JavaScriptCore-903.tar.gz

[apple/javascriptcore.git] / wtf / OSRandomSource.cpp

diff --git a/wtf/OSRandomSource.cpp b/wtf/OSRandomSource.cpp
new file mode 100644 (file)
index 0000000..7d86f6f
--- /dev/null
+++ b/wtf/OSRandomSource.cpp
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2011 Google Inc. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY GOOGLE, INC. ``AS IS'' AND ANY
+ * EXPRESS 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 APPLE COMPUTER, INC. OR
+ * 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. 
+ */
+
+#include "config.h"
+#include "OSRandomSource.h"
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#if OS(SYMBIAN)
+#include <e32math.h>
+#endif
+
+#if OS(UNIX)
+#include <fcntl.h>
+#include <unistd.h>
+#endif
+
+#if OS(WINDOWS)
+#include <windows.h>
+#include <wincrypt.h> // windows.h must be included before wincrypt.h.
+#endif
+
+namespace WTF {
+
+#if USE(OS_RANDOMNESS)
+void cryptographicallyRandomValuesFromOS(unsigned char* buffer, size_t length)
+{
+#if OS(SYMBIAN)
+    TInt random;
+    while (length > sizeof(random)) {
+        random = Math::Random();
+        memcpy(buffer, &random, sizeof(random));
+        length -= sizeof(random);
+        buffer += sizeof(random);
+    }
+    if (length > 0) {
+        random = Math::Random();
+        memcpy(buffer, &random, length);
+    }
+#elif OS(UNIX)
+    int fd = open("/dev/urandom", O_RDONLY, 0);
+    if (fd < 0)
+        CRASH(); // We need /dev/urandom for this API to work...
+
+    if (read(fd, buffer, length) != static_cast<ssize_t>(length))
+        CRASH();
+
+    close(fd);
+#elif OS(WINDOWS)
+    HCRYPTPROV hCryptProv = 0;
+    if (!CryptAcquireContext(&hCryptProv, 0, MS_DEF_PROV, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
+        CRASH();
+    if (!CryptGenRandom(hCryptProv, length, buffer))
+        CRASH();
+    CryptReleaseContext(hCryptProv, 0);
+#else
+    #error "This configuration doesn't have a strong source of randomness."
+    // WARNING: When adding new sources of OS randomness, the randomness must
+    //          be of cryptographic quality!
+#endif
+}
+#endif
+
+}