scripts: Initial version of Python imgtool
This is the start of a python implementation of imgtool. This
implements all of the functionality that was missing in the zep2newt.py
tool, namely creation of keypairs, and converting the public version of
these keys into C code.
diff --git a/scripts/imgtool.py b/scripts/imgtool.py
new file mode 100755
index 0000000..4f5e56b
--- /dev/null
+++ b/scripts/imgtool.py
@@ -0,0 +1,94 @@
+#! /usr/bin/env python3
+
+import argparse
+from imgtool import keys
+from imgtool import image
+from imgtool import version
+import sys
+
+def gen_rsa2048(args):
+ keys.RSA2048.generate().export_private(args.keyfile)
+def gen_ecdsa_p256(args):
+ keys.ecdsa256p1.generate().export_private(args.keyfile)
+def gen_ecdsa_p224(args):
+ print("TODO: p-224 not yet implemented")
+
+keygens = {
+ 'rsa-2048': gen_rsa2048,
+ 'ecdsa-p256': gen_ecdsa_p256,
+ 'ecdsa-p224': gen_ecdsa_p224, }
+
+def do_keygen(args):
+ if args.type not in keygens:
+ msg = "Unexpected key type: {}".format(args.type)
+ raise argparse.ArgumentTypeError(msg)
+ keygens[args.type](args)
+
+def do_getpub(args):
+ key = keys.load(args.key)
+ key.emit_c()
+
+def do_sign(args):
+ align = args.align
+ # print('sign:', args)
+ img = image.Image.load(args.infile, version=args.version,
+ header_size=args.header_size,
+ pad=args.pad)
+ key = keys.load(args.key)
+ img.sign(key)
+
+ if args.pad:
+ img.pad_to(args.pad, args.align)
+
+ img.save(args.outfile)
+
+subcmds = {
+ 'keygen': do_keygen,
+ 'getpub': do_getpub,
+ 'sign': do_sign, }
+
+def alignment_value(text):
+ value = int(text)
+ if value not in [1, 2, 4, 8]:
+ msg = "{} must be one of 1, 2, 4 or 8".format(value)
+ raise argparse.ArgumentTypeError(msg)
+ return value
+
+def intparse(text):
+ """Parse a command line argument as an integer.
+
+ Accepts 0x and other prefixes to allow other bases to be used."""
+ return int(text, 0)
+
+def args():
+ parser = argparse.ArgumentParser()
+ subs = parser.add_subparsers(help='subcommand help', dest='subcmd')
+
+ keygenp = subs.add_parser('keygen', help='Generate pub/private keypair')
+ keygenp.add_argument('-k', '--key', metavar='filename', required=True)
+ keygenp.add_argument('-t', '--type', metavar='type',
+ choices=['rsa-2048', 'ecdsa-p224', 'ecdsa-p256'],
+ required=True)
+
+ getpub = subs.add_parser('getpub', help='Get public key from keypair')
+ getpub.add_argument('-k', '--key', metavar='filename', required=True)
+
+ sign = subs.add_parser('sign', help='Sign an image with a private key')
+ sign.add_argument('-k', '--key', metavar='filename', required=True)
+ sign.add_argument("--align", type=alignment_value, required=True)
+ sign.add_argument("-v", "--version", type=version.decode_version, required=True)
+ sign.add_argument("-H", "--header-size", type=intparse, required=True)
+ sign.add_argument("--pad", type=intparse,
+ help='Pad image to this many bytes, adding trailer magic')
+ sign.add_argument("infile")
+ sign.add_argument("outfile")
+
+ args = parser.parse_args()
+ if args.subcmd is None:
+ print('Must specify a subcommand', file=sys.stderr)
+ sys.exit(1)
+
+ subcmds[args.subcmd](args)
+
+if __name__ == '__main__':
+ args()