Opened 6 years ago

Closed 6 years ago

Last modified 6 years ago

#616 closed defect (invalid)

Authenticate header on proxy pass is length-limited?

Reported by: Arne B. Owned by:
Priority: minor Milestone:
Component: nginx-core Version: 1.4.x
Keywords: Cc:
uname -a: Linux mon 3.13.0-24-generic #46-Ubuntu SMP Thu Apr 10 19:11:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
nginx -V: nginx version: nginx/1.4.6 (Ubuntu)
built by gcc 4.8.2 (Ubuntu 4.8.2-16ubuntu6)
TLS SNI support enabled
configure arguments: --with-cc-opt='-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2' --with-ld-opt='-Wl,-Bsymbolic-functions -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_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/buildd/nginx-1.4.6/debian/modules/nginx-auth-pam --add-module=/build/buildd/nginx-1.4.6/debian/modules/nginx-dav-ext-module --add-module=/build/buildd/nginx-1.4.6/debian/modules/nginx-echo --add-module=/build/buildd/nginx-1.4.6/debian/modules/nginx-upstream-fair --add-module=/build/buildd/nginx-1.4.6/debian/modules/ngx_http_substitutions_filter_module

Description

I am trying to use nginx as a proxy for a protected resource.
Nginx is supposed to supply the credentials; a user of the
proxy is supposed to be able to access the protected resource
without entering any credentials

Followed some tutorials, and arrived at this problem:

This works:

    # Credentials on protected resource: king:isnaked
    location /protected/ {
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Authorization "Basic a2luZzppc25ha2Vk";
        proxy_pass http://1.2.3.4:1234;
    }

While this doesn't:

    # Credentials on protected resource: admin:a6a437
    location /protected/ {
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Authorization "Basic YWRtaW46YTZhNDM3Cg";
        proxy_pass http://1.2.3.4:1234;
    }

(I initially tried with even longer passwords, but came down to this.)

Change History (4)

comment:1 by Maxim Dounin, 6 years ago

Resolution: invalid
Status: newclosed

In the second example base64 encoding is invalid, there is no required padding, and this likely the reason why it doesn't work - you have to check with your backend for the details. In either case, there is no limit on length of headers added with proxy_set_header.

comment:2 by Arne B., 6 years ago

Resolution: invalid
Status: closedreopened

Ah, yes, that must have been a copy and paste mistake (I did a lot of trials, the ticket describes only two of them).

Anyhow, I retested with the correct encoding YWRtaW46YTZhNDM3Cg== to be 100% sure that I didn't do a stupid mistake yesterday.

I can confirm, it does not work. Hence, I am reopening.

Last edited 6 years ago by Arne B. (previous) (diff)

comment:3 by Maxim Dounin, 6 years ago

Resolution: invalid
Status: reopenedclosed

As already shown above, if something doesn't work for you, it doesn't mean that there is a bug. There is no limit you are claiming, and the bug is certainly invalid, closing again. You may want to use mailing list for further question, see http://nginx.org/en/support.html.

As for stupid mistakes, please note that "YWRtaW46YTZhNDM3Cg==" includes newline, and it's highly unlikely it's something your backend expects to be in a password.

comment:4 by Arne B., 6 years ago

Ah, the newline. Stupid me. Sorry for opening this bug prematurely then.
Thanks

Last edited 6 years ago by Arne B. (previous) (diff)
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