diff options
Diffstat (limited to 'src/exhaustive/brainpool_rfc.c')
| -rw-r--r-- | src/exhaustive/brainpool_rfc.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/src/exhaustive/brainpool_rfc.c b/src/exhaustive/brainpool_rfc.c index b3c5e5e..1a9fea9 100644 --- a/src/exhaustive/brainpool_rfc.c +++ b/src/exhaustive/brainpool_rfc.c @@ -27,6 +27,8 @@ GENERATOR(brainpool_rfc_gen_seed_input) { brainpool_delegate(brainpool_gen_seed_input); } +#undef brainpool_delegate + GENERATOR(brainpool_rfc_gen_equation) { // field is definitely prime pari_sp btop = avma; @@ -42,7 +44,13 @@ GENERATOR(brainpool_rfc_gen_equation) { brainpool_hash(seed->seed, seed->brainpool.w, seed->brainpool.v); GEN a = bits_to_i(a_bits); bits_free(&a_bits); - z = Fp_sqrtn(a, stoi(4), curve->field, NULL); + GEN am = Fp_invsafe(a, curve->field); + if (am == NULL) { + brainpool_update_seed(seed->seed); + avma = btop; + continue; + } + z = Fp_sqrtn(Fp_muls(am, -1, curve->field), stoi(4), curve->field, NULL); if (z == NULL) { brainpool_update_seed(seed->seed); avma = btop; |