value // and increments it. func gcmInc32(counterBlock *[gcmBlockSize]byte) { ctr := counterBlock[len(counterBlock)-4:] byteorder.BEPutUint32(ctr, byteorder.BEUint32(ctr)+1) } // gcmAuthGeneric calculates GHASH(additionalData, ciphertext), masks the result // with tagMask and writes the result to out. func gcmAuthGeneric(out []byte, H, tagMask *[gcmBlockSize]byte, ciphertext, additionalData []byte) { checkGenericIsExpect() lenBlock := make([]byte, 16) byteorder.BEPutUint64(lenBlock[:8], uint64(le...