-fixing

[oweals/gnunet.git] / src / util / crypto_random.c

diff --git a/src/util/crypto_random.c b/src/util/crypto_random.c
index c74d60f4f8bc7ad2767e7e05d4a8395ed2d99ad0..29b25524dc84913b2b69057a18a52fd0e79d5398 100644 (file)
--- a/src/util/crypto_random.c
+++ b/src/util/crypto_random.c
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2001, 2002, 2003, 2004, 2005, 2006 Christian Grothoff (and other contributing authors)
+     (C) 2001, 2002, 2003, 2004, 2005, 2006, 2012 Christian Grothoff (and other contributing authors)
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
@@ -34,18 +34,77 @@
 
 #define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util", syscall)
 
+
+/**
+ * GNUNET_YES if we are using a 'weak' (low-entropy) PRNG.
+ */ 
+static int weak_random;
+
+
+
+/* TODO: ndurner, move this to plibc? */
+/* The code is derived from glibc, obviously */
+#if MINGW
+#ifdef RANDOM
+#undef RANDOM
+#endif
+#ifdef SRANDOM
+#undef SRANDOM
+#endif
+#define RANDOM() glibc_weak_rand32()
+#define SRANDOM(s) glibc_weak_srand32(s)
+#if defined(RAND_MAX)
+#undef RAND_MAX
+#endif
+#define RAND_MAX 0x7fffffff /* Hopefully this is correct */
+
+
+static int32_t glibc_weak_rand32_state = 1;
+
+
+void
+glibc_weak_srand32 (int32_t s)
+{
+  glibc_weak_rand32_state = s;
+}
+
+
+int32_t
+glibc_weak_rand32 ()
+{
+  int32_t val = glibc_weak_rand32_state;
+
+  val = ((glibc_weak_rand32_state * 1103515245) + 12345) & 0x7fffffff;
+  glibc_weak_rand32_state = val;
+  return val;
+}
+#endif
+
 /**
  * Create a cryptographically weak pseudo-random number in the interval of 0 to 1.
  *
  * @return number between 0 and 1.
  */
 static double
-weak_random ()
+get_weak_random ()
 {
   return ((double) RANDOM () / RAND_MAX);
 }
 
 
+/**
+ * Seed a weak random generator. Only GNUNET_CRYPTO_QUALITY_WEAK-mode generator
+ * can be seeded.
+ *
+ * @param seed the seed to use
+ */
+void
+GNUNET_CRYPTO_seed_weak_random (int32_t seed)
+{
+  SRANDOM (seed);
+}
+
+
 /**
  * Produce a random value.
  *
@@ -89,7 +148,7 @@ GNUNET_CRYPTO_random_u32 (enum GNUNET_CRYPTO_Quality mode, uint32_t i)
     while (ret >= ul);
     return ret % i;
   case GNUNET_CRYPTO_QUALITY_WEAK:
-    ret = i * weak_random ();
+    ret = i * get_weak_random ();
     if (ret >= i)
       ret = i - 1;
     return ret;
@@ -166,7 +225,7 @@ GNUNET_CRYPTO_random_u64 (enum GNUNET_CRYPTO_Quality mode, uint64_t max)
 
     return ret % max;
   case GNUNET_CRYPTO_QUALITY_WEAK:
-    ret = max * weak_random ();
+    ret = max * get_weak_random ();
     if (ret >= max)
       ret = max - 1;
     return ret;
@@ -176,6 +235,19 @@ GNUNET_CRYPTO_random_u64 (enum GNUNET_CRYPTO_Quality mode, uint64_t max)
   return 0;
 }
 
+
+/**
+ * Check if we are using weak random number generation.
+ *
+ * @return GNUNET_YES if weak number generation is on
+ */
+int
+GNUNET_CRYPTO_random_is_weak ()
+{
+  return weak_random;
+}
+
+
 /**
  * This function should only be called in testcases
  * where strong entropy gathering is not desired
@@ -184,6 +256,7 @@ GNUNET_CRYPTO_random_u64 (enum GNUNET_CRYPTO_Quality mode, uint64_t max)
 void
 GNUNET_CRYPTO_random_disable_entropy_gathering ()
 {
+  weak_random = GNUNET_YES;
   gcry_control (GCRYCTL_ENABLE_QUICK_RANDOM, 0);
 }
 
@@ -194,6 +267,7 @@ GNUNET_CRYPTO_random_disable_entropy_gathering ()
  */
 static struct GNUNET_OS_Process *genproc;
 
+
 /**
  * Function called by libgcrypt whenever we are
  * blocked gathering entropy.
@@ -215,7 +289,7 @@ entropy_generator (void *cls, const char *what, int printchar, int current,
       if (0 != GNUNET_OS_process_kill (genproc, SIGTERM))
         LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR, "kill");
       GNUNET_break (GNUNET_OK == GNUNET_OS_process_wait (genproc));
-      GNUNET_OS_process_close (genproc);
+      GNUNET_OS_process_destroy (genproc);
       genproc = NULL;
     }
     return;
@@ -233,15 +307,16 @@ entropy_generator (void *cls, const char *what, int printchar, int current,
     if (0 != GNUNET_OS_process_kill (genproc, SIGTERM))
       LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR, "kill");
     GNUNET_break (GNUNET_OK == GNUNET_OS_process_wait (genproc));
-    GNUNET_OS_process_close (genproc);
+    GNUNET_OS_process_destroy (genproc);
     genproc = NULL;
   }
   LOG (GNUNET_ERROR_TYPE_INFO, _("Starting `%s' process to generate entropy\n"),
        "find");
   genproc =
-      GNUNET_OS_start_process (NULL, NULL, "sh", "sh", "-c",
-                               "exec find / -mount -type f -exec cp {} /dev/null \\; 2>/dev/null",
-                               NULL);
+     GNUNET_OS_start_process (GNUNET_NO, 0, 
+                             NULL, NULL, "sh", "sh", "-c",
+                             "exec find / -mount -type f -exec cp {} /dev/null \\; 2>/dev/null",
+                             NULL);
 }
 
 
@@ -251,7 +326,7 @@ killfind ()
   if (genproc != NULL)
   {
     GNUNET_OS_process_kill (genproc, SIGKILL);
-    GNUNET_OS_process_close (genproc);
+    GNUNET_OS_process_destroy (genproc);
     genproc = NULL;
   }
 }
@@ -260,21 +335,25 @@ killfind ()
 void __attribute__ ((constructor)) GNUNET_CRYPTO_random_init ()
 {
   gcry_control (GCRYCTL_DISABLE_SECMEM, 0);
-  if (!gcry_check_version (GCRYPT_VERSION))
+  if (!gcry_check_version (NEED_LIBGCRYPT_VERSION))
   {
-    fprintf (stderr,
+    FPRINTF (stderr,
              _
              ("libgcrypt has not the expected version (version %s is required).\n"),
-             GCRYPT_VERSION);
-    abort ();
+             NEED_LIBGCRYPT_VERSION);
+    GNUNET_abort ();
   }
+#ifdef GCRYCTL_INITIALIZATION_FINISHED
+  gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
+#endif
 #ifdef gcry_fast_random_poll
   gcry_fast_random_poll ();
 #endif
   gcry_set_progress_handler (&entropy_generator, NULL);
   atexit (&killfind);
-  SRANDOM (time (NULL) ^
-           GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX));
+  GNUNET_CRYPTO_seed_weak_random (time (NULL) ^
+                                  GNUNET_CRYPTO_random_u32
+                                  (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX));
 }