Analysis The OpenSSL project, possibly the most widely used open-source cryptographic software, has a license to kill – specifically its own. But its effort to obtain permission to rewrite contributors' rights runs the risk of alienating the community that sustains it.

The software is licensed under the OpenSSL License, which includes its own terms and those dating back to the preceding SSLeay license.

Those driving the project announced plans to shift to a new license in 2015 and now the thousand or so people who have contributed code over the years have started receiving email messages asking them to grant permission to relicense their contributions under the Apache Software License, version 2.

Theo De Raadt, founder of OpenBSD, a contributor to OpenSSL, and creator of a LibreSSL – forked from OpenSSL in 2014 – expressed dissatisfaction with the relicensing campaign in a mailing list post, criticizing OpenSSL for failing to consult its community of authors.

"My worry is that the rights of the authors are being trampled upon, and they are only being given one choice of license which appears to be driven by a secret agreement between big corporations, Linux Foundation, lawyers, and such," he explained in an interview with The Register via phone and email.

For years, OpenSSL went largely unappreciated, until the Heartbleed vulnerability surfaced in 2014 and shamed the large companies that depend on the software for online security to contribute funds and code.

The planned licensing change comes with the endorsement of Intel and Oracle, among the companies that pledged $3.9 million to the Linux Foundation as atonement. A portion of that funding transformed OpenSSL into something more than the shoe-string operation it had been for years.

Rich Salz, a member of the OpenSSL development team and senior architect at Akamai Technologies, in a phone interview with The Register, said that in the year before Heartbleed, two people were responsible for almost all of the changes being incorporated into OpenSSL. Now there are at least 150 contributing and making pull requests, he said.

Salz cited several reasons for seeking a new license for OpenSSL.

"If you read the SSLeay license carefully, it says among other things you cannot distribute this code under any other license," he said. "What that means is for people who make derivations and want to license their changes, as long as their changes are derived from SSLeay license, they can't."

The license also includes advertising credit clauses, which Salz characterized as "obnoxious." He said, "We want to move to a license that's completely standard and well-known and widely accepted by the community, by the industry."

A source familiar with software licensing, who asked not to be named because of lack of employer authorization, echoed Salz's concerns, describing the SSLeay license as a contractual freak and a compliance nightmare. The license states that the code cannot be placed under another license, which makes it incompatible with some popular copyleft licenses because they stipulate additional terms can only ease restrictions, the source said.

The advertising clause mentioned by Salz, according to the source, requires that any mention of software including OpenSSL comes with attribution. "This does not say when you distribute, it says when you talk about it," the source said. "That's a restriction on use, which runs very contrary to the spirit of what the community has worked towards."