allowances/db.go

package main

import (
	"golang.org/x/crypto/bcrypt"
	"encoding/json"
	"io/ioutil"
	"log"
	"sync"
)

var dbMutex = sync.RWMutex{}

func get_passes(filename string) (cur_passes []string, err error) {
	b, err := ioutil.ReadFile(filename)
	if err != nil {
		log.Fatal(err)
	}
	err = json.Unmarshal(b, &cur_passes)
	if err != nil {
		log.Fatal(err)
	}
	return
}

func add_password(filename, new_pw string) (err error) {
	cur_passes, err := get_passes(filename)
	if err != nil {
		log.Fatal(err)
	}
	hpass, err := bcrypt.GenerateFromPassword(
		[]byte(*add_pw), bcrypt.DefaultCost)
	cur_passes = append(cur_passes, string(hpass))
	b, err := json.Marshal(cur_passes)
	err = ioutil.WriteFile(filename, b, 0644)
	if err != nil {
		log.Fatal(err)
	}
	return
}

func check_password(filename, attempt string) (result bool) {
	hashes, err := get_passes(filename)
	if err != nil {
		log.Fatal(err)
	}
	for _, hash := range hashes {
		err := bcrypt.CompareHashAndPassword([]byte(hash), []byte(attempt))
		if err == nil {
			result = true
			return
		}
	}
	return
}

func loadChildren(filename string) (children map[string]int) {
	dbMutex.RLock()
	defer dbMutex.RUnlock()
	b, err := ioutil.ReadFile(filename)
	if err != nil {
		log.Fatal(err)
	}
	err = json.Unmarshal(b, &children)
	if err != nil {
		log.Fatal(err)
	}
	return
}

func dumpChildren(filename string, children map[string]int) {
	dbMutex.Lock()
	defer dbMutex.Unlock()
    b, err := json.Marshal(children)
	err = ioutil.WriteFile(filename, b, 0644)
	if err != nil {
		log.Fatal("serious issue writing children db file", err)
	}
	return
}