---
summary: M_UNAUTHORIZED if 'Authorization' header value contains optional whitespace
---
created: 2015-07-14 18:36:22.0
creator: leonerd
description: |-
  It's a little unclear from the spec, but I believe the intention is that the federation {{Authorization}} header is supposed to follow RFC7235 format. To quote:

  {noformat}
   Authorization = credentials

    credentials = auth-scheme [ 1*SP ( token68 / [ ( "," / auth-param )
      *( OWS "," [ OWS auth-param ] ) ] ) ]
  {noformat}

  The {{OWS}} parts in there suggest that "optional whitespace" is allowed between comma-separated {{auth-param}} components.

  However, while synapse is happy with

  {noformat}
  Authorization: X-Matrix origin="localhost:33515",key="ed25519:1",sig="hNMLqNd1T+JUVc53JxpRUtV8uTeAFiz/H8ewf5BffPz4Pem3EiIOq7L06B3fNHmWrW+ZVBkdG1tGEU9Fyl+lAA"
  {noformat}

  it breaks with

  {noformat}
  Authorization: X-Matrix origin="localhost:48078", key="ed25519:1", sig="24xkXS8iJE9dCdU5j0GRym4eps+vzUYvYaPosjdjU/G2etNQGVc1erInpmjJJHlJoJu1GDb8H3JzXQga47oADg"
  {noformat}

  In the latter case, the resulting error message is:

  {noformat}
  400 Bad Request
  {"errcode":"M_UNAUTHORIZED","error":"Malformed Authorization header"}
  {noformat}
id: '11753'
key: SYN-437
number: '437'
priority: '3'
project: '10000'
reporter: leonerd
status: '10100'
type: '1'
updated: 2016-11-07 18:28:13.0
votes: '0'
watches: '2'
workflowId: '11854'
---
actions:
- author: richvdh
  body: 'Migrated to github: https://github.com/matrix-org/synapse/issues/1350'
  created: 2016-11-07 18:28:13.0
  id: '13671'
  issue: '11753'
  type: comment
  updateauthor: richvdh
  updated: 2016-11-07 18:28:13.0