fastpastebin/internal/structs/paste.go

141 lines
4.6 KiB
Go

// Fast Paste Bin - uberfast and easy-to-use pastebin.
//
// Copyright (c) 2018, Stanislav N. aka pztrn and Fast Paste Bin
// developers.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject
// to the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
// OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
package structs
import (
// stdlib
"crypto/sha256"
"fmt"
"math/rand"
"time"
// other
"golang.org/x/crypto/scrypt"
)
const (
PasteKeepForever = 0
PasteKeepForMinutes = 1
PasteKeepForHours = 2
PasteKeepForDays = 3
PasteKeepForMonths = 4
charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
)
var PasteKeepsCorrelation = map[string]int{
"M": PasteKeepForMinutes,
"h": PasteKeepForHours,
"d": PasteKeepForDays,
"m": PasteKeepForMonths,
"forever": PasteKeepForever,
}
// Paste represents paste itself.
type Paste struct {
CreatedAt *time.Time `db:"created_at" json:"created_at"`
Title string `db:"title" json:"title"`
Data string `db:"data" json:"data"`
Language string `db:"language" json:"language"`
Password string `db:"password" json:"password"`
PasswordSalt string `db:"password_salt" json:"password_salt"`
ID int `db:"id" json:"id"`
KeepFor int `db:"keep_for" json:"keep_for"`
KeepForUnitType int `db:"keep_for_unit_type" json:"keep_for_unit_type"`
Private bool `db:"private" json:"private"`
}
// CreatePassword creates password for current paste.
func (p *Paste) CreatePassword(password string) error {
// Create salt - random string.
seededRand := rand.New(rand.NewSource(time.Now().UnixNano()))
saltBytes := make([]byte, 64)
for i := range saltBytes {
saltBytes[i] = charset[seededRand.Intn(len(charset))]
}
saltHashBytes := sha256.Sum256(saltBytes)
p.PasswordSalt = fmt.Sprintf("%x", saltHashBytes)
// Create crypted password and hash it.
passwordCrypted, err := scrypt.Key([]byte(password), []byte(p.PasswordSalt), 131072, 8, 1, 64)
if err != nil {
return err
}
passwordHashBytes := sha256.Sum256(passwordCrypted)
p.Password = fmt.Sprintf("%x", passwordHashBytes)
return nil
}
// GenerateCryptedCookieValue generates crypted cookie value for paste.
func (p *Paste) GenerateCryptedCookieValue() string {
cookieValueCrypted, _ := scrypt.Key([]byte(p.Password), []byte(p.PasswordSalt), 131072, 8, 1, 64)
return fmt.Sprintf("%x", sha256.Sum256(cookieValueCrypted))
}
func (p *Paste) GetExpirationTime() time.Time {
var expirationTime time.Time
switch p.KeepForUnitType {
case PasteKeepForever:
expirationTime = time.Now().UTC().Add(time.Hour * 1)
case PasteKeepForMinutes:
expirationTime = p.CreatedAt.Add(time.Minute * time.Duration(p.KeepFor))
case PasteKeepForHours:
expirationTime = p.CreatedAt.Add(time.Hour * time.Duration(p.KeepFor))
case PasteKeepForDays:
expirationTime = p.CreatedAt.Add(time.Hour * 24 * time.Duration(p.KeepFor))
case PasteKeepForMonths:
expirationTime = p.CreatedAt.Add(time.Hour * 24 * 30 * time.Duration(p.KeepFor))
}
return expirationTime
}
// IsExpired checks if paste is already expired (or not).
func (p *Paste) IsExpired() bool {
curTime := time.Now().UTC()
expirationTime := p.GetExpirationTime()
return curTime.Sub(expirationTime).Seconds() > 0
}
// VerifyPassword verifies that provided password is valid.
func (p *Paste) VerifyPassword(password string) bool {
// Create crypted password and hash it.
passwordCrypted, err := scrypt.Key([]byte(password), []byte(p.PasswordSalt), 131072, 8, 1, 64)
if err != nil {
return false
}
passwordHashBytes := sha256.Sum256(passwordCrypted)
providedPassword := fmt.Sprintf("%x", passwordHashBytes)
return providedPassword == p.Password
}