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path: root/gocryptfs-xray/xray_main.go
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Diffstat (limited to 'gocryptfs-xray/xray_main.go')
-rw-r--r--gocryptfs-xray/xray_main.go72
1 files changed, 39 insertions, 33 deletions
diff --git a/gocryptfs-xray/xray_main.go b/gocryptfs-xray/xray_main.go
index ffcd239..8abd008 100644
--- a/gocryptfs-xray/xray_main.go
+++ b/gocryptfs-xray/xray_main.go
@@ -24,26 +24,22 @@ var GitVersion = "[GitVersion not set - please compile using ./build.bash]"
var BuildDate = "0000-00-00"
const (
- ivLen = contentenc.DefaultIVBits / 8
- authTagLen = cryptocore.AuthTagLen
- blockSize = contentenc.DefaultBS + ivLen + cryptocore.AuthTagLen
- myName = "gocryptfs-xray"
+ myName = "gocryptfs-xray"
)
+// blockSize is the ciphertext block size including overheads
+func blockSize(alg cryptocore.AEADTypeEnum) int {
+ return alg.NonceSize + contentenc.DefaultBS + cryptocore.AuthTagLen
+}
+
func errExit(err error) {
fmt.Println(err)
os.Exit(1)
}
-func prettyPrintHeader(h *contentenc.FileHeader, aessiv bool) {
+func prettyPrintHeader(h *contentenc.FileHeader, algo cryptocore.AEADTypeEnum) {
id := hex.EncodeToString(h.ID)
- msg := "Header: Version: %d, Id: %s"
- if aessiv {
- msg += ", assuming AES-SIV mode"
- } else {
- msg += ", assuming AES-GCM mode"
- }
- fmt.Printf(msg+"\n", h.Version, id)
+ fmt.Printf("Header: Version: %d, Id: %s, assuming %s mode\n", h.Version, id, algo.Name)
}
// printVersion prints a version string like this:
@@ -79,21 +75,25 @@ func sum(x ...*bool) (s int) {
return s
}
+type argContainer struct {
+ dumpmasterkey *bool
+ decryptPaths *bool
+ encryptPaths *bool
+ aessiv *bool
+ xchacha *bool
+ sep0 *bool
+ fido2 *string
+ version *bool
+}
+
func main() {
- var args struct {
- dumpmasterkey *bool
- decryptPaths *bool
- encryptPaths *bool
- aessiv *bool
- sep0 *bool
- fido2 *string
- version *bool
- }
+ var args argContainer
args.dumpmasterkey = flag.Bool("dumpmasterkey", false, "Decrypt and dump the master key")
args.decryptPaths = flag.Bool("decrypt-paths", false, "Decrypt file paths using gocryptfs control socket")
args.encryptPaths = flag.Bool("encrypt-paths", false, "Encrypt file paths using gocryptfs control socket")
args.sep0 = flag.Bool("0", false, "Use \\0 instead of \\n as separator")
args.aessiv = flag.Bool("aessiv", false, "Assume AES-SIV mode instead of AES-GCM")
+ args.xchacha = flag.Bool("xchacha", false, "Assume XChaCha20-Poly1305 mode instead of AES-GCM")
args.fido2 = flag.String("fido2", "", "Protect the masterkey using a FIDO2 token instead of a password")
args.version = flag.Bool("version", false, "Print version information")
@@ -121,15 +121,15 @@ func main() {
if *args.encryptPaths {
encryptPaths(fn, *args.sep0)
}
- fd, err := os.Open(fn)
+ f, err := os.Open(fn)
if err != nil {
errExit(err)
}
- defer fd.Close()
+ defer f.Close()
if *args.dumpmasterkey {
dumpMasterKey(fn, *args.fido2)
} else {
- inspectCiphertext(fd, *args.aessiv)
+ inspectCiphertext(&args, f)
}
}
@@ -166,7 +166,13 @@ func dumpMasterKey(fn string, fido2Path string) {
}
}
-func inspectCiphertext(fd *os.File, aessiv bool) {
+func inspectCiphertext(args *argContainer, fd *os.File) {
+ algo := cryptocore.BackendGoGCM
+ if *args.aessiv {
+ algo = cryptocore.BackendAESSIV
+ } else if *args.xchacha {
+ algo = cryptocore.BackendXChaCha20Poly1305
+ }
headerBytes := make([]byte, contentenc.HeaderLen)
n, err := fd.ReadAt(headerBytes, 0)
if err == io.EOF && n == 0 {
@@ -182,11 +188,11 @@ func inspectCiphertext(fd *os.File, aessiv bool) {
if err != nil {
errExit(err)
}
- prettyPrintHeader(header, aessiv)
+ prettyPrintHeader(header, algo)
var i int64
- buf := make([]byte, blockSize)
+ buf := make([]byte, blockSize(algo))
for i = 0; ; i++ {
- off := contentenc.HeaderLen + i*blockSize
+ off := contentenc.HeaderLen + i*int64(blockSize(algo))
n, err := fd.ReadAt(buf, off)
if err != nil && err != io.EOF {
errExit(err)
@@ -195,15 +201,15 @@ func inspectCiphertext(fd *os.File, aessiv bool) {
break
}
// A block contains at least the IV, the Auth Tag and 1 data byte
- if n < ivLen+authTagLen+1 {
+ if n < algo.NonceSize+cryptocore.AuthTagLen+1 {
errExit(fmt.Errorf("corrupt block: truncated data, len=%d", n))
}
data := buf[:n]
// Parse block data
- iv := data[:ivLen]
- tag := data[len(data)-authTagLen:]
- if aessiv {
- tag = data[ivLen : ivLen+authTagLen]
+ iv := data[:algo.NonceSize]
+ tag := data[len(data)-cryptocore.AuthTagLen:]
+ if *args.aessiv {
+ tag = data[algo.NonceSize : algo.NonceSize+cryptocore.AuthTagLen]
}
fmt.Printf("Block %2d: IV: %s, Tag: %s, Offset: %5d Len: %d\n",
i, hex.EncodeToString(iv), hex.EncodeToString(tag), off, len(data))