Salted Challenge Response Authentication Mechanism (SCRAM)

# Example from rfc (C = client, s = server)
# C: n,,n=user,r=fyko+d2lbbFgONRv9qkxdawL
# S: r=fyko+d2lbbFgONRv9qkxdawL3rfcNHYJY1ZVvWVs7j,s=QSXCR+Q6sek8bf92,i=4096
# C: c=biws,r=fyko+d2lbbFgONRv9qkxdawL3rfcNHYJY1ZVvWVs7j,
#    p=v0X8v3Bz2T0CJGbJQyF0X+HI4Ts=
# S: v=rmF9pqV8S7suAoZWja4dJRkFsKQ=
#
class MyClient {

  # Send client first message to server and return server response
  method client-first ( Str:D $client-first-message --> Str ) {

    # Send $client-first-message to server;

    # Get server response, this is the server first message
    'r=fyko+d2lbbFgONRv9qkxdawL3rfcNHYJY1ZVvWVs7j,s=QSXCR+Q6sek8bf92,i=4096';
  }

  # Send client final message to server and return server response
  method client-final ( Str:D $client-final-message --> Str ) {

    # Send $client-final-message to server.

    # Server response is server final message
    'v=rmF9pqV8S7suAoZWja4dJRkFsKQ=';
  }

  method error ( Str:D $message --> Str ) {
    # Errors? nah ... (Famous last words!)
  }
}

my Auth::SCRAM $sc .= new(
  :username<user>,
  :password<pencil>,
  :client-side(MyClient.new),
);

$sc.c-nonce-size = 24;
$sc.c-nonce = 'fyko+d2lbbFgONRv9qkxdawL';

my $error = $sc.start-scram;

$ zef install Auth-SCRAM

Marcel Timmerman (MARTIMM on github)