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authorJakob Unterwurzacher2016-02-06 19:20:54 +0100
committerJakob Unterwurzacher2016-02-06 19:22:35 +0100
commit2b8cbd944149afe51fadddbd67ee4499d1d86250 (patch)
tree76361984cc4394bbb9b19ae987aeaff71fb6073b /internal/configfile/kdf.go
parentadcfbd79a8b8bb85cbee25996ab622a05de0dbc1 (diff)
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
Diffstat (limited to 'internal/configfile/kdf.go')
-rw-r--r--internal/configfile/kdf.go57
1 files changed, 57 insertions, 0 deletions
diff --git a/internal/configfile/kdf.go b/internal/configfile/kdf.go
new file mode 100644
index 0000000..f1a7a40
--- /dev/null
+++ b/internal/configfile/kdf.go
@@ -0,0 +1,57 @@
+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)
+}