Add --sign option to `luarocks pack`

* Introduce a new module, `luarocks.signing`
* Add `--sign` option to `luarocks pack`, which produces a
  detached GPG signature
* Includes a basic test, along with some fixtures with
  a password-less GPG key

4 files changed, 39 insertions, 0 deletions

diff --git a/src/luarocks/cmd/pack.lua b/src/luarocks/cmd/pack.lua
index 52b2fbca..02e554d9 100644
--- a/src/luarocks/cmd/pack.lua
+++ b/src/luarocks/cmd/pack.lua
@@ -5,11 +5,14 @@ local cmd_pack = {}
 
 local util = require("luarocks.util")
 local pack = require("luarocks.pack")
+local signing = require("luarocks.signing")
 local queries = require("luarocks.queries")
 
 cmd_pack.help_summary = "Create a rock, packing sources or binaries."
 cmd_pack.help_arguments = "{<rockspec>|<name> [<version>]}"
 cmd_pack.help = [[
+--sign     Produce a signature file as well.
+
 Argument may be a rockspec file, for creating a source rock,
 or the name of an installed package, for creating a binary rock.
 In the latter case, the app version may be given as a second
@@ -40,7 +43,18 @@ function cmd_pack.command(flags, arg, version)
    if err then
       return nil, err
    else
+      local sigfile
+      if flags["sign"] then
+         sigfile, err = signing.sign_file(file)
+         util.printout()
+      end
       util.printout("Packed: "..file)
+      if sigfile then
+         util.printout("Sigature stored in: "..sigfile)
+      end
+      if err then
+         return nil, err
+      end
       return true
    end
 end
diff --git a/src/luarocks/core/cfg.lua b/src/luarocks/core/cfg.lua
index 5b9dec2f..c6824153 100644
--- a/src/luarocks/core/cfg.lua
+++ b/src/luarocks/core/cfg.lua
@@ -230,6 +230,8 @@ local function make_defaults(lua_version, target_cpu, platforms, home)
          SVN = "svn",
          HG = "hg",
 
+         GPG = "gpg",
+
          RSYNC = "rsync",
          WGET = "wget",
          SCP = "scp",
diff --git a/src/luarocks/signing.lua b/src/luarocks/signing.lua
new file mode 100644
index 00000000..7503768e
--- /dev/null
+++ b/src/luarocks/signing.lua
@@ -0,0 +1,22 @@
+local signing = {}
+
+local cfg = require("luarocks.core.cfg")
+local fs = require("luarocks.fs")
+
+function signing.sign_file(file)
+   local vars = cfg.variables
+   local gpg_ok, err = fs.is_tool_available(vars.GPG, "gpg")
+   if not gpg_ok then
+      return nil, err
+   end
+   local gpg = vars.GPG
+   
+   local sigfile = file .. ".asc"
+   if fs.execute(gpg, "--armor", "--output", sigfile, "--detach-sign", file) then
+      return sigfile
+   else
+      return nil, "failed running " .. gpg .. " to sign " .. file
+   end
+end
+
+return signing
diff --git a/src/luarocks/util.lua b/src/luarocks/util.lua
index 25c521ea..bba39457 100644
--- a/src/luarocks/util.lua
+++ b/src/luarocks/util.lua
@@ -149,6 +149,7 @@ local supported_flags = {
    ["rockspec"] = true,
    ["rockspec-format"] = "<ver>",
    ["server"] = "<server>",
+   ["sign"] = true,
    ["skip-pack"] = true,
    ["source"] = true,
    ["summary"] = "\"<text>\"",