add support of Cobo multisig (#268)

src/cryptoadvance/specter/devices/cobo.py

@@ -1,19 +1,63 @@
 import hashlib
-from ..device import Device
+# from ..device import Device
+from .sd_card_device import SDCardDevice
 from hwilib.serializations import PSBT
 from binascii import a2b_base64
 from .. import bcur
+from .electrum import b43_encode
 
-class Cobo(Device):
+class Cobo(SDCardDevice):
     def __init__(self, name, alias, device_type, keys, fullpath, manager):
         super().__init__(name, alias, 'cobo', keys, fullpath, manager)
-        self.sd_card_support = False
+        self.hwi_support = False
+        self.sd_card_support = True
         self.qr_code_support = True
+        self.exportable_to_wallet = True
+        self.wallet_export_type = 'qr'
 
     def create_psbts(self, base64_psbt, wallet):
-        # TODO - convert to bc-ur
+        psbts = super().create_psbts(base64_psbt, wallet)
         raw_psbt = a2b_base64(base64_psbt)
-        enc, hsh = bcur.bcur_encode(raw_psbt)
-        psbt = ("ur:bytes/%s/%s"% (hsh, enc)).upper()
-        psbts = { 'qrcode': psbt }
-        return psbts
+        if wallet.is_multisig:
+            qrpsbt = b43_encode(raw_psbt)
+        else:
+            enc, hsh = bcur.bcur_encode(raw_psbt)
+            qrpsbt = ("ur:bytes/%s/%s"% (hsh, enc)).upper()
+        psbts['qrcode'] = qrpsbt
+        return psbts
+
+    def export_wallet(self, wallet):
+        # Cobo uses ColdCard's style
+        CC_TYPES = {
+        'legacy': 'BIP45',
+        'p2sh-segwit': 'P2WSH-P2SH',
+        'bech32': 'P2WSH'
+        }
+        # try to find at least one derivation
+        # cc assume the same derivation for all keys :(
+        derivation = None
+        for k in wallet.keys:
+            if k.derivation != '':
+                derivation = k.derivation.replace("h","'")
+                break
+        if derivation is None:
+            return None
+        cc_file = """# CoboVault Multisig setup file (created on Specter Desktop)
+#
+Name: {}
+Policy: {} of {}
+Derivation: {}
+Format: {}
+""".format(wallet.name, wallet.sigs_required, 
+            len(wallet.keys), derivation,
+            CC_TYPES[wallet.address_type]
+            )
+        for k in wallet.keys:
+            # cc assumes fingerprint is known
+            fingerprint = k.fingerprint
+            if fingerprint == '':
+                fingerprint = get_xpub_fingerprint(k.xpub).hex()
+            cc_file += "{}: {}\n".format(fingerprint.upper(), k.xpub)
+        enc, hsh = bcur.bcur_encode(cc_file.encode())
+        cobo_qr = ("ur:bytes/%s/%s"% (hsh, enc)).upper()
+        return cobo_qr

src/cryptoadvance/specter/templates/device/new_device.jinja

@@ -329,6 +329,14 @@ upub5En4f7k8gaG2KDHvBeEYox...rFpJRHpiZ4DE
 					let str = `[${obj.MasterFingerprint}/${path}]${obj.ExtPubKey}`;
 					addKeys(str);
 					setDeviceType('cobo');
+				}else if( ("xfp" in obj) &&
+						  ("xpub" in obj) &&
+						  ("path" in obj)){
+					console.log(obj);
+					let path = obj.path.replace(/'/g,'h').replace("m/","");
+					let str = `[${obj.xfp}/${path}]${obj.xpub}`;
+					addKeys(str);
+					setDeviceType('cobo');
 				}else{
 					showError("Unknown key format");
 				}