Extrainfo documents are now ed-signed just as are router
descriptors, according to proposal 220. This patch also includes
some more tests for successful/failing parsing, and fixes a crash
bug in ed25519 descriptor parsing.
An earlier version of these tests was broken; now they're a nicer,
more robust, more black-box set of tests. The key is to have each
test check a handshake message that is wrong in _one_ way.
This includes the link handshake variations for proposal220.
We'll use this for testing first, and then use it to extend our
current code to support prop220.
When there are annotations on a router descriptor, the
ed25519-identity element won't be at position 0 or 1; it will be at
router+1 or router-1.
This patch also adds a missing smartlist function to search a list for
an item with a particular pointer.
With this patch:
* Authorities load the key-pinning log at startup.
* Authorities open a key-pinning log for writing at startup.
* Authorities reject any router with an ed25519 key where they have
previously seen that ed25519 key with a different RSA key, or vice
versa.
* Authorities warn about, but *do not* reject, RSA-only descriptors
when the RSA key has previously gone along with an Ed25519 key.
(We should make this a 'reject' too, but we can't do that until we're
sure there's no legit reason to downgrade to 0.2.5.)
This module implements a key-pinning mechanism to ensure that it's
safe to use RSA keys as identitifers even as we migrate to Ed25519
keys. It remembers, for every Ed25519 key we've seen, what the
associated Ed25519 key is. This way, if we see a different Ed25519
key with that RSA key, we'll know that there's a mismatch.
We persist these entries to disk using a simple format, where each
line has a base64-encoded RSA SHA1 hash, then a base64-endoded
Ed25519 key. Empty lines, misformed lines, and lines beginning with
a # are ignored. Lines beginning with @ are reserved for future
extensions.
Routers now use TAP and ntor onion keys to sign their identity keys,
and put these signatures in their descriptors. That allows other
parties to be confident that the onion keys are indeed controlled by
the router that generated the descriptor.
Routers now use TAP and ntor onion keys to sign their identity keys,
and put these signatures in their descriptors. That allows other
parties to be confident that the onion keys are indeed controlled by
the router that generated the descriptor.
For prop220, we have a new ed25519 certificate type. This patch
implements the code to create, parse, and validate those, along with
code for routers to maintain their own sets of certificates and
keys. (Some parts of master identity key encryption are done, but
the implementation of that isn't finished)
If the OpenSSL team accepts my patch to add an
SSL_get_client_ciphers function, this patch will make Tor use it
when available, thereby working better with openssl 1.1.
We previously used this function instead of SSL_set_cipher_list() to
set up a stack of client SSL_CIPHERs for these reasons:
A) In order to force a particular order of the results.
B) In order to be able to include dummy entries for ciphers that
this build of openssl did not support, so we could impersonate
Firefox harder.
But we no longer do B, since we merged proposal 198 and stopped
lying about what ciphers we know.
And A was actually pointless, since I had misread the implementation
of SSL_set_cipher_list(). It _does_ do some internal sorting, but
that is pre-sorting on the master list of ciphers, not sorting on
the user's preferred order.
As OpenSSL >= 1.0.0 is now required, ECDHE is now mandatory. The group
has to be validated at runtime, because of RedHat lawyers (P224 support
is entirely missing in the OpenSSL RPM, but P256 is present and is the
default).
Resolves ticket #16140.
The key here is to never touch ssl->cipher_list directly, but only
via SSL_get_ciphers(). But it's not so simple.
See, if there is no specialized cipher_list on the SSL object,
SSL_get_ciphers returns the cipher_list on the SSL_CTX. But we sure
don't want to modify that one! So we need to use
SSL_set_cipher_list first to make sure that we really have a cipher
list on the SSL object.
When set, this limits the maximum number of simultaneous streams per
rendezvous circuit on the server side of a HS, with further RELAY_BEGIN
cells being silently ignored.
This can be modified via "HiddenServiceMaxStreamsCloseCircuit", which
if set will cause offending rendezvous circuits to be torn down instead.
Addresses part of #16052.
