This is an automated email from the ASF dual-hosted git repository.
markt pushed a commit to branch 9.0.x
in repository https://gitbox.apache.org/repos/asf/tomcat.git
The following commit(s) were added to refs/heads/9.0.x by this push:
new 7b51ac0f20 Optimise conversion of HTTP/2 header field names to lower
case
7b51ac0f20 is described below
commit 7b51ac0f205a0a7906d8c1fcadc2065c7fca76e1
Author: Mark Thomas <[email protected]>
AuthorDate: Fri Apr 17 11:15:16 2026 +0100
Optimise conversion of HTTP/2 header field names to lower case
---
java/org/apache/coyote/http2/HPackHuffman.java | 28 +++++++++++++++++-----
java/org/apache/coyote/http2/Hpack.java | 7 ++++--
java/org/apache/coyote/http2/HpackEncoder.java | 19 +++++++++++----
test/org/apache/coyote/http2/TestHPackHuffman.java | 2 +-
webapps/docs/changelog.xml | 4 ++++
5 files changed, 46 insertions(+), 14 deletions(-)
diff --git a/java/org/apache/coyote/http2/HPackHuffman.java
b/java/org/apache/coyote/http2/HPackHuffman.java
index 726dbba9a5..0b669a7590 100644
--- a/java/org/apache/coyote/http2/HPackHuffman.java
+++ b/java/org/apache/coyote/http2/HPackHuffman.java
@@ -19,6 +19,7 @@ package org.apache.coyote.http2;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.HashSet;
+import java.util.Locale;
import java.util.Set;
import org.apache.tomcat.util.res.StringManager;
@@ -437,8 +438,29 @@ public class HPackHuffman {
* @param forceLowercase If the string should be encoded in lower case
*
* @return true if encoding succeeded
+ *
+ * @deprecated Unused. This method will be removed in Tomcat 12 onwards.
*/
+ @Deprecated
public static boolean encode(ByteBuffer buffer, String toEncode, boolean
forceLowercase) {
+ if (forceLowercase) {
+ return encode(buffer, toEncode.toLowerCase(Locale.ENGLISH));
+ } else {
+ return encode(buffer, toEncode);
+ }
+ }
+
+
+ /**
+ * Encodes the given string into the buffer. If there is not enough space
in the buffer, or the encoded version is
+ * bigger than the original it will return false and not modify the
buffers position.
+ *
+ * @param buffer The buffer to encode into
+ * @param toEncode The string to encode
+ *
+ * @return true if encoding succeeded
+ */
+ public static boolean encode(ByteBuffer buffer, String toEncode) {
if (buffer.remaining() <= toEncode.length()) {
return false;
}
@@ -453,9 +475,6 @@ public class HPackHuffman {
throw new IllegalArgumentException(
sm.getString("hpack.invalidCharacter",
Character.toString(c), Integer.valueOf(c)));
}
- if (forceLowercase) {
- c = Hpack.toLower(c);
- }
HuffmanCode code = HUFFMAN_CODES[c];
length += code.length;
}
@@ -469,9 +488,6 @@ public class HPackHuffman {
byte currentBufferByte = 0;
for (int i = 0; i < toEncode.length(); ++i) {
char c = toEncode.charAt(i);
- if (forceLowercase) {
- c = Hpack.toLower(c);
- }
HuffmanCode code = HUFFMAN_CODES[c];
if (code.length + bytePos <= 8) {
// it fits in the current byte
diff --git a/java/org/apache/coyote/http2/Hpack.java
b/java/org/apache/coyote/http2/Hpack.java
index 238a1a3720..cbae7e78a7 100644
--- a/java/org/apache/coyote/http2/Hpack.java
+++ b/java/org/apache/coyote/http2/Hpack.java
@@ -217,7 +217,10 @@ final class Hpack {
}
}
-
+ /*
+ * Unused. Will be removed in Tomcat 12 onwards.
+ */
+ @Deprecated
static char toLower(char c) {
if (c >= 'A' && c <= 'Z') {
return (char) (c + LOWER_DIFF);
@@ -225,7 +228,7 @@ final class Hpack {
return c;
}
+
private Hpack() {
}
-
}
diff --git a/java/org/apache/coyote/http2/HpackEncoder.java
b/java/org/apache/coyote/http2/HpackEncoder.java
index 391423ea8b..e4b99c5429 100644
--- a/java/org/apache/coyote/http2/HpackEncoder.java
+++ b/java/org/apache/coyote/http2/HpackEncoder.java
@@ -136,8 +136,11 @@ class HpackEncoder {
}
}
while (it < currentHeaders.size()) {
- // FIXME: Review lowercase policy
- String headerName =
headers.getName(it).toString().toLowerCase(Locale.US);
+ /*
+ * Need to ensure header names are lower case from this point
onwards as table lookups etc. are
+ * case-sensitive.
+ */
+ String headerName =
headers.getName(it).toString().toLowerCase(Locale.ENGLISH);
boolean skip = false;
if (firstPass) {
if (headerName.charAt(0) != ':') {
@@ -211,23 +214,29 @@ class HpackEncoder {
return State.COMPLETE;
}
+ /*
+ * headerName must be lower case by the time this method is called.
+ *
+ * The exception to the above rule is test cases which may deliberately
use some upper case characters to test how
+ * Tomcat responds to such invalid input.
+ */
private void writeHuffmanEncodableName(ByteBuffer target, String
headerName) {
if (hpackHeaderFunction.shouldUseHuffman(headerName)) {
- if (HPackHuffman.encode(target, headerName, true)) {
+ if (HPackHuffman.encode(target, headerName)) {
return;
}
}
target.put((byte) 0); // to use encodeInteger we need to place the
first byte in the buffer.
Hpack.encodeInteger(target, headerName.length(), 7);
for (int j = 0; j < headerName.length(); ++j) {
- target.put((byte) Hpack.toLower(headerName.charAt(j)));
+ target.put((byte) headerName.charAt(j));
}
}
private void writeHuffmanEncodableValue(ByteBuffer target, String
headerName, String val) {
if (hpackHeaderFunction.shouldUseHuffman(headerName, val)) {
- if (!HPackHuffman.encode(target, val, false)) {
+ if (!HPackHuffman.encode(target, val)) {
writeValueString(target, val);
}
} else {
diff --git a/test/org/apache/coyote/http2/TestHPackHuffman.java
b/test/org/apache/coyote/http2/TestHPackHuffman.java
index 7b970d499b..5aaf6ac8f9 100644
--- a/test/org/apache/coyote/http2/TestHPackHuffman.java
+++ b/test/org/apache/coyote/http2/TestHPackHuffman.java
@@ -31,7 +31,7 @@ public class TestHPackHuffman {
public void testValueLeftBrace() throws Exception {
ByteBuffer buf = ByteBuffer.allocate(10);
String data = "x-value{";
- HPackHuffman.encode(buf, data, false);
+ HPackHuffman.encode(buf, data);
buf.flip();
// Remove the header byte (in Tomcat this is parsed before the bytes
are passed to the HPACK decoder)
diff --git a/webapps/docs/changelog.xml b/webapps/docs/changelog.xml
index 891a68f7bc..7b84f8059a 100644
--- a/webapps/docs/changelog.xml
+++ b/webapps/docs/changelog.xml
@@ -175,6 +175,10 @@
decoding that could result in a valid header triggering an unexpected
connection close. (markt)
</fix>
+ <fix>
+ Refactor HTTP/2 HPACK encoding so field names are only converted to
+ lower case once during the encoding process. (markt)
+ </fix>
</changelog>
</subsection>
<subsection name="Other">
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