Exchange Tool

This repo contains a suit of tools for testing, generating data and cross checking against different tech env.

Foreword

The swap payload used by the Nano is in Protobuf format.

The private and public key are expected to be in ES256 format, using a secp256k1 or secp256r1 curve.

Usage

Generate

./exchange-tool generate (swap|sell) -c <curve> -p <private_key_file> [-f (raw|jwt)] <payload_in_json_format>

Example:

./exchange-tool generate swap -c k1 -p ./samples/sample-priv-key-secp256k1.pem ./samples/swap-payload-example.json

Check

./exchange-tool check -c <curve> (-p <public_key_file> | -x <public_key_in_hex_format>) [-f (raw|jwt)] <binary_payload_in_base64> <signature_in_base64>

Example:

./exchange-tool check -c k1 -p ../samples/sample-pub-key-secp256k1.pem CipiYzFxYXIwc3Jycjd4Zmt2eTVsNjQzbHlkbnc5cmU1OWd0enp3ZjVtZHEaKmJjMXFhcjBzcnJyN3hma3Z5NWw2NDNseWRudzlyZTU5Z3R6endmNHRlcSoqMHhiNzk0ZjVlYTBiYTM5NDk0Y2U4Mzk2MTNmZmZiYTc0Mjc5NTc5MjY4OgNCVENCA0JBVEoCBH5SBgV0-95gAGIgNQrqDJf3R_HQ92CBRhSkdSOAGxrrfQvLuqKk9Gv4GEs= ky2iRewy2Lbm8tR-kvnUGRKJBrUPwzQwPWWyP_xbNI3vxR9VSfdDvRW5pWEPU1nMbgJj4NuFw6WSOfEDDnupqg==

Read

./exchange-tool read -e (swap|sell) <binary_payload_in_base64>

Example:

./exchange-tool read -e swap CipiYzFxYXIwc3Jycjd4Zmt2eTVsNjQzbHlkbnc5cmU1OWd0enp3ZjVtZHEaKmJjMXFhcjBzcnJyN3hma3Z5NWw2NDNseWRudzlyZTU5Z3R6endmNHRlcSoqMHhiNzk0ZjVlYTBiYTM5NDk0Y2U4Mzk2MTNmZmZiYTc0Mjc5NTc5MjY4OgNCVENCA0JBVEoIMTIwMDAwMDBSCDExNTAwMDAwWgpBQkNERUZHSElK

Convert asn1 pubkey to hex value

./exchange-tool hex -c <curve> -t (private|public) <provider_public_key>

Example:

./exchange-tool hex -c k1 -t public ./samples/sample-pub-key-secp256k1.pem

Sign Provider

Generate an APDU to sign by Ledger, with the provider infos (name and public key).

./exchange-tool sign -c <curve> -n <provider_name> <provider_public_key>

Example:

./exchange-tool sign -c k1 -n SELL_TEST ./samples/sample-pub-key-secp256k1.pem

Generate CAL format for Provider info

Generate 2 provider info in CAL format: one for LedgerLive (test purpose only), one for CAL (example purpose only).

./exchange-tool cal -c <curve> -n <provider_name> -p <provider_public_key> -v <version> -a <application_name>

Example:

./exchange-tool cal -c k1 -p ./sample-public-key.pem -n SWAP_TEST -v 2 -a swap

Disclaimer DO NOT USE private key provided in this repository. Their goal is for test purpose only.

The code use to generate a payload has an amount limitation. To ease the JSON serialization, we are relying on uint64 type, which is not the best to suit crypto units.

Generate private/public key

Private key:

  openssl ecparam -name secp256k1 -genkey -noout -out sample-priv-key-secp256k1.pem

Public key (from private key):

  openssl ec -in sample-priv-key.pem -pubout > sample-pub-key-secp256k1.pem

Read file info

  openssl ec -text -in sample-priv-key-secp256k1.pem

(ecparam is for Eliptic Curves params)

Cross testing and consistency

To check if the code is still consistent with what is expected from Ledger:

  go test .

  # For log info
  go test . -v

Bash

  # Sign 'encoded_payload' content
  openssl dgst -sha256 -sign sample-priv-key-secp256r1.pem encoded_payload.txt > signature.der
  # Display R and S from DER format signature
  openssl asn1parse -inform DER -in signature.der
  # Verify signature
  openssl dgst -sha256 -verify sample-pub-key-secp256r1.pem -signature signature.der encoded_payload.txt

With current example value

  openssl dgst -sha256 -verify example/sample-pub-key-secp256k1.pem -signature example/signature-example-k1.der example/encoded_payload.txt

Generate DER file from R, S value

1. Copy asn1rs.template.cnf file (ex: into asn1rs-example.cnf)
2. Edit this file and replace {rvalue_in_hex} and {svalue_in_hex} value with R and S value
3. Call openssl asn1parse -genconf asn1rs-example.cnf -out signature-example.der

Extract R, S value from base64url signature

  var=$(basenc --base64url -d signature.txt | hexdump -ve '1/1 "%.2x"')
  printf '%s\n' "${var:0:${#var}/2}" "${var:${#var}/2}"
  unset var

Source

secp256k1 vs secp256r1

OID secp256r1

OID secp256k1

sec1

sec2

JWS RFC

JWA ES256

DER file from RS value

CLI description