DH *
choose_dh(int min, int wantbits, int max)
{
FILE *f;
char line[2048];
int best, bestcount, which;
int linenum;
struct dhgroup dhg;
if ((f = fopen(_PATH_DH_MODULI, "r")) == NULL &&
(f = fopen(_PATH_DH_PRIMES, "r")) == NULL) {
log("WARNING: %s does not exist, using old modulus", _PATH_DH_MODULI);
return (dh_new_group1());
}
linenum = 0;
best = bestcount = 0;
while (fgets(line, sizeof(line), f)) {
linenum++;
if (!parse_prime(linenum, line, &dhg))
continue;
BN_clear_free(dhg.g);
BN_clear_free(dhg.p);
if (dhg.size > max || dhg.size < min)
continue;
if ((dhg.size > wantbits && dhg.size < best) ||
(dhg.size > best && best < wantbits)) {
best = dhg.size;
bestcount = 0;
}
if (dhg.size == best)
bestcount++;
}
rewind(f);
if (bestcount == 0) {
fclose(f);
log("WARNING: no suitable primes in %s", _PATH_DH_PRIMES);
return (NULL);
}
linenum = 0;
which = arc4random() % bestcount;
while (fgets(line, sizeof(line), f)) {
if (!parse_prime(linenum, line, &dhg))
continue;
if ((dhg.size > max || dhg.size < min) ||
dhg.size != best ||
linenum++ != which) {
BN_clear_free(dhg.g);
BN_clear_free(dhg.p);
continue;
}
break;
}
fclose(f);
if (linenum != which+1)
fatal("WARNING: line %d disappeared in %s, giving up",
which, _PATH_DH_PRIMES);
return (dh_new_group(dhg.g, dhg.p));
}
DH *
choose_dh(int min, int wantbits, int max)
{
FILE *f;
char line[4096];
int best, bestcount, which;
int linenum;
struct dhgroup dhg;
if ((f = fopen(_PATH_DH_MODULI, "r")) == NULL) {
logit("WARNING: could open open %s (%s), using fixed modulus",
_PATH_DH_MODULI, strerror(errno));
return (dh_new_group_fallback(max));
}
linenum = 0;
best = bestcount = 0;
while (fgets(line, sizeof(line), f)) {
linenum++;
if (!parse_prime(linenum, line, &dhg))
continue;
BN_clear_free(dhg.g);
BN_clear_free(dhg.p);
if (dhg.size > max || dhg.size < min)
continue;
if ((dhg.size > wantbits && dhg.size < best) ||
(dhg.size > best && best < wantbits)) {
best = dhg.size;
bestcount = 0;
}
if (dhg.size == best)
bestcount++;
}
rewind(f);
if (bestcount == 0) {
fclose(f);
logit("WARNING: no suitable primes in %s", _PATH_DH_MODULI);
return (dh_new_group_fallback(max));
}
linenum = 0;
which = arc4random_uniform(bestcount);
while (fgets(line, sizeof(line), f)) {
if (!parse_prime(linenum, line, &dhg))
continue;
if ((dhg.size > max || dhg.size < min) ||
dhg.size != best ||
linenum++ != which) {
BN_clear_free(dhg.g);
BN_clear_free(dhg.p);
continue;
}
break;
}
fclose(f);
if (linenum != which+1) {
logit("WARNING: line %d disappeared in %s, giving up",
which, _PATH_DH_MODULI);
return (dh_new_group_fallback(max));
}
return (dh_new_group(dhg.g, dhg.p));
}
struct sshdh *
choose_dh(u_int min, u_int wantbits, u_int max)
{
FILE *f;
char line[4096];
u_int best, bestcount, which, linenum;
int r;
struct dhgroup dhg;
struct sshdh *dh = NULL;
if ((f = fopen(_PATH_DH_MODULI, "r")) == NULL &&
(f = fopen(_PATH_DH_PRIMES, "r")) == NULL) {
logit("WARNING: %s does not exist, using fixed modulus",
_PATH_DH_MODULI);
goto fallback;
}
linenum = 0;
best = bestcount = 0;
while (fgets(line, sizeof(line), f)) {
linenum++;
if (!parse_prime(linenum, line, &dhg))
continue;
sshbn_free(dhg.g);
sshbn_free(dhg.p);
if (dhg.size > max || dhg.size < min)
continue;
if ((dhg.size > wantbits && dhg.size < best) ||
(dhg.size > best && best < wantbits)) {
best = dhg.size;
bestcount = 0;
}
if (dhg.size == best)
bestcount++;
}
rewind(f);
if (bestcount == 0) {
fclose(f);
logit("WARNING: no suitable primes in %s", _PATH_DH_PRIMES);
goto fallback;
}
linenum = 0;
which = arc4random_uniform(bestcount);
while (fgets(line, sizeof(line), f)) {
if (!parse_prime(linenum, line, &dhg))
continue;
if ((dhg.size > max || dhg.size < min) ||
dhg.size != best ||
linenum++ != which) {
sshbn_free(dhg.g);
sshbn_free(dhg.p);
continue;
}
break;
}
fclose(f);
if (linenum != which+1) {
logit("WARNING: line %d disappeared in %s, giving up",
which, _PATH_DH_PRIMES);
fallback:
if ((r = dh_new_group_fallback(max, &dh)) != 0)
fatal("%s: dh_new_group_fallback: %s",
__func__, ssh_err(r));
return dh;
}
return (sshdh_new_group(dhg.g, dhg.p));
}
