implement hex/raw input

cmd/age-passgen/main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/hex"
 	"errors"
 	"flag"
 	"fmt"
@@ -10,6 +11,7 @@ import (
 	"os/signal"
 	"slices"
 	"strconv"
+	"strings"
 	"syscall"
 	"time"
 	"unsafe"
@@ -33,6 +35,7 @@ Options:
     -o, --output OUTPUT       Write the result to the file at path OUTPUT.
     --raw-output              Print stripped keys (without additional text or comments)
     --entropy-level VALUE     Manages required strenght of password (more info down below)
+    --input-type TYPE         Type of input from stdin. Can be 'password' (default), 'hash', 'raw'
 
 Mostly similar to age-keygen
 Required password strenght can be changes via --entropy-level flag. Possible values
@@ -46,10 +49,19 @@ Each word or number is mapped following this list:
 - stupid         - no limit
 `
 
+type InputType int
+
+const (
+	InputPassword InputType = iota
+	InputHash
+	InputRaw
+)
+
 type Flags struct {
 	RawOutput    bool
 	OutputFile   string
 	EntropyLevel int
+	InputType    InputType
 }
 
 func main() {
@@ -59,18 +71,27 @@ func main() {
 		errorf("error while parsing arguments: %s\n", err)
 	}
 
-	passbytes, err := getPasswordBytes()
-	if err != nil {
-		errorf("Failed to get password, error: %s\n", err)
-	}
-	valid := isEntropyValid(passbytes, flags.EntropyLevel)
-	if !valid {
-		errorf("You should choose stroger password!!! (or change entropy level, read more with --help)\n")
+	var secretKey [curve25519.ScalarSize]byte
+	if flags.InputType == InputPassword {
+		secretKey, err = getInputPassword(flags.EntropyLevel)
+		if err != nil {
+			errorf("Failed to get password, error: %s\n", err)
+		}
+	} else if flags.InputType == InputHash {
+		secretKey, err = getInputHash()
+		if err != nil {
+			errorf("Failed to read hash, error: %s\n", err)
+		}
+	} else if flags.InputType == InputRaw {
+		secretKey, err = getInputRaw()
+		if err != nil {
+			errorf("Failed to read raw data, error: %s\n", err)
+		}
+	} else {
+		errorf("No such input type implemented!!!")
 	}
 
-	sum := sha256.Sum256(passbytes)
-
-	k, err := newX25519IdentityFromScalar(sum[:])
+	k, err := newX25519IdentityFromScalar(secretKey[:])
 	if err != nil {
 		errorf("internal error: %v", err)
 	}
@@ -100,6 +121,57 @@ func main() {
 	}
 }
 
+func getInputPassword(entropyLevel int) ([curve25519.ScalarSize]byte, error) {
+	passbytes, err := getPasswordBytes()
+	if err != nil {
+		return [curve25519.ScalarSize]byte{}, err
+	}
+	valid := isEntropyValid(passbytes, entropyLevel)
+	if !valid {
+		return [curve25519.ScalarSize]byte{}, errors.New("You should choose stroger password!!! (or change entropy level, read more with --help)\n")
+	}
+
+	return sha256.Sum256(passbytes), nil
+}
+
+func getInputHash() ([curve25519.ScalarSize]byte, error) {
+	hashStringBytes, err := getPasswordBytes()
+	if err != nil {
+		return [curve25519.ScalarSize]byte{}, err
+	}
+	hashString := strings.TrimSpace(string(hashStringBytes))
+	passbytes, err := hex.DecodeString(hashString)
+	if err != nil {
+		fmt.Printf("HEXSTR:%s|\n", hashString)
+		return [curve25519.ScalarSize]byte{}, errors.New(fmt.Sprintf("Unable to decode hash, error: %s\n", err))
+	}
+	if len(passbytes) != curve25519.ScalarSize {
+		return [curve25519.ScalarSize]byte{}, errors.New(fmt.Sprintf("Wrong input lenght of sha256 hash! (may be it is not a hash at all) Expected %d bytes, got: %d\n", curve25519.ScalarSize, len(passbytes)))
+	}
+
+	// making `possibly` stack allocated out of the one in heap
+	var key [curve25519.ScalarSize]byte
+	copy(key[:], passbytes)
+
+	return key, nil
+}
+
+func getInputRaw() ([curve25519.ScalarSize]byte, error) {
+	passbytes, err := getPasswordBytes()
+	if err != nil {
+		return [curve25519.ScalarSize]byte{}, err
+	}
+	if len(passbytes) != curve25519.ScalarSize {
+		return [curve25519.ScalarSize]byte{}, errors.New(fmt.Sprintf("Wrong amount of entered data! Expected %d bytes, got: %d\n", curve25519.ScalarSize, len(passbytes)))
+	}
+
+	// making `possibly` stack allocated out of the one in heap
+	var key [curve25519.ScalarSize]byte
+	copy(key[:], passbytes)
+
+	return key, nil
+}
+
 func setSystemSignalHandlers() {
 	go handleSigpipe()
 }
@@ -123,12 +195,14 @@ func parseFlags() (*Flags, error) {
 		rawOutput    bool
 		outputFile   string
 		entropyLevel string
+		inputType    string
 	)
 
 	flag.BoolVar(&rawOutput, "raw-output", false, "Print stripped keys (without additional text or comments)")
 	flag.StringVar(&outputFile, "o", "", "Write the result to the file at path OUTPUT")
 	flag.StringVar(&outputFile, "output", "", "Write the result to the file at path OUTPUT")
 	flag.StringVar(&entropyLevel, "entropy-level", "medium", "Manages required strenght of password. Read more in --help")
+	flag.StringVar(&inputType, "input-type", "password", "Type of input from stdin. Can be 'password' (default), 'hash', 'raw'")
 	flag.Parse()
 
 	eLevel, err := parseEntropyLevel(entropyLevel)
@@ -136,13 +210,34 @@ func parseFlags() (*Flags, error) {
 		return nil, err
 	}
 
+	iType, err := parseInputType(inputType)
+	if err != nil {
+		return nil, err
+	}
+
 	return &Flags{
 		RawOutput:    rawOutput,
 		OutputFile:   outputFile,
 		EntropyLevel: eLevel,
+		InputType:    iType,
 	}, nil
 }
 
+func parseInputType(inputType string) (InputType, error) {
+	m := map[string]InputType{
+		"password": InputPassword,
+		"hash":     InputHash,
+		"raw":      InputRaw,
+	}
+
+	iType, ok := m[inputType]
+	if !ok {
+		return InputPassword, errors.New("wrong input type")
+	}
+
+	return iType, nil
+}
+
 func parseEntropyLevel(entropyLevel string) (int, error) {
 	if i, err := strconv.Atoi(entropyLevel); err == nil {
 		if i == 0 {