User Registration and Login Template using Golang, MongoDB and JWT

type User struct{ FirstName string `json:"firstname" bson:"firstname"` LastName string `json:"lastname" bson:"lastname"` Email string `json:"email" bson:"email"` Password string `json:"password" bson:"password"` } 

func userSignup(response http.ResponseWriter, request *http.Request{ response.Header().Set("Content-Type","application/json") var user User json.NewDecoder(request.Body).Decode(&user) user.Password = getHash([]byte(user.Password)) collection := client.Database("GODB").Collection("user") ctx,_ := context.WithTimeout(context.Background(), 10*time.Second) result,err := collection.InsertOne(ctx,user) if err!=nil{ response.WriteHeader(http.StatusInternalServerError) response.Write([]byte(`{"message":"`+err.Error()+`"}`)) return } json.NewEncoder(response).Encode(result) } 

func getHash(pwd []byte) string { hash, err := bcrypt.GenerateFromPassword(pwd, bcrypt.MinCost) if err != nil { log.Println(err) } return string(hash) } 

func userLogin(response http.ResponseWriter, request *http.Request){ response.Header().Set("Content-Type","application/json") var user User var dbUser User json.NewDecoder(request.Body).Decode(&user) collection:= client.Database("GODB").Collection("user") ctx,_ :=context.WithTimeout(context.Background(),10*time.Second) err:=collection.FindOne(ctx,bson.M{"email":user.Email}).Decode(&dbUser) if err!=nil{ response.WriteHeader(http.StatusInternalServerError) response.Write([]byte(`{"message":"`+err.Error()+`"}`)) return } userPass:= []byte(user.Password) dbPass:= []byte(dbUser.Password) passErr:= bcrypt.CompareHashAndPassword(dbPass, userPass) if passErr != nil{ log.Println(passErr) response.Write([]byte(`{"response":"Wrong Password!"}`)) return } jwtToken, err := GenerateJWT() if err != nil{ response.WriteHeader(http.StatusInternalServerError) response.Write([]byte(`{"message":"`+err.Error()+`"}`)) return } response.Write([]byte(`{"token":"`+jwtToken+`"}`)) } 

package main import ( "context" "time" "log" "net/http" "github.com/gorilla/mux" "encoding/json" "go.mongodb.org/mongo-driver/mongo" "go.mongodb.org/mongo-driver/mongo/options" "go.mongodb.org/mongo-driver/bson" "golang.org/x/crypto/bcrypt" "github.com/dgrijalva/jwt-go" ) var SECRET_KEY = []byte("gosecretkey") type User struct{ FirstName string `json:"firstname" bson:"firstname"` LastName string `json:"lastname" bson:"lastname"` Email string `json:"email" bson:"email"` Password string `json:"password" bson:"password"` } var client *mongo.Client func getHash(pwd []byte) string { hash, err := bcrypt.GenerateFromPassword(pwd, bcrypt.MinCost) if err != nil { log.Println(err) } return string(hash) } func GenerateJWT()(string,error){ token:= jwt.New(jwt.SigningMethodHS256) tokenString, err := token.SignedString(SECRET_KEY) if err !=nil{ log.Println("Error in JWT token generation") return "",err } return tokenString, nil } func userSignup(response http.ResponseWriter, request *http.Request){ response.Header().Set("Content-Type","application/json") var user User json.NewDecoder(request.Body).Decode(&user) user.Password = getHash([]byte(user.Password)) collection := client.Database("GODB").Collection("user") ctx,_ := context.WithTimeout(context.Background(), 10*time.Second) result,_ := collection.InsertOne(ctx,user) json.NewEncoder(response).Encode(result) } func userLogin(response http.ResponseWriter, request *http.Request){ response.Header().Set("Content-Type","application/json") var user User var dbUser User json.NewDecoder(request.Body).Decode(&user) collection:= client.Database("GODB").Collection("user") ctx,_ := context.WithTimeout(context.Background(),10*time.Second) err:= collection.FindOne(ctx, bson.M{"email":user.Email}).Decode(&dbUser) if err!=nil{ response.WriteHeader(http.StatusInternalServerError) response.Write([]byte(`{"message":"`+err.Error()+`"}`)) return } userPass:= []byte(user.Password) dbPass:= []byte(dbUser.Password) passErr:= bcrypt.CompareHashAndPassword(dbPass, userPass) if passErr != nil{ log.Println(passErr) response.Write([]byte(`{"response":"Wrong Password!"}`)) return } jwtToken, err := GenerateJWT() if err != nil{ response.WriteHeader(http.StatusInternalServerError) response.Write([]byte(`{"message":"`+err.Error()+`"}`)) return } response.Write([]byte(`{"token":"`+jwtToken+`"}`)) } func main(){ log.Println("Starting the application") router:= mux.NewRouter() ctx,_ := context.WithTimeout(context.Background(), 10*time.Second) client,_= mongo.Connect(ctx,options.Client().ApplyURI("mongodb://localhost:27017")) router.HandleFunc("/api/user/login",userLogin).Methods("POST") router.HandleFunc("/api/user/signup",userSignup).Methods("POST") log.Fatal(http.ListenAndServe(":8080", router)) }