Interoperability with python-ecdsa regarding the SECP160r1 curve about micro-ecc HOT 2 OPEN

@t123yh, did you ever find a solution to this?

I would also like to use it together with this Python library.
Any suggestions (possibly also alternatives that you end up using) would be welcome, thanks.

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I had the same problem and I was able to get it to work :)

As I understand it, uECC outputs by default a 40 byte signature formatted as [r19]...[r0][s19]...[s0], while python-ecdsa expects [r20]...[r0][s20]...[s0]. According to some guy on stackoverflow (no cryptographer here), r20 and s20 are \x00, so you just have to transform the signature a bit before passing it to python-ecdsa : sig = b'\x00' + raw_sig[:20] + b'\x00' + raw_sig[20:].

Also note that VerifyingKey.verify computes a hash of the given data whereas uECC_sign doesn't. If you want to verify the output <sig> of uECC_sign(<pub_key>, DATA, sizeof(DATA), <sig>, <curve>), you need to use VerifyingKey.verify_digest(<sig>, DATA).

I've written a small Python script that verifies a signature created by uECC using secp160r1, given the public key, the signature and the digest (all hex formatted).

import ecdsa
import argparse

parser = argparse.ArgumentParser()
parser.add_argument("pub_key")
parser.add_argument("sig")
parser.add_argument("data")
args = parser.parse_args()

key = ecdsa.VerifyingKey.from_string(bytes.fromhex(args.pub_key), curve=ecdsa.SECP160r1)
raw_sig = bytes.fromhex(args.sig)
data = bytes.fromhex(args.data)

sig = b'\x00' + raw_sig[:20] + b'\x00' + raw_sig[20:]
print(key.verify_digest(sig, data))

Example:

$ python3 check.py 3801ab235453d93bfc7f75a092aed1c22c598a3a4c0419e9269035968d98443ddd4be4268770f70a 7be90347cdfbc01eb7df7a0a8b4eb1a6793e3f8b72640c36a828022effb84118e172f10007e4a333 0b9c2625dc21ef05f6ad4ddf47c5f203837aa32c
True

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