exitcodes: pull all exit code definitions into the package

This commit defines all exit codes in one place in the exitcodes
package.

Also, it adds a test to verify the exit code on incorrect
password, which is what SiriKali cares about the most.

Fixes https://github.com/rfjakob/gocryptfs/issues/77 .

4 files changed, 50 insertions, 20 deletions

diff --git a/internal/configfile/scrypt.go b/internal/configfile/scrypt.go
index 0646754..b5a3edb 100644
--- a/internal/configfile/scrypt.go
+++ b/internal/configfile/scrypt.go
@@ -8,6 +8,7 @@ import (
 	"golang.org/x/crypto/scrypt"
 
 	"github.com/rfjakob/gocryptfs/internal/cryptocore"
+	"github.com/rfjakob/gocryptfs/internal/exitcodes"
 	"github.com/rfjakob/gocryptfs/internal/tlog"
 )
 
@@ -84,22 +85,22 @@ func (s *ScryptKDF) validateParams() {
 	minN := 1 << scryptMinLogN
 	if s.N < minN {
 		tlog.Fatal.Println("Fatal: scryptn below 10 is too low to make sense")
-		os.Exit(1)
+		os.Exit(exitcodes.ScryptParams)
 	}
 	if s.R < scryptMinR {
 		tlog.Fatal.Printf("Fatal: scrypt parameter R below minimum: value=%d, min=%d", s.R, scryptMinR)
-		os.Exit(1)
+		os.Exit(exitcodes.ScryptParams)
 	}
 	if s.P < scryptMinP {
 		tlog.Fatal.Printf("Fatal: scrypt parameter P below minimum: value=%d, min=%d", s.P, scryptMinP)
-		os.Exit(1)
+		os.Exit(exitcodes.ScryptParams)
 	}
 	if len(s.Salt) < scryptMinSaltLen {
 		tlog.Fatal.Printf("Fatal: scrypt salt length below minimum: value=%d, min=%d", len(s.Salt), scryptMinSaltLen)
-		os.Exit(1)
+		os.Exit(exitcodes.ScryptParams)
 	}
 	if s.KeyLen < cryptocore.KeyLen {
 		tlog.Fatal.Printf("Fatal: scrypt parameter KeyLen below minimum: value=%d, min=%d", len(s.Salt), cryptocore.KeyLen)
-		os.Exit(1)
+		os.Exit(exitcodes.ScryptParams)
 	}
 }
diff --git a/internal/exitcodes/exitcodes.go b/internal/exitcodes/exitcodes.go
index 2ec3ae6..7a2efdb 100644
--- a/internal/exitcodes/exitcodes.go
+++ b/internal/exitcodes/exitcodes.go
@@ -8,12 +8,39 @@ import (
 )
 
 const (
+	// Usage error: cli syntax etc
+	Usage = 1
+	// 2 is reserved because it is used by Go panic
+
+	// Mount is an error on mount
+	Mount = 3
+	// CipherDir means that the CIPHERDIR does not exist
+	CipherDir = 6
+	// Init is an error on filesystem init
+	Init = 7
+	// LoadConf is an error while loading gocryptfs.conf
+	LoadConf = 8
+	// ReadPassword means something went wrong reading the password
+	ReadPassword = 9
+	// MountPoint error means that the mountpoint is invalid (not empty etc).
+	MountPoint = 10
 	// Other error - please inspect the message
 	Other = 11
 	// PasswordIncorrect - the password was incorrect
 	PasswordIncorrect = 12
-	// TODO several other exit codes are defined in main.go. These will be
-	// ported over here.
+	// ScryptParams means that scrypt was called with invalid parameters
+	ScryptParams = 13
+	// MasterKey means that something went wrong when parsing the "-masterkey"
+	// command line option
+	MasterKey = 14
+	// SigInt means we got SIGINT
+	SigInt = 15
+	// PanicLog means the panic log was not empty when we were unmounted
+	PanicLog = 16
+	// ForkChild means forking the worker child failed
+	ForkChild = 17
+	// OpenSSL means you tried to enable OpenSSL, but we were compiled without it.
+	OpenSSL = 18
 )
 
 // Err wraps an error with an associated numeric exit code
diff --git a/internal/readpassword/read.go b/internal/readpassword/read.go
index 563c62d..058735d 100644
--- a/internal/readpassword/read.go
+++ b/internal/readpassword/read.go
@@ -12,11 +12,11 @@ import (
 
 	"golang.org/x/crypto/ssh/terminal"
 
+	"github.com/rfjakob/gocryptfs/internal/exitcodes"
 	"github.com/rfjakob/gocryptfs/internal/tlog"
 )
 
 const (
-	exitCode = 9
 	// 2kB limit like EncFS
 	maxPasswordLen = 2048
 )
@@ -46,7 +46,7 @@ func Twice(extpass string) string {
 	p2 := readPasswordTerminal("Repeat: ")
 	if p1 != p2 {
 		tlog.Fatal.Println("Passwords do not match")
-		os.Exit(exitCode)
+		os.Exit(exitcodes.ReadPassword)
 	}
 	return p1
 }
@@ -60,12 +60,12 @@ func readPasswordTerminal(prompt string) string {
 	p, err := terminal.ReadPassword(fd)
 	if err != nil {
 		tlog.Fatal.Printf("Could not read password from terminal: %v\n", err)
-		os.Exit(exitCode)
+		os.Exit(exitcodes.ReadPassword)
 	}
 	fmt.Fprintf(os.Stderr, "\n")
 	if len(p) == 0 {
 		tlog.Fatal.Println("Password is empty")
-		os.Exit(exitCode)
+		os.Exit(exitcodes.ReadPassword)
 	}
 	return string(p)
 }
@@ -77,7 +77,7 @@ func readPasswordStdin() string {
 	p := readLineUnbuffered(os.Stdin)
 	if len(p) == 0 {
 		tlog.Fatal.Println("Got empty password from stdin")
-		os.Exit(exitCode)
+		os.Exit(exitcodes.ReadPassword)
 	}
 	return p
 }
@@ -102,23 +102,23 @@ func readPasswordExtpass(extpass string) string {
 	pipe, err := cmd.StdoutPipe()
 	if err != nil {
 		tlog.Fatal.Printf("extpass pipe setup failed: %v", err)
-		os.Exit(exitCode)
+		os.Exit(exitcodes.ReadPassword)
 	}
 	err = cmd.Start()
 	if err != nil {
 		tlog.Fatal.Printf("extpass cmd start failed: %v", err)
-		os.Exit(exitCode)
+		os.Exit(exitcodes.ReadPassword)
 	}
 	p := readLineUnbuffered(pipe)
 	pipe.Close()
 	err = cmd.Wait()
 	if err != nil {
 		tlog.Fatal.Printf("extpass program returned an error: %v", err)
-		os.Exit(exitCode)
+		os.Exit(exitcodes.ReadPassword)
 	}
 	if len(p) == 0 {
 		tlog.Fatal.Println("extpass: password is empty")
-		os.Exit(exitCode)
+		os.Exit(exitcodes.ReadPassword)
 	}
 	return p
 }
@@ -130,7 +130,7 @@ func readLineUnbuffered(r io.Reader) (l string) {
 	for {
 		if len(l) > maxPasswordLen {
 			tlog.Fatal.Printf("fatal: maximum password length of %d bytes exceeded", maxPasswordLen)
-			os.Exit(exitCode)
+			os.Exit(exitcodes.ReadPassword)
 		}
 		n, err := r.Read(b)
 		if err == io.EOF {
@@ -138,7 +138,7 @@ func readLineUnbuffered(r io.Reader) (l string) {
 		}
 		if err != nil {
 			tlog.Fatal.Printf("readLineUnbuffered: %v", err)
-			os.Exit(exitCode)
+			os.Exit(exitcodes.ReadPassword)
 		}
 		if n == 0 {
 			continue
@@ -170,7 +170,7 @@ func CheckTrailingGarbage() {
 		n, _ := os.Stdin.Read(b)
 		if n > 0 {
 			tlog.Fatal.Printf("Received trailing garbage after the password")
-			os.Exit(exitCode)
+			os.Exit(exitcodes.ReadPassword)
 		}
 	}()
 	// Wait for the goroutine to start up plus one millisecond for the read to
diff --git a/internal/stupidgcm/without_openssl.go b/internal/stupidgcm/without_openssl.go
index 1c6ebcf..efd37f3 100644
--- a/internal/stupidgcm/without_openssl.go
+++ b/internal/stupidgcm/without_openssl.go
@@ -5,6 +5,8 @@ package stupidgcm
 import (
 	"fmt"
 	"os"
+
+	"github.com/rfjakob/gocryptfs/internal/exitcodes"
 )
 
 type stupidGCM struct{}
@@ -16,7 +18,7 @@ const (
 
 func errExit() {
 	fmt.Fprintln(os.Stderr, "gocryptfs has been compiled without openssl support but you are still trying to use openssl")
-	os.Exit(2)
+	os.Exit(exitcodes.OpenSSL)
 }
 
 func New(_ []byte, _ bool) stupidGCM {