Note that the SignatureSchemes passed to GetClientCertificate in TLS 1.2
are now filtered by the requested certificate type. This feels like an
improvement anyway, and the full list can be surfaced as well when
support for signature_algorithms_cert is added, which actually matches
the semantics of the CertificateRequest signature_algorithms in TLS 1.2.
Also, note a subtle behavior change in server side resumption: if a
certificate is requested but not required, and the resumed session did
not include one, it used not to invoke VerifyPeerCertificate. However,
if the resumed session did include a certificate, it would. (If a
certificate was required but not in the session, the session is rejected
in checkForResumption.) This inconsistency could be unexpected, even
dangerous, so now VerifyPeerCertificate is always invoked. Still not
consistent with the client behavior, which does not ever invoke
VerifyPeerCertificate on resumption, but it felt too surprising to
entirely change either.
Updates #9671
Change-Id: Ib2b0dbc30e659208dca3ac07d6c687a407d7aaaf
Reviewed-on: https://go-review.googlesource.com/c/147599
Reviewed-by: Adam Langley <agl@golang.org>
Also check original certificate validity when resuming TLS 1.0–1.2. Will
refuse to resume a session if the certificate is expired or if the
original connection had InsecureSkipVerify and the resumed one doesn't.
Support only PSK+DHE to protect forward secrecy even with lack of a
strong session ticket rotation story.
Tested with NSS because s_server does not provide any way of getting the
same session ticket key across invocations. Will self-test like TLS
1.0–1.2 once server side is implemented.
Incorporates CL 128477 by @santoshankr.
Fixes#24919
Updates #9671
Change-Id: Id3eaa5b6c77544a1357668bf9ff255f3420ecc34
Reviewed-on: https://go-review.googlesource.com/c/147420
Reviewed-by: Adam Langley <agl@golang.org>
Since TLS 1.3 delivers handshake messages (including KeyUpdate) after
the handshake, the want argument to readRecord had became almost
pointless: it only meant something when set to recordTypeChangeCipherSpec.
Replaced it with a bool to reflect that, and added two shorthands to
avoid anonymous bools in calls.
Took the occasion to simplify and formalize the invariants of readRecord.
The maxConsecutiveEmptyRecords loop became useless when readRecord
started retrying on any non-advancing record in CL 145297.
Replaced panics with errors, because failure is better than undefined
behavior, but contained failure is better than a DoS vulnerability. For
example, I suspect the panic at the top of readRecord was reachable from
handleRenegotiation, which calls readHandshake with handshakeComplete
false. Thankfully it was not a panic in 1.11, and it's allowed now.
Removed Client-TLSv13-RenegotiationRejected because OpenSSL isn't
actually willing to ask for renegotiation over TLS 1.3, the expected
error was due to NewSessionTicket messages, which didn't break the rest
of the tests because they stop too soon.
Updates #9671
Change-Id: I297a81bde5c8020a962a92891b70d6d70b90f5e3
Reviewed-on: https://go-review.googlesource.com/c/147418
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
Also, add support for the SSLKEYLOGFILE environment variable to the
tests, to simplify debugging of unexpected failures.
Updates #9671
Change-Id: I20a34a5824f083da93097b793d51e796d6eb302b
Reviewed-on: https://go-review.googlesource.com/c/147417
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
RFC 8446 recommends using the supported_versions extension to negotiate
lower versions as well, so begin by implementing it to negotiate the
currently supported versions.
Note that pickTLSVersion was incorrectly negotiating the ServerHello
version down on the client. If the server had illegally sent a version
higher than the ClientHello version, the client would have just
downgraded it, hopefully failing later in the handshake.
In TestGetConfigForClient, we were hitting the record version check
because the server would select TLS 1.1, the handshake would fail on the
client which required TLS 1.2, which would then send a TLS 1.0 record
header on its fatal alert (not having negotiated a version), while the
server would expect a TLS 1.1 header at that point. Now, the client gets
to communicate the minimum version through the extension and the
handshake fails on the server.
Updates #9671
Change-Id: Ie33c7124c0c769f62e10baad51cbed745c424e5b
Reviewed-on: https://go-review.googlesource.com/c/146217
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
Note that there is significant code duplication due to extensions with
the same format appearing in different messages in TLS 1.3. This will be
cleaned up in a future refactor once CL 145317 is merged.
Enforcing the presence/absence of each extension in each message is left
to the upper layer, based on both protocol version and extensions
advertised in CH and CR. Duplicated extensions and unknown extensions in
SH, EE, HRR, and CT will be tightened up in a future CL.
The TLS 1.2 CertificateStatus message was restricted to accepting only
type OCSP as any other type (none of which are specified so far) would
have to be negotiated.
Updates #9671
Change-Id: I7c42394c5cc0af01faa84b9b9f25fdc6e7cfbb9e
Reviewed-on: https://go-review.googlesource.com/c/145477
Reviewed-by: Adam Langley <agl@golang.org>
As a first round, rewrite those handshake message types which can be
reused in TLS 1.3 with golang.org/x/crypto/cryptobyte. All other types
changed significantly in TLS 1.3 and will require separate
implementations. They will be ported to cryptobyte in a later CL.
The only semantic changes should be enforcing the random length on the
marshaling side, enforcing a couple more "must not be empty" on the
unmarshaling side, and checking the rest of the SNI list even if we only
take the first.
Change-Id: Idd2ced60c558fafcf02ee489195b6f3b4735fe22
Reviewed-on: https://go-review.googlesource.com/c/144115
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
Use the format "RFC XXXX, Section X.X" (or "Appendix Y.X") as it fits
more properly in prose than a link, is more future-proof, and as there
are multiple ways to render an RFC. Capital "S" to follow the quoting
standard of RFCs themselves.
Applied the new goimports grouping to all files in those packages, too.
Change-Id: I01267bb3a3b02664f8f822e97b129075bb14d404
Reviewed-on: https://go-review.googlesource.com/c/141918
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
The existing implementation of TLS connection has a deadlock. It occurs
when client connects to TLS server and doesn't send data for
handshake, so server calls Close on this connection. This is because
server reads data under locked mutex, while Close method tries to
lock the same mutex.
Fixes#23518
Change-Id: I4fb0a2a770f3d911036bfd9a7da7cc41c1b27e19
Reviewed-on: https://go-review.googlesource.com/90155
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
This adds support for RSASSA-PSS signatures in handshake messages as
required by TLS 1.3. Even if TLS 1.2 is negotiated, it must support PSS
when advertised in the Client Hello (this will be done later as the
testdata will change).
Updates #9671
Change-Id: I8006b92e017453ae408c153233ce5ccef99b5c3f
Reviewed-on: https://go-review.googlesource.com/79736
Reviewed-by: Filippo Valsorda <filippo@golang.org>
ServerKeyExchange and CertificateVerify can share the same logic for
picking a signature algorithm (based on the certificate public key and
advertised algorithms), selecting a hash algorithm (depending on TLS
version) and signature verification.
Refactor the code to achieve code reuse, have common error checking
(especially for intersecting supported signature algorithms) and to
prepare for addition of new signature algorithms. Code should be easier
to read since version-dependent logic is concentrated at one place.
Change-Id: I978dec3815d28e33c3cfbc85f0c704b1894c25a3
Reviewed-on: https://go-review.googlesource.com/79735
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
I tested all fingerprints and confirmed that Chrome and Firefox are
working as intended.
Android fingerprints were grossly unpopular, which could a result of
incorrect merge, but either way we'll remove them for now.
This change implement keying material export as described in:
https://tools.ietf.org/html/rfc5705
I verified the implementation against openssl s_client and openssl
s_server.
Change-Id: I4dcdd2fb929c63ab4e92054616beab6dae7b1c55
Signed-off-by: Mike Danese <mikedanese@google.com>
Reviewed-on: https://go-review.googlesource.com/85115
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
Follows the wording in RFC4366 more precisely which allows a server
to optionally return a "certificate_status" when responding to a
client hello containing "status_request" extension.
fixes#8549
Change-Id: Ib02dc9f972da185b25554568fe6f8bc411d9c0b7
Reviewed-on: https://go-review.googlesource.com/86115
Reviewed-by: Adam Langley <agl@golang.org>
Consolidate the signature and hash fields (SignatureAndHashAlgorithm in
TLS 1.2) into a single uint16 (SignatureScheme in TLS 1.3 draft 21).
This makes it easier to add RSASSA-PSS for TLS 1.2 in the future.
Fields were named like "signatureAlgorithm" rather than
"signatureScheme" since that name is also used throughout the 1.3 draft.
The only new public symbol is ECDSAWithSHA1, other than that this is an
internal change with no new functionality.
Change-Id: Iba63d262ab1af895420583ac9e302d9705a7e0f0
Reviewed-on: https://go-review.googlesource.com/62210
Reviewed-by: Adam Langley <agl@golang.org>
strings.LastIndexByte was introduced in go1.5 and it can be used
effectively wherever the second argument to strings.LastIndex is
exactly one byte long.
This avoids generating unnecessary string symbols and saves
a few calls to strings.LastIndex.
Change-Id: I7b5679d616197b055cffe6882a8675d24a98b574
Reviewed-on: https://go-review.googlesource.com/66372
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
SNI values may not include a trailing dot according to
https://tools.ietf.org/html/rfc6066#section-3. Although crypto/tls
handled this correctly as a client, it didn't reject this as a server.
This change makes sending an SNI value with a trailing dot a fatal
error.
Updates #18114.
Change-Id: Ib7897ab40e98d4a7a4646ff8469a55233621f631
Reviewed-on: https://go-review.googlesource.com/33904
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Fix spelling of "original" and "occurred" in new gofmt docs. The same
misspelling of "occurred" was also present in crypto/tls, I fixed it there as
well.
Change-Id: I67b4f1c09bd1a2eb1844207d5514f08a9f525ff9
Reviewed-on: https://go-review.googlesource.com/33138
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Currently, the selection of a client certificate done internally based
on the limitations given by the server's request and the certifcates in
the Config. This means that it's not possible for an application to
control that selection based on details of the request.
This change adds a callback, GetClientCertificate, that is called by a
Client during the handshake and which allows applications to select the
best certificate at that time.
(Based on https://golang.org/cl/25570/ by Bernd Fix.)
Fixes#16626.
Change-Id: Ia4cea03235d2aa3c9fd49c99c227593c8e86ddd9
Reviewed-on: https://go-review.googlesource.com/32115
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
VerifyPeerCertificate returns an error if the peer should not be
trusted. It will be called after the initial handshake and before
any other verification checks on the cert or chain are performed.
This provides the callee an opportunity to augment the certificate
verification.
If VerifyPeerCertificate is not nil and returns an error,
then the handshake will fail.
Fixes#16363
Change-Id: I6a22f199f0e81b6f5d5f37c54d85ab878216bb22
Reviewed-on: https://go-review.googlesource.com/26654
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Since there's no aspect of key logging that OpenSSL can check for us,
the tests for it might as well just connect to another goroutine as this
is lower-maintainance.
Change-Id: I746d1dbad1b4bbfc8ef6ccf136ee4824dbda021e
Reviewed-on: https://go-review.googlesource.com/30089
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joonas Kuorilehto <joneskoo@derbian.fi>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Add support for writing TLS client random and master secret
in NSS key log format.
https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/Key_Log_Format
Normally this is enabled by a developer debugging TLS based
applications, especially HTTP/2, by setting the KeyLogWriter
to an open file. The keys negotiated in handshake are then
logged and can be used to decrypt TLS sessions e.g. in Wireshark.
Applications may choose to add support similar to NSS where this
is enabled by environment variable, but no such mechanism is
built in to Go. Instead each application must explicitly enable.
Fixes#13057.
Change-Id: If6edd2d58999903e8390b1674ba4257ecc747ae1
Reviewed-on: https://go-review.googlesource.com/27434
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This change causes TLS handshake messages to be buffered and written in
a single Write to the underlying net.Conn.
There are two reasons to want to do this:
Firstly, it's slightly preferable to do this in order to save sending
several, small packets over the network where a single one will do.
Secondly, since 37c28759ca46cf381a466e32168a793165d9c9e9 errors from
Write have been returned from a handshake. This means that, if a peer
closes the connection during a handshake, a “broken pipe” error may
result from tls.Conn.Handshake(). This can mask any, more detailed,
fatal alerts that the peer may have sent because a read will never
happen.
Buffering handshake messages means that the peer will not receive, and
possibly reject, any of a flow while it's still being written.
Fixes#15709
Change-Id: I38dcff1abecc06e52b2de647ea98713ce0fb9a21
Reviewed-on: https://go-review.googlesource.com/23609
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Andrew Gerrand <adg@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change adds Config.Renegotiation which controls whether a TLS
client will accept renegotiation requests from a server. This is used,
for example, by some web servers that wish to “add” a client certificate
to an HTTPS connection.
This is disabled by default because it significantly complicates the
state machine.
Originally, handshakeMutex was taken before locking either Conn.in or
Conn.out. However, if renegotiation is permitted then a handshake may
be triggered during a Read() call. If Conn.in were unlocked before
taking handshakeMutex then a concurrent Read() call could see an
intermediate state and trigger an error. Thus handshakeMutex is now
locked after Conn.in and the handshake functions assume that Conn.in is
locked for the duration of the handshake.
Additionally, handshakeMutex used to protect Conn.out also. With the
possibility of renegotiation that's no longer viable and so
writeRecordLocked has been split off.
Fixes#5742.
Change-Id: I935914db1f185d507ff39bba8274c148d756a1c8
Reviewed-on: https://go-review.googlesource.com/22475
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Error strings in this package were all over the place: some were
prefixed with “tls:”, some with “crypto/tls:” and some didn't have a
prefix.
This change makes everything use the prefix “tls:”.
Change-Id: Ie8b073c897764b691140412ecd6613da8c4e33a2
Reviewed-on: https://go-review.googlesource.com/21893
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Per RFC 5246, 7.4.1.3:
cipher_suite
The single cipher suite selected by the server from the list in
ClientHello.cipher_suites. For resumed sessions, this field is
the value from the state of the session being resumed.
The specifications are not very clearly written about resuming sessions
at the wrong version (i.e. is the TLS 1.0 notion of "session" the same
type as the TLS 1.1 notion of "session"?). But every other
implementation enforces this check and not doing so has some odd
semantics.
Change-Id: I6234708bd02b636c25139d83b0d35381167e5cad
Reviewed-on: https://go-review.googlesource.com/21153
Reviewed-by: Adam Langley <agl@golang.org>
This promotes a connection hang during TLS handshake to a proper error.
This doesn't fully address #14539 because the error reported in that
case is a write-on-socket-not-connected error, which implies that an
earlier error during connection setup is not being checked, but it is
an improvement over the current behaviour.
Updates #14539.
Change-Id: I0571a752d32d5303db48149ab448226868b19495
Reviewed-on: https://go-review.googlesource.com/19990
Reviewed-by: Adam Langley <agl@golang.org>
This is a followup change to #13111 for filtering out IPv6 literals and
absolute FQDNs from being as the SNI values.
Updates #13111.
Fixes#14404.
Change-Id: I09ab8d2a9153d9a92147e57ca141f2e97ddcef6e
Reviewed-on: https://go-review.googlesource.com/19704
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
During the TLS handshake, check the cipher suite the server selects is
one of those offered in the ClientHello. The code was checking it was
in the larger list that was sometimes whittled down for the ClientHello.
Fixes#13174
Change-Id: Iad8eebbcfa5027f30403b9700c43cfa949e135bb
Reviewed-on: https://go-review.googlesource.com/16698
Reviewed-by: Adam Langley <agl@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
(This relands commit a4dcc692011bf1ceca9b1a363fd83f3e59e399ee.)
https://tools.ietf.org/html/rfc6066#section-3 states:
“Literal IPv4 and IPv6 addresses are not permitted in "HostName".”
However, if an IP literal was set as Config.ServerName (which could
happen as easily as calling Dial with an IP address) then the code would
send the IP literal as the SNI value.
This change filters out IP literals, as recognised by net.ParseIP, from
being sent as the SNI value.
Fixes#13111.
Change-Id: I6e544a78a01388f8fe98150589d073b917087f75
Reviewed-on: https://go-review.googlesource.com/16776
Run-TryBot: Adam Langley <agl@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
https://tools.ietf.org/html/rfc6066#section-3 states:
“Literal IPv4 and IPv6 addresses are not permitted in "HostName".”
However, if an IP literal was set as Config.ServerName (which could
happen as easily as calling Dial with an IP address) then the code would
send the IP literal as the SNI value.
This change filters out IP literals, as recognised by net.ParseIP, from
being sent as the SNI value.
Fixes#13111.
Change-Id: Ie9ec7acc767ae172b48c9c6dd8d84fa27b1cf0de
Reviewed-on: https://go-review.googlesource.com/16742
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
Strengthening VerifyHostname exposed the fact that for resumed
connections, ConnectionState().VerifiedChains was not being saved
and restored during the ClientSessionCache operations.
Do that.
This change just saves the verified chains in the client's session
cache. It does not re-verify the certificates when resuming a
connection.
There are arguments both ways about this: we want fast, light-weight
resumption connections (thus suggesting that we shouldn't verify) but
it could also be a little surprising that, if the verification config
is changed, that would be ignored if the same session cache is used.
On the server side we do re-verify client-auth certificates, but the
situation is a little different there. The client session cache is an
object in memory that's reset each time the process restarts. But the
server's session cache is a conceptual object, held by the clients, so
can persist across server restarts. Thus the chance of a change in
verification config being surprisingly ignored is much higher in the
server case.
Fixes#12024.
Change-Id: I3081029623322ce3d9f4f3819659fdd9a381db16
Reviewed-on: https://go-review.googlesource.com/13164
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
Prior to TLS 1.2, the handshake had a pleasing property that one could
incrementally hash it and, from that, get the needed hashes for both
the CertificateVerify and Finished messages.
TLS 1.2 introduced negotiation for the signature and hash and it became
possible for the handshake hash to be, say, SHA-384, but for the
CertificateVerify to sign the handshake with SHA-1. The problem is that
one doesn't know in advance which hashes will be needed and thus the
handshake needs to be buffered.
Go ignored this, always kept a single handshake hash, and any signatures
over the handshake had to use that hash.
However, there are a set of servers that inspect the client's offered
signature hash functions and will abort the handshake if one of the
server's certificates is signed with a hash function outside of that
set. https://robertsspaceindustries.com/ is an example of such a server.
Clearly not a lot of thought happened when that server code was written,
but its out there and we have to deal with it.
This change decouples the handshake hash from the CertificateVerify
hash. This lays the groundwork for advertising support for SHA-384 but
doesn't actually make that change in the interests of reviewability.
Updating the advertised hash functions will cause changes in many of the
testdata/ files and some errors might get lost in the noise. This change
only needs to update four testdata/ files: one because a SHA-384-based
handshake is now being signed with SHA-256 and the others because the
TLS 1.2 CertificateRequest message now includes SHA-1.
This change also has the effect of adding support for
client-certificates in SSLv3 servers. However, SSLv3 is now disabled by
default so this should be moot.
It would be possible to avoid much of this change and just support
SHA-384 for the ServerKeyExchange as the SKX only signs over the nonces
and SKX params (a design mistake in TLS). However, that would leave Go
in the odd situation where it advertised support for SHA-384, but would
only use the handshake hash when signing client certificates. I fear
that'll just cause problems in the future.
Much of this code was written by davidben@ for the purposes of testing
BoringSSL.
Partly addresses #9757
Change-Id: I5137a472b6076812af387a5a69fc62c7373cd485
Reviewed-on: https://go-review.googlesource.com/9415
Run-TryBot: Adam Langley <agl@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
This change adds support for serving and receiving Signed Certificate
Timestamps as described in RFC 6962.
The server is now capable of serving SCTs listed in the Certificate
structure. The client now asks for SCTs and, if any are received,
they are exposed in the ConnectionState structure.
Fixes#10201
Change-Id: Ib3adae98cb4f173bc85cec04d2bdd3aa0fec70bb
Reviewed-on: https://go-review.googlesource.com/8988
Reviewed-by: Adam Langley <agl@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
Reviewed-by: Jonathan Rudenberg <jonathan@titanous.com>
Generalizes PRF calculation for TLS 1.2 to support arbitrary hashes (SHA-384 instead of SHA-256).
Testdata were all updated to correspond with the new cipher suites in the handshake.
Change-Id: I3d9fc48c19d1043899e38255a53c80dc952ee08f
Reviewed-on: https://go-review.googlesource.com/3265
Reviewed-by: Adam Langley <agl@golang.org>
