crypto_gcrypt.c File Reference

global initialization of libgcrypt More...

#include "platform.h"
#include "gnunet_util_lib.h"
#include <gcrypt.h>

Include dependency graph for crypto_gcrypt.c:

Go to the source code of this file.

Functions
static void *	w_malloc (size_t n)
	Allocation wrapper for libgcrypt, used to avoid bad locking strategy of libgcrypt implementation.
static int	w_check (const void *p)
	Allocation wrapper for libgcrypt, used to avoid bad locking strategy of libgcrypt implementation.
void	GNUNET_CRYPTO_gcrypt_init (void)
void	__attribute__ ((constructor))
	Initialize libgcrypt.
void	GNUNET_CRYPTO_gcrypt_fini (void)
void	__attribute__ ((destructor))
	Nicely shut down libgcrypt.

Detailed Description

global initialization of libgcrypt

Author

Martin Schanzenbach

Randomness generation is done with libsodium (see crypto_random.c), but ECC, RSA, CS, KDF, Paillier and the symmetric primitives still use libgcrypt. libgcrypt requires that gcry_check_version() runs before any other libgcrypt function; most entry points paper over a missing initialization by initializing themselves lazily, but some do not. gcry_mpi_const() – what GCRYMPI_CONST_ONE and friends expand to – calls log_bug() and aborts the process with "MPI subsystem not initialized" instead.

Hence this file, whose only job is to run that global bootstrap from a library constructor. Keep it free of anything else.

Definition in file crypto_gcrypt.c.

Function Documentation

w_malloc()

static void * w_malloc ( size_t  n )

static

Allocation wrapper for libgcrypt, used to avoid bad locking strategy of libgcrypt implementation.

Definition at line 50 of file crypto_gcrypt.c.

{
  return calloc (n, 1);
}

Referenced by __attribute__().

Here is the caller graph for this function:

w_check()

static int w_check ( const void *  p )

static

Allocation wrapper for libgcrypt, used to avoid bad locking strategy of libgcrypt implementation.

Definition at line 61 of file crypto_gcrypt.c.

{
  (void) p;
  return 0; /* not secure memory */
}

References p.

Referenced by __attribute__().

Here is the caller graph for this function:

GNUNET_CRYPTO_gcrypt_init()

void GNUNET_CRYPTO_gcrypt_init

(

void

)

__attribute__() [1/2]

void __attribute__

(

(constructor)

)

Initialize libgcrypt.

Definition at line 74 of file crypto_gcrypt.c.

{
  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);
  }
  /* set custom allocators */
  gcry_set_allocation_handler (&w_malloc, &w_malloc, &w_check, &realloc, &free);
  /* Disable use of secure memory */
  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);
}

References _, GNUNET_assert, w_check(), and w_malloc().

Here is the call graph for this function:

GNUNET_CRYPTO_gcrypt_fini()

void GNUNET_CRYPTO_gcrypt_fini

(

void

)

__attribute__() [2/2]

void __attribute__

(

(destructor)

)

Nicely shut down libgcrypt.

Definition at line 112 of file crypto_gcrypt.c.

{
  gcry_set_progress_handler (NULL, NULL);
#ifdef GCRYCTL_CLOSE_RANDOM_DEVICE
  (void) gcry_control (GCRYCTL_CLOSE_RANDOM_DEVICE, 0);
#endif
}