From d03e60b0565ed79961685d6d0df81883b0bcdf31 Mon Sep 17 00:00:00 2001
From: thomasv <thomasv@gitorious>
Date: Tue, 6 Dec 2011 15:40:04 +0100
Subject: [PATCH] fix key stretching

---
 client/electrum.py | 12 +++++++-----
 client/gui.py      |  7 ++++++-
 client/upgrade.py  | 38 ++++++++++++++++++++++++++++----------
 3 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/client/electrum.py b/client/electrum.py
index 8735d870c..8950cc1a5 100755
--- a/client/electrum.py
+++ b/client/electrum.py
@@ -215,6 +215,9 @@ class InvalidPassword(Exception):
 
 
 
+WALLET_VERSION = 3       # bump this everytime the wallet format is modified
+
+
 class Wallet:
     def __init__(self, wallet_path):
 
@@ -222,8 +225,7 @@ class Wallet:
         self.host = 'ecdsa.org'
         self.port = 50000
         self.fee = 0.005
-        self.version = 2             # bump this everytime the wallet format is modified
-
+        self.version = WALLET_VERSION
         self.servers = ['ecdsa.org','electrum.novit.ro']  # list of default servers
 
         # saved fields
@@ -286,8 +288,8 @@ class Wallet:
     def create_new_address(self, for_change, password):
         seed = self.pw_decode( self.seed, password)
         # strenghtening
+        oldseed = seed
         for i in range(100000):
-            oldseed = seed
             seed = hashlib.sha512(seed + oldseed).digest()
         i = len( self.addresses ) - len(self.change_addresses) if not for_change else len(self.change_addresses)
         seed = Hash( "%d:%d:"%(i,for_change) + seed )
@@ -382,8 +384,8 @@ class Wallet:
              self.labels, self.addressbook) = sequence
         except:
             raise BaseException("version error.")
-        if self.version == 1 and self.use_encryption:
-            raise BaseException("version error: please upgrade your wallet first")
+        if self.version != WALLET_VERSION:
+            raise BaseException("Wallet version error. Please use the upgrade script.")
         self.update_tx_history()
         return True
         
diff --git a/client/gui.py b/client/gui.py
index 07d38177e..93d968968 100644
--- a/client/gui.py
+++ b/client/gui.py
@@ -61,8 +61,13 @@ def show_seed_dialog(wallet, password, parent):
 
 def init_wallet(wallet):
 
-    if not wallet.read():
+    try:
+        found = wallet.read()
+    except BaseException, e:
+        show_message(e.message)
+        exit(1)
 
+    if not found: 
         # ask if the user wants to create a new wallet, or recover from a seed. 
         # if he wants to recover, and nothing is found, do not create wallet
         dialog = gtk.Dialog("electrum", parent=None, 
diff --git a/client/upgrade.py b/client/upgrade.py
index dca1791f6..18cbd1577 100644
--- a/client/upgrade.py
+++ b/client/upgrade.py
@@ -1,15 +1,7 @@
 import electrum, getpass, base64,ast,sys
 
 
-try:
-    path = sys.argv[1]
-except:
-    path = None
-wallet = electrum.Wallet(path)
-try:
-    wallet.read()
-    print "ok"
-except BaseException:
+def upgrade_wallet(wallet):
     if wallet.version == 1 and wallet.use_encryption:
         # version 1 used pycrypto for wallet encryption
         import Crypto
@@ -33,4 +25,30 @@ except BaseException:
         wallet.seed = wallet.pw_encode( seed, password)
         wallet.private_keys = wallet.pw_encode( repr( private_keys ), password)
         wallet.save()
-        print "upgrade successful"
+        print "upgraded to version 2"
+    if wallet.version < 3:
+        print """
+Your wallet is deprecated; its regeneration seed will not work with versions 0.31 and above.
+In order to upgrade, you need to create a new wallet (you may use your current seed), and to
+send your bitcoins to the new wallet, using a compatible version of Electrum ( http://ecdsa.org/electrum/Electrum-0.30.zip )
+
+We apologize for the inconvenience. We try to keep this kind of upgrades as rare as possible.
+"""
+
+
+if __name__ == "__main__":
+    try:
+        path = sys.argv[1]
+    except:
+        path = None
+    wallet = electrum.Wallet(path)
+    try:
+        found = wallet.read()
+        if found:
+            print wallet.path
+        else:
+            print "wallet not found."
+    except BaseException:
+        upgrade_wallet(wallet)
+        
+