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

3 files changed, 94 insertions, 0 deletions

diff --git a/internal/toggledlog/log.go b/internal/toggledlog/log.go
new file mode 100644
index 0000000..4a2ad03
--- /dev/null
+++ b/internal/toggledlog/log.go
@@ -0,0 +1,65 @@
+package toggledlog
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"os"
+)
+
+const (
+	ProgramName = "gocryptfs"
+)
+
+func JSONDump(obj interface{}) string {
+	b, err := json.MarshalIndent(obj, "", "\t")
+	if err != nil {
+		return err.Error()
+	} else {
+		return string(b)
+	}
+}
+
+// toggledLogger - a Logger than can be enabled and disabled
+type toggledLogger struct {
+	// Enable or disable output
+	Enabled bool
+	// Panic after logging a message, useful in regression tests
+	PanicAfter bool
+	*log.Logger
+}
+
+func (l *toggledLogger) Printf(format string, v ...interface{}) {
+	if !l.Enabled {
+		return
+	}
+	l.Logger.Printf(format, v...)
+	if l.PanicAfter {
+		panic("PanicAfter: " + fmt.Sprintf(format, v...))
+	}
+}
+func (l *toggledLogger) Println(v ...interface{}) {
+	if !l.Enabled {
+		return
+	}
+	l.Logger.Println(v...)
+	if l.PanicAfter {
+		panic("PanicAfter: " + fmt.Sprintln(v...))
+	}
+}
+
+// As defined by http://elinux.org/Debugging_by_printing#Log_Levels
+// Debug messages
+var Debug *toggledLogger
+
+// Informational message e.g. startup information
+var Info *toggledLogger
+
+// A warning, meaning nothing serious by itself but might indicate problems
+var Warn *toggledLogger
+
+func init() {
+	Debug = &toggledLogger{false, false, log.New(os.Stdout, "", 0)}
+	Info = &toggledLogger{true, false, log.New(os.Stdout, "", 0)}
+	Warn = &toggledLogger{true, false, log.New(os.Stderr, "", 0)}
+}
diff --git a/internal/toggledlog/log_go1.4.go b/internal/toggledlog/log_go1.4.go
new file mode 100644
index 0000000..4cdba44
--- /dev/null
+++ b/internal/toggledlog/log_go1.4.go
@@ -0,0 +1,12 @@
+// +build !go1.5
+// = go 1.4 or lower
+
+package toggledlog
+
+import (
+	"log/syslog"
+)
+
+func (l *toggledLogger) SwitchToSyslog(p syslog.Priority) {
+	Debug.Printf("Cannot switch to syslog - need Go 1.5 or higher")
+}
diff --git a/internal/toggledlog/log_go1.5.go b/internal/toggledlog/log_go1.5.go
new file mode 100644
index 0000000..e8e71f9
--- /dev/null
+++ b/internal/toggledlog/log_go1.5.go
@@ -0,0 +1,17 @@
+// +build go1.5
+// = go 1.5 or higher
+
+package toggledlog
+
+import (
+	"log/syslog"
+)
+
+func (l *toggledLogger) SwitchToSyslog(p syslog.Priority) {
+	w, err := syslog.New(p, ProgramName)
+	if err != nil {
+		Warn.Printf("Cannot switch 0x%02x to syslog: %v", p, err)
+	} else {
+		l.SetOutput(w)
+	}
+}