&g.cipher)) } gcmAesFinish(&g.productTable, &tagMask, &tagOut, uint64(len(plaintext)), uint64(len(data))) copy(out[len(plaintext):], tagOut[:]) } func open(out []byte, g *GCM, nonce, ciphertext, data []byte) error { if !supportsAESGCM { return openGeneric(out, g, nonce, ciphertext, data) } tag := ciphertext[len(ciphertext)-g.tagSize:] ciphertext = ciphertext[:len(ciphertext)-g.tagSize] // See GCM spec, section 7.1. var counter, tagMask [gcmBlockSize]byte if len(nonce) == gcmStandardNonceSize { //...