bionic (1) clevis-encrypt-sss.1.gz

NAME

       clevis-encrypt-sss -- Encrypts using a Shamir's Secret Sharing policy

SYNOPSIS

       clevis encrypt sss CONFIG < PT > JWE

OVERVIEW

       The clevis encrypt sss command encrypts using a Shamir's Secret Sharing policy.  Its only argument is the
       JSON configuration object.

       Shamir's Secret Sharing (SSS) provides a way to mix pins together to create sophisticated  unlocking  and
       high availability policies.  SSS is a thresholding scheme.  It creates a key and divides it into a number
       of pieces.  Each piece is encrypted using another pin (possibly even SSS recursively).  Additionally, you
       define  the threshold t.  If at least t pieces can be decrypted, then the encryption key can be recovered
       and decryption can succeed.

       For example, let's create a high-availability setup using Tang:

              $ cfg='{"t":1,"pins":{"tang":[{"url":...},{"url":...}]}}'
              $ clevis encrypt sss "$cfg" < PT > JWE

       In this policy, we are declaring that we have a threshold of 1, but that there are multiple key fragments
       encrypted using different Tang servers.  Since our threshold is 1, so long as any of the Tang servers are
       available, decryption will succeed.  As always, decryption is simply:

              $ clevis decrypt < JWE > PT

CONFIG

       This command uses the following configuration properties:

       • t (integer) : Number of pins required for decryption (REQUIRED)

       • pins (object) : Pins used for encrypting fragments (REQUIRED)

       The format of the pins property is as follows:

              {PIN:CFG,...} OR {PIN:[CFG,CFG,...],...}

       When the list version of the format is used, multiple pins of that type will receive key fragments.

SEE ALSO

       clevis-encrypt-http(1), clevis-encrypt-tang(1), clevis-decrypt(1)

AUTHORS

       Nathaniel McCallum <npmccallum@redhat.com>.

                                                  Sepember 2017                            CLEVIS-ENCRYPT-SSS(1)