Add krypton package; command-line client, daemon, and SSH integration (#2334)

* Add krypton package; command-line client, daemon, and SSH integration

* Added postinstall message

* Remove unnecessary dependencies

* Added checksum for cargo-web download

* sandboxing rustc and cargo for the install

* removed CARGO_HOME from PATH

* breaking up the long line for readability, also the check for existance is not really needed anymore with cargo sandboxed

* Update the sha256 missmatch abort method

packages/kr.rb

+require 'package'
+
+class Kr < Package
+  description 'Krypton command-line client, daemon, and SSH integration'
+  homepage 'https://krypt.co'
+  version '2.4.4'
+  source_url 'https://raw.githubusercontent.com/kryptco/kr/master/README.md'
+  source_sha256 'a0452783d22218a6fab914abbf5263459aaa1c8745512d7c4ebcf51fe08aaf7a'
+
+  depends_on "rust" => :build
+  depends_on "go" => :build
+  depends_on "libsodium" => :build
+  depends_on "rsync" => :build
+  depends_on "psmisc" => :build
+
+  def self.install
+    cargo_web_version = "0.6.10"
+    cargo_web_sha256 = "c8a92ed0185206ad7f2da8e1692d168b20044de7066b2eb086e4bbb0d06ff787"
+    ENV["GOPATH"] = "#{Dir.pwd}/go"
+    ENV["RUSTUP_HOME"] = "#{Dir.pwd}/.rustup"
+    ENV["CARGO_HOME"] = "#{Dir.pwd}/.cargo"
+    system "mkdir -p #{ENV["RUSTUP_HOME"]}"
+    system "mkdir -p #{ENV["CARGO_HOME"]}"
+
+    system "rustup", "install", "stable"
+    system "rustup", "default", "stable"
+    system "rustup", "target", "add", "wasm32-unknown-emscripten"
+
+    system "curl -Ls https://github.com/koute/cargo-web/archive/#{cargo_web_version}.zip -o cargo-web.zip"
+    abort "Checksum mismatch. :/  Try again.".lightred unless Digest::SHA256.hexdigest( File.read("cargo-web.zip") ) == "#{cargo_web_sha256}"
+    system "unzip cargo-web.zip && cd cargo-web-#{cargo_web_version}"
+    system "cargo build --release && cargo install"
+
+    system "mkdir -p #{Dir.pwd}/go/src"
+    system "go get github.com/kryptco/kr"
+    FileUtils.cd("go/src/github.com/kryptco/kr") do
+      ENV["PREFIX"] = "#{CREW_PREFIX}"
+      ENV["PWD"] = Dir.pwd
+      system "git checkout tags/2.4.4"
+      system "git submodule update --init --recursive"
+      system "git checkout -- Makefile"
+      system "sed -i '/^LINK_LIBSIGCHAIN_LDFLAGS/ s/$/ -fstack-protector/' Makefile"
+      system "sed -i '/^DSTBIN =/ s/.*/DSTBIN = #{CREW_DEST_PREFIX.gsub('/', '\/')}\\/bin/' Makefile"
+      system "sed -i '/^DSTLIB =/ s/.*/DSTLIB = #{CREW_DEST_PREFIX.gsub('/', '\/')}\\/lib/' Makefile"
+      system "make"
+      system "make", "install"
+    end
+  end
+
+  def self.postinstall
+    puts "============================"
+    puts "Krypton is now installed!"
+    puts "'kr pair' will automatically configure ~/.ssh/config to use Krypton. To prevent this, export KR_SKIP_SSH_CONFIG=1"
+    puts "============================"
+  end
+end