Issue #9554 - add javadoc for illegal vchar methods and move to HttpTokens

Signed-off-by: Lachlan Roberts <lachlan@webtide.com>

jetty-http/src/main/java/org/eclipse/jetty/http/HttpTokens.java

@@ -231,5 +231,60 @@ public class HttpTokens
             }
         }
     }
+
+    /**
+     * This is used when decoding to not decode illegal characters based on RFC9110.
+     * CR, LF, or NUL are replaced with ' ', all other control and multibyte characters
+     * are replaced with '?'. If this is given a legal character the same value will be returned.
+     *
+     * @param c the character to test.
+     * @return the original character or the replacement character ' ' or '?'.
+     */
+    public static char sanitizeFieldVchar(char c)
+    {
+        switch (c)
+        {
+            // A recipient of CR, LF, or NUL within a field value MUST either reject the message
+            // or replace each of those characters with SP before further processing
+            case '\r':
+            case '\n':
+            case 0x00:
+                return ' ';
+
+            default:
+                if (c >= 256 || c < ' ')
+                    return '?';
+        }
+
+        return c;
+    }
+
+    /**
+     * This is used when decoding to not decode illegal characters based on RFC9110.
+     * CR, LF, or NUL are replaced with ' ', all other control and multibyte characters
+     * are replaced with '?'. If this is given a legal character the same value will be returned.
+     *
+     * @param i the character to test.
+     * @return the original character or the replacement character ' ' or '?'.
+     */
+    public static int sanitizeFieldVchar(int i)
+    {
+        if (i > Character.MAX_VALUE)
+            return '?';
+        return sanitizeFieldVchar((char)i);
+    }
+
+    /**
+     * Checks whether this is an invalid VCHAR based on RFC9110.
+     * If this not a valid ISO-8859-1 character or a control character
+     * we say that it is illegal.
+     *
+     * @param c the character to test.
+     * @return true if this is invalid VCHAR.
+     */
+    public static boolean isIllegalFieldVchar(char c)
+    {
+        return (c >= 256 || c < ' ');
+    }
 }
 

jetty-http/src/main/java/org/eclipse/jetty/http/compression/Huffman.java

@@ -346,47 +346,4 @@ public class Huffman
             }
         }
     }
-
-    public static boolean isIllegalCharacter(char c)
-    {
-        return (c >= 256 || c < ' ');
-    }
-
-    public static char getReplacementCharacter(char c)
-    {
-        switch (c)
-        {
-            // A recipient of CR, LF, or NUL within a field value MUST either reject the message
-            // or replace each of those characters with SP before further processing
-            case '\r':
-            case '\n':
-            case 0x00:
-                return ' ';
-
-            default:
-                if (c >= 256 || c < ' ')
-                    return '?';
-        }
-
-        return c;
-    }
-
-    public static int getReplacementCharacter(int i)
-    {
-        switch (i)
-        {
-            // A recipient of CR, LF, or NUL within a field value MUST either reject the message
-            // or replace each of those characters with SP before further processing
-            case '\r':
-            case '\n':
-            case 0x00:
-                return ' ';
-
-            default:
-                if (i >= 256 || i < ' ')
-                    return '?';
-        }
-
-        return i;
-    }
 }

jetty-http/src/main/java/org/eclipse/jetty/http/compression/HuffmanDecoder.java

@@ -15,6 +15,7 @@ package org.eclipse.jetty.http.compression;
 
 import java.nio.ByteBuffer;
 
+import org.eclipse.jetty.http.HttpTokens;
 import org.eclipse.jetty.util.CharsetStringBuilder;
 
 import static org.eclipse.jetty.http.compression.Huffman.rowbits;
@@ -72,7 +73,7 @@ public class HuffmanDecoder
 
                     // terminal node
                     int i = 0xFF & rowsym[_node];
-                    i = Huffman.getReplacementCharacter(i);
+                    i = HttpTokens.sanitizeFieldVchar(i);
                     _builder.append((byte)i);
                     _bits -= rowbits[_node];
                     _node = 0;
@@ -107,7 +108,7 @@ public class HuffmanDecoder
             }
 
             int i = 0xFF & rowsym[_node];
-            i = Huffman.getReplacementCharacter(i);
+            i = HttpTokens.sanitizeFieldVchar(i);
             _builder.append((byte)i);
             _bits -= rowbits[_node];
             _node = 0;

jetty-http/src/main/java/org/eclipse/jetty/http/compression/HuffmanEncoder.java

@@ -15,6 +15,8 @@ package org.eclipse.jetty.http.compression;
 
 import java.nio.ByteBuffer;
 
+import org.eclipse.jetty.http.HttpTokens;
+
 import static org.eclipse.jetty.http.compression.Huffman.CODES;
 import static org.eclipse.jetty.http.compression.Huffman.LCCODES;
 
@@ -67,7 +69,7 @@ public class HuffmanEncoder
         for (int i = 0; i < len; i++)
         {
             char c = s.charAt(i);
-            if (Huffman.isIllegalCharacter(c))
+            if (HttpTokens.isIllegalFieldVchar(c))
                 return -1;
             needed += table[c][1];
         }
@@ -88,7 +90,7 @@ public class HuffmanEncoder
         for (int i = 0; i < len; i++)
         {
             char c = s.charAt(i);
-            if (Huffman.isIllegalCharacter(c))
+            if (HttpTokens.isIllegalFieldVchar(c))
                  throw new IllegalArgumentException();
             int code = table[c][0];
             int bits = table[c][1];

jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/HpackEncoder.java

@@ -25,10 +25,10 @@ import org.eclipse.jetty.http.HttpHeader;
 import org.eclipse.jetty.http.HttpMethod;
 import org.eclipse.jetty.http.HttpScheme;
 import org.eclipse.jetty.http.HttpStatus;
+import org.eclipse.jetty.http.HttpTokens;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.http.MetaData;
 import org.eclipse.jetty.http.PreEncodedHttpField;
-import org.eclipse.jetty.http.compression.Huffman;
 import org.eclipse.jetty.http.compression.HuffmanEncoder;
 import org.eclipse.jetty.http.compression.NBitIntegerEncoder;
 import org.eclipse.jetty.http2.hpack.HpackContext.Entry;
@@ -468,7 +468,7 @@ public class HpackEncoder
             for (int i = 0; i < value.length(); i++)
             {
                 char c = value.charAt(i);
-                c = Huffman.getReplacementCharacter(c);
+                c = HttpTokens.sanitizeFieldVchar(c);
                 buffer.put((byte)c);
             }
         }