vlc_rand_bytes: minor thread-safety fix

[vlc] / src / misc / rand.c

diff --git a/src/misc/rand.c b/src/misc/rand.c
index 97663ef7ff84336957955ce240eed2c1e76db30c..8932e407ad1343eb23d2dc04b7cefa323290f925 100644 (file)
--- a/src/misc/rand.c
+++ b/src/misc/rand.c
@@ -19,7 +19,11 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  *****************************************************************************/
 
-#include <vlc/vlc.h>
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <vlc_common.h>
 #include <vlc_rand.h>
 
 #ifndef WIN32
@@ -31,6 +35,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <pthread.h>
+#include <vlc_fs.h>
 
 #include <vlc_md5.h>
 
@@ -53,7 +58,7 @@ static void vlc_rand_init (void)
     uint8_t key[BLOCK_SIZE];
 
     /* Get non-predictible value as key for HMAC */
-    int fd = open (randfile, O_RDONLY);
+    int fd = vlc_open (randfile, O_RDONLY);
     if (fd == -1)
         return; /* Uho! */
 
@@ -80,55 +85,81 @@ void vlc_rand_bytes (void *buf, size_t len)
     static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
     static uint64_t counter = 0;
 
-    struct md5_s md;
     uint64_t stamp = NTPtime64 ();
 
     while (len > 0)
     {
         uint64_t val;
+        struct md5_s mdi, mdo;
+
+        InitMD5 (&mdi);
+        InitMD5 (&mdo);
 
         pthread_mutex_lock (&lock);
         if (counter == 0)
             vlc_rand_init ();
         val = counter++;
+
+        AddMD5 (&mdi, ikey, sizeof (ikey));
+        AddMD5 (&mdo, okey, sizeof (okey));
         pthread_mutex_unlock (&lock);
 
-        InitMD5 (&md);
-        AddMD5 (&md, ikey, sizeof (ikey));
-        AddMD5 (&md, &stamp, sizeof (stamp));
-        AddMD5 (&md, &val, sizeof (val));
-        EndMD5 (&md);
+        AddMD5 (&mdi, &stamp, sizeof (stamp));
+        AddMD5 (&mdi, &val, sizeof (val));
+        EndMD5 (&mdi);
+        AddMD5 (&mdo, mdi.p_digest, sizeof (mdi.p_digest));
+        EndMD5 (&mdo);
 
-        if (len < sizeof (md.p_digest))
+        if (len < sizeof (mdo.p_digest))
         {
-            memcpy (buf, md.p_digest, len);
+            memcpy (buf, mdo.p_digest, len);
             break;
         }
 
-        memcpy (buf, md.p_digest, sizeof (md.p_digest));
-        len -= sizeof (md.p_digest);
-        buf = ((uint8_t *)buf) + sizeof (md.p_digest);
+        memcpy (buf, mdo.p_digest, sizeof (mdo.p_digest));
+        len -= sizeof (mdo.p_digest);
+        buf = ((uint8_t *)buf) + sizeof (mdo.p_digest);
     }
 }
 
 #else /* WIN32 */
-#define _CRT_RAND_S
-#include <stdlib.h>
+
+#include <wincrypt.h>
 
 void vlc_rand_bytes (void *buf, size_t len)
 {
-    while (len > 0)
+    HCRYPTPROV hProv;
+    size_t count = len;
+    uint8_t *p_buf = (uint8_t *)buf;
+
+    /* fill buffer with pseudo-random data */
+    while (count > 0)
     {
         unsigned int val;
-        rand_s (&val);
-
-        if (len < sizeof (val))
+        val = rand();
+        if (count < sizeof (val))
         {
-            memcpy (buf, &val, len);
+            memcpy (p_buf, &val, count);
             break;
         }
+ 
+        memcpy (p_buf, &val, sizeof (val));
+        count -= sizeof (val);
+        p_buf += sizeof (val);
+    }
 
-        memcpy (buf, &val, sizeof (val));
+    /* acquire default encryption context */
+    if( CryptAcquireContext(
+        &hProv,            // Variable to hold returned handle.
+        NULL,              // Use default key container.
+        MS_DEF_PROV,       // Use default CSP.
+        PROV_RSA_FULL,     // Type of provider to acquire.
+        0) )
+    {
+        /* fill buffer with pseudo-random data, intial buffer content
+           is used as auxillary random seed */
+        CryptGenRandom(hProv, len, buf);
+        CryptReleaseContext(hProv, 0);
     }
 }
 #endif