/*
- This file is part of GNUnet.
- (C) 2001, 2002, 2003, 2004, 2005, 2006 Christian Grothoff (and other contributing authors)
+ This file is part of GNUnet. Copyright (C) 2001-2014 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
- by the Free Software Foundation; either version 2, or (at your
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
* @author Christian Grothoff
*/
#include "platform.h"
-#include "gnunet_common.h"
#include "gnunet_crypto_lib.h"
#include <gcrypt.h>
+#define LOG(kind,...) GNUNET_log_from (kind, "util-crypto-random", __VA_ARGS__)
+
+#define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util-crypto-random", syscall)
+
+
+/* TODO: ndurner, move this to plibc? */
+/* The code is derived from glibc, obviously */
+#if !HAVE_RANDOM || !HAVE_SRANDOM
+#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
+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);
+}
+
+
/**
+ * @ingroup crypto
+ * Fill block with a random values.
+ *
+ * @param mode desired quality of the random number
+ * @param buffer the buffer to fill
+ * @param length buffer length
+ */
+void
+GNUNET_CRYPTO_random_block (enum GNUNET_CRYPTO_Quality mode, void *buffer, size_t length)
+{
+#ifdef gcry_fast_random_poll
+ static unsigned int invokeCount;
+#endif
+ switch (mode)
+ {
+ case GNUNET_CRYPTO_QUALITY_STRONG:
+ /* see http://lists.gnupg.org/pipermail/gcrypt-devel/2004-May/000613.html */
+#ifdef gcry_fast_random_poll
+ if ((invokeCount++ % 256) == 0)
+ gcry_fast_random_poll ();
+#endif
+ gcry_randomize (buffer, length, GCRY_STRONG_RANDOM);
+ return;
+ case GNUNET_CRYPTO_QUALITY_NONCE:
+ gcry_create_nonce (buffer, length);
+ return;
+ case GNUNET_CRYPTO_QUALITY_WEAK:
+ /* see http://lists.gnupg.org/pipermail/gcrypt-devel/2004-May/000613.html */
+#ifdef gcry_fast_random_poll
+ if ((invokeCount++ % 256) == 0)
+ gcry_fast_random_poll ();
+#endif
+ gcry_randomize (buffer, length, GCRY_WEAK_RANDOM);
+ return;
+ default:
+ GNUNET_assert (0);
+ }
+}
+
+
+/**
+ * Produce a random unsigned 32-bit number modulo @a i.
+ *
+ * @param mode desired quality of the random number
+ * @param i the upper limit (exclusive) for the random number
* @return a random value in the interval [0,i[.
*/
-unsigned int
-GNUNET_CRYPTO_random_u32 (enum GNUNET_CRYPTO_Quality mode, unsigned int i)
+uint32_t
+GNUNET_CRYPTO_random_u32 (enum GNUNET_CRYPTO_Quality mode,
+ uint32_t i)
{
#ifdef gcry_fast_random_poll
static unsigned int invokeCount;
#endif
- unsigned int ret;
+ uint32_t ret;
+ uint32_t ul;
GNUNET_assert (i > 0);
- if (mode == GNUNET_CRYPTO_QUALITY_STRONG)
- {
- /* see http://lists.gnupg.org/pipermail/gcrypt-devel/2004-May/000613.html */
+ switch (mode)
+ {
+ case GNUNET_CRYPTO_QUALITY_STRONG:
+ /* see http://lists.gnupg.org/pipermail/gcrypt-devel/2004-May/000613.html */
#ifdef gcry_fast_random_poll
- if ((invokeCount++ % 256) == 0)
- gcry_fast_random_poll ();
+ if ((invokeCount++ % 256) == 0)
+ gcry_fast_random_poll ();
#endif
- ret = rand (); /* in case gcry_randomize fails,
- we at least get a pseudo-
- random number this way */
- gcry_randomize ((unsigned char *) &ret,
- sizeof (unsigned int), GCRY_STRONG_RANDOM);
- return ret % i;
+ ul = UINT32_MAX - (UINT32_MAX % i);
+ do
+ {
+ gcry_randomize ((unsigned char *) &ret, sizeof (uint32_t),
+ GCRY_STRONG_RANDOM);
}
- else
+ while (ret >= ul);
+ return ret % i;
+ case GNUNET_CRYPTO_QUALITY_NONCE:
+ ul = UINT32_MAX - (UINT32_MAX % i);
+ do
{
- ret = i * ((double) RANDOM () / RAND_MAX);
- if (ret >= i)
- ret = i - 1;
- return ret;
+ gcry_create_nonce (&ret, sizeof (ret));
}
+ while (ret >= ul);
+ return ret % i;
+ case GNUNET_CRYPTO_QUALITY_WEAK:
+ ret = i * get_weak_random ();
+ if (ret >= i)
+ ret = i - 1;
+ return ret;
+ default:
+ GNUNET_assert (0);
+ }
+ return 0;
}
/**
* Get an array with a random permutation of the
* numbers 0...n-1.
- * @param mode GNUNET_RANDOM_QUALITY_STRONG if the strong (but expensive)
- * PRNG should be used, GNUNET_RANDOM_QUALITY_WEAK otherwise
+ * @param mode #GNUNET_RANDOM_QUALITY_STRONG if the strong (but expensive)
+ * PRNG should be used, #GNUNET_RANDOM_QUALITY_WEAK otherwise
* @param n the size of the array
* @return the permutation array (allocated from heap)
*/
unsigned int *
-GNUNET_CRYPTO_random_permute (enum GNUNET_CRYPTO_Quality mode, unsigned int n)
+GNUNET_CRYPTO_random_permute (enum GNUNET_CRYPTO_Quality mode,
+ unsigned int n)
{
unsigned int *ret;
unsigned int i;
unsigned int tmp;
- unsigned int x;
+ uint32_t x;
GNUNET_assert (n > 0);
- ret = GNUNET_malloc (n * sizeof (int));
+ ret = GNUNET_malloc (n * sizeof (unsigned int));
for (i = 0; i < n; i++)
ret[i] = i;
- for (i = 0; i < n; i++)
- {
- x = GNUNET_CRYPTO_random_u32 (mode, n);
- tmp = ret[x];
- ret[x] = ret[i];
- ret[i] = tmp;
- }
+ for (i = n - 1; i > 0; i--)
+ {
+ x = GNUNET_CRYPTO_random_u32 (mode, i + 1);
+ tmp = ret[x];
+ ret[x] = ret[i];
+ ret[i] = tmp;
+ }
return ret;
}
+
/**
- * Random on unsigned 64-bit values.
+ * Generate random unsigned 64-bit value.
+ *
+ * @param mode desired quality of the random number
+ * @param max value returned will be in range [0,max) (exclusive)
+ * @return random 64-bit number
*/
-unsigned long long
-GNUNET_CRYPTO_random_u64 (enum GNUNET_CRYPTO_Quality mode,
- unsigned long long u)
+uint64_t
+GNUNET_CRYPTO_random_u64 (enum GNUNET_CRYPTO_Quality mode, uint64_t max)
{
- unsigned long long ret;
+ uint64_t ret;
+ uint64_t ul;
- GNUNET_assert (u > 0);
- if (mode == GNUNET_CRYPTO_QUALITY_STRONG)
+ GNUNET_assert (max > 0);
+ switch (mode)
+ {
+ case GNUNET_CRYPTO_QUALITY_STRONG:
+ ul = UINT64_MAX - (UINT64_MAX % max);
+ do
{
- gcry_randomize ((unsigned char *) &ret,
- sizeof (unsigned long long), GCRY_STRONG_RANDOM);
- return ret % u;
+ gcry_randomize ((unsigned char *) &ret, sizeof (uint64_t),
+ GCRY_STRONG_RANDOM);
}
- else
+ while (ret >= ul);
+ return ret % max;
+ case GNUNET_CRYPTO_QUALITY_NONCE:
+ ul = UINT64_MAX - (UINT64_MAX % max);
+ do
{
- ret = u * ((double) RANDOM () / RAND_MAX);
- if (ret >= u)
- ret = u - 1;
- return ret;
+ gcry_create_nonce (&ret, sizeof (ret));
}
+ while (ret >= ul);
+
+ return ret % max;
+ case GNUNET_CRYPTO_QUALITY_WEAK:
+ ret = max * get_weak_random ();
+ if (ret >= max)
+ ret = max - 1;
+ return ret;
+ default:
+ GNUNET_assert (0);
+ }
+ return 0;
}
+
/**
- * This function should only be called in testcases
- * where strong entropy gathering is not desired
- * (for example, for hostkey generation).
+ * Initialize libgcrypt.
*/
-void
-GNUNET_CRYPTO_random_disable_entropy_gathering ()
+void __attribute__ ((constructor))
+GNUNET_CRYPTO_random_init ()
+{
+ gcry_error_t rc;
+
+ if (! gcry_check_version (NEED_LIBGCRYPT_VERSION))
+ {
+ FPRINTF (stderr,
+ _("libgcrypt has not the expected version (version %s is required).\n"),
+ NEED_LIBGCRYPT_VERSION);
+ GNUNET_assert (0);
+ }
+ if ((rc = gcry_control (GCRYCTL_DISABLE_SECMEM, 0)))
+ FPRINTF (stderr,
+ "Failed to set libgcrypt option %s: %s\n",
+ "DISABLE_SECMEM",
+ gcry_strerror (rc));
+ /* Otherwise gnunet-ecc takes forever to complete, besides
+ we are fine with "just" using GCRY_STRONG_RANDOM */
+ if ((rc = gcry_control (GCRYCTL_ENABLE_QUICK_RANDOM, 0)))
+ FPRINTF (stderr,
+ "Failed to set libgcrypt option %s: %s\n",
+ "ENABLE_QUICK_RANDOM",
+ gcry_strerror (rc));
+ gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
+ gcry_fast_random_poll ();
+ GNUNET_CRYPTO_seed_weak_random (time (NULL) ^
+ GNUNET_CRYPTO_random_u32
+ (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX));
+}
+
+
+/**
+ * Nicely shut down libgcrypt.
+ */
+void __attribute__ ((destructor))
+GNUNET_CRYPTO_random_fini ()
{
- gcry_control (GCRYCTL_ENABLE_QUICK_RANDOM, 0);
+ gcry_set_progress_handler (NULL, NULL);
+#ifdef GCRYCTL_CLOSE_RANDOM_DEVICE
+ (void) gcry_control (GCRYCTL_CLOSE_RANDOM_DEVICE, 0);
+#endif
}
+
/* end of crypto_random.c */
projects / oweals / gnunet.git / blobdiff