/* This is to check a bug reported by bpgcrypt at itaparica.org on 2006-07-31 against libgcrypt 1.2.2. */ static void one_bit_only (int highbit) { gcry_mpi_t a; char *result; int i; wherestr = "one_bit_only"; show ("checking that set_%sbit does only set one bit\n", highbit?"high":""); a = gcry_mpi_new (0); gcry_mpi_randomize (a, 70, GCRY_WEAK_RANDOM); gcry_mpi_set_ui (a, 0); if (highbit) gcry_mpi_set_highbit (a, 42); else gcry_mpi_set_bit (a, 42); if (!gcry_mpi_test_bit (a, 42)) fail ("failed to set a bit\n"); gcry_mpi_clear_bit (a, 42); if (gcry_mpi_test_bit (a, 42)) fail ("failed to clear a bit\n"); result = mpi2bitstr (a, 70); assert (strlen (result) == 70); for (i=0; result[i]; i++) if ( result[i] != '0' ) break; if (result[i]) fail ("spurious bits detected\n"); xfree (result); gcry_mpi_release (a); }
static void mpz_randomize (gcry_mpi_t n, unsigned int nbits, struct GNUNET_HashCode * rnd) { struct GNUNET_HashCode hc; struct GNUNET_HashCode tmp; int bits_per_hc = sizeof (struct GNUNET_HashCode) * 8; int cnt; int i; GNUNET_assert (nbits > 0); cnt = (nbits + bits_per_hc - 1) / bits_per_hc; gcry_mpi_set_ui (n, 0); tmp = *rnd; for (i = 0; i < cnt; i++) { int j; if (i > 0) GNUNET_CRYPTO_hash (&hc, sizeof (struct GNUNET_HashCode), &tmp); for (j = 0; j < sizeof (struct GNUNET_HashCode) / sizeof (uint32_t); j++) { #if HAVE_GCRY_MPI_LSHIFT gcry_mpi_lshift (n, n, sizeof (uint32_t) * 8); #else gcry_mpi_mul_ui (n, n, 1 << (sizeof (uint32_t) * 4)); gcry_mpi_mul_ui (n, n, 1 << (sizeof (uint32_t) * 4)); #endif gcry_mpi_add_ui (n, n, ntohl (((uint32_t *) & tmp)[j])); } hc = tmp; } GNUNET_CRYPTO_hash (&hc, sizeof (struct GNUNET_HashCode), rnd); i = gcry_mpi_get_nbits (n); while (i > nbits) gcry_mpi_clear_bit (n, --i); }
/* * Test iterative X25519 computation through lower layer MPI routines. * * Input: K (as hex string), ITER, R (as hex string) * * where R is expected result of iterating X25519 by ITER times. * */ static void test_it (int testno, const char *k_str, int iter, const char *result_str) { gcry_ctx_t ctx; gpg_error_t err; void *buffer = NULL; size_t buflen; gcry_mpi_t mpi_k = NULL; gcry_mpi_t mpi_x = NULL; gcry_mpi_point_t P = NULL; gcry_mpi_point_t Q; int i; gcry_mpi_t mpi_kk = NULL; if (verbose > 1) info ("Running test %d: iteration=%d\n", testno, iter); gcry_mpi_ec_new (&ctx, NULL, "Curve25519"); Q = gcry_mpi_point_new (0); if (!(buffer = hex2buffer (k_str, &buflen)) || buflen != 32) { fail ("error scanning MPI for test %d, %s: %s", testno, "k", "invalid hex string"); goto leave; } reverse_buffer (buffer, buflen); if ((err = gcry_mpi_scan (&mpi_x, GCRYMPI_FMT_USG, buffer, buflen, NULL))) { fail ("error scanning MPI for test %d, %s: %s", testno, "x", gpg_strerror (err)); goto leave; } xfree (buffer); buffer = NULL; P = gcry_mpi_point_set (NULL, mpi_x, NULL, GCRYMPI_CONST_ONE); mpi_k = gcry_mpi_copy (mpi_x); if (debug) print_mpi ("k", mpi_k); for (i = 0; i < iter; i++) { /* * Another variant of decodeScalar25519 thing. */ mpi_kk = gcry_mpi_set (mpi_kk, mpi_k); gcry_mpi_set_bit (mpi_kk, 254); gcry_mpi_clear_bit (mpi_kk, 255); gcry_mpi_clear_bit (mpi_kk, 0); gcry_mpi_clear_bit (mpi_kk, 1); gcry_mpi_clear_bit (mpi_kk, 2); gcry_mpi_ec_mul (Q, mpi_kk, P, ctx); P = gcry_mpi_point_set (P, mpi_k, NULL, GCRYMPI_CONST_ONE); gcry_mpi_ec_get_affine (mpi_k, NULL, Q, ctx); if (debug) print_mpi ("k", mpi_k); } { unsigned char res[32]; char *r, *r0; gcry_mpi_print (GCRYMPI_FMT_USG, res, 32, NULL, mpi_k); reverse_buffer (res, 32); r0 = r = xmalloc (65); if (!r0) { fail ("memory allocation for test %d", testno); goto leave; } for (i=0; i < 32; i++, r += 2) snprintf (r, 3, "%02x", res[i]); if (strcmp (result_str, r0)) { fail ("curv25519 failed for test %d: %s", testno, "wrong value returned"); info (" expected: '%s'", result_str); info (" got: '%s'", r0); } xfree (r0); } leave: gcry_mpi_release (mpi_kk); gcry_mpi_release (mpi_k); gcry_mpi_point_release (P); gcry_mpi_release (mpi_x); xfree (buffer); gcry_mpi_point_release (Q); gcry_ctx_release (ctx); }