revealer: fix unlucky hex seed causing crash

electrum/plugins/revealer/qt.py

@@ -314,12 +314,7 @@ class Plugin(RevealerPlugin):
 
     def make_rawnoise(self, create_revealer=False):
         if not self.user_input:
-            version = self.LATEST_VERSION
-            hex_seed = bh2u(os.urandom(16))
-            checksum = self.code_hashid(version + hex_seed)
-            self.versioned_seed = VersionedSeed(version=version.upper(),
-                                                seed=hex_seed.upper(),
-                                                checksum=checksum.upper())
+            self.versioned_seed = self.gen_random_versioned_seed()
         assert self.versioned_seed
         w, h = self.SIZE
         rawnoise = QImage(w, h, QImage.Format_Mono)

electrum/plugins/revealer/revealer.py

@@ -1,4 +1,5 @@
 import random
+import os
 from hashlib import sha256
 from typing import NamedTuple, Optional, Dict, Tuple
 
@@ -59,9 +60,9 @@ class RevealerPlugin(BasePlugin):
                              checksum=checksum.upper())
 
     @classmethod
-    def get_noise_map(self, versioned_seed: VersionedSeed) -> Dict[Tuple[int, int], int]:
+    def get_noise_map(cls, versioned_seed: VersionedSeed) -> Dict[Tuple[int, int], int]:
         """Returns a map from (x,y) coordinate to pixel value 0/1, to be used as rawnoise."""
-        w, h = self.SIZE
+        w, h = cls.SIZE
         version  = versioned_seed.version
         hex_seed = versioned_seed.seed
         checksum = versioned_seed.checksum
@@ -76,6 +77,9 @@ class RevealerPlugin(BasePlugin):
             drbg = DRBG(prng_seed)
             num_noise_bytes = 1929  # ~ w*h
             noise_array = bin(int.from_bytes(drbg.generate(num_noise_bytes), 'big'))[2:]
+            # there's an approx 1/1024 chance that the generated number is 'too small'
+            # and we would get IndexError below. easiest backwards compat fix:
+            noise_array += '0' * (w * h - len(noise_array))
             i = 0
             for x in range(w):
                 for y in range(h):
@@ -84,3 +88,18 @@ class RevealerPlugin(BasePlugin):
         else:
             raise Exception(f"unexpected revealer version: {version}")
         return noise_map
+
+    @classmethod
+    def gen_random_versioned_seed(cls):
+        version = cls.LATEST_VERSION
+        hex_seed = bh2u(os.urandom(16))
+        checksum = cls.code_hashid(version + hex_seed)
+        return VersionedSeed(version=version.upper(),
+                             seed=hex_seed.upper(),
+                             checksum=checksum.upper())
+
+
+if __name__ == '__main__':
+    for i in range(10**4):
+        vs = RevealerPlugin.gen_random_versioned_seed()
+        nm = RevealerPlugin.get_noise_map(vs)

electrum/tests/test_revealer.py

@@ -24,3 +24,13 @@ class TestRevealer(SequentialTestCase):
                 bigint |= 1 << (y*RevealerPlugin.SIZE[1]+x)
         self.assertEqual(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,
                          bigint)
+
+    def test_version_1_noisemap_indexerror(self):
+        versioned_seed = RevealerPlugin.get_versioned_seed_from_user_input('1A082CBDC627FFA37ABD154A64AD2565D725')
+        noise_map = RevealerPlugin.get_noise_map(versioned_seed)
+        bigint = 0
+        for (x, y), pixel in noise_map.items():
+            if pixel:
+                bigint |= 1 << (y*RevealerPlugin.SIZE[1]+x)
+        self.assertEqual(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,
+                         bigint)