Cloak/internal/util/util.go

91 lines
2.1 KiB
Go

package util
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"io"
"net"
"time"
log "github.com/sirupsen/logrus"
)
func AESGCMEncrypt(nonce []byte, key []byte, plaintext []byte) ([]byte, error) {
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}
aesgcm, err := cipher.NewGCM(block)
if err != nil {
return nil, err
}
return aesgcm.Seal(nil, nonce, plaintext, nil), nil
}
func AESGCMDecrypt(nonce []byte, key []byte, ciphertext []byte) ([]byte, error) {
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}
aesgcm, err := cipher.NewGCM(block)
if err != nil {
return nil, err
}
plain, err := aesgcm.Open(nil, nonce, ciphertext, nil)
if err != nil {
return nil, err
}
return plain, nil
}
func CryptoRandRead(buf []byte) {
_, err := rand.Read(buf)
if err == nil {
return
}
waitDur := [10]time.Duration{5 * time.Millisecond, 10 * time.Millisecond, 30 * time.Millisecond, 50 * time.Millisecond,
100 * time.Millisecond, 300 * time.Millisecond, 500 * time.Millisecond, 1 * time.Second,
3 * time.Second, 5 * time.Second}
for i := 0; i < 10; i++ {
log.Errorf("Failed to get cryptographic random bytes: %v. Retrying...", err)
_, err = rand.Read(buf)
if err == nil {
return
}
time.Sleep(time.Millisecond * waitDur[i])
}
log.Fatal("Cannot get cryptographic random bytes after 10 retries")
}
// ReadTLS reads TLS data according to its record layer
//func ReadTLS(conn net.Conn, buffer []byte) (n int, err error) {
//}
func Pipe(dst net.Conn, src net.Conn, srcReadTimeout time.Duration) {
// The maximum size of TLS message will be 16380+14+16. 14 because of the stream header and 16
// because of the salt/mac
// 16408 is the max TLS message size on Firefox
buf := make([]byte, 16378)
if srcReadTimeout != 0 {
src.SetReadDeadline(time.Now().Add(srcReadTimeout))
}
for {
if srcReadTimeout != 0 {
src.SetReadDeadline(time.Now().Add(srcReadTimeout))
}
i, err := io.ReadAtLeast(src, buf, 1)
if err != nil {
dst.Close()
src.Close()
return
}
_, err = dst.Write(buf[:i])
if err != nil {
dst.Close()
src.Close()
return
}
}
}