diff options
| author | Nikos Mavrogiannopoulos <nmav@gnutls.org> | 2002-05-13 22:08:28 +0000 |
|---|---|---|
| committer | Nikos Mavrogiannopoulos <nmav@gnutls.org> | 2002-05-13 22:08:28 +0000 |
| commit | 6be325c1e0f7ce5c56bbe0bbcc371d371b3d9c46 (patch) | |
| tree | 507be9ebadc85c3e5647271056f43aa71efb6387 | |
| parent | 35be82272172c4f3e6cade802fd1b2bb9ff97426 (diff) | |
| download | gnutls-6be325c1e0f7ce5c56bbe0bbcc371d371b3d9c46.tar.gz | |
Some cleanups in the Diffie Hellman code.
| -rw-r--r-- | lib/gnutls_dh.c | 27 |
1 files changed, 8 insertions, 19 deletions
diff --git a/lib/gnutls_dh.c b/lib/gnutls_dh.c index 6df565f3d8..dd308ad440 100644 --- a/lib/gnutls_dh.c +++ b/lib/gnutls_dh.c @@ -40,29 +40,17 @@ */ -/* This function should return a resonable size for X - * (DH secret key). The input is the number of bits of - * the modulus. - * FIXME: This function is not correct - */ -static int get_x_size(int bits) -{ - if (bits <= 2048) - return 512; - if (bits <= 4096) - return 768; - return 1024; -} - /* returns the public value (X), and the secret (ret_x). */ GNUTLS_MPI gnutls_calc_dh_secret(GNUTLS_MPI * ret_x, GNUTLS_MPI g, GNUTLS_MPI prime) { GNUTLS_MPI e, x; - int x_size = get_x_size(_gnutls_mpi_get_nbits(prime)); - + int x_size = _gnutls_mpi_get_nbits(prime) - 1; + /* The size of the secret key is less than + * prime/2 + */ - x = _gnutls_mpi_new(x_size); /* FIXME: allocate in secure memory */ + x = _gnutls_mpi_new(x_size); if (x == NULL) { gnutls_assert(); if (ret_x) @@ -71,8 +59,9 @@ GNUTLS_MPI gnutls_calc_dh_secret(GNUTLS_MPI * ret_x, GNUTLS_MPI g, GNUTLS_MPI pr return NULL; } - _gnutls_mpi_randomize(x, x_size, GCRY_STRONG_RANDOM); - /* fixme: set high bit of x and select a larger one */ + /* x_size-7 is there to overcome a bug in libgcrypt + */ + _gnutls_mpi_randomize(x, x_size-7, GCRY_STRONG_RANDOM); e = _gnutls_mpi_alloc_like(prime); if (e == NULL) { |