travis encrypt secrets using shell commands

travis-encrypt.sh

#!/bin/sh

function shTravisEncrypt () {
  ## this shell function travis encrypts the secret $2 for github repo $1
  ## tested to work on linux and osx (mountain lion)
  local GITHUB_REPO="$1"
  local SECRET="$2"
  printf "fetching public rsa key from https://api.travis-ci.org/repos/$GITHUB_REPO/key ...\n"
  curl -3Ls https://api.travis-ci.org/repos/$GITHUB_REPO/key\
    | perl -ne 's/[^-]*//; s/"[^"]*$//; s/\\n/\n/g; s/ RSA / /g; print'\
    > /tmp/id_rsa.pub
  printf "encrypting value with fetched public rsa key ...\n"
  printf "$SECRET"\
    | openssl rsautl -encrypt -pubin -inkey /tmp/id_rsa.pub\
    | base64\
    | tr -d "\n"
  printf "\n"
}

# usage example
# $ source travis-encrypt.sh
# $ shTravisEncrypt kaizhu256/utility2 "SECRET=open-sesame"
# fetching public rsa key from https://api.travis-ci.org/repos/kaizhu256/utility2/key ...
# encrypting value with fetched public rsa key ...
# AAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8gISIjJCUmJygpKissLS4vMDEyMzQ1Njc4OT