tools: add getkey command to keyctl to retrieve the public key

tools/keyctl

@@ -29,6 +29,16 @@ def cli():
     pass
 
 
+@cli.command(help='')
+@click.argument('index', type=click.Choice(indexmap.keys()))
+def getkey(index):
+    index = indexmap[index]
+    t = get_trezor()
+    path = "10018'/%d'" % index
+    node = t.get_public_node(t.expand_path(path), ecdsa_curve_name='ed25519').node
+    print('%s' % (binascii.hexlify(node.public_key[1:]).decode()))
+
+
 @cli.command(help='')
 @click.argument('index', type=click.Choice(indexmap.keys()))
 @click.argument('filename')