Make tailssh ask LocalBackend for the SSH hostkeys, as we'll need to
distribute them to peers.
For now only the hacky use-same-as-actual-host mode is implemented.
Updates #3802
Change-Id: I819dcb25c14e42e6692c441186c1dc744441592b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We need to capture some tailnet-related information for some Docker
features we're building. This exposes the tailnet name and MagicDNS
information via `tailscale status --json`.
Fixestailscale/corp#3670
Signed-off-by: Ross Zurowski <ross@rosszurowski.com>
Our previous Hostinfo logging was all as a side effect of telling
control. And it got marked as verbose (as it was)
This adds a one-time Hostinfo logging that's not verbose, early in
start-up.
Change-Id: I1896222b207457b9bb12ffa7cf361761fa4d3b3a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I was about to add a third copy, so unify them now instead.
Change-Id: I3b93896aa1249b1250a6b1df4829d57717f2311a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Our current workaround made the user check too lax, thus allowing deleted
users. This patch adds a helper function to winutil that checks that the
uid's SID represents a valid Windows security principal.
Now if `lookupUserFromID` determines that the SID is invalid, we simply
propagate the error.
Updates https://github.com/tailscale/tailscale/issues/869
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
We're finding a bunch of host operating systems/firewalls interact poorly
with peerapi. We either get ICMP errors from the host or users need to run
commands to allow the peerapi port:
https://github.com/tailscale/tailscale/issues/3842#issuecomment-1025133727
... even though the peerapi should be an internal implementation detail.
Rather than fight the host OS & firewalls, this change handles the
server side of peerapi entirely in netstack (except on iOS), so it
never makes its way to the host OS where it might be messed with. Two
main downsides are:
1) netstack isn't as fast, but we don't really need speed for peerapi.
And actually, with fewer trips to/from the kernel, we might
actually make up for some of the netstack performance loss by
staying in userspace.
2) tcpdump / Wireshark etc packet captures will no longer see the peerapi
traffic. Oh well. Crawshaw's been wanting to add packet capture server
support to tailscaled, so we'll probably do that sooner now.
A future change might also then use peerapi for the client-side
(except on iOS).
Updates #3842 (probably fixes, as well as many exit node issues I bet)
Change-Id: Ibc25edbb895dc083d1f07bd3cab614134705aa39
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
So you can run Caddy etc as a non-root user and let it have access to
get certs.
Updates caddyserver/caddy#4541
Change-Id: Iecc5922274530e2b00ba107d4b536580f374109b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Disabled by default.
To use, run tailscaled with:
TS_SSH_ALLOW_LOGIN=you@bar.com
And enable with:
$ TAILSCALE_USE_WIP_CODE=true tailscale up --ssh=true
Then ssh [any-user]@[your-tailscale-ip] for a root bash shell.
(both the "root" and "bash" part are temporary)
Updates #3802
Change-Id: I268f8c3c95c8eed5f3231d712a5dc89615a406f0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
A new package can also later record/report which knobs are checked and
set. It also makes the code cleaner & easier to grep for env knobs.
Change-Id: Id8a123ab7539f1fadbd27e0cbeac79c2e4f09751
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
From Maisem's code review feedback where he mashed the merge
button by mistake.
Change-Id: I55abce036a6c25dc391250514983125dda10126c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This code was copied in a few places (Windows, Android), so unify it
and add tests.
Change-Id: Id0510c0f5974761365a2045279d1fb498feca11e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Fixes#3660
RELNOTE=MagicDNS now works over IPv6 when CGNAT IPv4 is disabled.
Change-Id: I001e983df5feeb65289abe5012dedd177b841b45
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This is for use by the Windows GUI client to log via when an
exit node is in use, so the logs don't go out via the exit node and
instead go directly, like tailscaled's. The dialer tried to do that
in the unprivileged GUI by binding to a specific interface, but the
"Internet Kill Switch" installed by tailscaled for exit nodes
precludes that from working and instead the GUI fails to dial out.
So, go through tailscaled (with a CONNECT request) instead.
Fixestailscale/corp#3169
Change-Id: I17a8efdc1d4b8fed53a29d1c19995592b651b215
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This moves the Windows-only initialization of the filelogger into
logpolicy. Previously we only did it when babysitting the tailscaled
subprocess, but this meant that log messages from the service itself
never made it to disk. Examples that weren't logged to disk:
* logtail unable to dial out,
* DNS flush messages from the service
* svc.ChangeRequest messages (#3581)
This is basically the same fix as #3571 but staying in the Logf type,
and avoiding build-tagged file (which wasn't quite a goal, but
happened and seemed nice)
Fixes#3570
Co-authored-by: Aaron Klotz <aaron@tailscale.com>
Change-Id: Iacd80c4720b7218365ec80ae143339d030842702
Make shrinkDefaultRoute a pure function.
Instead of calling interfaceRoutes, accept that information as parameters.
Hard-code those parameters in TestShrinkDefaultRoute.
Fixes#3580
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
One option was to just hide "offline" in the text output, but that
doesn't fix the JSON output.
The next option was to lie and say it's online in the JSON (which then
fixes the "offline" in the text output).
But instead, this sets the self node's "Online" to whether we're in an
active map poll.
Fixes#3564
Change-Id: I9b379989bd14655198959e37eec39bb570fb814a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
magicsock was hanging onto its netmap on logout,
which caused tailscale status to display partial
information about a bunch of zombie peers.
After logout, there should be no peers.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
I'm sick of this flaking. Even if this isn't the right fix, it
stops the alert fatigue.
Updates #3020
Change-Id: I4001c127d78f1056302f7741adec34210a72ee61
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
And it updates the build tag style on a couple files.
Change-Id: I84478d822c8de3f84b56fa1176c99d2ea5083237
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
fee2d9fad added support for cmd/tailscale to connect to IPNExtension.
It came in two parts: If no socket was provided, dial IPNExtension first,
and also, if dialing the socket failed, fall back to IPNExtension.
The second half of that support caused the integration tests to fail
when run on a machine that was also running IPNExtension.
The integration tests want to wait until the tailscaled instances
that they spun up are listening. They do that by dialing the new
instance. But when that dial failed, it was falling back to IPNExtension,
so it appeared (incorrectly) that tailscaled was running.
Hilarity predictably ensued.
If a user (or a test) explicitly provides a socket to dial,
it is a reasonable assumption that they have a specific tailscaled
in mind and don't want to fall back to IPNExtension.
It is certainly true of the integration tests.
Instead of adding a bool to Connect, split out the notion of a
connection strategy. For now, the implementation remains the same,
but with the details hidden a bit. Later, we can improve that.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
It's been a bunch of releases now since the TailscaleIPs slice
replacement was added.
Change-Id: I3bd80e1466b3d9e4a4ac5bedba8b4d3d3e430a03
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Allow users of CallbackRouter to supply a GetBaseConfig
implementation. This is expected to be used on Android,
which currently lacks both a) platform support for
Split-DNS and b) a way to retrieve the current DNS
servers.
iOS/macOS also use the CallbackRouter but have platform
support for SplitDNS, so don't need getBaseConfig.
Updates https://github.com/tailscale/tailscale/issues/2116
Updates https://github.com/tailscale/tailscale/issues/988
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
To make ExitDNS cheaper.
Might not finish client-side support in December before 1.20, but at
least server support can start rolling out ahead of clients being
ready for it.
Tested with curl against peerapi.
Updates #1713
Change-Id: I676fed5fb1aef67e78c542a3bc93bddd04dd11fe
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If the user has a "Taildrop" shared folder on startup and
the "tailscale" system user has read/write access to it,
then the user can "tailscale file cp" to their NAS.
Updates #2179 (would be fixes, but not super ideal/easy yet)
Change-Id: I68e59a99064b302abeb6d8cc84f7d2a09f764990
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
And simplify, unexport some tsdial/netstack stuff in the the process.
Fixes#3475
Change-Id: I186a5a5cbd8958e25c075b4676f7f6e70f3ff76e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The control plane is currently still eating it.
Updates #1713
Change-Id: I66a0698599d6794ab1302f9585bf29e38553c884
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This starts to refactor tsdial.Dialer's name resolution to have
different stages: in-memory MagicDNS vs system resolution. A future
change will plug in ExitDNS resolution.
This also plumbs a Dialer into netstack and unexports the dnsMap
internals.
And it removes some of the async AddNetworkMapCallback usage and
replaces it with synchronous updates of the Dialer's netmap
from LocalBackend, since the LocalBackend has the Dialer too.
Updates #3475
Change-Id: Idcb7b1169878c74f0522f5151031ccbc49fe4cb4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Without this, enabling an exit node immediately blackholes all traffic,
but doesn't correctly let it flow to the exit node until the next netmap
update.
Fixes#3447
Signed-off-by: David Anderson <danderson@tailscale.com>
In prep for moving stuff out of LocalBackend.
Change-Id: I9725aa9c3ebc7275f8c40e040b326483c0340127
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Not done yet, but this move more of the outbound dial special casing
from random packages into tsdial, which aspires to be the one unified
place for all outbound dialing shenanigans.
Then this plumbs it all around, so everybody is ultimately
holding on to the same dialer.
As of this commit, macOS/iOS using an exit node should be able to
reach to the exit node's DoH DNS proxy over peerapi, doing the sockopt
to stay within the Network Extension.
A number of steps remain, including but limited to:
* move a bunch more random dialing stuff
* make netstack-mode tailscaled be able to use exit node's DNS proxy,
teaching tsdial's resolver to use it when an exit node is in use.
Updates #1713
Change-Id: I1e8ee378f125421c2b816f47bc2c6d913ddcd2f5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
So Taildrop sends work even if the local tailscaled is running in
netstack mode, as it often is on Synology, etc.
Updates #2179 (which is primarily about receiving, but both important)
Change-Id: I9bd1afdc8d25717e0ab6802c7cf2f5e0bd89a3b2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Don't be a DoH DNS server to peers unless the Tailnet admin has permitted
that peer autogroup:internet access.
Updates #1713
Change-Id: Iec69360d8e4d24d5187c26904b6a75c1dabc8979
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If IP forwarding is disabled globally, but enabled per-interface on all interfaces,
don't complain. If only some interfaces have forwarding enabled, warn that some
subnet routing/exit node traffic may not work.
Fixes#1586
Signed-off-by: David Anderson <danderson@tailscale.com>
We were missing an argument here.
Also, switch to %q, in case anything weird
is happening with these strings.
Updates tailscale/corp#461
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
And annotate magicsock as a start.
And add localapi and debug handlers with the Prometheus-format
exporter.
Updates #3307
Change-Id: I47c5d535fe54424741df143d052760387248f8d3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Was done as part of e6fbc0cd54 for ssh
work, but wasn't committed yet. Including it here both to minimize the
ssh diff size, and because I need it for a separate change.
Change-Id: If6eb54a2ca7150ace96488ed14582c2c05ca3422
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
More work towards removing the massive ipnserver.Run and ipnserver.Options
and making composable pieces.
Work remains. (The getEngine retry loop on Windows complicates things.)
For now some duplicate code exists. Once the Windows side is fixed
to either not need the retry loop or to move the retry loop into a
custom wgengine.Engine wrapper, then we can unify tailscaled_windows.go
too.
Change-Id: If84d16e3cd15b54ead3c3bb301f27ae78d055f80
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Fixes regression from 81cabf48ec which made
all map errors be sent to the frontend UI.
Fixes#3230
Change-Id: I7f142c801c7d15e268a24ddf901c3e6348b6729c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
For debugging Synology. Like the existing goroutines handler, in that
it's owner-only.
Change-Id: I852f0626be8e1c0b6794c1e062111d14adc3e6ac
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
github.com/go-multierror/multierror served us well.
But we need a few feature from it (implement Is),
and it's not worth maintaining a fork of such a small module.
Instead, I did a clean room implementation inspired by its API.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
At least until js/wasm starts using browser LocalStorage or something.
But for the foreseeable future, any login from a browser should
be considered ephemeral as the tab can close at any time and lose
the wireguard key, never to be seen again.
Updates #3157
Change-Id: I6c410d86dc7f9f233c3edd623313d9dee2085aac
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
So future refactors can only deal with a net.Listener and
be unconcerned with their caller's (Windows-specific) struggles.
Change-Id: I0af588b9a769ab65c59b0bd21f8a0c99abfa1784
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I'll keep ipnserver.Run for compatibility, but it'll be a wrapper
around several smaller pieces. (more testable too)
For now, start untangling some things in preparation.
Plan is to have to have a constructor for the just-exported
ipnserver.Server type that takes a LocalBackend and can
accept (in a new method) on a provided listener.
Change-Id: Ide73aadaac1a82605c97a2af1321d0d8f60b2a8c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It's all opaque, there's no constructor, and no exported
methods, so it's useless at this point, but this is one
small refactoring step.
Change-Id: Id961e8880cf0c84f1a0a989eefff48ecb3735add
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Moving this information into a centralized place so that it is accessible to
code in subsequent commits.
Updates #3011
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
The "go generate" command blindly looks for "//go:generate" anywhere
in the file regardless of whether it is truly a comment.
Prevent this false positive in cloner.go by mangling the string
to look less like "//go:generate".
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
From https://github.com/tailscale/tailscale/pull/1919 with
edits by bradfitz@.
This change introduces a new storage provider for the state file. It
allows users to leverage AWS SSM parameter store natively within
tailscaled, like:
$ tailscaled --state=arn:aws:ssm:eu-west-1:123456789:parameter/foo
Known limitations:
- it is not currently possible to specific a custom KMS key ID
RELNOTE=tailscaled on Linux supports using AWS SSM for state
Edits-By: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Maxime VISONNEAU <maxime.visonneau@gmail.com>
iOS and Android no longer use these. They both now (as of today)
use the hostinfo.SetFoo setters instead.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Turns out the iOS client has been only sending the OS version it first
started at. This whole hostinfo-via-prefs mechanism was never a good idea.
Start removing it.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This fixes "tailscale cert" on Synology where the var directory is
typically like /volume2/@appdata/Tailscale, or any other tailscaled
user who specifies a non-standard state file location.
This is a interim fix on the way to #2932.
Fixes#2927
Updates #2932
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We unconditionally set appropriate perms on the statefile dir.
We look at the basename of the statefile dir, and if it is "tailscale", then
we set perms as appropriate.
Fixes#2925
Updates #2856
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
This was already possible on Linux if you ran tailscaled with --debug
(which runs net/http/pprof), but it requires the user have the Go
toolchain around.
Also, it wasn't possible on macOS, as there's no way to run the IPNExtension
with a debug server (it doesn't run tailscaled).
And on Windows it's super tedious: beyond what users want to do or
what we want to explain.
Instead, put it in "tailscale debug" so it works and works the same on
all platforms. Then we can ask users to run it when we're debugging something
and they can email us the output files.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
ProgramData has a permissive ACL. For us to safely store machine-wide
state information, we must set a more restrictive ACL on our state directory.
We set the ACL so that only talescaled's user (ie, LocalSystem) and the
Administrators group may access our directory.
We must include Administrators to ensure that logs continue to be easily
accessible; omitting that group would force users to use special tools to
log in interactively as LocalSystem, which is not ideal.
(Note that the ACL we apply matches the ACL that was used for LocalSystem's
AppData\Local).
There are two cases where we need to reset perms: One is during migration
from the old location to the new. The second case is for clean installations
where we are creating the file store for the first time.
Updates #2856
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
tailscale-ipn.exe (the GUI) shouldn't use C:\ProgramData.
Also, migrate the earlier misnamed wg32/wg64 conf files if they're present.
(That was stopped in 2db877caa3, but the
files exist from fresh 1.14 installs)
Updates #2856
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
C:\WINDOWS\system32\config\systemprofile\AppData\Local\
is frequently cleared for almost any reason: Windows updates,
System Restore, even various System Cleaner utilities.
The server-state.conf file in AppData\Local could be deleted
at any time, which would break login until the node is removed
from the Admin Panel allowing it to create a new key.
Carefully copy any AppData state to ProgramData at startup.
If copying the state fails, continue to use AppData so at
least there will be connectivity. If there is no state,
use ProgramData.
We also migrate the log.conf file. Very old versions of
Tailscale named the EXE tailscale-ipn, so the log conf was
tailscale-ipn.log.conf and more recent versions preserved
this filename and cmdName in logs. In this migration we
always update the filename to
c:\ProgramData\Tailscale\tailscaled.log.conf
Updates https://github.com/tailscale/tailscale/issues/2856
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
So if the control plane knows that something's broken about the node, it can
include problem(s) in MapResponse and "tailscale status" will show it.
(and GUIs in the future, as it's in ipnstate.Status/JSON)
This also bumps the MapRequest.Version, though it's not strictly
required. Doesn't hurt.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
LocalBackend.Shutdown's docs say:
> The backend can no longer be used after Shutdown returns.
Nevertheless, TestStateMachine blithely calls Shutdown, talks some smack,
and continues on, expecting things to work. Other uses of Shutdown
in the codebase are as intended.
Things mostly kinda work anyway, except that the wgengine.Engine has been
shut down, so calls to Reconfig fail. Those get logged:
> local.go:603: wgengine status error: engine closing; no status
but otherwise ignored.
However, the Reconfig failure caused one fewer call to pause/unpause
than normal. Now the assertCalls lines match the equivalent ones
earlier in the test.
I don't see an obvious correct replacement for Shutdown in the context
of this test; I'm not sure entirely what it is trying to accomplish.
It is possible that many of the tests remaining after the prior call
to Shutdown are now extraneous. They don't harm anything, though,
so err on the side of safety and leave them for now.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Use helpers and variadic functions to make the call sites
a lot easier to read, since they occur a lot.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Concurrent calls to LocalBackend.setWgengineStatus
could result in some of the status updates being dropped.
This was exacerbated by 92077ae78c,
which increases the probability of concurrent status updates,
causing test failures (tailscale/corp#2579).
It's going to take a bit of work to fix this test.
The ipnlocal state machine is difficult to reason about,
particularly in the face of concurrency.
We could fix the test trivially by throwing a new mutex around
setWgengineStatus to serialize calls to it,
but I'd like to at least try to do better than cosmetics.
In the meantime, commit the test.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Spelling out the command to run for every type
means that changing the command makes for a large, repetitive diff.
Stop doing that.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
In prep for other bug fixes & tests. It's hard to test when it was
intermingled into LocalBackend.authReconfig.
Now it's a pure function.
And rename variable 'uc' (user config?) to the since idiomatic
'prefs'.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We currently plumb full URLs for DNS resolvers from the control server
down to the client. But when we pass the values into the net/dns
package, we throw away any URL that isn't a bare IP. This commit
continues the plumbing, and gets the URL all the way to the built in
forwarder. (It stops before plumbing URLs into the OS configurations
that can handle them.)
For #2596
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
And in the process, fix the related confusing error messages from
pinging your own IP or hostname.
Fixes#2803
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
* Revert "Revert "types/key: add MachinePrivate and MachinePublic.""
This reverts commit 61c3b98a24.
Signed-off-by: David Anderson <danderson@tailscale.com>
* types/key: add ControlPrivate, with custom serialization.
ControlPrivate is just a MachinePrivate that serializes differently
in JSON, to be compatible with how the Tailscale control plane
historically serialized its private key.
Signed-off-by: David Anderson <danderson@tailscale.com>
Plumb throughout the codebase as a replacement for the mixed use of
tailcfg.MachineKey and wgkey.Private/Public.
Signed-off-by: David Anderson <danderson@tailscale.com>
And add health check errors to ipnstate.Status (tailscale status --json).
Updates #2746
Updates #2775
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The number of packet filters can grow very large,
so this log entry can be very large.
We can get the packet filter server-side,
so reduce verbosity here to just the number of filters present.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Now that we have the easier-to-parse go:build build tags,
it is straightforward to simplify them. Yay.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
magicsock makes multiple calls to Now per packet.
Move to mono.Now. Changing some of the calls to
use package mono has a cascading effect,
causing non-per-packet call sites to also switch.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
The fact that Hash returns a [sha256.Size]byte leaks details about
the underlying hash implementation. This could very well be any other
hashing algorithm with a possible different block size.
Abstract this implementation detail away by declaring an opaque type
that is comparable. While we are changing the signature of UpdateHash,
rename it to just Update to reduce stutter (e.g., deephash.Update).
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
