When trying to parse encapsulated values, check that the content can …

…be parsed as well. Closes #79 on GitHub.
lapo-luchini · Mar 30, 2024 · 8f048ac · 8f048ac
1 parent 405c036
commit 8f048ac
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Showing 3 changed files with 28 additions and 7 deletions.
diff --git a/asn1.js b/asn1.js
@@ -195,7 +195,7 @@ class Stream {
         let s = this.parseStringISO(start, end).str,
             m = (shortYear ? reTimeS : reTimeL).exec(s);
         if (!m)
-            return 'Unrecognized time: ' + s;
+            throw new Error('Unrecognized time: ' + s);
         if (shortYear) {
             // to avoid querying the timer, use the fixed range [1970, 2069]
             // it will conform with ITU X.400 [-10, +40] sliding window until 2030
@@ -590,9 +590,15 @@ class ASN1 {
                     if (stream.get() != 0)
                         throw new Error('BIT STRINGs with unused bits cannot encapsulate.');
                 getSub();
-                for (let i = 0; i < sub.length; ++i)
-                    if (sub[i].tag.isEOC())
+                for (let s of sub) {
+                    if (s.tag.isEOC())
                         throw new Error('EOC is not supposed to be actual content.');
+                    try {
+                        s.content();
+                    } catch (e) {
+                        throw new Error('Unable to parse content: ' + e);
+                    }
+                }
             } catch (e) {
                 // but silently ignore when they don't
                 sub = null;

diff --git a/dom.js b/dom.js
@@ -80,7 +80,12 @@ class ASN1DOM extends ASN1 {
             }
         }
         head.appendChild(DOM.text(typeName));
-        let content = this.content(contentLength);
+        let content;
+        try {
+            content = this.content(contentLength);
+        } catch (e) {
+            content = 'Cannot decode: ' + e;
+        }
         let oid;
         if (content !== null) {
             let preview = DOM.tag('span', 'preview'),

diff --git a/test.js b/test.js
@@ -86,6 +86,8 @@ const tests = [
     ['0420041EE4E3B7ED350CC24D034E436D9A1CB15BB1E328D37062FB82E84618AB0A3C', '(32 byte)\n041EE4E3B7ED350CC24D034E436D9A1CB15BB1E328D37062FB82E84618AB0A3C', 'Do not mix encapsulated and structured octet strings'], // GitHub issue #47
     ['181531393835313130363231303632372E332D31323334', '1985-11-06 21:06:27.3 UTC-12:34', 'UTC offsets with minutes'], // GitHub issue #54
     ['181331393835313130363231303632372E332B3134', '1985-11-06 21:06:27.3 UTC+14:00', 'UTC offset +13 and +14'], // GitHub issue #54
+    ['032100171E83C1B251803F86DD01E9CFA886BE89A7316D8372649AC2231EC669F81A84', n => { if (n.sub != null) return 'Should not decode content: ' + n.sub[0].content(); }, 'Key that resembles an UTCTime'], // GitHub issue #79
+    ['171E83C1B251803F86DD01E9CFA886BE89A7316D8372649AC2231EC669F81A84', /^Exception:\nError: Unrecognized time: /, 'Invalid UTCTime'], // GitHub issue #79
 ];
 
 let
@@ -98,17 +100,25 @@ tests.forEach(function (t) {
         comment = t[2];
     let result;
     try {
-        result = ASN1.decode(Hex.decode(input)).content();
+        let node = ASN1.decode(Hex.decode(input));
+        if (typeof expected == 'function')
+            result = expected(node);
+        else
+            result = node.content();
         //TODO: check structure, not only first level content
     } catch (e) {
         result = 'Exception:\n' + e;
     }
+    if (expected instanceof RegExp)
+        result = expected.test(result) ? null : 'does not match';
     ++run;
-    if (result == expected) {
+    if (!result || result == expected) {
         if (all) console.log('\x1B[1m\x1B[32mOK \x1B[39m\x1B[22m ' + comment);
     } else {
         ++error;
-        console.log('\x1B[1m\x1B[31mERR\x1B[39m\x1B[22m ' + comment + '\n' + result);
+        console.log('\x1B[1m\x1B[31mERR\x1B[39m\x1B[22m ' + comment);
+        console.log('  \x1B[1m\x1B[34mEXP\x1B[39m\x1B[22m ' + expected.toString().replace(/\n/g, '\n      '));
+        console.log('  \x1B[1m\x1B[33mGOT\x1B[39m\x1B[22m ' + result.replace(/\n/g, '\n      '));
     }
 });
 console.log(run + ' tested, ' + expErr + ' expected, ' + error + ' errors.');