Double code
Hello,
I found that the following code {{{ int crypto_expand_key_material_TAP(const uint8_t *key_in, size_t key_in_len, uint8_t *key_out, size_t key_out_len) { int i; uint8_t *cp, *tmp = tor_malloc(key_in_len+1); uint8_t digest[DIGEST_LEN];
/* If we try to get more than this amount of key data, we'll repeat blocks./ tor_assert(key_out_len <= DIGEST_LEN256);
memcpy(tmp, key_in, key_in_len); for (cp = key_out, i=0; cp < key_out+key_out_len; ++i, cp += DIGEST_LEN) { tmp[key_in_len] = i; if (crypto_digest((char*)digest, (const char *)tmp, key_in_len+1)) goto err; memcpy(cp, digest, MIN(DIGEST_LEN, key_out_len-(cp-key_out))); } memwipe(tmp, 0, key_in_len+1); tor_free(tmp); memwipe(digest, 0, sizeof(digest)); return 0;
err: memwipe(tmp, 0, key_in_len+1); tor_free(tmp); memwipe(digest, 0, sizeof(digest)); return -1; } }}}
contains twice this code
memwipe(tmp, 0, key_in_len+1);
tor_free(tmp);
memwipe(digest, 0, sizeof(digest));
then I think it will be ok to modify like this
int crypto_expand_key_material_TAP(const uint8_t *key_in, size_t key_in_len,
uint8_t *key_out, size_t key_out_len)
{
int i, r = -1;
uint8_t *cp, *tmp = tor_malloc(key_in_len+1);
uint8_t digest[DIGEST_LEN];
/* If we try to get more than this amount of key data, we'll repeat blocks.*/
tor_assert(key_out_len <= DIGEST_LEN*256);
memcpy(tmp, key_in, key_in_len);
for (cp = key_out, i=0; cp < key_out+key_out_len;
++i, cp += DIGEST_LEN) {
tmp[key_in_len] = i;
if (crypto_digest((char*)digest, (const char *)tmp, key_in_len+1))
goto exit;
memcpy(cp, digest, MIN(DIGEST_LEN, key_out_len-(cp-key_out)));
}
r = 0;
exit:
memwipe(tmp, 0, key_in_len+1);
tor_free(tmp);
memwipe(digest, 0, sizeof(digest));
return r;
}
Trac:
Username: pfrankw