Fix Unsafe atom operation

lib/mimemail.ex

@@ -1,4 +1,7 @@
 defmodule MimeMail do
+  @on_load :preload_atoms
+  @atoms_to_preload [:'content-transfer-encoding', :'content-type', :'content-disposition', :'content-id', :'delivered-to']
+
   @type header :: {:raw,binary} | MimeMail.Header.t #ever the raw line or any term implementing MimeMail.Header.to_ascii
   @type body :: binary | [MimeMail.t] | {:raw,binary} #ever the raw body or list of mail for multipart or binary for decoded content
   @type t :: %MimeMail{headers: [{key::binary,header}], body: body}
@@ -10,6 +13,8 @@ defmodule MimeMail do
   defdelegate get(dict,k,v), to: Map
   defdelegate pop(dict,k), to: Map
 
+  def preload_atoms, do: @atoms_to_preload |> Enum.each(&is_atom/1)
+
   def from_string(data) do
     [headers, body] = case String.split(data, "\r\n\r\n", parts: 2) do
       two_parts = [_, _] -> two_parts
@@ -19,7 +24,14 @@ defmodule MimeMail do
     |> String.replace(~r/\r\n([^\t ])/,"\r\n!\\1")
     |> String.split("\r\n!")
     |> Enum.map(&{String.split(&1,~r/\s*:/,parts: 2),&1})
-    headers=for {[k,_],v}<-headers, do: {:"#{String.downcase(k)}", {:raw,v}}
+    headers = for {[k,_],v}<-headers do
+      k = k |> String.downcase
+      try do
+        {k |> String.to_existing_atom, {:raw,v}}
+      rescue
+        ArgumentError -> {k, {:raw,v}}
+      end
+    end
     %MimeMail{headers: headers, body: {:raw,body}}
   end
 

lib/mimemail_headers.ex

@@ -23,7 +23,7 @@ defmodule MimeMail.Emails do
     parsed=for {k,{:raw,v}}<-headers, k in [:from,:to,:cc,:cci,:'delivered-to'] do
       {k,v|>MimeMail.header_value|>parse_header}
     end
-    %{mail| headers: Enum.reduce(parsed,headers, fn {k,v},acc-> Dict.put(acc,k,v) end)}
+    %{mail| headers: Enum.reduce(parsed,headers, fn {k,v},acc-> List.keystore(acc,k,0,{k,v}) end)}
   end
   defimpl MimeMail.Header, for: List do # a list header is a mailbox spec list
     def to_ascii(mail_list) do # a mail is a struct %{name: nil, address: ""}
@@ -40,9 +40,9 @@ defmodule MimeMail.Params do
   def parse_kv(<<c,rest::binary>>,:key,keyacc,acc) when c in [?\s,?\t,?\r,?\n,?;], do: 
     parse_kv(rest,:key,keyacc,acc) # not allowed characters in key, skip
   def parse_kv(<<?=,?",rest::binary>>,:key,keyacc,acc), do: 
-    parse_kv(rest,:quotedvalue,[],[{:"#{keyacc|>Enum.reverse|>to_string|>String.downcase}",""}|acc]) # enter in a quoted value, save key in res acc
+    parse_kv(rest,:quotedvalue,[],[{keyacc|>Enum.reverse|>to_string|>String.downcase|>String.to_existing_atom,""}|acc]) # enter in a quoted value, save key in res acc
   def parse_kv(<<?=,rest::binary>>,:key,keyacc,acc), do: 
-    parse_kv(rest,:value,[],[{:"#{keyacc|>Enum.reverse|>to_string|>String.downcase}",""}|acc]) # enter in a simple value, save key in res acc
+    parse_kv(rest,:value,[],[{keyacc|>Enum.reverse|>to_string|>String.downcase|>String.to_existing_atom,""}|acc]) # enter in a simple value, save key in res acc
   def parse_kv(<<c,rest::binary>>,:key,keyacc,acc), do: 
     parse_kv(rest,:key,[c|keyacc],acc) # allowed char in key, add to key acc
   def parse_kv(<<?\\,?",rest::binary>>,:quotedvalue,valueacc,acc), do:
@@ -71,7 +71,7 @@ defmodule MimeMail.CTParams do
   end
   def decode_headers(%MimeMail{headers: headers}=mail) do
     parsed_mail_headers=for {k,{:raw,v}}<-headers,match?("content-"<>_,"#{k}"), do: {k,v|>MimeMail.header_value|>parse_header}
-    %{mail| headers: Enum.reduce(parsed_mail_headers,headers, fn {k,v},acc-> Dict.put(acc,k,v) end)}
+    %{mail| headers: Enum.reduce(parsed_mail_headers,headers, fn {k,v},acc-> List.keystore(acc,k,0,{k,v}) end)}
   end
 
   defimpl MimeMail.Header, for: Tuple do # a 2 tuple header is "value; key1=value1; key2=value2"
@@ -129,7 +129,7 @@ defmodule MimeMail.Words do
 
   def decode_headers(%MimeMail{headers: headers}=mail) do
     parsed_mail_headers=for {k,{:raw,v}}<-headers, k in [:subject], do: {k,v|>MimeMail.header_value|>word_decode}
-    %{mail| headers: Enum.reduce(parsed_mail_headers,headers, fn {k,v},acc-> Dict.put(acc,k,v) end)}
+    %{mail| headers: Enum.reduce(parsed_mail_headers,headers, fn {k,v},acc-> List.keystore(acc,k,0,{k,v}) end)}
   end
 
   defimpl MimeMail.Header, for: BitString do # a 2 tuple header is "value; key1=value1; key2=value2"

mix.exs

@@ -34,7 +34,7 @@ defmodule Mailibex.Mixfile do
 
   def project do
     [app: :mailibex,
-     version: "0.1.1",
+     version: "0.2.0",
      elixir: "~> 1.0",
      description: description,
      package: package,