If it decrypts something that turns out to start with a NUL byte,
then decrypt_desc_layer() will return 0 to indicate the length of
its result. But 0 also indicates an error, which causes the result
not to be freed by decrypt_desc_layer()'s callers.
Since we're trying to stabilize 0.3.2.x, I've opted for the simpler
possible fix here and made it so that an empty decrypted string will
also count as an error.
Fixes bug 24150 and OSS-Fuzz issue 3994.
The original bug was present but unreachable in 0.3.1.1-alpha. I'm
calling this a bugfix on 0.3.2.1-alpha since that's the first version
where you could actually try to decrypt these descriptors.
The new decryption function performs no decryption, skips the salt,
and doesn't check the mac. This allows us to fuzz the
hs_descriptor.c code using unencrypted descriptor test, and exercise
more of the code.
Related to 21509.
This commit only moves code into a function. The client code will need a way
to take a bunch of descriptor link specifier object and encode them into link
specifiers objects.
Make this a public function so it can be used outside of hs_descriptor.c.
Signed-off-by: David Goulet <dgoulet@torproject.org>
We want to reupload our descriptor if its set of responsible HSDirs
changed to minimize reachability issues.
This patch adds a callback everytime we get new dirinfo which checks if
the hash ring changed and reuploads descriptor if needed.
We used to use NULL subcredential which is a terrible terrible idea. Refactor
HS unittests to use subcredentials.
Also add some non-fatal asserts to make sure that we always use subcredentials
when decoding/encoding descs.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This commit adds the functionality for a service to build its descriptor.
Also, a global call to build all descriptors for all services is added to the
service scheduled events.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Add a new and free function for hs_desc_intro_point_t so the service can use
them to setup those objects properly.
Signed-off-by: David Goulet <dgoulet@torproject.org>
A prop224 descriptor was missing the onion key for an introduction point which
is needed to extend to it by the client.
Closes#22979
Signed-off-by: David Goulet <dgoulet@torproject.org>
It is possible that at some point in time a client will encounter unknown or
new fields for an introduction point in a descriptor so let them ignore it for
forward compatibility.
Signed-off-by: David Goulet <dgoulet@torproject.org>
A descriptor only contains the curve25519 public key in the enc-key field so
the private key should not be in that data structure. The service data
structures will have access to the full keypair (#20657).
Furthermore, ticket #21871 has highlighted an issue in the proposal 224 about
the encryption key and legacy key being mutually exclusive. This is very wrong
and this commit fixes the code to follow the change to the proposal of that
ticket.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Also, relaxed the checks of encrypted_data_length_is_valid() since now
only one encrypted section has padding requirements and we don't
actually care to check that all the padding is there.
Consider starting code review from function encode_superencrypted_data().
- Refactor our HS desc crypto funcs to be able to differentiate between
the superencrypted layer and the encrypted layer so that different
crypto constants and padding is used in each layer.
- Introduce some string constants.
- Add some comments.
Since both the client and service will use that data structure to store the
descriptor decoded data, only the public keys are common to both.
Fixes#20572.
Signed-off-by: David Goulet <dgoulet@torproject.org>
