BUG/MINOR: h2: reject more chars from the :path pseudo header

Origin: https://git.haproxy.org/?p=haproxy-2.2.git;a=commit;h=e0c9008874b89621449f7ff3e9bc6db4e94fac6d

This is the h2 version of this previous fix:

    BUG/MINOR: h1: do not accept '#' as part of the URI component

In addition to the current NUL/CR/LF, this will also reject all other
control chars, the space and '#' from the :path pseudo-header, to avoid
taking the '#' for a part of the path. It's still possible to fall back
to the previous behavior using "option accept-invalid-http-request".

This patch modifies the request parser to change the ":path" pseudo header
validation function with a new one that rejects 0x00-0x1F (control chars),
space and '#'. This way such chars will be dropped early in the chain, and
the search for '#' doesn't incur a second pass over the header's value.

This should be progressively backported to stable versions, along with the
following commits it relies on:

     REGTESTS: http-rules: add accept-invalid-http-request for normalize-uri tests
     REORG: http: move has_forbidden_char() from h2.c to http.h
     MINOR: ist: add new function ist_find_range() to find a character range
     MINOR: http: add new function http_path_has_forbidden_char()
     MINOR: h2: pass accept-invalid-http-request down the request parser

(cherry picked from commit b3119d4fb4588087e2483a80b01d322683719e29)
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit 462a8600ce9e478573a957e046b446a7dcffd286)
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit 648e59e30723b8fd4e71aab02cb679f6ea7446e7)
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit c8e07f2fd8b5462527f102f7145d6027c0d041da)
[wt: minor ctx adjustments]
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit af232e47e6264122bed3681210b054ff38ec8de8)
Signed-off-by: Willy Tarreau <w@1wt.eu>
Gbp-Pq: Name BUG-MINOR-h2-reject-more-chars-from-the-path-pseudo-.patch

diff --git a/src/h2.c b/src/h2.c
index c19ea37c0749cbd3dd8a7bd5368399a97ca145ce..79116fe88b6977e23d77f9841d17659c81714eae 100644 (file)
--- a/src/h2.c
+++ b/src/h2.c
@@ -398,11 +398,18 @@ int h2_make_htx_request(struct http_hdr *list, struct htx *htx, unsigned int *ms
                }
 
                /* RFC7540#10.3: intermediaries forwarding to HTTP/1 must take care of
-                * rejecting NUL, CR and LF characters.
+                * rejecting NUL, CR and LF characters. For :path we reject all CTL
+                * chars, spaces, and '#'.
                 */
-               ctl = ist_find_ctl(list[idx].v);
-               if (unlikely(ctl) && has_forbidden_char(list[idx].v, ctl))
-                       goto fail;
+               if (phdr == H2_PHDR_IDX_PATH && !relaxed) {
+                       ctl = ist_find_range(list[idx].v, 0, '#');
+                       if (unlikely(ctl) && http_path_has_forbidden_char(list[idx].v, ctl))
+                               goto fail;
+               } else {
+                       ctl = ist_find_ctl(list[idx].v);
+                       if (unlikely(ctl) && has_forbidden_char(list[idx].v, ctl))
+                               goto fail;
+               }
 
                if (phdr > 0 && phdr < H2_PHDR_NUM_ENTRIES) {
                        /* insert a pseudo header by its index (in phdr) and value (in value) */