| // SPDX-License-Identifier: BSD-2-Clause |
| /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
| * |
| * LibTomCrypt is a library that provides various cryptographic |
| * algorithms in a highly modular and flexible manner. |
| * |
| * The library is free for all purposes without any express |
| * guarantee it works. |
| */ |
| #include "tomcrypt_private.h" |
| |
| /** |
| @file dsa_make_key.c |
| DSA implementation, generate a DSA key |
| */ |
| |
| #ifdef LTC_MDSA |
| |
| /** |
| Create a DSA key |
| @param prng An active PRNG state |
| @param wprng The index of the PRNG desired |
| @param key [in/out] Where to store the created key |
| @return CRYPT_OK if successful. |
| */ |
| int dsa_generate_key(prng_state *prng, int wprng, dsa_key *key) |
| { |
| int err; |
| |
| LTC_ARGCHK(key != NULL); |
| LTC_ARGCHK(ltc_mp.name != NULL); |
| |
| /* so now we have our DH structure, generator g, order q, modulus p |
| Now we need a random exponent [mod q] and it's power g^x mod p |
| */ |
| /* private key x should be from range: 1 <= x <= q-1 (see FIPS 186-4 B.1.2) */ |
| if ((err = rand_bn_upto(key->x, key->q, prng, wprng)) != CRYPT_OK) { return err; } |
| if ((err = mp_exptmod(key->g, key->x, key->p, key->y)) != CRYPT_OK) { return err; } |
| key->type = PK_PRIVATE; |
| |
| return CRYPT_OK; |
| } |
| |
| #endif |
| |
| /* ref: $Format:%D$ */ |
| /* git commit: $Format:%H$ */ |
| /* commit time: $Format:%ai$ */ |