Recently I had a customer that was receiving errors from an Authorize.Net web submit form in their shopping cart. The error simply stated:

“The gateway no longer supports the requested method of integration.”

While doing some digging I found that they were using a very old web submit method that Authorize.Net no longer supported. There were two ways to fix the problem:

1. Change to AIM method of submission, which required an SSL certificate that the client did not have.
2. Change to SIM method of submission, which required either PHP 5.1.2 installed to use the hash_hmac function, or for PHP 4.3.9 it required that mhash be installed on the server.

Since the client did not want to spend the extra cash for the SSL certificate, and I could not install PHP 5.1.2 because I had too many other clients on the server that were not ready for the upgrade, I decided to do some searching for a way to install mhash.

It turned out that the Red Hat repositories did not carry php-mhash for RHEL 4, so this meant I needed to look in other areas. After reading many different blog and BB postings saying that it required an install, then a recompile of PHP I started to get a little worried. I did not look forward to recompiling PHP.

Finally I found some posts that brought a ray of hope. There are RPMs available to install php-mhash without the PHP recompile, but it required that libmhash be installed first. Here are the steps I followed:

• I went to http://dag.wieers.com/packages/libmhash/ and downloaded the newest version of libmhash for my server.
• Then I installed using the following to satisfy dependencies of mhash:

  rpm -iv libmhash-0.9.1-1.rhel3.dag.i386.rpm

• Next I downloaded the php-mhash by using:

  wget ftp://rpmfind.net/linux/sourceforge/p/ph/phprpms/php-mhash-4.3.2-19.ent.2.i386.rpm

• I followed that by installing it using:

  rpm -iv php-mhash-4.3.2-19.ent.2.i386.rpm

After following those steps I created a phpinfo script to see that everything went well:

I could now plainly see that mhash was installed perfectly, and with further tests I confirmed it was working.