The Linux Foundation today embraced a sigstore project founded by Red Hat, Google and Purdue University to make it simpler for developers to employ cryptographic software, enabled by transparency log technologies, to secure software supply chains.
Luke Hinds, security engineering lead in the office of the CTO at Red Hat, said he and Dan Lorenc, a staff software engineer for Google, led a small team creating a lightweight mechanism for signing software artifacts, such as release files, container images and binaries, in way that creates an immutable, tamper-proof log.
Now, the goal is to take that project to the next level by contributing it to the Linux Foundation, at a time when the focus on software supply chain security has increased in the wake of a spate of high-profile breaches. As part of that effort, a free service, based on sigstore, will also be made available by the Linux Foundation to make the cryptographic software easily accessible to a wide range of developers.
Hinds said one of the reasons that artifacts are not signed by developers is that the current processes employed are too cumbersome. The cryptographic software is designed to be integrated as an extension of existing workflows, Hinds noted.
Because the log created is immutable, everyone participating in the software development process, including auditors, can now transparently track chain of custody for any software artifact, Hinds said. At its core, sigstore creates a set of short-lived ephemeral keys with a trust root based on an auditable public log.
Existing approaches rely on digests stored on insecure systems that are susceptible to tampering. Cybercriminals can, for example, swap out digests if they can gain access to compromised credentials. Those types of targeted attacks can be thwarted using sigstore, because the log management system that underpins it is immutable, said Hinds.
Of course, no system for securing software supply chains is going to be useful if developers won’t employ it. Key management, key compromise/revocation and the distribution of public keys and artifact digests are challenging to manage. Developers, then, need to determine which keys to trust in addition to learning how to sign them when different platforms are employed. Digests and public keys are also often distributed across vulnerable websites susceptible to hacks, or stored as a README file on a public git repository.
As organizations embrace DevSecOps best practices, it’s only a matter of time before the entire software supply chain comes under greater scrutiny. Ultimately, the issue will come down to finding a way to secure those supply chains, either from the top down by deploying and maintaining a platform, or simply making it easier for developers to better secure artifacts from the bottom up.
Regardless of approach, the signing of software artifacts should, one way or another, become more routine in the weeks and months ahead. The biggest challenge will be overcoming the simple inertia that currently exists among developers who routinely ignore the whole process.
