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cipher.go
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cipher.go
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package p2p
import (
"crypto/aes"
"crypto/cipher"
"crypto/md5"
"crypto/rand"
"crypto/sha256"
"io"
)
type CipherKey []byte
type CryptCipherKey []byte
func NewCipherKey() (key CipherKey, err error) {
bs := make([]byte, 10)
_, err = io.ReadFull(rand.Reader, bs)
if err != nil {
return
}
sha256Sum := sha256.Sum256(bs)
md5Sum := md5.Sum(sha256Sum[:])
key = md5Sum[:]
return
}
func (key CipherKey) Encode(bs []byte) (rs []byte, err error) {
var block cipher.Block
block, err = aes.NewCipher(key)
if err != nil {
return
}
var gcm cipher.AEAD
gcm, err = cipher.NewGCM(block)
if err != nil {
return
}
nonce := make([]byte, gcm.NonceSize())
_, err = io.ReadFull(rand.Reader, nonce)
if err != nil {
return
}
rs = gcm.Seal(nonce, nonce, bs, nil)
return
}
func (key CipherKey) Decode(bs []byte) (rs []byte, err error) {
var block cipher.Block
block, err = aes.NewCipher(key)
if err != nil {
return
}
var gcm cipher.AEAD
gcm, err = cipher.NewGCM(block)
if err != nil {
return
}
nonceSize := gcm.NonceSize()
nonce, cipherText := bs[:nonceSize], bs[nonceSize:]
rs, err = gcm.Open(nil, nonce, cipherText, nil)
return
}