summaryrefslogtreecommitdiff
path: root/internal/cryptocore/nonce.go
diff options
context:
space:
mode:
authorJakob Unterwurzacher2016-02-06 19:20:54 +0100
committerJakob Unterwurzacher2016-02-06 19:22:35 +0100
commit2b8cbd944149afe51fadddbd67ee4499d1d86250 (patch)
tree76361984cc4394bbb9b19ae987aeaff71fb6073b /internal/cryptocore/nonce.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/cryptocore/nonce.go')
-rw-r--r--internal/cryptocore/nonce.go44
1 files changed, 44 insertions, 0 deletions
diff --git a/internal/cryptocore/nonce.go b/internal/cryptocore/nonce.go
new file mode 100644
index 0000000..72d8588
--- /dev/null
+++ b/internal/cryptocore/nonce.go
@@ -0,0 +1,44 @@
+package cryptocore
+
+import (
+ "bytes"
+ "crypto/rand"
+ "encoding/binary"
+ "encoding/hex"
+ "fmt"
+
+ "github.com/rfjakob/gocryptfs/internal/toggledlog"
+)
+
+// Get "n" random bytes from /dev/urandom or panic
+func RandBytes(n int) []byte {
+ b := make([]byte, n)
+ _, err := rand.Read(b)
+ if err != nil {
+ panic("Failed to read random bytes: " + err.Error())
+ }
+ return b
+}
+
+// Return a secure random uint64
+func RandUint64() uint64 {
+ b := RandBytes(8)
+ return binary.BigEndian.Uint64(b)
+}
+
+type nonceGenerator struct {
+ lastNonce []byte
+ nonceLen int // bytes
+}
+
+// Get a random "nonceLen"-byte nonce
+func (n *nonceGenerator) Get() []byte {
+ nonce := RandBytes(n.nonceLen)
+ toggledlog.Debug.Printf("nonceGenerator.Get(): %s\n", hex.EncodeToString(nonce))
+ if bytes.Equal(nonce, n.lastNonce) {
+ m := fmt.Sprintf("Got the same nonce twice: %s. This should never happen!", hex.EncodeToString(nonce))
+ panic(m)
+ }
+ n.lastNonce = nonce
+ return nonce
+}