JSON support was not enabled-Modsecurity

Question

1) I have compiled modsecurity using YAJL using --with-yajl but in the config log I see that the yajl library is not picked and in the modsecurity log I get "JSON support was not enabled"

Answer 1

I initially had mod_security working with PHP 5.5 and Apache 2.4, with Ubuntu 12.04, but after enabling JSON request inspection I got the same error as you reported.

To fix it, I had to make yajl, re-compile mod_security with the yajl configure option, and then ensure that Apache was using the updated mod_security, and restart Apache.

mod_security was then able to successfully parse json request body and not output the error any longer.

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I went to http://lloyd.github.io/yajl/ and found the download package for yajl-2.1.0, and then referred to https://gist.github.com/rpfilomeno/1140359f4bd360137a98.

For example:

tar -xvzf lloyd-yajl-2.1.0-0-ga0ecdde.tar.gz cd lloyd-yajl-66cb08c/ sudo ./configure sudo make sudo make install sudo ldconfig That should install yajl. Then cd to the folder with the mod_security files, and run

cd ../modsecurity-2.9.1/ sudo ./configure --with-yajl="/usr/local/lib /usr/local" sudo make sudo make install

I then configured it to run with Apache 2.4, and have been able to parse requests with a JSON body.

*Note that when making yajl, if there is an error relating to cmake not being installed, run the following sudo apt-get install cmake, and then try making it again.

Answer 2

Check your config.log if it has following

checking for libyajl config script... no
checking for yajl install... no
configure: optional yajl library not found

Then create a link to yajl.pc as

# ln -s /usr/local/share/pkgconfig/yajl.pc /usr/share/pkgconfig/yajl.pc

In my case file yajl.pc was in /usr/local/share/pkgconfig/ location. If you cannot find it there try " find / -name yajl.pc " to locate it.

Hope this helps you.