libgocryptfs/internal/configfile/kdf.go
Jakob Unterwurzacher 2b8cbd9441 Major refactoring: Split up "cryptfs" into several internal packages
"git status" for reference:

deleted:    cryptfs/cryptfs.go
deleted:    cryptfs/names_core.go
modified:   integration_tests/cli_test.go
modified:   integration_tests/helpers.go
renamed:    cryptfs/config_file.go -> internal/configfile/config_file.go
renamed:    cryptfs/config_test.go -> internal/configfile/config_test.go
renamed:    cryptfs/config_test/.gitignore -> internal/configfile/config_test/.gitignore
renamed:    cryptfs/config_test/PlaintextNames.conf -> internal/configfile/config_test/PlaintextNames.conf
renamed:    cryptfs/config_test/StrangeFeature.conf -> internal/configfile/config_test/StrangeFeature.conf
renamed:    cryptfs/config_test/v1.conf -> internal/configfile/config_test/v1.conf
renamed:    cryptfs/config_test/v2.conf -> internal/configfile/config_test/v2.conf
renamed:    cryptfs/kdf.go -> internal/configfile/kdf.go
renamed:    cryptfs/kdf_test.go -> internal/configfile/kdf_test.go
renamed:    cryptfs/cryptfs_content.go -> internal/contentenc/content.go
new file:   internal/contentenc/content_api.go
renamed:    cryptfs/content_test.go -> internal/contentenc/content_test.go
renamed:    cryptfs/file_header.go -> internal/contentenc/file_header.go
renamed:    cryptfs/intrablock.go -> internal/contentenc/intrablock.go
renamed:    cryptfs/address_translation.go -> internal/contentenc/offsets.go
new file:   internal/cryptocore/crypto_api.go
renamed:    cryptfs/gcm_go1.4.go -> internal/cryptocore/gcm_go1.4.go
renamed:    cryptfs/gcm_go1.5.go -> internal/cryptocore/gcm_go1.5.go
renamed:    cryptfs/nonce.go -> internal/cryptocore/nonce.go
renamed:    cryptfs/openssl_aead.go -> internal/cryptocore/openssl_aead.go
renamed:    cryptfs/openssl_benchmark.bash -> internal/cryptocore/openssl_benchmark.bash
renamed:    cryptfs/openssl_test.go -> internal/cryptocore/openssl_test.go
new file:   internal/nametransform/name_api.go
new file:   internal/nametransform/names_core.go
renamed:    cryptfs/names_diriv.go -> internal/nametransform/names_diriv.go
renamed:    cryptfs/names_noiv.go -> internal/nametransform/names_noiv.go
renamed:    cryptfs/names_test.go -> internal/nametransform/names_test.go
new file:   internal/nametransform/pad16.go
renamed:    cryptfs/log.go -> internal/toggledlog/log.go
renamed:    cryptfs/log_go1.4.go -> internal/toggledlog/log_go1.4.go
renamed:    cryptfs/log_go1.5.go -> internal/toggledlog/log_go1.5.go
modified:   main.go
modified:   masterkey.go
modified:   pathfs_frontend/file.go
modified:   pathfs_frontend/file_holes.go
modified:   pathfs_frontend/fs.go
modified:   pathfs_frontend/fs_dir.go
modified:   pathfs_frontend/names.go
modified:   test.bash
2016-02-06 19:22:35 +01:00

58 lines
1.1 KiB
Go

package configfile
import (
"fmt"
"math"
"os"
"golang.org/x/crypto/scrypt"
"github.com/rfjakob/gocryptfs/internal/cryptocore"
)
const (
// 1 << 16 uses 64MB of memory,
// takes 4 seconds on my Atom Z3735F netbook
ScryptDefaultLogN = 16
)
type scryptKdf struct {
Salt []byte
N int
R int
P int
KeyLen int
}
func NewScryptKdf(logN int) scryptKdf {
var s scryptKdf
s.Salt = cryptocore.RandBytes(cryptocore.KeyLen)
if logN <= 0 {
s.N = 1 << ScryptDefaultLogN
} else {
if logN < 10 {
fmt.Println("Error: scryptn below 10 is too low to make sense. Aborting.")
os.Exit(1)
}
s.N = 1 << uint32(logN)
}
s.R = 8 // Always 8
s.P = 1 // Always 1
s.KeyLen = cryptocore.KeyLen
return s
}
func (s *scryptKdf) DeriveKey(pw string) []byte {
k, err := scrypt.Key([]byte(pw), s.Salt, s.N, s.R, s.P, s.KeyLen)
if err != nil {
panic(fmt.Sprintf("DeriveKey failed: %s", err.Error()))
}
return k
}
// LogN - N is saved as 2^LogN, but LogN is much easier to work with.
// This function gives you LogN = Log2(N).
func (s *scryptKdf) LogN() int {
return int(math.Log2(float64(s.N)) + 0.5)
}