void
afsnode::mkfh (nfs_fh *fhp)
{
if (!fhsecret_initialized) {
rnd.getbytes (fhsecret, sizeof (fhsecret));
fhsecret_initialized = true;
}
bzero (fhp->data.base (), fhp->data.size ());
puthyper (fhp->data.base (), ino);
memcpy (fhp->data.base () + 8, fhsecret, sizeof (fhsecret));
}
bool
ocb::decrypt (void *_ptext, u_int64_t nonce, const void *_ctext,
const blk *tag, size_t len) const
{
char *ptext = static_cast <char *> (_ptext);
const char *ctext = static_cast <const char *> (_ctext);
blk r;
blkclear (&r);
puthyper (r.c + (r.nc - 8), nonce);
blkxor (&r, l[0]);
k.encipher_bytes (r.c);
blk s;
blkclear (&s);
size_t i = 1;
blk tmp;
while (len > blk::nc) {
blkxor (&r, l[ffs (i) - 1]);
tmp.get (ctext);
blkxor (&tmp, r);
k.decipher_bytes (tmp.c);
blkxor (&tmp, r);
tmp.put (ptext);
blkxor (&s, tmp);
ptext += blk::nc;
ctext += blk::nc;
len -= blk::nc;
i++;
};
blkxor (&r, l[ffs (i) - 1]);
blkxor (&tmp, l[-1], r);
tmp.c[tmp.nc - 1] ^= len << 3;
k.encipher_bytes (tmp.c);
blkxor (&s, tmp);
for (u_int b = 0; b < len; b++) {
s.c[b] ^= ctext[b];
ptext[b] = tmp.c[b] ^ ctext[b];
}
blkxor (&tmp, s, r);
k.encipher_bytes (tmp.c);
return !memcmp (tag->c, tmp.c, tag->nc);
}
void
sha1oracle_init (sha1oracle_ctx *soc, size_t nbytes, u_int64_t idx)
{
u_char prefix[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
size_t i;
mdblock_init (&soc->mdb, sha1oracle_consume);
puthyper (prefix + 8, idx);
mdblock_update (&soc->mdb, prefix, sizeof (prefix));
soc->firstblock = 1;
soc->nbytes = nbytes;
soc->nstate = (nbytes + 19) / 20;
soc->state = malloc (20 * soc->nstate);
for (i = 0; i < soc->nstate; i++)
sha1_newstate (soc->state[i]);
}
static void
sha1oracle_consume (struct mdblock *mp, const u_char block[64])
{
sha1oracle_ctx *soc = (sha1oracle_ctx *) mp;
size_t i;
if (soc->firstblock) {
u_char wblock[64];
memcpy (wblock, block, sizeof (wblock));
for (i = 0; i < soc->nstate; i++) {
puthyper (wblock, i);
sha1_transform (soc->state[i], wblock);
}
soc->firstblock = 0;
return;
}
for (i = 0; i < soc->nstate; i++)
sha1_transform (soc->state[i], block);
}