tailscale

Commit Graph

Author	SHA1	Message	Date
Nick Khyl	961ee321e8	ipn/{ipnauth,ipnlocal,ipnserver,localapi}: start baby step toward moving access checks from the localapi.Handler to the LocalBackend Currently, we use PermitRead/PermitWrite/PermitCert permission flags to determine which operations are allowed for a LocalAPI client. These checks are performed when localapi.Handler handles a request. Additionally, certain operations (e.g., changing the serve config) requires the connected user to be a local admin. This approach is inherently racey and is subject to TOCTOU issues. We consider it to be more critical on Windows environments, which are inherently multi-user, and therefore we prevent more than one OS user from connecting and utilizing the LocalBackend at the same time. However, the same type of issues is also applicable to other platforms when switching between profiles that have different OperatorUser values in ipn.Prefs. We'd like to allow more than one Windows user to connect, but limit what they can see and do based on their access rights on the device (e.g., an local admin or not) and to the currently active LoginProfile (e.g., owner/operator or not), while preventing TOCTOU issues on Windows and other platforms. Therefore, we'd like to pass an actor from the LocalAPI to the LocalBackend to represent the user performing the operation. The LocalBackend, or the profileManager down the line, will then check the actor's access rights to perform a given operation on the device and against the current (and/or the target) profile. This PR does not change the current permission model in any way, but it introduces the concept of an actor and includes some preparatory work to pass it around. Temporarily, the ipnauth.Actor interface has methods like IsLocalSystem and IsLocalAdmin, which are only relevant to the current permission model. It also lacks methods that will actually be used in the new model. We'll be adding these gradually in the next PRs and removing the deprecated methods and the Permit* flags at the end of the transition. Updates tailscale/corp#18342 Signed-off-by: Nick Khyl <nickk@tailscale.com>	3 months ago
Brad Fitzpatrick	61a1644c2a	go.mod, all: move away from inet.af domain seized by Taliban Updates inetaf/tcpproxy#39 Change-Id: I7fee276b116bd08397347c6c949011d76a2842cf Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	10 months ago
Will Norris	236531c5fc	ipn/ipnserver: always allow Windows SYSTEM user to connect When establishing connections to the ipnserver, we validate that the local user is allowed to connect. If Tailscale is currently being managed by a different user (primarily for multi-user Windows installs), we don't allow the connection. With the new device web UI, the inbound connection is coming from tailscaled itself, which is often running as "NT AUTHORITY\SYSTEM". In this case, we still want to allow the connection, even though it doesn't match the user running the Tailscale GUI. The SYSTEM user has full access to everything on the system anyway, so this doesn't escalate privileges. Eventually, we want the device web UI to run outside of the tailscaled process, at which point this exception would probably not be needed. Updates tailscale/corp#16393 Signed-off-by: Will Norris <will@tailscale.com>	11 months ago
Andrew Lytvynov	2716250ee8	all: cleanup unused code, part 2 (#10670 ) And enable U1000 check in staticcheck. Updates #cleanup Signed-off-by: Andrew Lytvynov <awly@tailscale.com>	11 months ago
Aaron Klotz	fbc18410ad	ipn/ipnauth: improve the Windows token administrator check (Token).IsAdministrator is supposed to return true even when the user is running with a UAC limited token. The idea is that, for the purposes of this check, we don't care whether the user is currently* running with full Admin rights, we just want to know whether the user can potentially do so. We accomplish this by querying for the token's "linked token," which should be the fully-elevated variant, and checking its group memberships. We also switch ipn/ipnserver/(*Server).connIsLocalAdmin to use the elevation check to preserve those semantics for tailscale serve; I want the IsAdministrator check to be used for less sensitive things like toggling auto-update on and off. Fixes #10036 Signed-off-by: Aaron Klotz <aaron@tailscale.com>	1 year ago
Aaron Klotz	95671b71a6	ipn, safesocket: use Windows token in LocalAPI On Windows, the idiomatic way to check access on a named pipe is for the server to impersonate the client on its current OS thread, perform access checks using the client's access token, and then revert the OS thread's access token back to its true self. The access token is a better representation of the client's rights than just a username/userid check, as it represents the client's effective rights at connection time, which might differ from their normal rights. This patch updates safesocket to do the aforementioned impersonation, extract the token handle, and then revert the impersonation. We retain the token handle for the remaining duration of the connection (the token continues to be valid even after we have reverted back to self). Since the token is a property of the connection, I changed ipnauth to wrap the concrete net.Conn to include the token. I then plumbed that change through ipnlocal, ipnserver, and localapi as necessary. I also added a PermitLocalAdmin flag to the localapi Handler which I intend to use for controlling access to a few new localapi endpoints intended for configuring auto-update. Updates https://github.com/tailscale/tailscale/issues/755 Signed-off-by: Aaron Klotz <aaron@tailscale.com>	1 year ago
Will Norris	71029cea2d	all: update copyright and license headers This updates all source files to use a new standard header for copyright and license declaration. Notably, copyright no longer includes a date, and we now use the standard SPDX-License-Identifier header. This commit was done almost entirely mechanically with perl, and then some minimal manual fixes. Updates #6865 Signed-off-by: Will Norris <will@tailscale.com>	2 years ago
Maisem Ali	adc302f428	all: use named pipes on windows Signed-off-by: Maisem Ali <maisem@tailscale.com>	2 years ago
Aaron Klotz	6e33d2da2b	ipn/ipnauth, util/winutil: add temporary LookupPseudoUser workaround to address os/user.LookupId errors on Windows I added util/winutil/LookupPseudoUser, which essentially consists of the bits that I am in the process of adding to Go's standard library. We check the provided SID for "S-1-5-x" where 17 <= x <= 20 (which are the known pseudo-users) and then manually populate a os/user.User struct with the correct information. Fixes https://github.com/tailscale/tailscale/issues/869 Fixes https://github.com/tailscale/tailscale/issues/2894 Signed-off-by: Aaron Klotz <aaron@tailscale.com>	2 years ago
Brad Fitzpatrick	8049053f86	ipn/*: make new WindowsUserID type to consolidate docs The "userID is empty everywhere but Windows" docs on lots of places but not everywhere while using just a string type was getting confusing. This makes a new type to wrap up those rules, however weird/historical they might be. Change-Id: I142e85a8e38760988d6c0c91d0efecedade81b9b Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Brad Fitzpatrick	b0545873e5	ipn/ipnserver: remove protoSwitchConn shenanigans; just use http.Server early Now that everything's just HTTP, there's no longer a need to have a header-sniffing net.Conn wraper that dispatches which route to take. Refactor to just use an http.Server earlier instead. Updates #6417 Change-Id: I12a2054db4e56f48660c46f81233db224fdc77cb Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Brad Fitzpatrick	0a842f353c	ipn/ipnserver: move more connection acceptance logic to LocalBackend Follow-up to #6467 and #6506. LocalBackend knows the server-mode state, so move more auth checking there, removing some bookkeeping from ipnserver.Server. Updates #6417 Updates tailscale/corp#8051 Change-Id: Ic5d14a077bf0dccc92a3621bd2646bab2cc5b837 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Brad Fitzpatrick	7bff7345cc	ipn/ipnauth: start splitting ipnserver into new ipnauth package We're trying to gut 90% of the ipnserver package. A lot will get deleted, some will move to LocalBackend, and a lot is being moved into this new ipn/ipnauth package which will be leaf-y and testable. This is a baby step towards moving some stuff to ipnauth. Update #6417 Updates tailscale/corp#8051 Change-Id: I28bc2126764f46597d92a2d72565009dc6927ee0 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago

13 Commits (2aa9125ac438ffa902158b5bedf9791c93117b9b)