Add find-wallet-depths command: quickly find walletdepths from master secret

webcash/walletclient.py

@@ -21,6 +21,7 @@
 import secrets
 import hashlib
 import datetime
+import string
 import struct
 import os
 import sys
@@ -45,6 +46,9 @@
 # unused?
 FEE_AMOUNT = 0
 
+BATCH_SIZE = 25
+STOP_AFTER_N_TESTED_UNKNOWN_TOKENS = 5 * BATCH_SIZE
+
 WALLET_NAME = "default_wallet.webcash"
 
 CHAIN_CODES = {
@@ -54,6 +58,22 @@
     "MINING": 3,
 }
 
+
+def is_master_secret(s):
+    return len(s) == 64 and all(c in string.hexdigits for c in s)
+
+
+def get_deterministic_secret(master_secret_hex, chain_code, wallet_depth):
+    assert is_master_secret(master_secret_hex)
+    assert chain_code == chain_code.upper()
+    assert wallet_depth >= 0
+    tag = hashlib.sha256(b"webcashwalletv1").digest()
+    secret = hashlib.sha256(tag + tag)
+    secret.update(convert_secret_hex_to_bytes(master_secret_hex))
+    secret.update(struct.pack(">Q", CHAIN_CODES[chain_code])) # big-endian
+    secret.update(struct.pack(">Q", wallet_depth))
+    return secret.hexdigest()
+
 def convert_secret_hex_to_bytes(secret):
     """
     Convert a string secret to bytes.
@@ -71,15 +91,7 @@ def generate_new_secret(webcash_wallet=None, chain_code="RECEIVE", walletdepth=N
         else:
             walletdepth = walletdepth
 
-        master_secret = webcash_wallet["master_secret"]
-        master_secret_bytes = convert_secret_hex_to_bytes(master_secret)
-
-        tag = hashlib.sha256(b"webcashwalletv1").digest()
-        new_secret = hashlib.sha256(tag + tag)
-        new_secret.update(master_secret_bytes)
-        new_secret.update(struct.pack(">Q", CHAIN_CODES[chain_code.upper()])) # big-endian
-        new_secret.update(struct.pack(">Q", walletdepth))
-        new_secret = new_secret.hexdigest()
+        new_secret = get_deterministic_secret(webcash_wallet["master_secret"], chain_code, walletdepth)
 
         # Record the change in walletdepth, but don't record the new secret
         # because (1) it can be re-constructed even if it is lost, and (2) the
@@ -239,7 +251,7 @@ def webcash_server_request(url, json_data):
         raise Exception(f"Something went wrong on the server: {response.content}")
     json_response = response.json()
     if json_response.get("status", "") != "success":
-        raise Exception(f"Something went wrong on the server: {response}")
+        raise Exception(f"Something went wrong on the server: {response.content}")
     return json_response
 
 def check_wallet():
@@ -255,9 +267,9 @@ def check_wallet():
         outputs[str(sk.to_public().hashed_value)] = webcash
 
     while outputs:
-        # Batch into no more than 25 at a time
+        # Batch into no more than BATCH_SIZE at a time
         batch = {}
-        while outputs and len(batch) < 25:
+        while outputs and len(batch) < BATCH_SIZE:
             item = outputs.popitem()
             batch[item[0]] = item[1]
 
@@ -297,6 +309,62 @@ def check_wallet():
 def check():
     return check_wallet()
 
+@cli.command(
+    "find-wallet-depths", short_help="[advanced] Find the 'walletdepths' parameters of a given master secret key by scanning."
+)
+@click.argument("master_secret")
+def find_wallet_depths(master_secret):
+    if not is_master_secret(master_secret):
+        raise click.ClickException(
+            "Invalid master secret. Hex string of length 64 expected."
+        )
+
+    resulting_wallet_depths = {}
+    for chain_code in CHAIN_CODES.keys():
+        max_used_wallet_depth = -1
+        for step_size in [100000, 10000, 1000, 100, 10, 1]:
+            wallet_depth = max(0, max_used_wallet_depth)
+            unknown_count = 0
+            while unknown_count < STOP_AFTER_N_TESTED_UNKNOWN_TOKENS:
+                hash_to_webcash_and_depth = {}
+                while len(hash_to_webcash_and_depth) < BATCH_SIZE:
+                    hex_secret = get_deterministic_secret(
+                        master_secret, chain_code, wallet_depth
+                    )
+                    secret_webcash = SecretWebcash.deserialize(f"e1:secret:{hex_secret}")
+                    public_webhash = secret_webcash.to_public()
+                    hash_to_webcash_and_depth[
+                        public_webhash.hashed_value
+                    ] = (secret_webcash, wallet_depth)
+                    wallet_depth += step_size
+
+                health_check_request = [
+                    str(o[0].to_public()) for o in hash_to_webcash_and_depth.values()
+                ]
+                response = webcash_server_request(
+                    WEBCASH_ENDPOINT_HEALTH_CHECK, health_check_request
+                )
+
+                assert len(hash_to_webcash_and_depth) == BATCH_SIZE
+                assert len(response["results"]) == BATCH_SIZE
+
+                found_new = False
+                for public_webcash, result in response["results"].items():
+                    secret_webcash, found_at_wallet_depth = hash_to_webcash_and_depth[PublicWebcash.deserialize(public_webcash).hashed_value]
+                    spent = result["spent"]
+                    amount = result.get("amount")
+                    token_is_unknown = spent is None and amount is None
+                    if token_is_unknown:
+                        unknown_count += 1
+                        continue
+                    if found_at_wallet_depth > max_used_wallet_depth:
+                        max_used_wallet_depth = found_at_wallet_depth
+                        found_new = True
+                if found_new:
+                    print(f"Scanning... Found used walled depth {chain_code}:{max_used_wallet_depth}")
+        resulting_wallet_depths[chain_code] = max_used_wallet_depth + 1
+    print(f"\"walletdepths\": {resulting_wallet_depths}")
+
 @cli.command("recover", short_help="Recover webcash using the wallet's master secret.")
 @click.option("--gaplimit", default=20)
 @lock_wallet