From d81b4c952dae3468e73f4df701c62ac3a8644ba0 Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Tue, 8 Aug 2023 15:40:49 +0200 Subject: BUG/MINOR: h2: reject more chars from the :path pseudo header 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 (cherry picked from commit 462a8600ce9e478573a957e046b446a7dcffd286) Signed-off-by: Amaury Denoyelle (cherry picked from commit 648e59e30723b8fd4e71aab02cb679f6ea7446e7) Signed-off-by: Amaury Denoyelle (cherry picked from commit c8e07f2fd8b5462527f102f7145d6027c0d041da) [wt: minor ctx adjustments] Signed-off-by: Willy Tarreau (cherry picked from commit af232e47e6264122bed3681210b054ff38ec8de8) Signed-off-by: Willy Tarreau (cherry picked from commit e0c9008874b89621449f7ff3e9bc6db4e94fac6d) [wt: note: added as well for legacy mode, though since h2 is turned to h1 in this mode, this will be rejected anyway] Signed-off-by: Willy Tarreau (cherry picked from commit ad05bf865cdc77e1c48d2e608ef8c39bd6c08c31) [wt: dropped the htx part] Signed-off-by: Willy Tarreau --- src/h2.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/src/h2.c b/src/h2.c index cb40b2e1b..ff8ae4572 100644 --- a/src/h2.c +++ b/src/h2.c @@ -208,9 +208,15 @@ int h2_make_h1_request(struct http_hdr *list, char *out, int osize, unsigned int /* RFC7540#10.3: intermediaries forwarding to HTTP/1 must take care of * rejecting NUL, CR and LF characters. */ - 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) */ -- 2.35.3