Add hashlib to WIZnet EVB-Pico Ethernet boards

[anecdata]

Issue arose in HTTPServer library in the context of websockets:
adafruit/Adafruit_CircuitPython_HTTPServer#73
The library can be improved with a flexible import that looks for either the native hashlib module or the adafruit_hashlib library (web sockets could be run on a board without hashlib, for example with an ethernet featherwing), but the native module is faster.

Awaiting testing.

addendum: oops... looks like not enough space on some builds

[jepler]

It looks like right now the inclusion of "mbedtls" header & library is conditional on CIRCUITPY_SSL only. This will have to be fixed in ports/raspberrypi/Makefile, selecting a different mbedtls subset when SSL is off but HASHLIB is enabled. I don't know exactly what that will end up looking like.

[anecdata]

I'm not sure I understand. There is no TLS right now on Ethernet boards or Ethernet SPI configs (wish there was).

Should I put this in draft, or close it?

[jepler]

I'll try explaining again, sorry for being unclear. I was trying to offer you advice about how to fix the build errors.

I looked at the failing build. It appeared to me that this was the salient portion of the build error:

./common-hal/hashlib/Hash.h:29:10: fatal error: mbedtls/sha1.h: No such file or directory
   29 | #include "mbedtls/sha1.h"
      |          ^~~~~~~~~~~~~~~~

I believe this occurs because the Makefile only decides to include mbedtls when ssl is enabled. It needs to be changed so that it includes mbedtls (probably with different configuration options) when hashlib is enabled and ssl is not enabled.

This means editing the Makefile for ports/raspberrypi but without actually doing the work I can't say exactly what it would look like in any detail. It probably involves some new conditional block similar to the one for SSL:

ifeq ($(CIRCUITPY_SSL),1)
CFLAGS += -isystem $(TOP)/mbedtls/include
... # lots more stuff
endif

becoming

ifeq ($(CIRCUITPY_SSL),1)
CFLAGS += -isystem $(TOP)/mbedtls/include
... # lots more stuff
else ifeq ($(CIRCUITPY_HASHLIB),1)
CFLAGS += -isystem $(TOP)/mbedtls/include
... # A new block modeled after the previous block but only enabling the hash functions
endif

[anecdata]

Thanks for the detailed explanation. I know approximately zero about makefiles (and mbedtls for that matter), so I'm not too inclined to go messing with them. I had interpreted the errors as the builds being too big in some languages (didn't look deep enough).

[anecdata]

Closing in favor of #8749