Changeset 1738 for pjproject/trunk/third_party/srtp/crypto/rng/rand_source.c

Timestamp:

Jan 24, 2008 3:27:30 PM (16 years ago)

Author:

bennylp

Message:

More ticket #61: SRTP will try to use /dev/urandom as RNG if fcntl.h and unistd.h is present. If it fails, it will fallback to using rand()

File:

• pjproject/trunk/third_party/srtp/crypto/rng/rand_source.c (modified) (4 diffs)

pjproject/trunk/third_party/srtp/crypto/rng/rand_source.c

@@ -45 +45 @@
 #include "srtp_config.h"
 
-#ifdef DEV_URANDOM
+#if defined(DEV_URANDOM) || defined(PJ_DEV_URANDOM)
 # include <fcntl.h>          /* for open()  */
 # include <unistd.h>         /* for close() */
@@ -88 +88 @@
   if (dev_random_fdes < 0)
     return err_status_init_fail;
+#elif defined(PJ_DEV_URANDOM)
+  /* open random source for reading */
+  dev_random_fdes = open(PJ_DEV_URANDOM, O_RDONLY);
+  if (dev_random_fdes < 0) {
+    err_report(3,"Ugh: /dev/urandom not present, using rand() instead");
+    return err_status_ok;  /* it's ok, it'll fallback to using rand() */
+  }
 #elif (_MSC_VER >= 1400)
   dev_random_fdes = RAND_SOURCE_READY;
@@ -124 +131 @@
   }
 #else
+  uint8_t *dst = (uint8_t *)dest;
+
+  /* First try with /dev/urandom, if it's opened */
+  if (dev_random_fdes >= 0) {
+    if (read(dev_random_fdes, dest, len) == len)
+        return err_status_ok;   /* success */
+  }
+
   /* Generic C-library (rand()) version */
   /* This is a random source of last resort */
-  uint8_t *dst = (uint8_t *)dest;
   while (len)
   {
@@ -142 +156 @@
 err_status_t
 rand_source_deinit(void) {
+#ifndef PJ_DEV_URANDOM
   if (dev_random_fdes < 0)
     return err_status_dealloc_fail;  /* well, we haven't really failed, *
                                       * but there is something wrong    */
-#ifdef DEV_URANDOM
-  close(dev_random_fdes);  
 #endif
+
+  if (dev_random_fdes >= 0)
+    close(dev_random_fdes);  
+
   dev_random_fdes = RAND_SOURCE_NOT_READY;
   
   return err_status_ok;  
 }
+