{"id":14064,"date":"2020-05-11T08:46:52","date_gmt":"2020-05-11T06:46:52","guid":{"rendered":"https:\/\/daniel.haxx.se\/blog\/?p=14064"},"modified":"2020-05-11T08:51:01","modified_gmt":"2020-05-11T06:51:01","slug":"manual-curl-curl","status":"publish","type":"post","link":"https:\/\/daniel.haxx.se\/blog\/2020\/05\/11\/manual-curl-curl\/","title":{"rendered":"Manual cURL cURL"},"content":{"rendered":"\n
\"\"<\/figure><\/div>\n\n\n\n

The HP Color LaserJet CP3525 Printer looks like any other ordinary printer done by HP. But there’s a difference!<\/p>\n\n\n\n

A friend of mine fell over this gem, and told me. <\/p>\n\n\n\n

TCP\/IP Settings<\/h2>\n\n\n\n

If you go to the machine’s TCP\/IP settings using the built-in web server, the printer offers the ordinary network configure options but also one that sticks out a little exta. The “Manual cURL cURL” option<\/em>! It looks like this:<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

I could easily confirm that this is genuine. I did this screenshot above by just googling for the string and printer model, since there appears to exist printers like this exposing their settings web server to the Internet. Hilarious!<\/p>\n\n\n\n

What?<\/h2>\n\n\n\n

How on earth did that string end up there? Certainly there’s no relation to curl at all except for the actual name used there? Is it a sign that there’s basically no humans left at HP that understand what the individual settings on that screen are actually meant for?<\/p>\n\n\n\n

Given the contents in the text field, a URL containing the letters WPAD twice, I can only presume this field is actually meant for Web Proxy Auto-Discovery<\/a>. I spent some time trying to find the user manual for this printer configuration screen but failed. It would’ve been fun to find “manual cURL cURL” described in a manual! They do offer a busload of various manuals<\/a>, maybe I just missed the right one.<\/p>\n\n\n\n

Does it use curl?<\/h2>\n\n\n\n

Yes, it seems HP generally use curl at least as I found the “Open-Source Software License Agreements for HP LaserJet and ScanJet Printers<\/a>” and it contains the curl license:<\/p>\n\n\n\n

\"\"
The curl license as found in the HP printer open source report.<\/figcaption><\/figure>\n\n\n\n

HP using curl for Print-Uri?<\/h2>\n\n\n\n

Independently, someone else recently told me about another possible HP + curl connection. This user said his HP printer makes HTTP requests using the user-agent libcurl-agent\/1.0<\/code>:<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

I haven’t managed to get this confirmed by anyone else (although the license snippet above certainly implies they use curl) and that particular user-agent string has been used everywhere for a long time, as I believe it is copied widely from the popular libcurl example getinmemory.c<\/a> where I made up the user-agent and put it there already in 2004.<\/p>\n\n\n\n

Credits<\/h2>\n\n\n\n

Frank Gevaerts tricked me into going down this rabbit hole as he told me about this string.<\/p>\n","protected":false},"excerpt":{"rendered":"

The HP Color LaserJet CP3525 Printer looks like any other ordinary printer done by HP. But there’s a difference! A friend of mine fell over this gem, and told me. TCP\/IP Settings If you go to the machine’s TCP\/IP settings using the built-in web server, the printer offers the ordinary network configure options but also … Continue reading Manual cURL cURL<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":5,"featured_media":11315,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[33,89,299],"class_list":["post-14064","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-curl","tag-curl-and-libcurl","tag-funny","tag-printer"],"_links":{"self":[{"href":"https:\/\/daniel.haxx.se\/blog\/wp-json\/wp\/v2\/posts\/14064","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/daniel.haxx.se\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/daniel.haxx.se\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/daniel.haxx.se\/blog\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/daniel.haxx.se\/blog\/wp-json\/wp\/v2\/comments?post=14064"}],"version-history":[{"count":8,"href":"https:\/\/daniel.haxx.se\/blog\/wp-json\/wp\/v2\/posts\/14064\/revisions"}],"predecessor-version":[{"id":14092,"href":"https:\/\/daniel.haxx.se\/blog\/wp-json\/wp\/v2\/posts\/14064\/revisions\/14092"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/daniel.haxx.se\/blog\/wp-json\/wp\/v2\/media\/11315"}],"wp:attachment":[{"href":"https:\/\/daniel.haxx.se\/blog\/wp-json\/wp\/v2\/media?parent=14064"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/daniel.haxx.se\/blog\/wp-json\/wp\/v2\/categories?post=14064"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/daniel.haxx.se\/blog\/wp-json\/wp\/v2\/tags?post=14064"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}