package common import ( "crypto/aes" "crypto/cipher" "crypto/rand" "errors" "io" "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 } if len(nonce) != aesgcm.NonceSize() { // check here so it doesn't panic return nil, errors.New("incorrect nonce size") } 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 } if len(nonce) != aesgcm.NonceSize() { // check here so it doesn't panic return nil, errors.New("incorrect nonce size") } plain, err := aesgcm.Open(nil, nonce, ciphertext, nil) if err != nil { return nil, err } return plain, nil } func CryptoRandRead(buf []byte) { RandRead(rand.Reader, buf) } func RandRead(randSource io.Reader, buf []byte) { _, err := randSource.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 random bytes: %v. Retrying...", err) _, err = randSource.Read(buf) if err == nil { return } time.Sleep(waitDur[i]) } log.Fatal("Cannot get random bytes after 10 retries") }