CFSSL's CA trust store repository
Clone or download
Latest commit ac5a0d9 Jan 18, 2019


This is the trust stores CloudFlare uses for CFSSL. It also includes the sources of the trust chain that can be built using the mkbundle utility from CFSSL.


├── ca-bundle.crt
├── ca-bundle.crt.metadata
├── certdata
│   └── trusted_roots
│       ├── froyo.pem
│       ├── gingerbread.pem
│       ├── honeycomb.pem
│       ├── ics.pem
│       ├── ios.pem
│       ├── kitkat.pem
│       ├── nss.pem
│       ├── osx.pem
│       ├── ubuntu.pem
│       └── windows.pem
├── int-bundle.crt

The ca-bundle.crt file contains the trusted roots. CFSSL uses the ca-bundle.crt.metadata when building bundles to assist in building bundles that need to verified in the maximum number of trust stores on different systems. The int-bundle.crt file contains a number of known intermediates; these are preloaded for performance reasons and occasionally updated as CFSSL finds more intermediates. If an intermediate isn't in this bundle, but can be found through following the AIA CA Issuers fields, it will be downloaded and eventually merged into here.

The trusted_roots directory contains the root stores from a number of systems. Currently, we have trust stores from

  • NSS (Firefox, Chrome)
  • OS X
  • Windows
  • Android 2.2 (Frozen Yogurt)
  • Android 2.3 (Gingerbread)
  • Android 3.x (Honeycomb)
  • Android 4.0 (Ice Cream Sandwich)
  • Android 4.4 (KitKat)



$ go get -u
$ go get -u
$ go get -u


The final bundles (i.e. ca-bundle.crt and int-bundle.crt) may be built as follows:

$ ./

This command automatically removes expiring certificates, and pushes the changes to a new release branch.

The content of 'ca-bundle.crt.metadata' is crucial to building ubiquitous bundle. Feel free to tune its content. Make sure the paths to individual trust root stores are correctly specified.

Adding new roots or intermediates

New roots and intermediates can be added using the same command, just by providing values for the NEW_ROOTS and NEW_INTERMEDIATES variables:

$ NEW_ROOTS="/path/to/root1 /path/to/root2" NEW_INTERMEDIATES="/path/to/int1 /path/to/int22" ./

Check for expiring roots or intermediates

To verify that an intermediate or root certificate is expiring or revoked without creating a release, the expiring command can be used from the project root directory.

To check for expiring or revoked intermediate certificates in the database provided in this repo:

$ cfssl-trust -d ./cert.db -b int expiring

To check for expiring or revoked root certificates:

$ cfssl-trust -d ./cert.db -b ca expiring

./cert.db which is specified as the database using the -d flag, contains both intermediate and root certificates. Any certificate database can be used here in place of ./cert.db

These calls to the expiring command will provide an output showing if there are any expiring or revoked certificates.

1 certificates expiring.
0 certificates revoked.