X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=lib%2Fsup%2Fcrypto.rb;h=772b8b696c4f4f41682fe2e51f4656bc66603254;hb=2388e4a48a6d3ea5e626fccf9588a6a177e7065e;hp=456241208e5901ee0b5f224b4c9f0b624cd0bd0f;hpb=534d85c189215862abca271ec2434ae7385ae016;p=sup

diff --git a/lib/sup/crypto.rb b/lib/sup/crypto.rb
index 4562412..772b8b6 100644
--- a/lib/sup/crypto.rb
+++ b/lib/sup/crypto.rb
@@ -3,45 +3,158 @@ module Redwood
 class CryptoManager
   include Singleton
 
+  class Error < StandardError; end
+
+  OUTGOING_MESSAGE_OPERATIONS = OrderedHash.new(
+    [:sign, "Sign"],
+    [:sign_and_encrypt, "Sign and encrypt"],
+    [:encrypt, "Encrypt only"]
+  )
+
   def initialize
     @mutex = Mutex.new
-    self.class.i_am_the_instance self
 
-    @cmd = `which gpg`.chomp
-    @cmd = `which pgp`.chomp unless @cmd =~ /\S/
-    @cmd = nil unless @cmd =~ /\S/
+    bin = `which gpg`.chomp
+    @cmd =
+      case bin
+      when /\S/
+        debug "crypto: detected gpg binary in #{bin}"
+        "#{bin} --quiet --batch --no-verbose --logger-fd 1 --use-agent"
+      else
+        debug "crypto: no gpg binary detected"
+        nil
+      end
   end
 
-  def verify payload, signature # both RubyMail::Message objects
-    return unknown unless @cmd
+  def have_crypto?; !@cmd.nil? end
+
+  def sign from, to, payload
+    payload_fn = Tempfile.new "redwood.payload"
+    payload_fn.write format_payload(payload)
+    payload_fn.close
+
+    output = run_gpg "--output - --armor --detach-sign --textmode --local-user '#{from}' #{payload_fn.path}"
+
+    raise Error, (output || "gpg command failed: #{cmd}") unless $?.success?
+
+    envelope = RMail::Message.new
+    envelope.header["Content-Type"] = 'multipart/signed; protocol=application/pgp-signature; micalg=pgp-sha1'
+
+    envelope.add_part payload
+    signature = RMail::Message.make_attachment output, "application/pgp-signature", nil, "signature.asc"
+    envelope.add_part signature
+    envelope
+  end
+
+  def encrypt from, to, payload, sign=false
+    payload_fn = Tempfile.new "redwood.payload"
+    payload_fn.write format_payload(payload)
+    payload_fn.close
+
+    recipient_opts = (to + [ from ] ).map { |r| "--recipient '<#{r}>'" }.join(" ")
+    sign_opts = sign ? "--sign --local-user '#{from}'" : ""
+    gpg_output = run_gpg "--output - --armor --encrypt --textmode #{sign_opts} #{recipient_opts} #{payload_fn.path}"
+    raise Error, (gpg_output || "gpg command failed: #{cmd}") unless $?.success?
+
+    encrypted_payload = RMail::Message.new
+    encrypted_payload.header["Content-Type"] = "application/octet-stream"
+    encrypted_payload.header["Content-Disposition"] = 'inline; filename="msg.asc"'
+    encrypted_payload.body = gpg_output
+
+    control = RMail::Message.new
+    control.header["Content-Type"] = "application/pgp-encrypted"
+    control.header["Content-Disposition"] = "attachment"
+    control.body = "Version: 1\n"
+
+    envelope = RMail::Message.new
+    envelope.header["Content-Type"] = 'multipart/encrypted; protocol="application/pgp-encrypted"'
+
+    envelope.add_part control
+    envelope.add_part encrypted_payload
+    envelope
+  end
 
-    payload_fn = File.open("payload", "w") # Tempfile.new "redwood.payload"
-    signature_fn = File.open("signature", "w") #Tempfile.new "redwood.signature"
+  def sign_and_encrypt from, to, payload
+    encrypt from, to, payload, true
+  end
+
+  def verify payload, signature # both RubyMail::Message objects
+    return unknown_status(cant_find_binary) unless @cmd
 
-    payload_fn.write payload.to_s.gsub(/(^|[^\r])\n/, "\\1\r\n").gsub(/^MIME-Version: .*\r\n/, "")
+    payload_fn = Tempfile.new "redwood.payload"
+    payload_fn.write format_payload(payload)
     payload_fn.close
 
+    signature_fn = Tempfile.new "redwood.signature"
     signature_fn.write signature.decode
     signature_fn.close
 
-    cmd = "#{@cmd} --quiet --batch --no-verbose --verify --logger-fd 1 #{signature_fn.path} #{payload_fn.path} 2> /dev/null"
+    output = run_gpg "--verify #{signature_fn.path} #{payload_fn.path}"
+    output_lines = output.split(/\n/)
+
+    if output =~ /^gpg: (.* signature from .*$)/
+      if $? == 0
+        Chunk::CryptoNotice.new :valid, $1, output_lines
+      else
+        Chunk::CryptoNotice.new :invalid, $1, output_lines
+      end
+    else
+      unknown_status output_lines
+    end
+  end
+
+  ## returns decrypted_message, status, desc, lines
+  def decrypt payload # a RubyMail::Message object
+    return unknown_status(cant_find_binary) unless @cmd
+
+    payload_fn = Tempfile.new "redwood.payload"
+    payload_fn.write payload.to_s
+    payload_fn.close
+
+    output = run_gpg "--decrypt #{payload_fn.path}"
+
+    if $?.success?
+      decrypted_payload, sig_lines = if output =~ /\A(.*?)((^gpg: .*$)+)\Z/m
+        [$1, $2]
+      else
+        [output, nil]
+      end
 
-    #Redwood::log "gpg: running: #{cmd}"
-    gpg_output = `#{cmd}`
-    #Redwood::log "got output: #{gpg_output.inspect}"
-    lines = gpg_output.split(/\n/)
+      sig = if sig_lines # encrypted & signed
+        if sig_lines =~ /^gpg: (Good signature from .*$)/
+          Chunk::CryptoNotice.new :valid, $1, sig_lines.split("\n")
+        else
+          Chunk::CryptoNotice.new :invalid, $1, sig_lines.split("\n")
+        end
+      end
 
-    if gpg_output =~ /^gpg: (.* signature from .*$)/
-      $? == 0 ? [:valid, $1, lines] : [:invalid, $1, lines]
+      notice = Chunk::CryptoNotice.new :valid, "This message has been decrypted for display"
+      [notice, sig, RMail::Parser.read(decrypted_payload)]
     else
-      unknown
+      Chunk::CryptoNotice.new :invalid, "This message could not be decrypted", output.split("\n")
     end
   end
 
 private
 
-  def unknown
-    [:unknown, "Unable to determine validity of cryptographic signature", []]
+  def unknown_status lines=[]
+    Chunk::CryptoNotice.new :unknown, "Unable to determine validity of cryptographic signature", lines
+  end
+
+  def cant_find_binary
+    ["Can't find gpg binary in path."]
+  end
+
+  ## here's where we munge rmail output into the format that signed/encrypted
+  ## PGP/GPG messages should be
+  def format_payload payload
+    payload.to_s.gsub(/(^|[^\r])\n/, "\\1\r\n").gsub(/^MIME-Version: .*\r\n/, "")
+  end
+
+  def run_gpg args
+    cmd = "#{@cmd} #{args} 2> /dev/null"
+    output = `#{cmd}`
+    output
   end
 end
 end