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package cache
import (
"errors"
"github.com/jackyzha0/ctrl-v/security"
"sync"
"github.com/jackyzha0/ctrl-v/db"
)
type Cache struct {
m map[string]db.Paste
lock sync.RWMutex
}
var C *Cache
var PasteNotFound = errors.New("could not find a paste with that hash")
var UserUnauthorized = errors.New("paste is password protected")
func init() {
C = &Cache{
m: map[string]db.Paste{},
}
}
func (c *Cache) Get(hash, userPassword string) (db.Paste, error) {
c.lock.RLock()
// check if hash in cache
p, ok := c.m[hash]
c.lock.RUnlock()
// if it doesnt, lookup from db
if !ok {
var err error
p, err = db.Lookup(hash)
if err != nil {
return db.Paste{}, PasteNotFound
}
c.add(p)
}
// if there is a password, check the provided one against it
if p.Password != "" {
// if passwords do not match, the user is unauthorized
if !security.PasswordsEqual(p.Password, userPassword) {
return db.Paste{}, UserUnauthorized
}
// if password matches, decrypt content
key, _, err := security.DeriveKey(userPassword, p.Salt)
if err != nil {
return db.Paste{}, security.EncryptionError
}
decryptedContent, err := security.Decrypt(key, p.Content)
if err != nil {
return db.Paste{}, security.EncryptionError
}
p.Content = decryptedContent
}
return p, nil
}
func (c *Cache) add(p db.Paste) {
c.lock.Lock()
defer c.lock.Unlock()
c.m[p.Hash] = p
}
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