External flash encryption

[danielinux]

External partitions content can now be encrypted using ChaCha20.

Keytools can generate 'signed_and_encrypted.bin' version of the updates to be stored on external devices.

Details in the manual page.

Depends on wolfcrypt-py PR #14 and PR#15.

[dgarske]

Using the latest wolfcrypt-py its still not working on the mac. Here are my logs:

make USBTTY=/dev/cu.usbmodem1452203 test-enc-update
	[CC-ARM] hal/stm32wb.o
	[CC-ARM] src/loader.o
	[CC-ARM] src/string.o
	[CC-ARM] src/image.o
	[CC-ARM] src/libwolfboot.o
	[CC-ARM] src/boot_arm.o
	[CC-ARM] src/uart_flash.o
	[CC-ARM] src/ecc256_pub_key.o
	[CC-ARM] src/update_flash.o
	[CC-ARM] src/xmalloc_ecc.o
	[LD] wolfboot.elf
	[BIN] wolfboot.bin

	[SIZE]
   text	   data	    bss	    dec	    hex	filename
  23820	      0	  13908	  37728	   9360	wolfboot.elf

	[CC-ARM] ../src/libwolfboot.o
	[LD] image.elf
	[BIN] image.bin
   text	   data	    bss	    dec	    hex	filename
   4184	     52	   4384	   8620	   21ac	test-app/image.elf
	[SIGN] test-app/image.bin
Update type:          Firmware
Input image:          test-app/image.bin
Selected cipher:      ecc256
Public key:           ecc256.der
Output image:         test-app/image_v1_signed.bin
Not Encrypted
Calculating sha256 digest...
Signing the firmware...
Done.
Output image successfully created.
	[MERGE] factory.bin
gcc -Wall -DWOLFSSL_DEBUG -DTFM_TIMING_RESISTANT -DWOLFBOOT_SIGN_ECC256 -DWOLFBOOT_HASH_SHA256 -g -ggdb -I../../include -I../../hal -Wextra   -c -o ../../src/libwolfboot.o ../../src/libwolfboot.c
gcc -o ufserver ufserver.o ../../src/libwolfboot.o -Wall -DWOLFSSL_DEBUG -DTFM_TIMING_RESISTANT -DWOLFBOOT_SIGN_ECC256 -DWOLFBOOT_HASH_SHA256 -g -ggdb -I../../include -I../../hal -Wextra
Update type:          Firmware
Input image:          test-app/image.bin
Selected cipher:      ecc256
Public key:           ecc256.der
Output image:         test-app/image_v2_signed.bin
Encrypted using:      /tmp/enc_key.der
Calculating sha256 digest...
Signing the firmware...
Done.
Output image successfully created.
Update type:          Firmware
Input image:          test-app/image.bin
Selected cipher:      ecc256
Public key:           ecc256.der
Output image:         test-app/image_v2_signed.bin
Encrypted using:      /tmp/enc_key.der
Calculating sha256 digest...
Signing the firmware...
Done.
Output image successfully created.
st-flash 1.6.0-32-gcda2215
2020-06-18T08:18:36 INFO common.c: Loading device parameters....
2020-06-18T08:18:36 INFO common.c: Device connected is: WB55 device, id 0x20016495
2020-06-18T08:18:36 INFO common.c: SRAM size: 0x40000 bytes (256 KiB), Flash: 0x100000 bytes (1024 KiB) in pages of 4096 bytes
2020-06-18T08:18:36 INFO common.c: Attempting to write 70028 (0x1118c) bytes to stm32 address: 134217728 (0x8000000)
Flash page at addr: 0x08011000 erased
2020-06-18T08:18:37 INFO common.c: Finished erasing 18 pages of 4096 (0x1000) bytes
Writing
Starting  17 page write
2020-06-18T08:18:46 INFO common.c: Starting verification of write complete
2020-06-18T08:18:47 INFO common.c: Flash written and verified! jolly good!
Warning: the binary file provided does not appear to contain a valid firmware partition file.
[|] Fetching update blocks 			st-flash 1.6.0-32-gcda2215
2020-06-18T08:18:54 INFO common.c: Loading device parameters....
2020-06-18T08:18:54 INFO common.c: Device connected is: WB55 device, id 0x20016495
2020-06-18T08:18:54 INFO common.c: SRAM size: 0x40000 bytes (256 KiB), Flash: 0x100000 bytes (1024 KiB) in pages of 4096 bytes

** TARGET REBOOT **
Version running on target: 1
[/] Fetching update blocks 			st-flash 1.6.0-32-gcda2215
2020-06-18T08:19:54 INFO common.c: Loading device parameters....
2020-06-18T08:19:54 INFO common.c: Device connected is: WB55 device, id 0x20016495
2020-06-18T08:19:54 INFO common.c: SRAM size: 0x40000 bytes (256 KiB), Flash: 0x100000 bytes (1024 KiB) in pages of 4096 bytes

** TARGET REBOOT **
Version running on target: 1
[|] Fetching update blocks 			st-flash 1.6.0-32-gcda2215
2020-06-18T08:19:55 INFO common.c: Loading device parameters....
2020-06-18T08:19:55 INFO common.c: Device connected is: WB55 device, id 0x20016495
2020-06-18T08:19:55 INFO common.c: SRAM size: 0x40000 bytes (256 KiB), Flash: 0x100000 bytes (1024 KiB) in pages of 4096 bytes
1+0 records in
1+0 records out
4096 bytes transferred in 0.000042 secs (97612893 bytes/sec)
Binary files boot.bin and boot_compare.bin differ
TEST FAILED
make: *** [test-enc-update] Error 1

[dgarske]

Thanks Daniele! Awesome work