From 61e37b2439f0b8a7c16458e73cb57c7428fe61f2 Mon Sep 17 00:00:00 2001 From: Jakob Unterwurzacher Date: Tue, 14 Sep 2021 18:47:07 +0200 Subject: stupidgcm: add CpuHasAES() Makes the code clearer, and will be used in the next commit. --- internal/stupidgcm/prefer.go | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/internal/stupidgcm/prefer.go b/internal/stupidgcm/prefer.go index ffbaf58..bb613c3 100644 --- a/internal/stupidgcm/prefer.go +++ b/internal/stupidgcm/prefer.go @@ -21,17 +21,11 @@ func PreferOpenSSLAES256GCM() bool { if BuiltWithoutOpenssl { return false } - // Safe to call on other architectures - will just read false. - if cpu.X86.HasAES || cpu.ARM64.HasAES { - // Go stdlib is probably faster + // If the CPU has AES acceleration, Go stdlib is faster + if CpuHasAES() { return false } - // On the Apple M1, Go stdlib is faster than OpenSSL, despite cpu.ARM64.HasAES - // reading false: https://github.com/rfjakob/gocryptfs/issues/556#issuecomment-848079309 - if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" { - return false - } - // OpenSSL is probably faster + // Otherwise OpenSSL is probably faster return true } @@ -49,3 +43,18 @@ func PreferOpenSSLXchacha20poly1305() bool { // On arm64 and arm, OpenSSL is faster. Probably everwhere else too. return true } + +// CpuHasAES tells you if the CPU we are running has AES acceleration that is +// usable by the Go crypto library. +func CpuHasAES() bool { + // Safe to call on other architectures - will just read false. + if cpu.X86.HasAES || cpu.ARM64.HasAES { + return true + } + // On the Apple M1, the CPU has AES acceleration, despite cpu.ARM64.HasAES + // reading false: https://github.com/rfjakob/gocryptfs/issues/556#issuecomment-848079309 + if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" { + return true + } + return false +} -- cgit v1.2.3