Use the new "dcb" and "dcz" content encodings of Compressed Dictionary

The spec of Compression Dictionary Transport has been changed to use
new `dcb` and `dcz` content encodings.
httpwg/http-extensions#2784

To follow the spec change, this CL changes the Chromium implementation
and tests as follows:

- Use "dcb" content encoding name instead of "br-d".
- Use "dcz" content encoding name instead of "zstd-d".
- Remove the "Content-Dictionary" response header.
- Check the magic number and the sha256 hash in the head of the
  Dictionary-Compressed streams using
  SharedDictionaryHeaderCheckerSourceStream.
- Re-generate test files using the new content encodings.

Bug: 1413922
Change-Id: I4f2f40c1f0c3666b4f0b54e34ad966ffccadd96b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5552563
Reviewed-by: Kenichi Ishibashi <bashi@chromium.org>
Commit-Queue: Tsuyoshi Horo <horo@chromium.org>
Reviewed-by: Patrick Meenan <pmeenan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1304826}

fetch/compression-dictionary/dictionary-decompression.tentative.https.html

@@ -20,7 +20,7 @@
 
   // Check if the data compressed using Brotli with the dictionary can be
   // decompressed.
-  const data_url = `${kCompressedDataPath}?content_encoding=br-d`;
+  const data_url = `${kCompressedDataPath}?content_encoding=dcb`;
   assert_equals(await (await fetch(data_url)).text(), kExpectedCompressedData);
 }, 'Decompresion using Brotli with the dictionary works as expected');
 
@@ -34,7 +34,7 @@
 
   // Check if the data compressed using Zstandard with the dictionary can be
   // decompressed.
-  const data_url = `${kCompressedDataPath}?content_encoding=zstd-d`;
+  const data_url = `${kCompressedDataPath}?content_encoding=dcz`;
   assert_equals(await (await fetch(data_url)).text(), kExpectedCompressedData);
 }, 'Decompresion using Zstandard with the dictionary works as expected');
 
@@ -50,7 +50,7 @@
   // Check if the data compressed using Brotli with the dictionary can be
   // decompressed.
   const data_url =
-      getRemoteHostUrl(`${kCompressedDataPath}?content_encoding=br-d`);
+      getRemoteHostUrl(`${kCompressedDataPath}?content_encoding=dcb`);
   assert_equals(await (await fetch(data_url)).text(), kExpectedCompressedData);
 }, 'Decompresion of a cross origin resource works as expected');
 

fetch/compression-dictionary/dictionary-fetch-with-link-element.tentative.https.html

@@ -41,7 +41,7 @@
       kDefaultDictionaryHashBase64);
   // Check if the data compressed using Brotli with the dictionary can be
   // decompressed.
-  const data_url = `${kCompressedDataPath}?content_encoding=br-d`;
+  const data_url = `${kCompressedDataPath}?content_encoding=dcb`;
   assert_equals(await (await fetch(data_url)).text(), kExpectedCompressedData);
 }, 'Fetch same origin dictionary using link element');
 
@@ -64,7 +64,7 @@
   // Check if the data compressed using Brotli with the dictionary can be
   // decompressed.
   const data_url =
-      getRemoteHostUrl(`${kCompressedDataPath}?content_encoding=br-d`);
+      getRemoteHostUrl(`${kCompressedDataPath}?content_encoding=dcb`);
   assert_equals(await (await fetch(data_url)).text(), kExpectedCompressedData);
 }, 'Fetch cross origin dictionary using link element');
 

fetch/compression-dictionary/dictionary-fetch-with-link-header.tentative.https.html

@@ -46,7 +46,7 @@
       kDefaultDictionaryHashBase64);
   // Check if the data compressed using Brotli with the dictionary can be
   // decompressed.
-  const data_url = `${kCompressedDataPath}?content_encoding=br-d`;
+  const data_url = `${kCompressedDataPath}?content_encoding=dcb`;
   assert_equals(await (await fetch(data_url)).text(), kExpectedCompressedData);
 }, 'Fetch same origin dictionary using link header');
 

fetch/compression-dictionary/resources/compressed-data.py

@@ -1,28 +1,31 @@
 def main(request, response):
     response.headers.set(b"Access-Control-Allow-Origin", b"*")
     response.headers.set(b"Content-Type", b"text/plain")
-    response.headers.set(
-        b"Content-Dictionary",
-        b":U5abz16WDg7b8KS93msLPpOB4Vbef1uRzoORYkJw9BY=:")
 
-    # `br_d_data` and `zstd_d_data` are generated using the following commands:
+    # `dcb_data` and `dcz_data` are generated using the following commands:
     #
     # $ echo "This is a test dictionary." > /tmp/dict
     # $ echo -n "This is compressed test data using a test dictionary" \
     #    > /tmp/data
-    # $ brotli -o /tmp/out.brd -D /tmp/dict /tmp/data
-    # $ xxd -p /tmp/out.brd | tr -d '\n' | sed 's/\(..\)/\\x\1/g'
-    br_d_data = b"\xa1\x98\x01\x80\x62\xa4\x4c\x1d\xdf\x12\x84\x8c\xae\xc2\xca\x60\x22\x07\x6e\x81\x05\x14\xc9\xb7\xc3\x44\x8e\xbc\x16\xe0\x15\x0e\xec\xc1\xee\x34\x33\x3e\x0d"
-    # $ zstd -o /tmp/out.zstdd -D /tmp/dict /tmp/data
-    # $ xxd -p /tmp/out.zstdd | tr -d '\n' | sed 's/\(..\)/\\x\1/g'
-    zstd_d_data = b"\x28\xb5\x2f\xfd\x24\x34\xf5\x00\x00\x98\x63\x6f\x6d\x70\x72\x65\x73\x73\x65\x64\x61\x74\x61\x20\x75\x73\x69\x6e\x67\x03\x00\x59\xf9\x73\x54\x46\x27\x26\x10\x9e\x99\xf2\xbc"
+    #
+    # $ echo -en '\xffDCB' > /tmp/out.dcb
+    # $ openssl dgst -sha256 -binary /tmp/dict >> /tmp/out.dcb
+    # $ brotli --stdout -D /tmp/dict /tmp/data >> /tmp/out.dcb
+    # $ xxd -p /tmp/out.dcb | tr -d '\n' | sed 's/\(..\)/\\x\1/g'
+    dcb_data = b"\xff\x44\x43\x42\x53\x96\x9b\xcf\x5e\x96\x0e\x0e\xdb\xf0\xa4\xbd\xde\x6b\x0b\x3e\x93\x81\xe1\x56\xde\x7f\x5b\x91\xce\x83\x91\x62\x42\x70\xf4\x16\xa1\x98\x01\x80\x62\xa4\x4c\x1d\xdf\x12\x84\x8c\xae\xc2\xca\x60\x22\x07\x6e\x81\x05\x14\xc9\xb7\xc3\x44\x8e\xbc\x16\xe0\x15\x0e\xec\xc1\xee\x34\x33\x3e\x0d"
+    # $ echo -en '\x5e\x2a\x4d\x18\x20\x00\x00\x00' > /tmp/out.dcz
+    # $ openssl dgst -sha256 -binary /tmp/dict >> /tmp/out.dcz
+    # $ zstd -D /tmp/dict -f -o /tmp/tmp.zstd /tmp/data
+    # $ cat /tmp/tmp.zstd >> /tmp/out.dcz
+    # $ xxd -p /tmp/out.dcz | tr -d '\n' | sed 's/\(..\)/\\x\1/g'
+    dcz_data = b"\x5e\x2a\x4d\x18\x20\x00\x00\x00\x53\x96\x9b\xcf\x5e\x96\x0e\x0e\xdb\xf0\xa4\xbd\xde\x6b\x0b\x3e\x93\x81\xe1\x56\xde\x7f\x5b\x91\xce\x83\x91\x62\x42\x70\xf4\x16\x28\xb5\x2f\xfd\x24\x34\xf5\x00\x00\x98\x63\x6f\x6d\x70\x72\x65\x73\x73\x65\x64\x61\x74\x61\x20\x75\x73\x69\x6e\x67\x03\x00\x59\xf9\x73\x54\x46\x27\x26\x10\x9e\x99\xf2\xbc"
 
     if b'content_encoding' in request.GET:
         content_encoding = request.GET.first(b"content_encoding")
         response.headers.set(b"Content-Encoding", content_encoding)
-        if content_encoding == b"br-d":
+        if content_encoding == b"dcb":
             # Send the pre compressed file
-            response.content = br_d_data
-        if content_encoding == b"zstd-d":
+            response.content = dcb_data
+        if content_encoding == b"dcz":
             # Send the pre compressed file
-            response.content = zstd_d_data
+            response.content = dcz_data