This is in preparation for upcoming experiments which will require
supporting multiple experimental versions of TLS 1.3 with, on the
server, the ability to enable multiple variants at once. This means the
version <-> wire bijection no longer exists, even when limiting to a
single SSL*. Thus version_to_wire is removed and instead we treat the
wire version as the canonical version value.
There is a mapping from valid wire versions to protocol versions which
describe the high-level handshake protocol in use. This mapping is not
injective, so uses of version_from_wire are rewritten differently.
All the version-munging logic is moved to ssl_versions.c with a master
preference list of all TLS and DTLS versions. The legacy version
negotiation is converted to the new scheme. The version lists and
negotiation are driven by the preference lists and a
ssl_supports_version API.
To simplify the mess around SSL_SESSION and versions, version_from_wire
is now DTLS/TLS-agnostic, with any filtering being done by
ssl_supports_version. This is screwy but allows parsing SSL_SESSIONs to
sanity-check it and reject all bogus versions in SSL_SESSION. This
reduces a mess of error cases.
As part of this, the weird logic where ssl->version is set early when
sending the ClientHello is removed. The one place where we were relying
on this behavior is tweaked to query hs->max_version instead.
Change-Id: Ic91b348481ceba94d9ae06d6781187c11adc15b0
Reviewed-on: https://boringssl-review.googlesource.com/17524
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
BUG=76
Change-Id: Ie894ea5d327f88e66b234767de437dbe5c67c41d
Reviewed-on: https://boringssl-review.googlesource.com/12960
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
This adds support on the server and client to accept data-less early
data. The server will still fail to parse early data with any
contents, so this should remain disabled.
BUG=76
Change-Id: Id85d192d8e0360b8de4b6971511b5e8a0e8012f7
Reviewed-on: https://boringssl-review.googlesource.com/12921
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
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The TLS 1.2 state machine now looks actually much closer to the TLS 1.3
one on the write side. Although the write states still have a BIO-style
return, they don't actually send anything anymore. Only the BIO flush
state does. Reads are still integrated into the states themselves
though, so I haven't made it match TLS 1.3 yet.
BUG=72
Change-Id: I7708162efca13cd335723efa5080718a5f2808ab
Reviewed-on: https://boringssl-review.googlesource.com/13228
Reviewed-by: Adam Langley <agl@google.com>
On the TLS side, we introduce a running buffer of ciphertext. Queuing up
pending data consists of encrypting the record into the buffer. This
effectively reimplements what the buffer BIO was doing previously, but
this resizes to fit the whole flight.
As part of this, rename all the functions to add to the pending flight
to be more uniform. This CL proposes "add_foo" to add to the pending
flight and "flush_flight" to drain it.
We add an add_alert hook for alerts but, for now, only the SSL 3.0
warning alert (sent mid-handshake) uses this mechanism. Later work will
push this down to the rest of the write path so closure alerts use it
too, as in DTLS. The intended end state is that all the ssl_buffer.c and
wpend_ret logic will only be used for application data and eventually
optionally replaced by the in-place API, while all "incidental" data
will be handled internally.
For now, the two buffers are mutually exclusive. Moving closure alerts
to "incidentals" will change this, but flushing application data early
is tricky due to wpend_ret. (If we call ssl_write_buffer_flush,
do_ssl3_write doesn't realize it still has a wpend_ret to replay.) That
too is all left alone in this change.
To keep the diff down, write_message is retained for now and will be
removed from the state machines in a follow-up change.
BUG=72
Change-Id: Ibce882f5f7196880648f25d5005322ca4055c71d
Reviewed-on: https://boringssl-review.googlesource.com/13224
Reviewed-by: Adam Langley <agl@google.com>
Instead, "writing" a message merely adds it to the outgoing_messages
structure. The code to write the flight then loops over it all and now
shares code with retransmission. The verbs here are all a little odd,
but they'll be fixed in later commits.
In doing so, this fixes a slight miscalculation of the record-layer
overhead when retransmitting a flight that spans two epochs. (We'd use
the encrypted epoch's overhead for the unencrypted epoch.)
BUG=72
Change-Id: I8ac897c955cc74799f8b5ca6923906e97d6dad17
Reviewed-on: https://boringssl-review.googlesource.com/13223
Reviewed-by: Adam Langley <agl@google.com>
This is the first part to removing the buffer BIO. The eventual end
state is the SSL_PROTOCOL_METHOD is responsible for maintaining one
flight's worth of messages. In TLS, it will just be a buffer containing
the flight's ciphertext. In DTLS, it's the existing structure for
retransmit purposes. There will be hooks:
- add_message (synchronous)
- add_change_cipher_spec (synchronous)
- add_warning_alert (synchronous; needed until we lose SSLv3 client auth
and TLS 1.3 draft 18; draft 19 will switch end_of_early_data to a
handshake message)
- write_flight (BIO; flush_flight will be renamed to this)
This also preserves the exact return value of BIO_flush. Eventually all
the BIO_write calls will be hidden behind BIO_flush to, to be consistent
with other BIO-based calls, preserve the return value.
BUG=72
Change-Id: I74cd23759a17356aab3bb475a8ea42bd2cd115c9
Reviewed-on: https://boringssl-review.googlesource.com/13222
Reviewed-by: Adam Langley <agl@google.com>
Most C standard library functions are undefined if passed NULL, even
when the corresponding length is zero. This gives them (and, in turn,
all functions which call them) surprising behavior on empty arrays.
Some compilers will miscompile code due to this rule. See also
https://www.imperialviolet.org/2016/06/26/nonnull.html
Add OPENSSL_memcpy, etc., wrappers which avoid this problem.
BUG=23
Change-Id: I95f42b23e92945af0e681264fffaf578e7f8465e
Reviewed-on: https://boringssl-review.googlesource.com/12928
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
s3_lib.c is nearly gone. ssl_get_cipher_preferences will fall away once
we remove the version-specific cipher lists. ssl_get_algorithm_prf and
the PRF stuff in general needs some revising (it was the motivation for
all the SSL_HANDSHAKE business). I've left ssl3_new / ssl3_free alone
for now because we don't have a good separation between common TLS/DTLS
connection state and state internal to the TLS SSL_PROTOCOL_METHOD.
Leaving that alone for now as there's lower-hanging fruit.
Change-Id: Idf7989123a387938aa89b6a052161c9fff4cbfb3
Reviewed-on: https://boringssl-review.googlesource.com/12584
Reviewed-by: Adam Langley <agl@google.com>
For TLS 1.3 draft 18, it will be useful to get at the full current
message and not just the body. Add a hook to expose it and replace
hash_current_message with a wrapper over it.
BUG=112
Change-Id: Ib9e00dd1b78e8b72e12409d85c80e96c5b411a8b
Reviewed-on: https://boringssl-review.googlesource.com/12238
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
This is to allow for PSK binders to be munged into the ClientHello as part of
draft 18.
BUG=112
Change-Id: Ic4fd3b70fa45669389b6aaf55e61d5839f296748
Reviewed-on: https://boringssl-review.googlesource.com/12228
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
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This is in preparation for using the supported_versions extension to
experiment with draft TLS 1.3 versions, since we don't wish to restore
the fallback. With versions begin opaque values, we will want
version_from_wire to reject unknown values, not attempt to preserve
order in some way.
This means ClientHello.version processing needs to be separate code.
That's just written out fully in negotiate_version now. It also means
SSL_set_{min,max}_version will notice invalid inputs which aligns us
better with upstream's versions of those APIs.
This CL doesn't replace ssl->version with an internal-representation
version, though follow work should do it once a couple of changes land
in consumers.
BUG=90
Change-Id: Id2f5e1fa72847c823ee7f082e9e69f55e51ce9da
Reviewed-on: https://boringssl-review.googlesource.com/11122
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
With the previous DTLS change, the dispatch layer only cares about the
end of the handshake to know when to drop the current message. TLS 1.3
post-handshake messages will need a similar hook, so convert it to this
lower-level one.
BUG=83
Change-Id: I4c8c3ba55ba793afa065bf261a7bccac8816c348
Reviewed-on: https://boringssl-review.googlesource.com/8989
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
This is in preparation for switching finish_handshake to a
release_current_message hook. finish_handshake in DTLS is also
responsible for releasing any memory associated with extra messages in
the handshake.
Except that's not right and we need to make it an error anyway. Given
that the rest of the DTLS dispatch layer already strongly assumes there
is only one message in epoch one, putting the check in the fragment
processing works fine enough. Add tests for this.
This will certainly need revising when DTLS 1.3 happens (perhaps just a
version check, perhaps bringing finish_handshake back as a function that
can fail... which means we need a state just before SSL_ST_OK), but DTLS
1.3 post-handshake messages haven't really been written down, so let's
do the easy thing for now and add a test for when it gets more
interesting.
This removes the sequence number reset in the DTLS code. That reset
never did anything becase we don't and never will renego. We should make
sure DTLS 1.3 does not bring the reset back for post-handshake stuff.
(It was wrong in 1.2 too. Penultimate-flight retransmits and renego
requests are ambiguous in DTLS.)
BUG=83
Change-Id: I33d645a8550f73e74606030b9815fdac0c9fb682
Reviewed-on: https://boringssl-review.googlesource.com/8988
Reviewed-by: Adam Langley <agl@google.com>
For TLS 1.3, we will need to process more complex post-handshake
messages. It is simplest if we use the same mechanism. In preparation,
allow ssl3_get_message to be called at any point.
Note that this stops reserving SSL3_RT_MAX_PLAIN_LENGTH in init_buf
right off the bat. Instead it will grow as-needed to accomodate the
handshake. SSL3_RT_MAX_PLAIN_LENGTH is rather larger than we probably
need to receive, particularly as a server, so this seems a good plan.
BUG=83
Change-Id: Id7f4024afc4c8a713b46b0d1625432315594350e
Reviewed-on: https://boringssl-review.googlesource.com/8985
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
This API needs to be improved but, for the time being, keep the
invariant reasonable.
Change-Id: If94d41e7e7936e44de5ecb36da45f89f80df7784
Reviewed-on: https://boringssl-review.googlesource.com/8984
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
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This is the equivalent of FragmentAcrossChangeCipherSuite for DTLS. It
is possible for us to, while receiving pre-CCS handshake messages, to
buffer up a message with sequence number meant for a post-CCS Finished.
When we then get to the new epoch and attempt to read the Finished, we
will process the buffered Finished although it was sent with the wrong
encryption.
Move ssl_set_{read,write}_state to SSL_PROTOCOL_METHOD hooks as this is
a property of the transport. Notably, read_state may fail. In DTLS
check the handshake buffer size. We could place this check in
read_change_cipher_spec, but TLS 1.3 has no ChangeCipherSpec message, so
we will need to implement this at the cipher change point anyway. (For
now, there is only an assert on the TLS side. This will be replaced with
a proper check in TLS 1.3.)
Change-Id: Ia52b0b81e7db53e9ed2d4f6d334a1cce13e93297
Reviewed-on: https://boringssl-review.googlesource.com/8790
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
This machinery is so different between TLS and DTLS that there is no
sense in having them share structures. This switches us to maintaining
the full reassembled message in hm_fragment and get_message just lets
the caller read out of that when ready.
This removes the last direct handshake dependency on init_buf,
ssl3_hash_message.
Change-Id: I4eccfb6e6021116255daead5359a0aa3f4d5be7b
Reviewed-on: https://boringssl-review.googlesource.com/8667
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Both DTLS and TLS still use it, but that will change in the following
commit. This also removes the handshake's knowledge of the
dtls_clear_incoming_messages function.
(It's possible we'll want to get rid of begin_handshake in favor of
allocating it lazily depending on how TLS 1.3 post-handshake messages
end up working out. But this should work for now.)
Change-Id: I0f512788bbc330ab2c947890939c73e0a1aca18b
Reviewed-on: https://boringssl-review.googlesource.com/8666
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
These are where the DTLS- and TLS-specific transport layer hooks will be
defined. Later we can probably move much of the implementations of these
hooks into these files so those functions can be static.
While I'm here, fix up the naming of some constants.
Change-Id: I1009dd9fdc3cc4fd49fbff0802f6289931abec3d
Reviewed-on: https://boringssl-review.googlesource.com/8665
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
