Handling responses with length >= 256

[BrightSoul]

I'm sending ADPU commands using the inDataExchange method. The PN532 breakout board is communicating to an Arduino UNO via its SPI interface.
Everything worked fine so far but now I'm sending an INTERNAL AUTHENTICATE command which is expecting a response of length 256.
Unfortunately, the length variable is defined as a uint8_t and read off of a single preamble octet.

Adafruit-PN532/Adafruit_PN532.cpp

Line 678 in 941cac4

uint8_t length = pn532_packetbuffer[3];

Actually, no more than 252 bytes may be read into the responseBuffer.

Adafruit-PN532/Adafruit_PN532.cpp

Line 695 in 941cac4

length -= 3;

But the packetBuffer size is even smaller.

Adafruit-PN532/Adafruit_PN532.cpp

Line 80 in 941cac4

#define PN532_PACKBUFFSIZ 64

The INTERNAL AUTHENTICATE command doesn't seem to allow the reading of a response in chunks like the READ BINARY command does.

If I don't go wrong, the library is not supporting the extended frame response that's documented here:
https://cdn-shop.adafruit.com/datasheets/PN532C106_Application+Note_v1.2.pdf#page=10