package handlers import ( "crypto/sha256" "encoding/json" "errors" "fmt" "gopkg.in/gorp.v1" "io" "log" "net/http" "strings" ) type User struct { UserId int64 DefaultCurrency int64 // SecurityId of default currency, or ISO4217 code for it if creating new user Name string Username string Password string `db:"-"` PasswordHash string `json:"-"` Email string } const BogusPassword = "password" type UserExistsError struct{} func (ueu UserExistsError) Error() string { return "User exists" } func (u *User) Write(w http.ResponseWriter) error { enc := json.NewEncoder(w) return enc.Encode(u) } func (u *User) Read(json_str string) error { dec := json.NewDecoder(strings.NewReader(json_str)) return dec.Decode(u) } func (u *User) HashPassword() { password_hasher := sha256.New() io.WriteString(password_hasher, u.Password) u.PasswordHash = fmt.Sprintf("%x", password_hasher.Sum(nil)) u.Password = "" } func GetUser(db *DB, userid int64) (*User, error) { var u User err := db.SelectOne(&u, "SELECT * from users where UserId=?", userid) if err != nil { return nil, err } return &u, nil } func GetUserTx(transaction *gorp.Transaction, userid int64) (*User, error) { var u User err := transaction.SelectOne(&u, "SELECT * from users where UserId=?", userid) if err != nil { return nil, err } return &u, nil } func GetUserByUsername(db *DB, username string) (*User, error) { var u User err := db.SelectOne(&u, "SELECT * from users where Username=?", username) if err != nil { return nil, err } return &u, nil } func InsertUser(db *DB, u *User) error { transaction, err := db.Begin() if err != nil { return err } security_template := FindCurrencyTemplate(u.DefaultCurrency) if security_template == nil { transaction.Rollback() return errors.New("Invalid ISO4217 Default Currency") } existing, err := transaction.SelectInt("SELECT count(*) from users where Username=?", u.Username) if err != nil { transaction.Rollback() return err } if existing > 0 { transaction.Rollback() return UserExistsError{} } err = transaction.Insert(u) if err != nil { transaction.Rollback() return err } // Copy the security template and give it our new UserId var security Security security = *security_template security.UserId = u.UserId err = InsertSecurityTx(transaction, &security) if err != nil { transaction.Rollback() return err } // Update the user's DefaultCurrency to our new SecurityId u.DefaultCurrency = security.SecurityId count, err := transaction.Update(u) if err != nil { transaction.Rollback() return err } else if count != 1 { transaction.Rollback() return errors.New("Would have updated more than one user") } err = transaction.Commit() if err != nil { transaction.Rollback() return err } return nil } func GetUserFromSession(db *DB, r *http.Request) (*User, error) { s, err := GetSession(db, r) if err != nil { return nil, err } return GetUser(db, s.UserId) } func UpdateUser(db *DB, u *User) error { transaction, err := db.Begin() if err != nil { return err } security, err := GetSecurityTx(transaction, u.DefaultCurrency, u.UserId) if err != nil { transaction.Rollback() return err } else if security.UserId != u.UserId || security.SecurityId != u.DefaultCurrency { transaction.Rollback() return errors.New("UserId and DefaultCurrency don't match the fetched security") } else if security.Type != Currency { transaction.Rollback() return errors.New("New DefaultCurrency security is not a currency") } count, err := transaction.Update(u) if err != nil { transaction.Rollback() return err } else if count != 1 { transaction.Rollback() return errors.New("Would have updated more than one user") } err = transaction.Commit() if err != nil { transaction.Rollback() return err } return nil } func UserHandler(w http.ResponseWriter, r *http.Request, db *DB) { if r.Method == "POST" { user_json := r.PostFormValue("user") if user_json == "" { WriteError(w, 3 /*Invalid Request*/) return } var user User err := user.Read(user_json) if err != nil { WriteError(w, 3 /*Invalid Request*/) return } user.UserId = -1 user.HashPassword() err = InsertUser(db, &user) if err != nil { if _, ok := err.(UserExistsError); ok { WriteError(w, 4 /*User Exists*/) } else { WriteError(w, 999 /*Internal Error*/) log.Print(err) } return } w.WriteHeader(201 /*Created*/) err = user.Write(w) if err != nil { WriteError(w, 999 /*Internal Error*/) log.Print(err) return } } else { user, err := GetUserFromSession(db, r) if err != nil { WriteError(w, 1 /*Not Signed In*/) return } userid, err := GetURLID(r.URL.Path) if err != nil { WriteError(w, 3 /*Invalid Request*/) return } if userid != user.UserId { WriteError(w, 2 /*Unauthorized Access*/) return } if r.Method == "GET" { err = user.Write(w) if err != nil { WriteError(w, 999 /*Internal Error*/) log.Print(err) return } } else if r.Method == "PUT" { user_json := r.PostFormValue("user") if user_json == "" { WriteError(w, 3 /*Invalid Request*/) return } // Save old PWHash in case the new password is bogus old_pwhash := user.PasswordHash err = user.Read(user_json) if err != nil || user.UserId != userid { WriteError(w, 3 /*Invalid Request*/) return } // If the user didn't create a new password, keep their old one if user.Password != BogusPassword { user.HashPassword() } else { user.Password = "" user.PasswordHash = old_pwhash } err = UpdateUser(db, user) if err != nil { WriteError(w, 999 /*Internal Error*/) log.Print(err) return } err = user.Write(w) if err != nil { WriteError(w, 999 /*Internal Error*/) log.Print(err) return } } else if r.Method == "DELETE" { count, err := db.Delete(user) if count != 1 || err != nil { WriteError(w, 999 /*Internal Error*/) log.Print(err) return } WriteSuccess(w) } } }