func Benchmark4kEncAESSIV(b *testing.B) {
key := randBytes(32)
authData := randBytes(24)
iv := randBytes(16)
in := make([]byte, 4096)
b.SetBytes(int64(len(in)))
gGCM := siv_aead.New(key)
for i := 0; i < b.N; i++ {
// Encrypt and append to nonce
gGCM.Seal(iv, iv, in, authData)
}
}
// New returns a new CryptoCore object or panics.
//
// Even though the "GCMIV128" feature flag is now mandatory, we must still
// support 96-bit IVs here because they are used for encrypting the master
// key in gocryptfs.conf.
func New(key []byte, backend BackendTypeEnum, IVBitLen int) *CryptoCore {
if len(key) != KeyLen {
log.Panic(fmt.Sprintf("Unsupported key length %d", len(key)))
}
// We want the IV size in bytes
IVLen := IVBitLen / 8
// Name encryption always uses built-in Go AES through BlockCipher.
// Content encryption uses BlockCipher only if useOpenssl=false.
blockCipher, err := aes.NewCipher(key)
if err != nil {
log.Panic(err)
}
var aeadCipher cipher.AEAD
switch backend {
case BackendOpenSSL:
if IVLen != 16 {
log.Panic("stupidgcm only supports 128-bit IVs")
}
aeadCipher = stupidgcm.New(key)
case BackendGoGCM:
aeadCipher, err = goGCMWrapper(blockCipher, IVLen)
case BackendAESSIV:
if IVLen != 16 {
// SIV supports any nonce size, but we only use 16.
log.Panic("AES-SIV must use 16-byte nonces")
}
// AES-SIV uses 1/2 of the key for authentication, 1/2 for
// encryption, so we need a 64-bytes key for AES-256. Derive it from
// the master key by hashing it with SHA-512.
key64 := sha512.Sum512(key)
aeadCipher = siv_aead.New(key64[:])
default:
log.Panic("unknown backend cipher")
}
if err != nil {
log.Panic(err)
}
return &CryptoCore{
BlockCipher: blockCipher,
AEADCipher: aeadCipher,
AEADBackend: backend,
IVGenerator: &nonceGenerator{nonceLen: IVLen},
IVLen: IVLen,
}
}
