[Add] First commit

scripts/imgtool/aestool.py

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+
+#
+# AES cryptography tool
+#
+
+import sys, argparse
+import codecs
+import re
+import macro_parser
+from imglib.keys.aes_ctr import crypto
+
+VERSION = "aestool.py 0.1"
+
+offset_re = re.compile(r"^.*\s*RE_([0-9A-Z_]+)_OFFSET\s*(.*)")
+
+def main():
+    cmd = argparse.ArgumentParser(
+        prog="aestool.py",
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        description = '''
+        \rAES implementation in counter mode. This version supports 128 bits key encryption only.
+        ''',
+        epilog = '''
+        \rExemplary usage:\n
+        \r1) Encryption
+        \r$ python aes-ctr.py -i plaintext -o ciphertext -k abcdef1234567890abcdef1234567890 -s 0x08000000\n
+        \r2) Decryption
+        \r$ aes-ctr.py -d -i ciphertext -o plaintext -k abcdef1234567890abcdef1234567890 -s 0x08000000
+        ''')
+
+    cmd.add_argument('-c', '--config', metavar='filename', required=True,
+                          help='Location of the file that contains macros')
+    cmd.add_argument('-t', '--type', metavar='type', required=True,
+                          help='SYS_SET / MBL / SYS_STATUS / IMG_0_PROT / IMG_0_AROT / IMG_0_NSPE / IMG_1_PROT / IMG_1_AROT / IMG_1_NSPE')
+    cmd.add_argument("-d", "--decrypt", help="Use decrypt instead of default encrypt", action="store_true")
+    cmd.add_argument("-i", "--input", help="File containing plaintext/ciphertext", type=str, required=True, metavar="IN")
+    cmd.add_argument("-o", "--output", help="Output file to store result of the program", type=str, required=True, metavar="OUT")
+    cmd.add_argument("-k", "--key", help="Encryption 128bits key", type=str, required=True)
+    cmd.add_argument("-v", "--version", action="version", version=VERSION)
+    args = cmd.parse_args()
+
+    offsets = macro_parser.evaluate_macro(args.config, offset_re, 1, 2)
+
+    out_file = args.output
+
+
+    in_file = args.input
+
+    key = validateHex(args.key)
+
+    try:
+        startAddress = offsets[args.type]
+        print("startAddress = ", startAddress)
+    except KeyError:
+        print("Invalid Start address")
+        return
+    # Get the Address[23:4]
+    startAddress = (startAddress & 0xffffff) >> 4
+
+    iv = '{:0>32x}'.format(startAddress)
+    iv = validateHex(iv)
+
+
+    if key and iv:
+        if args.decrypt:
+            crypto(in_file, key, iv, out_file, encrypt=False)
+        else:
+            crypto(in_file, key, iv, out_file)
+    else:
+        print("Invalid Key or iv")
+
+'''
+ Validate if passed value is hexadecimal and has proper length
+ Function returns passed argument if value is correct
+ If passed value is not valid, function returns False
+'''
+def validateHex(hex):
+    if len(hex) != 32:
+        return False
+    else:
+        try:
+            int(hex, 16)
+            return hex
+        except ValueError:
+            return False
+
+if __name__ == '__main__':
+    main()