error handling in the apis and basic functionality prepared

book.html

                            </div>
                            <div class="form-group">
                                <div class="col-xs-offset-3 col-xs-6">
                                    <button type="submit" class="btn btn-default">Update Passphrase</button>
                                    <button name="cmd" value="update" type="submit" class="btn btn-default">Update Passphrase</button>
                                </div>
                                <div class="col-xs-3 text-right">
                                    <button type="submit" value="delete" class="btn btn-danger">Delete Profile</button>
                                    <button name="cmd" value="delete" type="submit" class="btn btn-danger">Delete Profile</button>
                                </div>
                            </div>
                        </form>

main.go

import (
	"bytes"
	"compress/gzip"
	"crypto/sha1"
	"crypto/md5"
	"crypto/sha512"
	"encoding/json"
	"fmt"
func main() {
	http.HandleFunc("/api/generate", func(w http.ResponseWriter, r *http.Request) {
		profile := r.FormValue("profile")
		//passphrase := r.FormValue("p")
		passphrase := r.FormValue("p")
		host := r.FormValue("host")
		minimumLength, _ := strconv.Atoi(r.FormValue("minimumLength"))
		maximumLength, _ := strconv.Atoi(r.FormValue("maximumLength"))
		minimumSpecialCharacters, _ := strconv.Atoi(r.FormValue("minimumSpecialCharacters"))
		specialCharacters := r.FormValue("specialCharacters")
		if profile == "" || passphrase == "" || host == "" {
			http.Error(w, "Missing credentials", http.StatusUnauthorized)
			return
		}
		site := Site{
			Host:                      host,
			MinimumLength:             minimumLength,
		}
		book := getBookname(profile)
		sites, err := Read(book)
		sites, err := Read(book, passphrase)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		sites = append(sites, site)
		err = Save(book, sites)
		err = Save(book, passphrase, sites)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
	})
	http.HandleFunc("/api/update", func(w http.ResponseWriter, r *http.Request) {
		profile := r.FormValue("profile")
		//passphrase := r.FormValue("p")
		//newPassphrase := r.FormValue("newPassphrase")
		//confirmPassphrase := r.FormValue("confirmPassphrase")
		passphrase := r.FormValue("p")
		newPassphrase := r.FormValue("newPassphrase")
		confirmPassphrase := r.FormValue("confirmPassphrase")
		cmd := r.FormValue("cmd")
		if profile == "" || passphrase == "" || newPassphrase == "" || confirmPassphrase == "" || cmd == "" {
			http.Error(w, "Missing credentials", http.StatusUnauthorized)
			return
		}
		book := getBookname(profile)
		err := os.Remove(book)
		if err != nil {
			// Return an error
		if cmd == "delete" {
			err := os.Remove(book)
			if err != nil {
				// Return an error
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
		} else if cmd == "update" {
			if newPassphrase != confirmPassphrase {
			}
			sites, err := Read(book, passphrase)
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
			err = Save(book, newPassphrase, sites)
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
		}
	})
	http.HandleFunc("/api/refresh", func(w http.ResponseWriter, r *http.Request) {
		profile := r.FormValue("profile")
		//passphrase := r.FormValue("p")
		passphrase := r.FormValue("p")
		host := r.FormValue("host")
		if profile == "" || passphrase == "" || host == "" {
			http.Error(w, "Missing credentials", http.StatusUnauthorized)
			return
		}
		// Update the revision number and generate a new password
		book := getBookname(profile)
		sites, err := Read(book)
		sites, err := Read(book, passphrase)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		for _, site := range sites {
			if site.Host == host {
				break
			}
		}
		err = Save(book, sites)
		err = Save(book, passphrase, sites)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
	})
	http.HandleFunc("/api/remove", func(w http.ResponseWriter, r *http.Request) {
		profile := r.FormValue("profile")
		//passphrase := r.FormValue("p")
		passphrase := r.FormValue("p")
		host := r.FormValue("host")
		if profile == "" || passphrase == "" || host == "host" {
			http.Error(w, "Missing credentials", http.StatusUnauthorized)
			return
		}
		// Remove the site from our book and save it
		book := getBookname(profile)
		sites, err := Read(book)
		sites, err := Read(book, passphrase)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		for i, site := range sites {
			if site.Host == host {
				break
			}
		}
		err = Save(book, passphrase, sites)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
	})
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
	//}
}
func Save(file string, sites []Site) error {
func Save(file, passphrase string, sites []Site) error {
	// If the file doesn't exist then create it
	if _, err := os.Stat(file); os.IsNotExist(err) {
		_, err = os.Create(file)
}
// Read the password book
func Read(file string) ([]Site, error) {
func Read(file, passphrase string) ([]Site, error) {
	// If the file doesn't exist yet no worries
	if _, err := os.Stat(file); os.IsNotExist(err) {
		return []Site{}, nil
// Get the book name
func getBookname(profile string) string {
	sha := sha1.New()
	sha.Write([]byte(profile))
	return string(sha.Sum(nil))
	hash := md5.New()
	hash.Write([]byte(profile))
	return fmt.Sprintf("%s", string(hash.Sum(nil)))
}
// Encrypt the password book