This mainly cleans up the few bits of code where we explicitly kept
support for Go 1.15.x. With v0.1.0 released, we can drop support now,
since the next v0.2.0 release will only support Go 1.16.x.
Also updates all modules, including test ones, to 'go 1.16'.
Note that the TOOLEXEC_IMPORTPATH refactor is not done here, despite all
the TODOs about doing so when we drop 1.15 support. This is because that
refactor needs to be done carefully and might have side effects, so it's
best to keep it to a separate commit.
Finally, update the deps.
The TODO I left there didn't take long to surface as a bug. If the
package path ends with a word containing a hyphen, that's not a valid
identifier, so we end up with invalid Go syntax.
Add that test case, as well as one where an import was already named.
To fix the issue, we just need to use the package name we got from
'go list -json'.
Fixes#243.
We used to rely on a parallel implementation of an object file parser
and writer to be able to obfuscate import paths. After compiling each
package, we would parse the object file, replace the import paths, and
write the updated object file in-place.
That worked well, in most cases. Unfortunately, it had some flaws:
* Complexity. Even when most of the code is maintained in a separate
module, the import_obfuscation.go file was still close to a thousand
lines of code.
* Go compatibility. The object file format changes between Go releases,
so we were supporting Go 1.15, but not 1.16. Fixing the object file
package to work with 1.16 would probably break 1.15 support.
* Bugs. For example, we recently had to add a workaround for #224, since
import paths containing dots after the domain would end up escaped.
Another example is #190, which seems to be caused by the object file
parser or writer corrupting the compiled code and causing segfaults in
some rare edge cases.
Instead, let's drop that method entirely, and force the compiler and
linker to do the work for us. The steps necessary when compiling a
package to obfuscate are:
1) Replace its "package foo" lines with the obfuscated package path. No
need to separate the package path and name, since the obfuscated path
does not contain slashes.
2) Replace the "-p pkg/foo" flag with the obfuscated path.
3) Replace the "import" spec lines with the obfuscated package paths,
for those dependencies which were obfuscated.
4) Replace the "-importcfg [...]" file with a version that uses the
obfuscated paths instead.
The linker also needs that last step, since it also uses an importcfg
file to find object files.
There are three noteworthy drawbacks to this new method:
1) Since we no longer write object files, we can't use them to store
data to be cached. As such, the -debugdir flag goes back to using the
"-a" build flag to always rebuild all packages. On the plus side,
that caching didn't work very well; see #176.
2) The package name "main" remains in all declarations under it, not
just "func main", since we can only rename entire packages. This
seems fine, as it gives little information to the end user.
3) The -tiny mode no longer sets all lines to 0, since it did that by
modifying object files. As a temporary measure, we instead set all
top-level declarations to be on line 1. A TODO is added to hopefully
improve this again in the near future.
The upside is that we get rid of all the issues mentioned before. Plus,
garble now nearly works with Go 1.16, with the exception of two very
minor bugs that look fixable. A follow-up PR will take care of that and
start testing on 1.16.
Fixes#176.
Fixes#190.
First, make isPrivate panic on malformed import paths, since that should
never happen. This catches the errors that some users had run into with
packages like gopkg.in/yaml.v2 and github.com/satori/go.uuid:
panic: malformed import path "gopkg.in/garbletest%2ev2": invalid char '%'
This seems to trigger when a module path contains a dot after the first
element, *and* that module is fetched via the proxy. This results in the
toolchain URL-encoding the second dot, and garble ends up seeing that
encoded path.
We reproduce this behavior with a fake gopkg.in module added to the test
module proxy. Using yaml.v2 directly would have been easier, but it's
pretty large. Note that we tried a replace directive, but that does not
trigger the URL-encoding bug.
Also note that we do not obfuscate the gopkg.in package; that's fine, as
the isPrivate path validity check catches the bug either way.
For now, make initImport use url.PathUnescape to work around this issue.
The underlying bug is likely in either the goobj2 fork, or in the
upstream Go toolchain itself.
hashImport also gives a better error if it cannot find a package now,
rather than just an "empty seed" panic.
Finally, the sanity check in isPrivate unearthed the fact that we do not
support garbling test packages at all, since they were invalid paths
which never matched GOPRIVATE. Add an explicit check and TODO about
that.
Fixes#224.
Fixes#228.
main.go includes a lengthy comment that documents this edge case, why it
happened, and how we are fixing it. To summarize, we should no longer
error with a build error in those cases. Read the comment for details.
A few other minor changes were done to allow writing this patch.
First, the actionID and contentID funcs were renamed, since they started
to collide with variable names.
Second, the logging has been improved a bit, which allowed me to debug
the issue.
Third, the "cache" global shared by all garble sub-processes now
includes the necessary parameters to run "go list -toolexec", including
the path to garble and the build flags being used.
Thanks to lu4p for writing a test case, which also applied gofmt to that
testdata Go file.
Fixes#180.
Closes#181, since it includes its test case.
If code includes a linkname directive pointing at a name in an imported
package, like:
//go:linkname localName importedpackage.RemoteName
func localName()
We should rewrite the comment to replace "RemoteName" with its
obfuscated counterpart, if the package in question was obfuscated and
that name was as well.
We already had some code to handle linkname directives, but only to
ensure that "localName" was never obfuscated. This behavior is kept, to
ensure that the directive applies to the right name. In the future, we
could instead rewrite "localName" in the directive, like we do with
"RemoteName".
Add plenty of tests, too. The linkname directive used to be tested in
imports.txt and syntax.txt, but that was hard to maintain as each file
tested different edge cases.
Now that we have build caching, adding one extra testscript file isn't a
big problem anymoree. Add linkname.txt, which is self-explanatory. The
other two scripts also get a bit less complex.
Fixes#197.
It turns out that the modules we include in testdata/mod via
txtar-addmod don't result in the same h1 hash that one gets when using
proxy.golang.org.
As proof:
$ go clean -modcache && go get -d rsc.io/quote@v1.5.2 && go test -short
[...]
--- FAIL: TestScripts/imports (0.06s)
> garble build -tags buildtag
go list error: exit status 1: verifying rsc.io/quote@v1.5.2: checksum mismatch
downloaded: h1:w5fcysjrx7yqtD/aO+QwRjYZOKnaM9Uh2b40tElTs3Y=
go.sum: h1:3fEykkD9k7lYzXqCYrwGAf7iNhbk4yCjHmKBN9td4L0=
The added comment explains the situation in detail.
For now, simply work around the issue by not sharing GOMODCACHE with the
host.
In Go 1.15, if a dependency is required but not listed in go.mod/go.sum,
it's resolved and added automatically.
This is changing in 1.16. From that release, one will have to explicitly
update the mod files via 'go mod tidy' or 'go get'.
To get ahead of the curve, start using -mod=readonly to get the same
behavior in 1.15, and fix all existing tests.
The only tests that failed were imports.txt and syntax.txt, the only
ones to require other modules. But since we're here, let's add the 'go'
line to all go.mod files as well.
* fix bug where structs would get garbled in some packages but not in others
* only check if struct/field was not defined in current package
* fix a related bug when two objects share the same name in the same package and one is garbled but the other one is not
* renamed parameter for clarity
As per the discussion in https://github.com/golang/go/issues/41145, it
turns out that we don't need special support for build caching in
-toolexec. We can simply modify the behavior of "[...]/compile -V=full"
and "[...]/link -V=full" so that they include garble's own version and
options in the printed build ID.
The part of the build ID that matters is the last, since it's the
"content ID" which is used to work out whether there is a need to redo
the action (build) or not. Since cmd/go parses the last word in the
output as "buildID=...", we simply add "+garble buildID=_/_/_/${hash}".
The slashes let us imitate a full binary build ID, but we assume that
the other components such as the action ID are not necessary, since the
only reader here is cmd/go and it only consumes the content ID.
The reported content ID includes the tool's original content ID,
garble's own content ID from the built binary, and the garble options
which modify how we obfuscate code. If any of the three changes, we
should use a different build cache key. GOPRIVATE also affects caching,
since a different GOPRIVATE value means that we might have to garble a
different set of packages.
Include tests, which mainly check that 'garble build -v' prints package
lines when we expect to always need to rebuild packages, and that it
prints nothing when we should be reusing the build cache even when the
built binary is missing.
After this change, 'go test' on Go 1.15.2 stabilizes at about 8s on my
machine, whereas it used to be at around 25s before.
Finally, finally this is done. This allows import paths to be obfuscated by modifying
object/archive files and garbling import paths contained within. The bulk of the
code that makes parsing and writing Go object/archive files possible lives at
https://github.com/Binject/debug/tree/master/goobj2, which I wrote as well.
I have tested by garbling and checking for import paths via strings and grep
(in order of difficulty) https://github.com/lu4p/binclude, garble itself, and
https://github.com/dominikh/go-tools/tree/master/cmd/staticcheck.
This only supports object/archive files produced from the Go 1.15 compiler.
The object file format changed at 1.15, and 1.14 and earlier is not supported.
Fixes#13.
basic.txt just builds main.go without a module. Similarly, we leave
imports.txt without a GOPRIVATE, to test the 'go list -m' fallback.
For all other tests, explicitly set GOPRIVATE, to avoid two exec calls -
both 'go env GOPRIVATE' as well as 'go list -m'. Each of those calls
takes in the order of 10ms, so saving ~26 exec calls should easily add
to 200-300ms saved from 'go test -short'.
Fixes#93.
The second typecheck lead to the creation of different type objects,
which didn't match the types in the blacklist anymore.
It turns out we don't need the second typecheck,
therfore it is now removed.
Otherwise any build flags like -tags won't be used, and we might easily
end up with errors or incorrect packages.
The common case with -tags is covered by one of the integration test
scripts. On top of that, we add a table-driven unit test to cover all
edge cases, since there are many we can do quickly in a unit test.
Fixes#82.
In the added test, the unexported field used to be garbled.
Reflection can only reach exported methods, exported fields, and
unexported fields. Exported methods and fields are currently never
garbled, so unexported fields was the only missing piece.
Carefully select a default that will do the right thing when inside a
module, as well as when building ad-hoc packages.
This means we no longer need to look at the compiler's -std flag, which
is nice.
Also replace foo.com/ with test/, as per golang/go#37641.
Fixes#7.
We use 'go list -json -export' to locate required modules. This works
fine to locate direct module dependencies; since we're building in the
current module, we run 'go list' in the correct directory.
However, if we're building one of those module dependencies, and it has
other module dependencies of its own, we would fail with cryptic errors
like:
typecheck error: [...] go list error: updates to go.sum needed, disabled by -mod=readonly
This is because we would try to run 'go list' outside of the main
module, probably inside the module cache. Instead, use a $GARBLE_DIR env
var from the top-level 'garble build' call to always run 'go list' in
the original directory.
We add a few small modules to properly test this.
Updates #9.
The problem with the "grep" built-in command is that it prints the
entire data if there is an error. We don't want megabytes of binary
output for a test.
Daniel Martí
Andrew LeFevre
lu4p