From 831c077c6d3a9466417f8a7b310177fca946a4cc Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Wed, 2 Aug 2023 23:34:48 +0200
Subject: [PATCH] http: return error when receiving too large header set
To avoid abuse. The limit is set to 300 KB for the accumulated size of
all received HTTP headers for a single response. Incomplete research
suggests that Chrome uses a 256-300 KB limit, while Firefox allows up to
1MB.
Closes #11582
(cherry picked from commit 3ee79c1674fd6f99e8efca52cd7510e08b766770)
Signed-off-by: Jan Macku <jamacku@redhat.com>
---
lib/c-hyper.c | 12 +++++++-----
lib/cf-h1-proxy.c | 4 +++-
lib/http.c | 34 ++++++++++++++++++++++++++++++----
lib/http.h | 9 +++++++++
lib/pingpong.c | 4 +++-
lib/urldata.h | 17 ++++++++---------
6 files changed, 60 insertions(+), 20 deletions(-)
diff --git a/lib/c-hyper.c b/lib/c-hyper.c
index c29983c0b..0b9d9ab47 100644
--- a/lib/c-hyper.c
+++ b/lib/c-hyper.c
@@ -182,8 +182,11 @@ static int hyper_each_header(void *userdata,
}
}
- data->info.header_size += (curl_off_t)len;
- data->req.headerbytecount += (curl_off_t)len;
+ result = Curl_bump_headersize(data, len, FALSE);
+ if(result) {
+ data->state.hresult = result;
+ return HYPER_ITER_BREAK;
+ }
return HYPER_ITER_CONTINUE;
}
@@ -313,9 +316,8 @@ static CURLcode status_line(struct Curl_easy *data,
if(result)
return result;
}
- data->info.header_size += (curl_off_t)len;
- data->req.headerbytecount += (curl_off_t)len;
- return CURLE_OK;
+ result = Curl_bump_headersize(data, len, FALSE);
+ return result;
}
/*
diff --git a/lib/cf-h1-proxy.c b/lib/cf-h1-proxy.c
index c9b157c9b..b1d8cb618 100644
--- a/lib/cf-h1-proxy.c
+++ b/lib/cf-h1-proxy.c
@@ -587,7 +587,9 @@ static CURLcode recv_CONNECT_resp(struct Curl_cfilter *cf,
return result;
}
- data->info.header_size += (long)perline;
+ result = Curl_bump_headersize(data, perline, TRUE);
+ if(result)
+ return result;
/* Newlines are CRLF, so the CR is ignored as the line isn't
really terminated until the LF comes. Treat a following CR
diff --git a/lib/http.c b/lib/http.c
index e611d2789..ebf48660d 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -3918,6 +3918,29 @@ static CURLcode verify_header(struct Curl_easy *data)
return CURLE_OK;
}
+CURLcode Curl_bump_headersize(struct Curl_easy *data,
+ size_t delta,
+ bool connect_only)
+{
+ size_t bad = 0;
+ if(delta < MAX_HTTP_RESP_HEADER_SIZE) {
+ if(!connect_only)
+ data->req.headerbytecount += (unsigned int)delta;
+ data->info.header_size += (unsigned int)delta;
+ if(data->info.header_size > MAX_HTTP_RESP_HEADER_SIZE)
+ bad = data->info.header_size;
+ }
+ else
+ bad = data->info.header_size + delta;
+ if(bad) {
+ failf(data, "Too large response headers: %zu > %zu",
+ bad, MAX_HTTP_RESP_HEADER_SIZE);
+ return CURLE_RECV_ERROR;
+ }
+ return CURLE_OK;
+}
+
+
/*
* Read any HTTP header lines from the server and pass them to the client app.
*/
@@ -4165,8 +4188,9 @@ CURLcode Curl_http_readwrite_headers(struct Curl_easy *data,
if(result)
return result;
- data->info.header_size += (long)headerlen;
- data->req.headerbytecount += (long)headerlen;
+ result = Curl_bump_headersize(data, headerlen, FALSE);
+ if(result)
+ return result;
/*
* When all the headers have been parsed, see if we should give
@@ -4488,8 +4512,10 @@ CURLcode Curl_http_readwrite_headers(struct Curl_easy *data,
if(result)
return result;
- data->info.header_size += Curl_dyn_len(&data->state.headerb);
- data->req.headerbytecount += Curl_dyn_len(&data->state.headerb);
+ result = Curl_bump_headersize(data, Curl_dyn_len(&data->state.headerb),
+ FALSE);
+ if(result)
+ return result;
Curl_dyn_reset(&data->state.headerb);
}
diff --git a/lib/http.h b/lib/http.h
index df3b4e38b..4aeabc345 100644
--- a/lib/http.h
+++ b/lib/http.h
@@ -64,6 +64,10 @@ extern const struct Curl_handler Curl_handler_wss;
struct dynhds;
+CURLcode Curl_bump_headersize(struct Curl_easy *data,
+ size_t delta,
+ bool connect_only);
+
/* Header specific functions */
bool Curl_compareheader(const char *headerline, /* line to check */
const char *header, /* header keyword _with_ colon */
@@ -183,6 +187,11 @@ CURLcode Curl_http_auth_act(struct Curl_easy *data);
#define EXPECT_100_THRESHOLD (1024*1024)
#endif
+/* MAX_HTTP_RESP_HEADER_SIZE is the maximum size of all response headers
+ combined that libcurl allows for a single HTTP response, any HTTP
+ version. This count includes CONNECT response headers. */
+#define MAX_HTTP_RESP_HEADER_SIZE (300*1024)
+
#endif /* CURL_DISABLE_HTTP */
/****************************************************************************
diff --git a/lib/pingpong.c b/lib/pingpong.c
index f3f7cb93c..523bbec18 100644
--- a/lib/pingpong.c
+++ b/lib/pingpong.c
@@ -341,7 +341,9 @@ CURLcode Curl_pp_readresp(struct Curl_easy *data,
ssize_t clipamount = 0;
bool restart = FALSE;
- data->req.headerbytecount += (long)gotbytes;
+ result = Curl_bump_headersize(data, gotbytes, FALSE);
+ if(result)
+ return result;
pp->nread_resp += gotbytes;
for(i = 0; i < gotbytes; ptr++, i++) {
diff --git a/lib/urldata.h b/lib/urldata.h
index c45913b31..ddb2938d7 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -629,17 +629,16 @@ struct SingleRequest {
curl_off_t bytecount; /* total number of bytes read */
curl_off_t writebytecount; /* number of bytes written */
- curl_off_t headerbytecount; /* only count received headers */
- curl_off_t deductheadercount; /* this amount of bytes doesn't count when we
- check if anything has been transferred at
- the end of a connection. We use this
- counter to make only a 100 reply (without a
- following second response code) result in a
- CURLE_GOT_NOTHING error code */
-
curl_off_t pendingheader; /* this many bytes left to send is actually
header and not body */
struct curltime start; /* transfer started at this time */
+ unsigned int headerbytecount; /* only count received headers */
+ unsigned int deductheadercount; /* this amount of bytes doesn't count when
+ we check if anything has been transferred
+ at the end of a connection. We use this
+ counter to make only a 100 reply (without
+ a following second response code) result
+ in a CURLE_GOT_NOTHING error code */
enum {
HEADER_NORMAL, /* no bad header at all */
HEADER_PARTHEADER, /* part of the chunk is a bad header, the rest
@@ -1089,7 +1088,6 @@ struct PureInfo {
int httpversion; /* the http version number X.Y = X*10+Y */
time_t filetime; /* If requested, this is might get set. Set to -1 if the
time was unretrievable. */
- curl_off_t header_size; /* size of read header(s) in bytes */
curl_off_t request_size; /* the amount of bytes sent in the request(s) */
unsigned long proxyauthavail; /* what proxy auth types were announced */
unsigned long httpauthavail; /* what host auth types were announced */
@@ -1097,6 +1095,7 @@ struct PureInfo {
char *contenttype; /* the content type of the object */
char *wouldredirect; /* URL this would've been redirected to if asked to */
curl_off_t retry_after; /* info from Retry-After: header */
+ unsigned int header_size; /* size of read header(s) in bytes */
/* PureInfo members 'conn_primary_ip', 'conn_primary_port', 'conn_local_ip'
and, 'conn_local_port' are copied over from the connectdata struct in
--
2.41.0