In protover.c, the `expand_protocol_list()` function expands a `smartlist_t` of
`proto_entry_t`s to their protocol name concatenated with each version number.
For example, given a `proto_entry_t` like so:
proto_entry_t *proto = tor_malloc(sizeof(proto_entry_t));
proto_range_t *range = tor_malloc_zero(sizeof(proto_range_t));
proto->name = tor_strdup("DoSaaaaaaaaaaaaaaaaaaaaaa[19KB]aaa");
proto->ranges = smartlist_new();
range->low = 1;
range->high = 65536;
smartlist_add(proto->ranges, range);
(Where `[19KB]` is roughly 19KB of `"a"` bytes.) This would expand in
`expand_protocol_list()` to a `smartlist_t` containing 65536 copies of the
string, e.g.:
"DoSaaaaaaaaaaaaaaaaaaaaaa[19KB]aaa=1"
"DoSaaaaaaaaaaaaaaaaaaaaaa[19KB]aaa=2"
[…]
"DoSaaaaaaaaaaaaaaaaaaaaaa[19KB]aaa=65535"
Thus constituting a potential resource exhaustion attack.
The Rust implementation is not subject to this attack, because it instead
expands the above string into a `HashMap<String, HashSet<u32>` prior to #24031,
and a `HashMap<UnvalidatedProtocol, ProtoSet>` after). Neither Rust version is
subject to this attack, because it only stores the `String` once per protocol.
(Although a related, but apparently of too minor impact to be usable, DoS bug
has been fixed in #24031. [0])
[0]: https://bugs.torproject.org/24031
* ADDS hard limit on protocol name lengths in protover.c and checks in
parse_single_entry() and expand_protocol_list().
* ADDS tests to ensure the bug is caught.
* FIXES#25517: https://bugs.torproject.org/25517
In protover.c, the `expand_protocol_list()` function expands a `smartlist_t` of
`proto_entry_t`s to their protocol name concatenated with each version number.
For example, given a `proto_entry_t` like so:
proto_entry_t *proto = tor_malloc(sizeof(proto_entry_t));
proto_range_t *range = tor_malloc_zero(sizeof(proto_range_t));
proto->name = tor_strdup("DoSaaaaaaaaaaaaaaaaaaaaaa[19KB]aaa");
proto->ranges = smartlist_new();
range->low = 1;
range->high = 65536;
smartlist_add(proto->ranges, range);
(Where `[19KB]` is roughly 19KB of `"a"` bytes.) This would expand in
`expand_protocol_list()` to a `smartlist_t` containing 65536 copies of the
string, e.g.:
"DoSaaaaaaaaaaaaaaaaaaaaaa[19KB]aaa=1"
"DoSaaaaaaaaaaaaaaaaaaaaaa[19KB]aaa=2"
[…]
"DoSaaaaaaaaaaaaaaaaaaaaaa[19KB]aaa=65535"
Thus constituting a potential resource exhaustion attack.
The Rust implementation is not subject to this attack, because it instead
expands the above string into a `HashMap<String, HashSet<u32>` prior to #24031,
and a `HashMap<UnvalidatedProtocol, ProtoSet>` after). Neither Rust version is
subject to this attack, because it only stores the `String` once per protocol.
(Although a related, but apparently of too minor impact to be usable, DoS bug
has been fixed in #24031. [0])
[0]: https://bugs.torproject.org/24031
* ADDS hard limit on protocol name lengths in protover.c and checks in
parse_single_entry() and expand_protocol_list().
* ADDS tests to ensure the bug is caught.
* FIXES#25517: https://bugs.torproject.org/25517
Add two new files (crypto_hkdf.c, crypto_hkdf.h) as new module of crypto.[ch].
This new module includes all functions and dependencies related to HKDF
operations. Those have been removed from crypto.[ch].
Follows #24658.
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
i don't know if whitespace is ok to have before preprocessing
directives on all platforms, but anyway we almost never have it,
so now things are more uniform.
Before this commit, the control events were never triggered. It was introduced
with commit 0c19ce7bde.
Fixes#26082
Signed-off-by: David Goulet <dgoulet@torproject.org>
The specification describes the signature token to be right after a newline
(\n) then the token "signature" and then a white-space followed by the encoded
signature.
This commit makes sure that when we parse the signature from the descriptor,
we are always looking for that extra white-space at the end of the token.
It will allow us also to support future fields that might start with
"signature".
Fixes#26069
Signed-off-by: David Goulet <dgoulet@torproject.org>
There are three cases where this can happen: changes in our
controller events, changes in our DisableNetwork setting, and
changes in our hibernation state.
Closes ticket 26063.
Two new values in each direction. DELIVERED counts valid end-to-end circuit
data that is accepted by our end and OVERHEAD counts the slack unused data in
each of the relay command cells for those accepted cells.
Control port changes are in the next commit.
We still do this time update here, since we do it from all
callbacks, but it is no longer a reason to keep the once-per-second
callback enabled.
Closes ticket 26009.
Since we're going to be disabling the second-elapsed callback, we're
going to sometimes have long periods when no events file, and so the
current second is not updated. Handle that by having a better means
to detect "clock jumps" as opposed to "being idle for a while".
Tolerate far more of the latter.
Part of #26009.
The any_client_port_set() returns true if the ControlPort is set which is
wrong because we can have that port open but still not behave as a tor client
(like many relays for instance).
Fixes#26062
Signed-off-by: David Goulet <dgoulet@torproject.org>
The options_any_client_port_set() returns true if the ControlPort is set which
is wrong because we can have that port open but still not behave as a tor
client (like many relays for instance).
Fixes#26062
Signed-off-by: David Goulet <dgoulet@torproject.org>
