id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
1056	Maximum Content-Length value	davehope@…		"In troubleshooting an issue I'm having publishing a Microsoft SSTP service (1) via ngx_http_proxy_module it appears that nginx returns a ""400 Bad Request"" when the Content-Length request header is a certain size.

{{{
2016/08/20 13:55:41 [debug] 5524#0: *1 http process request line
2016/08/20 13:55:41 [debug] 5524#0: *1 http request line: ""SSTP_DUPLEX_POST /sra_{BA195980-CD49-458b-9E23-C84EE0ADCD75}/ HTTP/1.1""
2016/08/20 13:55:41 [debug] 5524#0: *1 http uri: ""/sra_{BA195980-CD49-458b-9E23-C84EE0ADCD75}/""
2016/08/20 13:55:41 [debug] 5524#0: *1 http args: """"
2016/08/20 13:55:41 [debug] 5524#0: *1 http exten: """"
2016/08/20 13:55:41 [debug] 5524#0: *1 http process request header line
2016/08/20 13:55:41 [debug] 5524#0: *1 http header: ""SSTPCORRELATIONID: {D88F83A0-42C4-4835-95AA-1BC32C58C26A}""
2016/08/20 13:55:41 [debug] 5524#0: *1 http header: ""Content-Length: 18446744073709551615""
2016/08/20 13:55:41 [debug] 5524#0: *1 http header: ""Host: xxxx""
2016/08/20 13:55:41 [debug] 5524#0: *1 http header done
2016/08/20 13:55:41 [info] 5524#0: *1 client sent invalid ""Content-Length"" header while reading client request headers, client: 10.99.99.74, server: xxxx, request: ""SSTP_DUPLEX_POST /sra_{BA195980-CD49-458b-9E23-C84EE0ADCD75}/ HTTP/1.1"", host: ""xxxx""
2016/08/20 13:55:41 [debug] 5524#0: *1 http finalize request: 400, ""/sra_{BA195980-CD49-458b-9E23-C84EE0ADCD75}/?"" a:1, c:1
2016/08/20 13:55:41 [debug] 5524#0: *1 event timer del: 7: 1471697801120
2016/08/20 13:55:41 [debug] 5524#0: *1 http special response: 400, ""/sra_{BA195980-CD49-458b-9E23-C84EE0ADCD75}/?""
2016/08/20 13:55:41 [debug] 5524#0: *1 http set discard body
2016/08/20 13:55:41 [debug] 5524#0: *1 xslt filter header
2016/08/20 13:55:41 [debug] 5524#0: *1 posix_memalign: 000000000137A860:4096 @16
2016/08/20 13:55:41 [debug] 5524#0: *1 HTTP/1.1 400 Bad Request
Server: nginx/1.6.2
Date: Sat, 20 Aug 2016 12:55:41 GMT
Content-Type: text/html
Content-Length: 172
Connection: close
}}}

An SSTP client will set the content-length request header to a constant size, 18446744073709551615 (corresponding to unsigned long long).

Following advise in #ngix, I've tried setting more_clear_input_headers from nginx-extras without success.

Looking at the HTTP RFC (2), it looks like a content-length value greater than or equal to 0 is a valid value.


[1] https://msdn.microsoft.com/en-us/library/cc247338.aspx
[2] https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.13"	defect	closed	minor		nginx-core	1.9.x	wontfix			Linux FW01 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt25-2+deb8u3 (2016-07-02) x86_64 GNU/Linux	"nginx version: nginx/1.6.2
TLS SNI support enabled
configure arguments: --with-cc-opt='-g -O2 -fstack-protector-strong -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2' --with-ld-opt=-Wl,-z,relro --prefix=/usr/share/nginx --conf-path=/etc/nginx/nginx.conf --http-log-path=/var/log/nginx/access.log --error-log-path=/var/log/nginx/error.log --lock-path=/var/lock/nginx.lock --pid-path=/run/nginx.pid --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --with-debug --with-pcre-jit --with-ipv6 --with-http_ssl_module --with-http_stub_status_module --with-http_realip_module --with-http_auth_request_module --with-http_addition_module --with-http_dav_module --with-http_geoip_module --with-http_gzip_static_module --with-http_image_filter_module --with-http_spdy_module --with-http_sub_module --with-http_xslt_module --with-mail --with-mail_ssl_module --add-module=/build/nginx-ryOGNl/nginx-1.6.2/debian/modules/nginx-auth-pam --add-module=/build/nginx-ryOGNl/nginx-1.6.2/debian/modules/nginx-dav-ext-module --add-module=/build/nginx-ryOGNl/nginx-1.6.2/debian/modules/nginx-echo --add-module=/build/nginx-ryOGNl/nginx-1.6.2/debian/modules/nginx-upstream-fair --add-module=/build/nginx-ryOGNl/nginx-1.6.2/debian/modules/ngx_http_substitutions_filter_module "