fix overflow when processing punycode encoded URLs like xn--55555577

servo · Jun 16, 2024 · d40d472 · d40d472
1 parent 8db8034
commit d40d472
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/idna/src/punycode.rs b/idna/src/punycode.rs
@@ -215,7 +215,7 @@ impl Decoder {
                 if C::EXTERNAL_CALLER && (digit > (u32::MAX - i) / weight) {
                     return Err(()); // Overflow
                 }
-                i += digit * weight;
+                i = i.checked_add(digit * weight).ok_or(())?;
                 let t = if k <= bias {
                     T_MIN
                 } else if k >= bias + T_MAX {

diff --git a/idna/tests/unit.rs b/idna/tests/unit.rs
@@ -43,7 +43,7 @@ fn test_punycode_prefix_without_length_check() {
 #[test]
 fn test_punycode_invalid_encoding() {
     let config = idna::Config::default();
-    assert_eq!(config.to_ascii("xn--55555577").unwrap_err().to_string(), "Errors { punycode }");
+    assert!(config.to_ascii("xn--55555577").is_err());
 }
 
 // http://www.unicode.org/reports/tr46/#Table_Example_Processing