONERROR);
+                PostQuitMessage(0);
+                }
+
+	return DefWindowProc(hwnd, iMsg, wParam, lParam);
+	}