On a CPU without AES-NI:
$ go test -bench .
Benchmark4kEncStupidGCM-2 50000 24155 ns/op 169.57 MB/s
Benchmark4kEncGoGCM-2 20000 93965 ns/op 43.59 MB/s
Benchmark4kEncGCMSIV-2 500 2576193 ns/op 1.59 MB/s
[...]/stupidgcm/locking.go:16:2:
warning: indirection of non-volatile null pointer will
be deleted, not trap [-Wnull-dereference]
[...]/stupidgcm/locking.go:16:2:
note: consider using __builtin_trap() or qualifying
pointer with 'volatile'
https://github.com/rfjakob/gocryptfs/issues/15
In general, OpenSSL is only threadsafe if you provide a locking function
through CRYPTO_set_locking_callback. However, the GCM operations that
stupidgcm uses never call that function.
To guard against that ever changing, set a dummy locking callback
that crashes the app.
Quoting from the patch:
We compare against Go's built-in GCM implementation. Since stupidgcm only
supports 128-bit IVs and Go only supports that from 1.5 onward, we cannot
run these tests on older Go versions.
This fixes the test failures on Travis CI.
Quoting from 07a4ff79d2
/* Set expected tag value. A restriction in OpenSSL 1.0.1c and earlier
* required the tag before any AAD or ciphertext */
...complete with tests and benchmark.
This will allow us to get rid of the dependency to spacemonkeygo/openssl
that causes problems on Arch Linux
( https://github.com/rfjakob/gocryptfs/issues/21 )
Jakob Unterwurzacher