src[gcmBlockSize:] } if len(src) > 0 { aes.EncryptBlockInternal(b, mask[:], counter[:]) gcmInc32(counter) subtle.XORBytes(out, src, mask[:]) } } // gcmInc32 treats the final four bytes of counterBlock as a big-endian 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...