diff options
Diffstat (limited to 'src/or/onion.c')
| -rw-r--r-- | src/or/onion.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/or/onion.c b/src/or/onion.c index bd80c2f503..829be12bae 100644 --- a/src/or/onion.c +++ b/src/or/onion.c @@ -67,6 +67,7 @@ #include "circuitlist.h" #include "config.h" #include "cpuworker.h" +#include "crypto_util.h" #include "networkstatus.h" #include "onion.h" #include "onion_fast.h" @@ -521,6 +522,11 @@ onion_skin_create(int type, return r; } +/* This is the maximum value for keys_out_len passed to + * onion_skin_server_handshake, plus 16. We can make it bigger if needed: + * It just defines how many bytes to stack-allocate. */ +#define MAX_KEYS_TMP_LEN 128 + /** Perform the second (server-side) step of a circuit-creation handshake of * type <b>type</b>, responding to the client request in <b>onion_skin</b> * using the keys in <b>keys</b>. On success, write our response into @@ -563,20 +569,21 @@ onion_skin_server_handshake(int type, return -1; { size_t keys_tmp_len = keys_out_len + DIGEST_LEN; - uint8_t *keys_tmp = tor_malloc(keys_out_len + DIGEST_LEN); + tor_assert(keys_tmp_len <= MAX_KEYS_TMP_LEN); + uint8_t keys_tmp[MAX_KEYS_TMP_LEN]; if (onion_skin_ntor_server_handshake( onion_skin, keys->curve25519_key_map, keys->junk_keypair, keys->my_identity, reply_out, keys_tmp, keys_tmp_len)<0) { - tor_free(keys_tmp); + /* no need to memwipe here, since the output will never be used */ return -1; } + memcpy(keys_out, keys_tmp, keys_out_len); memcpy(rend_nonce_out, keys_tmp+keys_out_len, DIGEST_LEN); - memwipe(keys_tmp, 0, keys_tmp_len); - tor_free(keys_tmp); + memwipe(keys_tmp, 0, sizeof(keys_tmp)); r = NTOR_REPLY_LEN; } break; |