Add support for OAuth plaintext signature method

README.md

@@ -442,6 +442,10 @@ the following changes to the OAuth options object:
 * Instead of `consumer_secret`, specify a `private_key` string in
   [PEM format](http://how2ssl.com/articles/working_with_pem_files/)
 
+For [PLAINTEXT signing](http://oauth.net/core/1.0/#anchor22), make
+the following changes to the OAuth options object:
+* Pass `signature_method : 'PLAINTEXT'`
+
 To send OAuth parameters via query params or in a post body as described in The
 [Consumer Request Parameters](http://oauth.net/core/1.0/#consumer_req_param)
 section of the oauth1 spec:

package.json

@@ -33,7 +33,7 @@
     "tunnel-agent": "~0.4.0",
     "tough-cookie": ">=0.12.0",
     "http-signature": "~0.10.0",
-    "oauth-sign": "~0.5.0",
+    "oauth-sign": "~0.6.0",
     "hawk": "1.1.1",
     "aws-sign2": "~0.5.0",
     "stringstream": "~0.0.4",

tests/test-oauth.js

@@ -302,6 +302,23 @@ tape('rfc5849 RSA example', function(t) {
   })
 })
 
+tape('plaintext signature method', function(t) {
+  var plaintext = request.post(
+    { url: 'https://dummy.com'
+    , oauth:
+      { consumer_secret: 'consumer_secret'
+      , token_secret: 'token_secret'
+      , signature_method: 'PLAINTEXT'
+      }
+    })
+
+  process.nextTick(function() {
+    t.equal('consumer_secret&token_secret', getSignature(plaintext))
+    plaintext.abort()
+    t.end()
+  })
+})
+
 tape('invalid transport_method', function(t) {
   t.throws(
     function () {