The Great Renaming: hkexsh -> xs (Xperimental Shell)

Signed-off-by: Russ Magee <rmagee@gmail.com>

xspasswd/Makefile

@@ -0,0 +1,16 @@
+.PHONY: clean all vis lint
+
+EXTPKGS = bytes,errors,flag,fmt,internal,io,log,net,os,path,runtime,time,strings,sync,syscall,binary,encoding
+EXE = $(notdir $(shell pwd))
+
+all:
+	go build $(BUILDOPTS) .
+
+clean:
+	$(RM) $(EXE) $(EXE).exe
+
+vis:
+	go-callvis -format png -file xspasswd-vis -ignore $(EXTPKGS) -group pkg,type .
+
+lint:
+	-gometalinter --deadline=60s | sort

xspasswd/xspasswd.go

@@ -0,0 +1,160 @@
+// Util to generate/store passwords for users in a file akin to /etc/passwd
+// suitable for the demo hkexsh server, using bcrypt.
+//
+// Copyright (c) 2017-2019 Russell Magee
+// Licensed under the terms of the MIT license (see LICENSE.mit in this
+// distribution)
+//
+// golang implementation by Russ Magee (rmagee_at_gmail.com)
+package main
+
+import (
+	"bytes"
+	"encoding/csv"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+
+	hkexsh "blitter.com/go/hkexsh"
+	"github.com/jameskeane/bcrypt"
+)
+
+var (
+	version   string
+	gitCommit string
+)
+
+// nolint: gocyclo
+func main() {
+	var vopt bool
+	var pfName string
+	var newpw string
+	var confirmpw string
+	var userName string
+
+	flag.BoolVar(&vopt, "v", false, "show version")
+	flag.StringVar(&userName, "u", "", "username")
+	flag.StringVar(&pfName, "f", "/etc/xs.passwd", "passwd file")
+	flag.Parse()
+
+	if vopt {
+		fmt.Printf("version %s (%s)\n", version, gitCommit)
+		os.Exit(0)
+	}
+
+	var uname string
+	if len(userName) == 0 {
+		log.Println("specify username with -u")
+		os.Exit(1)
+	}
+
+	//u, err := user.Lookup(userName)
+	//if err != nil {
+	//	log.Printf("Invalid user %s\n", userName)
+	//	log.Fatal(err)
+	//}
+	//uname = u.Username
+	uname = userName
+
+	fmt.Printf("New Password:")
+	ab, err := hkexsh.ReadPassword(int(os.Stdin.Fd()))
+	fmt.Printf("\r\n")
+	if err != nil {
+		log.Fatal(err)
+		os.Exit(1)
+	}
+	newpw = string(ab)
+
+	fmt.Printf("Confirm:")
+	ab, err = hkexsh.ReadPassword(int(os.Stdin.Fd()))
+	fmt.Printf("\r\n")
+	if err != nil {
+		log.Fatal(err)
+		os.Exit(1)
+	}
+	confirmpw = string(ab)
+
+	if confirmpw != newpw {
+		log.Println("New passwords do not match.")
+		os.Exit(1)
+	}
+
+	// generate a random salt with specific rounds of complexity
+	// (default in jameskeane/bcrypt is 12 but we'll be explicit here)
+	salt, err := bcrypt.Salt(12)
+	if err != nil {
+		fmt.Println("ERROR: bcrypt.Salt() failed.")
+		os.Exit(2)
+	}
+
+	// hash and verify a password with explicit (random) salt
+	hash, err := bcrypt.Hash(newpw, salt)
+	if err != nil || !bcrypt.Match(newpw, hash) {
+		fmt.Println("ERROR: bcrypt.Match() failed.")
+		log.Fatal(err)
+	}
+	//fmt.Println("Salt:", salt, "Hash:", hash)
+
+	b, err := ioutil.ReadFile(pfName) // nolint: gosec
+	if err != nil {
+		log.Fatal(err)
+	}
+	r := csv.NewReader(bytes.NewReader(b))
+
+	r.Comma = ':'
+	r.Comment = '#'
+	r.FieldsPerRecord = 3 // username:salt:authCookie [TODO:disallowedCmdList (a,b,...)]
+
+	records, err := r.ReadAll()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	recFound := false
+	for i := range records {
+		//fmt.Println(records[i])
+		if records[i][0] == uname {
+			recFound = true
+			records[i][1] = salt
+			records[i][2] = hash
+		}
+		//// csv lib doesn't preserve comment in record, so put it back
+		//if records[i][0][0] == '!' {
+		//	records[i][0] = "#" + records[i][0]
+		//}
+	}
+	if !recFound {
+		newRec := []string{uname, salt, hash}
+		records = append(records, newRec)
+	}
+
+	outFile, err := ioutil.TempFile("", "xs-passwd")
+	if err != nil {
+		log.Fatal(err)
+	}
+	w := csv.NewWriter(outFile)
+	w.Comma = ':'
+	//w.FieldsPerRecord = 4 // username:salt:authCookie:disallowedCmdList (a,b,...)
+	err = w.Write([]string{"#username", "salt", "authCookie" /*, "disallowedCmdList"*/})
+	if err != nil {
+		log.Fatal(err)
+	}
+	err = w.WriteAll(records)
+	if err != nil {
+		log.Fatal(err)
+	}
+	if err = w.Error(); err != nil {
+		log.Fatal(err)
+	}
+
+	err = os.Remove(pfName)
+	if err != nil {
+		log.Fatal(err)
+	}
+	err = os.Rename(outFile.Name(), pfName)
+	if err != nil {
+		log.Fatal(err)
+	}
+}