1 - AHAB signature block parser:

This tool is developed to assist users to parse the AHAB signature block
from a signed container image. The tool also generates the certificates,
signatures, SRK table and SRK Hash.

2 - Requirements:

	python3 ($ apt-get install python3)
	python-cryptography ($ pip3 install cryptography)

3 - Usage:

	$ python3 parse_sig_blk.py <filepath> <offset>
		filepath: Path for image container binary to be analyzed.
		offset:   Container header offset in binary

	Note: Only one container header can be parsed at once.

	The tool creates a output directory with the following contents:
	IMG_sign.bin - Container header signature
	SGK_cert.bin - SGK key certificate (If included)
	SGK_sign.bin - SGK key signature (If included)
	SRKHash.bin  - SRK hash fuses
	SRKTable.bin - SRK table

4 - Example:

Usage example based in 2nd container of a L4.19.35_1.1.0 i.MX8QM image:

	$ python3 parse_sig_blk.py flash.bin 0x400
	$ tree
	  └── output
	      ├── IMG_sign.bin
	      ├── SGK_cert.bin
	      ├── SGK_sign.bin
	      ├── SRKHash.bin
	      └── SRKTable.bin

5 - Contents:

parse_sig_blk.py - Program to parse signature block in the boot image
common.py        - Definitions and common functions
README           - This file

6 - Release Notes:

CST 3.3.0 - Initial version
