commit ab2e007ffbb6a6cdf8765e4beaa2bb69c1289036 Author: Andrea Shepard <andrea@persephoneslair.org> Date: Fri Jun 15 21:17:02 2012 -0700 In rend_service_load_keys(), clear extended descriptor cookie and buffer, clear temporary heap space for client key, and check if serializing client key fails --- src/or/rendservice.c | 21 ++++++++++++++++++--- 1 files changed, 18 insertions(+), 3 deletions(-) diff --git a/src/or/rendservice.c b/src/or/rendservice.c index acc3cea..b257c7a 100644 --- a/src/or/rendservice.c +++ b/src/or/rendservice.c @@ -619,6 +619,7 @@ rend_service_load_keys(void) char buf[1500]; char desc_cook_out[3*REND_DESC_COOKIE_LEN_BASE64+1]; char service_id[16+1]; + char extended_desc_cookie[REND_DESC_COOKIE_LEN+1]; SMARTLIST_FOREACH_BEGIN(rend_service_list, rend_service_t *, s) { if (s->private_key) @@ -765,15 +766,25 @@ rend_service_load_keys(void) } if (client->client_key) { char *client_key_out = NULL; - crypto_pk_write_private_key_to_string(client->client_key, - &client_key_out, &len); + if ( crypto_pk_write_private_key_to_string(client->client_key, + &client_key_out, &len) != 0 ) { + log_warn(LD_BUG, "Internal error: " + "crypto_pk_write_private_key_to_string() failed."); + goto err; + } if (rend_get_service_id(client->client_key, service_id)<0) { log_warn(LD_BUG, "Internal error: couldn't encode service ID."); + /* + * len is string length, not buffer length, but last byte is NUL + * anyway. + */ + memset(client_key_out, 0, len); tor_free(client_key_out); goto err; } written = tor_snprintf(buf + written, sizeof(buf) - written, "client-key\n%s", client_key_out); + memset(client_key_out, 0, len); tor_free(client_key_out); if (written < 0) { log_warn(LD_BUG, "Could not write client entry."); @@ -794,7 +805,6 @@ rend_service_load_keys(void) tor_snprintf(buf, sizeof(buf),"%s.onion %s # client: %s\n", s->service_id, desc_cook_out, client->client_name); } else { - char extended_desc_cookie[REND_DESC_COOKIE_LEN+1]; memcpy(extended_desc_cookie, client->descriptor_cookie, REND_DESC_COOKIE_LEN); extended_desc_cookie[REND_DESC_COOKIE_LEN] = @@ -827,8 +837,11 @@ rend_service_load_keys(void) strmap_free(parsed_clients, rend_authorized_client_strmap_item_free); if (r<0) { /* Clear these here for the early error exit */ + /* We have to clear buf because encoded keys can get written to it */ + memset(buf, 0, sizeof(buf)); memset(desc_cook_out, 0, sizeof(desc_cook_out)); memset(service_id, 0, sizeof(service_id)); + memset(extended_desc_cookie, 0, sizeof(extended_desc_cookie)); if (open_cfile) abort_writing_to_file(open_cfile); if (open_hfile) @@ -847,8 +860,10 @@ rend_service_load_keys(void) * and so forth) that otherwise might have leftover key from the * previous iteration on the stack. */ + memset(buf, 0, sizeof(buf)); memset(desc_cook_out, 0, sizeof(desc_cook_out)); memset(service_id, 0, sizeof(service_id)); + memset(extended_desc_cookie, 0, sizeof(extended_desc_cookie)); } SMARTLIST_FOREACH_END(s); return r;