Bug 22132: Add Basic authentication to the API

This patch implements Basic authentication for the API to aid testers
and developers with tools like Postman.

To test:
- Apply this patches
- Run:
  $ kshell
 k$ prove t/db_dependent/api/v1/auth_basic.t
=> SUCCESS: Tests pass!
- Open Postman or your favourite tool
- In Authorization, choose Basic auth.
- Enter the username and password of a known privileged user.
- Hit an endpoint with Postman, for example:
  ] GET http://kohadev-intra.myDNSname.org:8081/api/v1/patrons
=> SUCCESS: Basic authentication is great!
- Sign off :-D

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>

Koha/REST/V1/Auth.pm

@@ -19,7 +19,7 @@ package Koha::REST::V1::Auth;
 
 use Mojo::Base 'Mojolicious::Controller';
 
-use C4::Auth qw( check_cookie_auth get_session haspermission );
+use C4::Auth qw( check_cookie_auth checkpw_internal get_session haspermission );
 use C4::Context;
 
 use Koha::ApiKeys;
@@ -35,6 +35,7 @@ use Koha::Exceptions;
 use Koha::Exceptions::Authentication;
 use Koha::Exceptions::Authorization;
 
+use MIME::Base64;
 use Module::Load::Conditional;
 use Scalar::Util qw( blessed );
 use Try::Tiny;
@@ -87,7 +88,7 @@ sub under {
             return $c->render(status => 401, json => { error => $_->error });
         }
         elsif ($_->isa('Koha::Exceptions::Authentication')) {
-            return $c->render(status => 500, json => { error => $_->error });
+            return $c->render(status => 401, json => { error => $_->error });
         }
         elsif ($_->isa('Koha::Exceptions::BadParameter')) {
             return $c->render(status => 400, json => $_->error );
@@ -163,6 +164,21 @@ sub authenticate_api_request {
             );
         }
     }
+    elsif ( $authorization_header and $authorization_header =~ /^Basic / ) {
+        unless ( C4::Context->preference('RESTBasicAuth') ) {
+            Koha::Exceptions::Authentication::Required->throw(
+                error => 'Basic authentication disabled'
+            );
+        }
+        $user = $c->_basic_auth( $authorization_header );
+        unless ( $user ) {
+            # If we have "Authorization: Basic" header and authentication
+            # failed, do not try other authentication means
+            Koha::Exceptions::Authentication::Required->throw(
+                error => 'Authentication failure.'
+            );
+        }
+    }
     else {
 
         my $cookie = $c->cookie('CGISESSID');
@@ -402,4 +418,30 @@ sub _object_ownership_by_reserve_id {
     return $reserve && $user->borrowernumber == $reserve->borrowernumber;
 }
 
+=head3 _basic_auth
+
+Internal method that performs Basic authentication.
+
+=cut
+
+sub _basic_auth {
+    my ( $c, $authorization_header ) = @_;
+
+    my ( $type, $credentials ) = split / /, $authorization_header;
+
+    unless ($credentials) {
+        Koha::Exceptions::Authentication::Required->throw( error => 'Authentication failure.' );
+    }
+
+    my $decoded_credentials = decode_base64( $credentials );
+    my ( $user_id, $password ) = split( /:/, $decoded_credentials, 2 );
+
+    my $dbh = C4::Context->dbh;
+    unless ( checkpw_internal($dbh, $user_id, $password ) ) {
+        Koha::Exceptions::Authorization::Unauthorized->throw( error => 'Invalid password' );
+    }
+
+    return Koha::Patrons->find({ userid => $user_id });
+}
+
 1;