libgocryptfs/internal/stupidgcm/gcm.go
Jakob Unterwurzacher e2ec048a09 stupidgcm: introduce stupidAEADCommon and use for both chacha & gcm
Nice deduplication and brings the GCM decrypt speed up to par.

internal/speed$ benchstat old new
name                old time/op   new time/op   delta
StupidGCM-4          4.71µs ± 0%   4.66µs ± 0%   -0.99%  (p=0.008 n=5+5)
StupidGCMDecrypt-4   5.77µs ± 1%   4.51µs ± 0%  -21.80%  (p=0.008 n=5+5)

name                old speed     new speed     delta
StupidGCM-4         870MB/s ± 0%  879MB/s ± 0%   +1.01%  (p=0.008 n=5+5)
StupidGCMDecrypt-4  710MB/s ± 1%  908MB/s ± 0%  +27.87%  (p=0.008 n=5+5)
2021-09-07 18:14:05 +02:00

46 lines
988 B
Go

// +build !without_openssl
// Package stupidgcm is a thin wrapper for OpenSSL's GCM encryption and
// decryption functions. It only support 32-byte keys and 16-bit IVs.
package stupidgcm
// #include <openssl/evp.h>
import "C"
import (
"crypto/cipher"
"log"
)
const (
// BuiltWithoutOpenssl indicates if openssl been disabled at compile-time
BuiltWithoutOpenssl = false
keyLen = 32
ivLen = 16
tagLen = 16
)
// StupidGCM implements the cipher.AEAD interface
type StupidGCM struct {
stupidAEADCommon
}
// Verify that we satisfy the interface
var _ cipher.AEAD = &StupidGCM{}
// New returns a new cipher.AEAD implementation..
func New(keyIn []byte, forceDecode bool) cipher.AEAD {
if len(keyIn) != keyLen {
log.Panicf("Only %d-byte keys are supported", keyLen)
}
return &StupidGCM{
stupidAEADCommon{
// Create a private copy of the key
key: append([]byte{}, keyIn...),
openSSLEVPCipher: C.EVP_aes_256_gcm(),
nonceSize: ivLen,
},
}
}