mirror of https://github.com/schollz/croc.git
244 lines
5.9 KiB
Go
244 lines
5.9 KiB
Go
package crypt
|
|
|
|
import (
|
|
"bytes"
|
|
"crypto/aes"
|
|
"crypto/cipher"
|
|
"crypto/rand"
|
|
"crypto/sha256"
|
|
"fmt"
|
|
"io"
|
|
"io/ioutil"
|
|
"log"
|
|
"math/big"
|
|
"strings"
|
|
|
|
"filippo.io/age"
|
|
"golang.org/x/crypto/argon2"
|
|
"golang.org/x/crypto/chacha20poly1305"
|
|
"golang.org/x/crypto/pbkdf2"
|
|
)
|
|
|
|
// New generates a new key based on a passphrase and salt
|
|
func New(passphrase []byte, usersalt []byte) (key []byte, salt []byte, err error) {
|
|
if len(passphrase) < 1 {
|
|
err = fmt.Errorf("need more than that for passphrase")
|
|
return
|
|
}
|
|
if usersalt == nil {
|
|
salt = make([]byte, 8)
|
|
// http://www.ietf.org/rfc/rfc2898.txt
|
|
// Salt.
|
|
if _, err := rand.Read(salt); err != nil {
|
|
log.Fatalf("can't get random salt: %v", err)
|
|
}
|
|
} else {
|
|
salt = usersalt
|
|
}
|
|
key = pbkdf2.Key(passphrase, salt, 100, 32, sha256.New)
|
|
return
|
|
}
|
|
|
|
// Encrypt will encrypt using the pre-generated key
|
|
func Encrypt(plaintext []byte, key []byte) (encrypted []byte, err error) {
|
|
// generate a random iv each time
|
|
// http://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf
|
|
// Section 8.2
|
|
ivBytes := make([]byte, 12)
|
|
if _, err := rand.Read(ivBytes); err != nil {
|
|
log.Fatalf("can't initialize crypto: %v", err)
|
|
}
|
|
b, err := aes.NewCipher(key)
|
|
if err != nil {
|
|
return
|
|
}
|
|
aesgcm, err := cipher.NewGCM(b)
|
|
if err != nil {
|
|
return
|
|
}
|
|
encrypted = aesgcm.Seal(nil, ivBytes, plaintext, nil)
|
|
encrypted = append(ivBytes, encrypted...)
|
|
return
|
|
}
|
|
|
|
// Decrypt using the pre-generated key
|
|
func Decrypt(encrypted []byte, key []byte) (plaintext []byte, err error) {
|
|
if len(encrypted) < 13 {
|
|
err = fmt.Errorf("incorrect passphrase")
|
|
return
|
|
}
|
|
b, err := aes.NewCipher(key)
|
|
if err != nil {
|
|
return
|
|
}
|
|
aesgcm, err := cipher.NewGCM(b)
|
|
if err != nil {
|
|
return
|
|
}
|
|
plaintext, err = aesgcm.Open(nil, encrypted[:12], encrypted[12:], nil)
|
|
return
|
|
}
|
|
|
|
// GenerateIdentityAndPassword will generate a file with a public age identity and password
|
|
func GenerateIdentityAndPassword(fname string) (err error) {
|
|
keyPublic, keyPrivate, err := NewAge()
|
|
if err != nil {
|
|
return
|
|
}
|
|
password, err := GenerateRandomString(6)
|
|
if err != nil {
|
|
return
|
|
}
|
|
err = ioutil.WriteFile(fname, []byte(fmt.Sprintf("%s\n%s\n%s", keyPrivate, keyPublic, password)), 0644)
|
|
return
|
|
}
|
|
|
|
// LoadIdentityAndPassword will load a file with a public age identity and password
|
|
func LoadIdentityAndPassword(fname string) (keyPrivate string, keyPublic string, password string, err error) {
|
|
b, err := ioutil.ReadFile(fname)
|
|
if err != nil {
|
|
return
|
|
}
|
|
foo := strings.Fields(string(b))
|
|
if len(foo) < 3 {
|
|
err = fmt.Errorf("malformed file")
|
|
return
|
|
}
|
|
keyPrivate = foo[0]
|
|
keyPublic = foo[1]
|
|
password = foo[2]
|
|
|
|
_, err = age.ParseX25519Identity(keyPrivate)
|
|
if err != nil {
|
|
return
|
|
}
|
|
_, err = age.ParseX25519Recipient(keyPublic)
|
|
if err != nil {
|
|
return
|
|
}
|
|
return
|
|
}
|
|
|
|
// GenerateRandomString returns a securely generated random string.
|
|
// It will return an error if the system's secure random
|
|
// number generator fails to function correctly, in which
|
|
// case the caller should not continue.
|
|
func GenerateRandomString(n int) (string, error) {
|
|
const letters = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
|
|
ret := make([]byte, n)
|
|
for i := 0; i < n; i++ {
|
|
num, err := rand.Int(rand.Reader, big.NewInt(int64(len(letters))))
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
ret[i] = letters[num.Int64()]
|
|
}
|
|
|
|
return string(ret), nil
|
|
}
|
|
|
|
func NewAge() (pubkey string, privkey string, err error) {
|
|
identity, err := age.GenerateX25519Identity()
|
|
if err != nil {
|
|
return
|
|
}
|
|
pubkey = identity.Recipient().String()
|
|
privkey = identity.String()
|
|
return
|
|
}
|
|
|
|
func EncryptAge(data []byte, pubkey string) (encrypted []byte, err error) {
|
|
recipient, err := age.ParseX25519Recipient(pubkey)
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
out := &bytes.Buffer{}
|
|
w, err := age.Encrypt(out, recipient)
|
|
if err != nil {
|
|
return
|
|
}
|
|
_, err = w.Write(data)
|
|
if err != nil {
|
|
return
|
|
}
|
|
err = w.Close()
|
|
if err != nil {
|
|
return
|
|
}
|
|
encrypted = out.Bytes()
|
|
return
|
|
}
|
|
|
|
func DecryptAge(encrypted []byte, privkey string) (data []byte, err error) {
|
|
identity, err := age.ParseX25519Identity(privkey)
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
r, err := age.Decrypt(bytes.NewReader(encrypted), identity)
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
out := &bytes.Buffer{}
|
|
_, err = io.Copy(out, r)
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
data = out.Bytes()
|
|
return
|
|
}
|
|
|
|
// NewArgon2 generates a new key based on a passphrase and salt
|
|
// using argon2
|
|
// https://pkg.go.dev/golang.org/x/crypto/argon2
|
|
func NewArgon2(passphrase []byte, usersalt []byte) (aead cipher.AEAD, salt []byte, err error) {
|
|
if len(passphrase) < 1 {
|
|
err = fmt.Errorf("need more than that for passphrase")
|
|
return
|
|
}
|
|
if usersalt == nil {
|
|
salt = make([]byte, 8)
|
|
// http://www.ietf.org/rfc/rfc2898.txt
|
|
// Salt.
|
|
if _, err := rand.Read(salt); err != nil {
|
|
log.Fatalf("can't get random salt: %v", err)
|
|
}
|
|
} else {
|
|
salt = usersalt
|
|
}
|
|
aead, err = chacha20poly1305.NewX(argon2.IDKey(passphrase, salt, 1, 64*1024, 4, 32))
|
|
return
|
|
}
|
|
|
|
// EncryptChaCha will encrypt ChaCha20-Poly1305 using the pre-generated key
|
|
// https://pkg.go.dev/golang.org/x/crypto/chacha20poly1305
|
|
func EncryptChaCha(plaintext []byte, aead cipher.AEAD) (encrypted []byte, err error) {
|
|
nonce := make([]byte, aead.NonceSize(), aead.NonceSize()+len(plaintext)+aead.Overhead())
|
|
if _, err := rand.Read(nonce); err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
// Encrypt the message and append the ciphertext to the nonce.
|
|
encrypted = aead.Seal(nonce, nonce, plaintext, nil)
|
|
return
|
|
}
|
|
|
|
// DecryptChaCha will encrypt ChaCha20-Poly1305 using the pre-generated key
|
|
// https://pkg.go.dev/golang.org/x/crypto/chacha20poly1305
|
|
func DecryptChaCha(encryptedMsg []byte, aead cipher.AEAD) (encrypted []byte, err error) {
|
|
if len(encryptedMsg) < aead.NonceSize() {
|
|
err = fmt.Errorf("ciphertext too short")
|
|
return
|
|
}
|
|
|
|
// Split nonce and ciphertext.
|
|
nonce, ciphertext := encryptedMsg[:aead.NonceSize()], encryptedMsg[aead.NonceSize():]
|
|
|
|
// Decrypt the message and check it wasn't tampered with.
|
|
encrypted, err = aead.Open(nil, nonce, ciphertext, nil)
|
|
return
|
|
}
|