Who do you trust?

Paranoia is a tool to analyse and export trust bundles (e.g., "ca-certificates") from container images. These certificates identify the certificate authorities that your container trusts when establishing TLS connections. The design of TLS is that any certificate authority that your container trusts can issue a certificate for any domain. This means that a malicious or compromised certificate authority could issue a certificate to impersonate any other service, including your internal infrastructure.

Paranoia can be used to inspect and validate the certificates within your container images. This gives you visibility into which certificate authorities your container images are trusting; allows you to forbid or require certificates at build-time in CI; and help you decide who to trust in your container images.

Paranoia is built by Jetstack and made available under the Apache 2.0 license, see LICENSE.txt.

On macOS and Linux, if you have Homebrew you can install Paranoia with:

brew install jetstack/jetstack/paranoia

This will also install man pages and shell completion.

Binaries for common platforms and architectures are provided on the releases. Man pages are also attached to the release. You can generate shell completion from Paranoia itself with paranoia completion.

If you have Go installed you can install Paranoia using Go directly.

go install github.com/jetstack/paranoia@latest

Paranoia can be used to list out the certificates in a container image:

$ paranoia export alpine:latest
File Location Subject 
/etc/ssl/certs/ca-certificates.crt CN=ACCVRAIZ1,OU=PKIACCV,O=ACCV,C=ES 
/etc/ssl/certs/ca-certificates.crt OU=AC RAIZ FNMT-RCM,O=FNMT-RCM,C=ES 
/etc/ssl/certs/ca-certificates.crt CN=AC RAIZ FNMT-RCM SERVIDORES SEGUROS,OU=Ceres,O=FNMT-RCM,C=ES,2.5.4.97=#130f56415445532d51323832363030344a 
...
/etc/ssl/certs/ca-certificates.crt CN=vTrus ECC Root CA,O=iTrusChina Co.,円Ltd.,C=CN 
/etc/ssl/certs/ca-certificates.crt CN=vTrus Root CA,O=iTrusChina Co.,円Ltd.,C=CN 
Found 140 certificates

Export them for further audit:

paranoia export --output json python:3 | jq '.certificates[].fingerprintSHA256' | head -n 5
"ebd41040e4bb3ec742c9e381d31ef2a41a48b6685c96e7cef3c1df6cd4331c99"
"6dc47172e01cbcb0bf62580d895fe2b8ac9ad4f873801e0c10b9c837d21eb177"
"16af57a9f676b0ab126095aa5ebadef22ab31119d644ac95cd4b93dbf3f26aeb"
"73c176434f1bc6d5adf45b0e76e727287c8de57616c1e6e6141a2b2cbc7d8e4c"
"d7a7a0fb5d7e2731d771e9484ebcdef71d5f0c3e0a2948782bc83ee0ea699ef4"

Detect internal certificates left over from internal testing:

cat << EOF > .paranoia.yaml
version: "1"
forbid:
 - comment: "An internal-only cert"
 fingerprints:
 sha256: bd40be0eccfce513ab318882f03962e4e2ec3799b51392e82805d9249e426d28
EOF
paranoia validate my-image

Find certificates inside binaries:

paranoia export -o json consul:latest | jq '.certificates[] | select(.fileLocation == "/bin/consul")'
{
 "fileLocation": "/bin/consul",
 "owner": "CN=Circonus Certificate Authority,OU=Circonus,O=Circonus\\, Inc.,L=Columbia,ST=Maryland,C=US,1.2.840.113549.1.9.1=#0c0f636140636972636f6e75732e6e6574",
 "parser": "pem",
 "signature": "01C1B65D790706D2CAAD1D30406911D41884789A9D4FEBBCE31EE7B7628019A8C7B6643C46C1FDB684B18272B33880DAB68EB51C5546D731B9948C8A3D918890EC2F1CC8A751FAD1786BF2599FEEA17A63EB1997B577E8A65B9F67B368EA11B6C425F5D86A10C7BCCE02FBEA9F5867913AF409749A08A27D3B5EC8D8E332E216",
 "notBefore": "2009年12月23日T19:17:06Z",
 "notAfter": "2019年12月21日T19:17:06Z",
 "fingerprintSHA1": "063ff657e055b0036d794cda892c85417c07739a",
 "fingerprintSHA256": "0c97e0898343c5b1973c6568a15c8c853dd663d363020071e34f789859ece19f"
}

Paranoia will detect certificate authorities in most cases, and is especially useful at finding accidental inclusion or for conducting a certificate authority inventory. However, there are some limitations to bear in mind while using Paranoia:

• Paranoia only functions on container images, not running containers. Anything added into the container at runtime is not seen.
• If a certificate is found, that doesn’t guarantee that the container will trust it as a certificate authority. It could, for example, be an unused leftover file.
• It’s possible for an attacker to ‘hide’ a certificate authority from Paranoia (e.g., by encoding it in a format Paranoia doesn’t understand). In general Paranoia isn’t designed to defend against an adversary with supply chain write access intentionally sneaking obfuscated certificate authorities into container images.

The usage documentation for Paranoia is included in the help text. Invoke a command with --help for usage instructions, or see the manual pages.