add an internal api to osl to collect 'native' random numbers

use /dev/urandom on unixes
and
rand_s() on windows

Change-Id: Iccd6e01706f16d82f23cda0f0a410953c32fbc02
Reviewed-on: https://gerrit.libreoffice.org/15473
Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>

sal/Library_sal.mk

@@ -162,6 +162,7 @@ $(eval $(call gb_Library_add_exception_objects,sal,\
 	sal/osl/unx/process \
 	sal/osl/unx/process_impl \
 	sal/osl/unx/profile \
+	sal/osl/unx/random \
 	sal/osl/unx/readwrite_helper \
 	sal/osl/unx/security \
 	sal/osl/unx/signal \
@@ -236,6 +237,7 @@ $(eval $(call gb_Library_add_cobjects,sal,\
 	sal/osl/w32/mutex \
 	sal/osl/w32/nlsupport \
 	sal/osl/w32/pipe \
+	sal/osl/w32/random \
 	sal/osl/w32/security \
 	sal/osl/w32/thread \
 	sal/osl/w32/time \

sal/inc/internal/oslrandom.h

@@ -0,0 +1,25 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#ifndef INCLUDED_SAL_INC_INTERNAL_OSLRANDOM_H
+#define INCLUDED_SAL_INC_INTERNAL_OSLRANDOM_H
+
+#if defined __cplusplus
+extern "C" {
+#endif
+
+int osl_get_system_random_data(char* buffer, size_t desired_len);
+
+#if defined __cplusplus
+}
+#endif
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

sal/osl/unx/random.cxx

@@ -0,0 +1,48 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include "system.hxx"
+#include "internal/oslrandom.h"
+
+#include <assert.h>
+
+int osl_get_system_random_data(char* buffer, size_t desired_len)
+{
+    ssize_t nb_read;
+    int fd;
+
+    assert(buffer);
+    fd = open("/dev/urandom", O_RDONLY);
+    if(fd != -1)
+    {
+        while(desired_len)
+        {
+            if ((nb_read = read(fd, buffer, desired_len)) == -1)
+            {
+                if (errno != EINTR)
+                {
+                    return false;
+                }
+            }
+            else
+            {
+                buffer  += nb_read;
+                desired_len -= nb_read;
+            }
+        }
+        close(fd);
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

sal/osl/w32/random.c

@@ -0,0 +1,61 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+#define _CRT_RAND_S
+
+#include <stdlib.h>
+#include <memory.h>
+
+int osl_get_system_random_data(char* buffer, size_t desired_len)
+{
+    unsigned int val;
+
+    /* if unaligned fill to alignment */
+    if((int)buffer & 3)
+    {
+        size_t len = 4 - ((size_t)(buffer) & 3);
+
+        if(len > desired_len)
+        {
+            len = desired_len;
+        }
+        if(rand_s(&val))
+        {
+            return 0;
+        }
+        memcpy(buffer, &val, len);
+        buffer += len;
+        desired_len -= len;
+    }
+    /* fill directly into the buffer as long as we can */
+    while(desired_len >= 4)
+    {
+        if(rand_s((unsigned int*)buffer))
+        {
+            return 0;
+        }
+        else
+        {
+            buffer += 4;
+            desired_len -= 4;
+        }
+    }
+    /* deal with the partial int reminder to fill */
+    if(desired_len)
+    {
+        if(rand_s(&val))
+        {
+            return 0;
+        }
+        memcpy(buffer, &val, desired_len);
+    }
+    return 1;
+}
+
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */