putty/sshecdsag.c

72 строки
1.8 KiB
C

/*
* EC key generation.
*/
#include "ssh.h"
/* Forward reference from sshecc.c */
struct ec_point *ecp_mul(const struct ec_point *a, const Bignum b);
int ec_generate(struct ec_key *key, int bits, progfn_t pfn,
void *pfnparam)
{
struct ec_point *publicKey;
if (!ec_nist_alg_and_curve_by_bits(bits, &key->publicKey.curve,
&key->signalg))
return 0;
key->privateKey = bignum_random_in_range(One, key->publicKey.curve->w.n);
if (!key->privateKey) return 0;
publicKey = ec_public(key->privateKey, key->publicKey.curve);
if (!publicKey) {
freebn(key->privateKey);
key->privateKey = NULL;
return 0;
}
key->publicKey.x = publicKey->x;
key->publicKey.y = publicKey->y;
key->publicKey.z = NULL;
sfree(publicKey);
return 1;
}
int ec_edgenerate(struct ec_key *key, int bits, progfn_t pfn,
void *pfnparam)
{
struct ec_point *publicKey;
if (!ec_ed_alg_and_curve_by_bits(bits, &key->publicKey.curve,
&key->signalg))
return 0;
{
/* EdDSA secret keys are just 32 bytes of hash preimage; the
* 64-byte SHA-512 hash of that key will be used when signing,
* but the form of the key stored on disk is the preimage
* only. */
Bignum privMax = bn_power_2(bits);
if (!privMax) return 0;
key->privateKey = bignum_random_in_range(Zero, privMax);
freebn(privMax);
if (!key->privateKey) return 0;
}
publicKey = ec_public(key->privateKey, key->publicKey.curve);
if (!publicKey) {
freebn(key->privateKey);
key->privateKey = NULL;
return 0;
}
key->publicKey.x = publicKey->x;
key->publicKey.y = publicKey->y;
key->publicKey.z = NULL;
sfree(publicKey);
return 1;
}