configfile: rename "kdf.go" -> "scrypt.go"

This really only handles scrypt and no other key-derivation functions.
Renaming the files prevents confusion once we introduce HKDF.

renamed:    internal/configfile/kdf.go -> internal/configfile/scrypt.go
renamed:    internal/configfile/kdf_test.go -> internal/configfile/scrypt_test.go

1 files changed, 0 insertions, 62 deletions

diff --git a/internal/configfile/kdf.go b/internal/configfile/kdf.go
deleted file mode 100644
index 31bcbe4..0000000
--- a/internal/configfile/kdf.go
+++ /dev/null
@@ -1,62 +0,0 @@
-package configfile
-
-import (
-	"log"
-	"math"
-	"os"
-
-	"golang.org/x/crypto/scrypt"
-
-	"github.com/rfjakob/gocryptfs/internal/cryptocore"
-	"github.com/rfjakob/gocryptfs/internal/tlog"
-)
-
-const (
-	// ScryptDefaultLogN is the default scrypt logN configuration parameter.
-	// 1 << 16 uses 64MB of memory,
-	// takes 4 seconds on my Atom Z3735F netbook
-	ScryptDefaultLogN = 16
-)
-
-// ScryptKDF is an instance of the scrypt key deriviation function.
-type ScryptKDF struct {
-	Salt   []byte
-	N      int
-	R      int
-	P      int
-	KeyLen int
-}
-
-// NewScryptKDF returns a new instance of ScryptKDF.
-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 {
-			tlog.Fatal.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
-}
-
-// DeriveKey returns a new key from a supplied password.
-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 {
-		log.Panicf("DeriveKey failed: %v", err)
-	}
-	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)
-}