Implement read_uint64_from_prover

HerodotusDev · Dec 21, 2023 · ed537c6 · ed537c6
1 parent 0384ac7
commit ed537c6
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Showing 2 changed files with 19 additions and 0 deletions.
diff --git a/src/channel/channel.cairo b/src/channel/channel.cairo
@@ -88,4 +88,18 @@ impl ChannelImpl of ChannelTrait {
 
         self.digest = blake2s(hash_data).flip_endiannes();
     }
+
+    fn read_uint64_from_prover(ref self: Channel, value: u64) {
+        let mut hash_data = ArrayTrait::<u32>::new();
+
+        assert(self.digest.low != 0xffffffffffffffffffffffffffffffff, 'digest low is 2^128-1');
+        (self.digest + 1).to_array_be(ref hash_data);
+
+        let low: u32 = (value % 0x100000000).try_into().unwrap();
+        let high: u32 = (value / 0x100000000).try_into().unwrap();
+        hash_data.append(high.flip_endiannes());
+        hash_data.append(low.flip_endiannes());
+
+        self.digest = blake2s(hash_data).flip_endiannes();
+    }
 }
diff --git a/src/channel/tests/test_channel.cairo b/src/channel/tests/test_channel.cairo
@@ -55,4 +55,9 @@ fn test_read_from_prover() {
 
     assert(channel.counter == 0, 'invalid read felts');
     assert(channel.digest == 0x413b1e08fe14f181acc48007a89e4d044a9edb54523e8eae5829fde606d4074d, 'invalid read felts');
+
+    channel.read_uint64_from_prover(6969);
+
+    assert(channel.counter == 0, 'invalid read uint64');
+    assert(channel.digest == 0xeeee1f1910516152d49bea3829151bdd149fcd878fe4e7b52881300c113395ce, 'invalid read uint64');
 }