core/crypt/crypt.go

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package crypt
import (
"crypto/cipher"
"crypto/rand"
"log"
"golang.org/x/crypto/chacha20poly1305"
)
type Crypt struct {
key []byte
ads []byte
aead cipher.AEAD
}
func NewChacha20poly1305Key() []byte {
k := make([]byte, chacha20poly1305.KeySize)
if _, err := rand.Read(k); err != nil {
panic(err)
}
return k
}
func NewCrypt(key []byte, ads []byte) *Crypt {
if len(key) == 0 {
// log.Printf(" == GENERATE NEW KEY ==\n")
key = NewChacha20poly1305Key()
}
aead, err := chacha20poly1305.New(key)
if err != nil {
panic(err)
}
return &Crypt{key: key, ads: ads, aead: aead}
}
func (c *Crypt) GenNonce(length int) []byte {
nonce := make([]byte, c.aead.NonceSize(), c.aead.NonceSize()+length+c.aead.Overhead())
if _, err := rand.Read(nonce); err != nil {
panic(err)
}
return nonce
}
func (c *Crypt) Encrypt(msg []byte) []byte {
nonce := c.GenNonce(len(msg))
encryptedMsg := c.aead.Seal(nonce, nonce, msg, c.ads)
return encryptedMsg
}
func (c *Crypt) Decrypt(encrypted []byte) ([]byte, bool) {
done := true
nonce, ciphertext := encrypted[:c.aead.NonceSize()], encrypted[c.aead.NonceSize():]
plaintext, err := c.aead.Open(nil, nonce, ciphertext, c.ads)
if err != nil {
done = false
log.Printf(" error decrypt data : %v\n", err)
}
return plaintext, done
}