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 causes the GetCertificate callback to be called if
Certificates is empty. Previously this configuration would result in an
error.
This allows people to have servers that depend entirely on dynamic
certificate selection, even when the client doesn't send SNI.
Fixes#9208.
Change-Id: I2f5a5551215958b88b154c64a114590300dfc461
Reviewed-on: https://go-review.googlesource.com/8792
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
This change adds a new method to tls.Config, SetSessionTicketKeys, that
changes the key used to encrypt session tickets while the server is
running. Additional keys may be provided that will be used to maintain
continuity while rotating keys. If a ticket encrypted with an old key is
provided by the client, the server will resume the session and provide
the client with a ticket encrypted using the new key.
Fixes#9994
Change-Id: Idbc16b10ff39616109a51ed39a6fa208faad5b4e
Reviewed-on: https://go-review.googlesource.com/9072
Reviewed-by: Jonathan Rudenberg <jonathan@titanous.com>
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>
This is a follow on to 28f33b4a which removes one of the boolean flags
and adds a test for the key-driven cipher selection.
Change-Id: If2a400de807eb19110352912a9f467491cc8986c
Reviewed-on: https://go-review.googlesource.com/8428
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
Reviewed-by: Jacob Haven <jacob@cloudflare.com>
This change replaces all direct ECDSA/RSA sign and decrypt operations
with calls through the crypto.Signer and crypto.Decrypter interfaces.
This is a follow-up to https://go-review.googlesource.com/#/c/3900/
which added crypto.Decrypter and implemented it for RSA.
Change-Id: Ie0f3928448b285f329efcd3a93ca3fd5e3b3e42d
Reviewed-on: https://go-review.googlesource.com/7804
Reviewed-by: Adam Langley <agl@golang.org>
Only documentation / comment changes. Update references to
point to golang.org permalinks or go.googlesource.com/go.
References in historical release notes under doc are left as is.
Change-Id: Icfc14e4998723e2c2d48f9877a91c5abef6794ea
Reviewed-on: https://go-review.googlesource.com/4060
Reviewed-by: Ian Lance Taylor <iant@golang.org>
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>
Fix TLS_FALLBACK_SCSV check when comparing the client version to the
default max version. This enables the TLS_FALLBACK_SCSV check by default
in servers that do not explicitly set a max version in the tls config.
Change-Id: I5a51f9da6d71b79bc6c2ba45032be51d0f704b5e
Reviewed-on: https://go-review.googlesource.com/1776
Reviewed-by: Adam Langley <agl@golang.org>
A new attack on CBC padding in SSLv3 was released yesterday[1]. Go only
supports SSLv3 as a server, not as a client. An easy fix is to change
the default minimum version to TLS 1.0 but that seems a little much
this late in the 1.4 process as it may break some things.
Thus this patch adds server support for TLS_FALLBACK_SCSV[2] -- a
mechanism for solving the fallback problem overall. Chrome has
implemented this since February and Google has urged others to do so in
light of yesterday's news.
With this change, clients can indicate that they are doing a fallback
connection and Go servers will be able to correctly reject them.
[1] http://googleonlinesecurity.blogspot.com/2014/10/this-poodle-bites-exploiting-ssl-30.html
[2] https://tools.ietf.org/html/draft-ietf-tls-downgrade-scsv-00
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/157090043
Currently a write error will cause future reads to return that same error.
However, there may have been extra information from a peer pending on
the read direction that is now unavailable.
This change splits the single connErr into errors for the read, write and
handshake. (Splitting off the handshake error is needed because both read
and write paths check the handshake error.)
Fixes#7414.
LGTM=bradfitz, r
R=golang-codereviews, r, bradfitz
CC=golang-codereviews
https://golang.org/cl/69090044
Currently an ECDHE handshake uses the client's curve preference. This
generally means that we use P-521. However, P-521's strength is
mismatched with the rest of the cipher suite in most cases and we have
a fast, constant-time implementation of P-256.
With this change, Go servers will use P-256 where the client supports
it although that can be overridden in the Config.
LGTM=bradfitz
R=bradfitz
CC=golang-codereviews
https://golang.org/cl/66060043
The renegotiation extension was introduced[1] due to an attack by Ray in
which a client's handshake was spliced into a connection that was
renegotiating, thus giving an attacker the ability to inject an
arbitary prefix into the connection.
Go has never supported renegotiation as a server and so this attack
doesn't apply. As a client, it's possible that at some point in the
future the population of servers will be sufficiently updated that
it'll be possible to reject connections where the server hasn't
demonstrated that it has been updated to address this problem.
We're not at that point yet, but it's good for Go servers to support
the extension so that it might be possible to do in the future.
[1] https://tools.ietf.org/search/rfc5746
R=golang-codereviews, mikioh.mikioh
CC=golang-codereviews
https://golang.org/cl/48580043
Despite SHA256 support being required for TLS 1.2 handshakes, some
servers are aborting handshakes that don't offer SHA1 support.
This change adds support for signing TLS 1.2 ServerKeyExchange messages
with SHA1. It does not add support for signing TLS 1.2 client
certificates with SHA1 as that would require the handshake to be
buffered.
Fixes#6618.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/15650043
AES-GCM cipher suites are only defined for TLS 1.2, although there's
nothing really version specific about them. However, development
versions of NSS (meaning Firefox and Chrome) have an issue where
they'll advertise TLS 1.2-only cipher suites in a TLS 1.1 ClientHello
but then balk when the server selects one.
This change causes Go clients not to advertise TLS 1.2 cipher suites
unless TLS 1.2 is being used, and prevents servers from selecting them
unless TLS 1.2 has been negotiated.
https://code.google.com/p/chromium/issues/detail?id=297151https://bugzilla.mozilla.org/show_bug.cgi?id=919677
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13573047
47ec7a68b1a2 added support for ECDSA ciphersuites but didn't alter the
cipher suite selection to take that into account. Thus Go servers could
try and select an ECDSA cipher suite while only having an RSA
certificate, leading to connection failures.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13239053
With TLS 1.2, when sending client certificates the code was omitting
the new (in TLS 1.2) signature and hash fields.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13413050
AES-GCM is the only current TLS ciphersuite that doesn't have
cryptographic weaknesses (RC4), nor major construction issues (CBC mode
ciphers) and has some deployment (i.e. not-CCM).
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13249044
Add support for ECDHE-ECDSA (RFC4492), which uses an ephemeral server
key pair to perform ECDH with ECDSA signatures. Like ECDHE-RSA,
ECDHE-ECDSA also provides PFS.
R=agl
CC=golang-dev
https://golang.org/cl/7006047
This does not include AES-GCM yet. Also, it assumes that the handshake and
certificate signature hash are always SHA-256, which is true of the ciphersuites
that we currently support.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/10762044
The significant change between TLS 1.0 and 1.1 is the addition of an explicit IV in the case of CBC encrypted records. Support for TLS 1.1 is needed in order to support TLS 1.2.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/7880043
This isn't clearly a bug on Go's part, but it triggers a bug in Firefox
which means that crypto/tls and net/http cannot be wired up together
unless NextProtos includes "http/1.1". When net/http sets up the
tls.Config, it does this and so works fine. But anyone setting up the
tls.Config themselves will hit the Firefox bug.
Fixes#5445.
R=golang-dev, bradfitz, r
CC=golang-dev
https://golang.org/cl/9539045
Previously, Go TLS servers always took the client's preferences into
account when selecting a ciphersuite. This change adds the option of
using the server's preferences, which can be expressed by setting
tls.Config.CipherSuites.
This mirrors Apache's SSLHonorCipherOrder directive.
R=golang-dev, nightlyone, bradfitz, ality
CC=golang-dev
https://golang.org/cl/7163043
Session resumption saves a round trip and removes the need to perform
the public-key operations of a TLS handshake when both the client and
server support it (which is true of Firefox and Chrome, at least).
R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/6555051
If we aren't explicit about the KeyUsages, the verifier
will treat the certificate as a server certificate and require
it to have a ExtKeyUsageServerAuth key usage.
R=golang-dev
CC=golang-dev
https://golang.org/cl/6453148
When SNI based certificate selection is enabled, we previously used
the default private key even if we selected a non-default certificate.
Fixes#3367.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5987058
The existing code that tried to prevent ECC ciphersuites from being
selected when there were no mutual curves still left |suite| set.
This lead to a panic on a nil pointer when there were no acceptable
ciphersuites at all.
Thanks to George Kadianakis for pointing it out.
R=golang-dev, r, bradfitz
CC=golang-dev
https://golang.org/cl/5857043
Not a Go 1 issue, but appeared to be fairly easy to fix.
- Note that a few existing test cases look slightly worse but
those cases were not representative for real code. All real
code looks better now.
- Manual move of the comment in go/scanner/example_test.go
before applying gofmt.
- gofmt -w $GOROOT/src $GOROOT/misc
Fixes#3062.
R=rsc
CC=golang-dev
https://golang.org/cl/5674093
Fix incorrect marshal/unmarshal of certificateRequest.
Add support for configuring client-auth on the server side.
Fix the certificate selection in the client side.
Update generate_cert.go to new time package
Fixes#2521.
R=krautz, agl, bradfitz
CC=golang-dev, mikkel
https://golang.org/cl/5448093
The code in hash functions themselves could write directly into the
output buffer for a savings of about 50ns. But it's a little ugly so I
wasted a copy.
R=bradfitz
CC=golang-dev
https://golang.org/cl/5440111
This is the result of running `gofix -r hashsum` over the tree, changing
the hash function implementations by hand and then fixing a couple of
instances where gofix didn't catch something.
The changed implementations are as simple as possible while still
working: I'm not trying to optimise in this CL.
R=rsc, cw, rogpeppe
CC=golang-dev
https://golang.org/cl/5448065
Previously we were using the map iteration order to set the order of
the cipher suites in the ClientHello.
R=bradfitz
CC=golang-dev
https://golang.org/cl/5440048
With this in place, a TLS server is capable of selecting the correct
certificate based on the client's ServerNameIndication extension.
The need to call Config.BuildNameToCertificate is unfortunate, but
adding a sync.Once to the Config structure made it uncopyable and I
felt that was too high a price to pay. Parsing the leaf certificates
in each handshake was too inefficient to consider.
R=bradfitz, rsc
CC=golang-dev
https://golang.org/cl/5151048
It would be nice not to have to support this since all the clients
that we care about support TLSv1 by now. However, due to buggy
implementations of SSLv3 on the Internet which can't do version
negotiation correctly, browsers will sometimes switch to SSLv3. Since
there's no good way for a browser tell a network problem from a buggy
server, this downgrade can occur even if the server in question is
actually working correctly.
So we need to support SSLv3 for robustness :(
Fixes#1703.
R=bradfitz
CC=golang-dev
https://golang.org/cl/5018045
This is a core API change.
1) gofix misc src
2) Manual adjustments to the following files under src/pkg:
gob/decode.go
rpc/client.go
os/error.go
io/io.go
bufio/bufio.go
http/request.go
websocket/client.go
as well as:
src/cmd/gofix/testdata/*.go.in (reverted)
test/fixedbugs/bug243.go
3) Implemented gofix patch (oserrorstring.go) and test case (oserrorstring_test.go)
Compiles and runs all tests.
R=r, rsc, gri
CC=golang-dev
https://golang.org/cl/4607052
We already had support on the client side. I also changed the name of
the flag in the ServerHello structure to match the name of the same
flag in the ClientHello (ocspStapling).
R=bradfitzgo
CC=golang-dev
https://golang.org/cl/4408044
Previously, the outer loop would continue until we selected the
client's least preferable ciphersuite.
R=golang-dev, r2
CC=golang-dev
https://golang.org/cl/4029056
The crypto package is added as a common place to store identifiers for
hash functions. At the moment, the rsa package has an enumeration of
hash functions and knowledge of their digest lengths. This is an
unfortunate coupling and other high level crypto packages tend to need
to duplicate this enumeration and knowledge (i.e. openpgp).
crypto pulls this code out into a common location.
It would also make sense to add similar support for ciphers to crypto,
but the problem there isn't as acute that isn't done in this change.
R=bradfitzgo, r, rsc
CC=golang-dev
https://golang.org/cl/4080046
This is largely based on ality's CL 2747042.
crypto/rc4: API break in order to conform to crypto/cipher's
Stream interface
cipher/cipher: promote to the default build
Since CBC differs between TLS 1.0 and 1.1, we downgrade and
support only 1.0 at the current time. 1.0 is what most of the
world uses.
Given this CL, it would be trival to add support for AES 256,
SHA 256 etc, but I haven't in order to keep the change smaller.
R=rsc
CC=ality, golang-dev
https://golang.org/cl/3659041
This changeset implements client certificate support in crypto/tls
for both handshake_server.go and handshake_client.go
The updated server implementation sends an empty CertificateAuthorities
field in the CertificateRequest, thus allowing clients to send any
certificates they wish. Likewise, the client code will only respond
with its certificate when the server requests a certificate with this
field empty.
R=agl, rsc, agl1
CC=golang-dev
https://golang.org/cl/1975042
parsing and printing to new syntax.
Use -oldparser to parse the old syntax,
use -oldprinter to print the old syntax.
2) Change default gofmt formatting settings
to use tabs for indentation only and to use
spaces for alignment. This will make the code
alignment insensitive to an editor's tabwidth.
Use -spaces=false to use tabs for alignment.
3) Manually changed src/exp/parser/parser_test.go
so that it doesn't try to parse the parser's
source files using the old syntax (they have
new syntax now).
4) gofmt -w src misc test/bench
1st set of files.
R=rsc
CC=agl, golang-dev, iant, ken2, r
https://golang.org/cl/180047
(With hindsight, record_process might have been designed wrong, but it
works for now. It'll get redrawn when client support is added.)
R=rsc
CC=r
http://go/go-review/1018032
