diff options
Diffstat (limited to 'external/nettle-3.3/nettle/rsa.c')
-rw-r--r-- | external/nettle-3.3/nettle/rsa.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/external/nettle-3.3/nettle/rsa.c b/external/nettle-3.3/nettle/rsa.c new file mode 100644 index 0000000..22fae77 --- /dev/null +++ b/external/nettle-3.3/nettle/rsa.c @@ -0,0 +1,86 @@ +/* rsa.c + + The RSA publickey algorithm. + + Copyright (C) 2001 Niels Möller + + This file is part of GNU Nettle. + + GNU Nettle is free software: you can redistribute it and/or + modify it under the terms of either: + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + + or + + * the GNU General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + + or both in parallel, as here. + + GNU Nettle is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received copies of the GNU General Public License and + the GNU Lesser General Public License along with this program. If + not, see http://www.gnu.org/licenses/. +*/ + +#if HAVE_CONFIG_H +# include "config.h" +#endif + +#include "rsa.h" + +#include "bignum.h" + +void +rsa_public_key_init(struct rsa_public_key *key) +{ + mpz_init(key->n); + mpz_init(key->e); + + /* Not really necessary, but it seems cleaner to initialize all the + * storage. */ + key->size = 0; +} + +void +rsa_public_key_clear(struct rsa_public_key *key) +{ + mpz_clear(key->n); + mpz_clear(key->e); +} + +/* Computes the size, in octets, of a the modulo. Returns 0 if the + * modulo is too small to be useful, or otherwise appears invalid. */ +size_t +_rsa_check_size(mpz_t n) +{ + /* Round upwards */ + size_t size; + + /* Even moduli are invalid, and not supported by mpz_powm_sec. */ + if (mpz_even_p (n)) + return 0; + + size = (mpz_sizeinbase(n, 2) + 7) / 8; + + if (size < RSA_MINIMUM_N_OCTETS) + return 0; + + return size; +} + +int +rsa_public_key_prepare(struct rsa_public_key *key) +{ + key->size = _rsa_check_size(key->n); + + return (key->size > 0); +} |