Minor work wrt #686, use StreamReadException until better type found

Author: cowtowncoder

src/main/java/com/fasterxml/jackson/core/sym/ByteQuadsCanonicalizer.java

@@ -3,6 +3,8 @@
 import java.util.Arrays;
 import java.util.concurrent.atomic.AtomicReference;
 
+import com.fasterxml.jackson.core.JacksonException;
+import com.fasterxml.jackson.core.exc.StreamReadException;
 import com.fasterxml.jackson.core.json.JsonFactory;
 import com.fasterxml.jackson.core.util.InternCache;
 
@@ -1314,10 +1316,13 @@ protected void _reportTooManyCollisions()
         if (_hashSize <= 1024) { // would have spill-over area of 128 entries
             return;
         }
-        throw new IllegalStateException("Spill-over slots in symbol table with "+_count
-                +" entries, hash area of "+_hashSize+" slots is now full (all "
-                +(_hashSize >> 3)+" slots -- suspect a DoS attack based on hash collisions."
-                +" You can disable the check via `JsonFactory.Feature.FAIL_ON_SYMBOL_HASH_OVERFLOW`");
+        // 20-Mar-2021, tatu: [core#686]: should use Jackson-specific exception
+        //    (to use new "processing limit" exception when available)
+        throw new StreamReadException(null,
+"Spill-over slots in symbol table with "+_count
++" entries, hash area of "+_hashSize+" slots is now full (all "
++(_hashSize >> 3)+" slots -- suspect a DoS attack based on hash collisions."
++" You can disable the check via `TokenStreamFactory.Feature.FAIL_ON_SYMBOL_HASH_OVERFLOW`");
     }
 
     static int _calcTertiaryShift(int primarySlots)

src/main/java/com/fasterxml/jackson/core/sym/CharsToNameCanonicalizer.java

@@ -4,6 +4,7 @@
 import java.util.BitSet;
 import java.util.concurrent.atomic.AtomicReference;
 
+import com.fasterxml.jackson.core.exc.StreamReadException;
 import com.fasterxml.jackson.core.json.JsonFactory;
 import com.fasterxml.jackson.core.util.InternCache;
 
@@ -531,7 +532,7 @@ private void _handleSpillOverflow(int bucketIndex, Bucket newBucket, int mainInd
             if (_overflows.get(bucketIndex)) {
                 // Has happened once already for this bucket index, so probably not coincidental...
                 if (JsonFactory.Feature.FAIL_ON_SYMBOL_HASH_OVERFLOW.enabledIn(_flags)) {
-                    reportTooManyCollisions(MAX_COLL_CHAIN_LENGTH);
+                    _reportTooManyCollisions(MAX_COLL_CHAIN_LENGTH);
                 }
                 // but even if we don't fail, we will stop canonicalizing as safety measure
                 // (so as not to cause problems with PermGen)
@@ -700,9 +701,13 @@ private void rehash() {
         }
     }
 
-    protected void reportTooManyCollisions(int maxLen) {
-        throw new IllegalStateException("Longest collision chain in symbol table (of size "+_size
-                +") now exceeds maximum, "+maxLen+" -- suspect a DoS attack based on hash collisions");
+    // 20-Mar-2021, tatu: [core#686]: should use Jackson-specific exception
+    //    (to use new "processing limit" exception when available)
+    protected void _reportTooManyCollisions(int maxLen) {
+        throw new StreamReadException(null,
+"Longest collision chain in symbol table (of size "+_size
++") now exceeds maximum, "+maxLen+" -- suspect a DoS attack based on hash collisions."
++" You can disable the check via `TokenStreamFactory.Feature.FAIL_ON_SYMBOL_HASH_OVERFLOW`");
     }
 
     // Diagnostics method that will verify that internal data structures are consistent;

src/test/java/com/fasterxml/jackson/core/sym/TestHashCollisionChars.java

@@ -63,8 +63,9 @@ public void testReaderCollisions() throws Exception
                 ;
             }
             fail("Should have failed");
-        } catch (IllegalStateException e) {
-            verifyException(e, "hash collision");
+        } catch (JacksonException e) {
+            verifyException(e, "Longest collision chain in symbol table");
+            verifyException(e, "suspect a DoS attack");
         }
         p.close();