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package Koha::REST::V1::Plugins::KohaliciousSwagtenticator; |
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|
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use Modern::Perl; |
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|
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use base qw(Mojolicious::Plugin::Swagger2); |
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|
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use Digest::SHA qw(hmac_sha256_hex); |
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use Try::Tiny; |
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use Scalar::Util qw(blessed); |
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|
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use C4::Auth; |
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|
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use Koha::Exception::BadAuthenticationToken; |
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use Koha::Exception::UnknownProgramState; |
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use Koha::Exception::NoPermission; |
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|
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use constant DEBUG => $ENV{SWAGGER2_DEBUG} || 0; |
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|
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|
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|
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################################################################################ |
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###################### STARTING OVERLOADING SUBROUTINES ###################### |
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################################################################################ |
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|
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|
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|
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=head _generate_request_handler |
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@OVERLOADS Mojolicious::Plugin::Swagger2::_generate_request_handler() |
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This is just a copy-paste of the parent function with a small incision to inject the Koha-authentication mechanism. |
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Keep code changes minimal for upstream compatibility, so when problems arise, copy-pasting fixes them! |
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|
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=cut |
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|
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sub _generate_request_handler { |
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my ($self, $method, $config) = @_; |
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my $controller = $config->{'x-mojo-controller'} || $self->{controller}; # back compat |
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|
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return sub { |
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my $c = shift; |
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my $method_ref; |
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|
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unless (eval "require $controller;1") { |
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$c->app->log->error($@); |
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return $c->render_swagger($self->_not_implemented('Controller not implemented.'), {}, 501); |
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} |
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unless ($method_ref = $controller->can($method)) { |
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$method_ref = $controller->can(sprintf '%s_%s', $method, lc $c->req->method) |
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and warn "HTTP method name is not used in method name lookup anymore!"; |
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} |
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unless ($method_ref) { |
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$c->app->log->error( |
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qq(Can't locate object method "$method" via package "$controller. (Something is wrong in @{[$self->url]})")); |
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return $c->render_swagger($self->_not_implemented('Method not implemented.'), {}, 501); |
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} |
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### Koha-overload starts here ### |
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## Check for user api-key authentication and permissions. |
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my ($error, $data, $statusCode) = _koha_authenticate($c, $config); |
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return $c->render_swagger($error, $data, $statusCode) if $error; |
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### END OF Koha-overload ### |
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|
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bless $c, $controller; # ugly hack? |
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|
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$c->delay( |
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sub { |
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my ($delay) = @_; |
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my ($v, $input) = $self->_validate_input($c, $config); |
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|
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return $c->render_swagger($v, {}, 400) unless $v->{valid}; |
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return $c->$method_ref($input, $delay->begin); |
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}, |
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sub { |
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my $delay = shift; |
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my $data = shift; |
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my $status = shift || 200; |
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my $format = $config->{responses}{$status} || $config->{responses}{default} || {}; |
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my @err = $self->_validator->validate($data, $format->{schema}); |
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|
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return $c->render_swagger({errors => \@err, valid => Mojo::JSON->false}, $data, 500) if @err; |
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return $c->render_swagger({}, $data, $status); |
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}, |
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); |
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}; |
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} |
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|
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|
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|
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=head _validate_input |
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@OVERLOADS Mojolicious::Plugin::Swagger2::_validate_input() |
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|
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Validates the parameters from the "Operation Object" from Swagger2 specification. |
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Overloading to allow OPTIONAL parameters. |
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=cut |
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|
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sub _validate_input { |
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my ($self, $c, $config) = @_; |
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my $headers = $c->req->headers; |
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my $query = $c->req->url->query; |
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my (%input, %v); |
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warn "[Swagtenticator] Successful subclassing _validate_input()!\n"; |
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|
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for my $p (@{$config->{parameters} || []}) { |
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my ($in, $name) = @$p{qw( in name )}; |
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my ($value, @e); |
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|
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$value |
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= $in eq 'query' ? $query->param($name) |
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: $in eq 'path' ? $c->stash($name) |
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: $in eq 'header' ? $headers->header($name) |
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: $in eq 'body' ? $c->req->json |
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: $in eq 'formData' ? $c->req->body_params->to_hash |
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: "Invalid 'in' for parameter $name in schema definition"; |
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|
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if (defined $value or $p->{required}) { |
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my $type = $p->{type} || 'object'; |
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$value += 0 if $type =~ /^(?:integer|number)/ and $value =~ /^\d/; |
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$value = ($value eq 'false' or !$value) ? Mojo::JSON->false : Mojo::JSON->true if $type eq 'boolean'; |
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|
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if ($in eq 'body' or $in eq 'formData') { |
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warn "[Swagger2] Validate $in @{[$c->req->body]}\n"; |
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push @e, map { $_->{path} = "/$name$_->{path}"; $_; } $self->_validator->validate($value, $p->{schema}); |
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} |
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else { |
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warn "[Swagger2] Validate $in $name=$value\n"; |
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push @e, $self->_validator->validate({$name => $value}, {properties => {$name => $p}}); |
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} |
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} |
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|
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$input{$name} = $value unless @e; |
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push @{$v{errors}}, @e; |
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} |
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|
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$v{valid} = @{$v{errors} || []} ? Mojo::JSON->false : Mojo::JSON->true; |
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return \%v, \%input; |
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} |
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|
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|
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|
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################################################################################ |
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######### END OF OVERLOADED SUBROUTINES, STARTING EXTENDED FEATURES ########## |
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################################################################################ |
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|
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|
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|
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=head _koha_authenticate |
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|
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_koha_authenticate($c, $config); |
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|
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Checks all authentications in Koha, and prepares the data for a |
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Mojolicious::Plugin::Swagger2->render_swagger($errors, $data, $statusCode) -response |
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if authentication failed for some reason. |
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|
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@PARAM1 Mojolicious::Controller or a subclass |
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@PARAM2 Reference to HASH, the "Operation Object" from Swagger2.0 specification, |
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matching the given "Path Item Object"'s HTTP Verb. |
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@RETURNS List of: HASH Ref, errors encountered |
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HASH Ref, data to be sent |
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String, status code from the Koha::REST::V1::check_key_auth() |
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=cut |
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|
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sub _koha_authenticate { |
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my ($c, $config) = @_; |
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my ($error, $data, $statusCode); |
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|
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try { |
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check_key_auth($c, $config); |
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} catch { |
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if (blessed($_)) { |
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if ($_->isa('Koha::Exception::BadAuthenticationToken') || |
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$_->isa('Koha::Exception::NoPermission') ) { |
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$error = {valid => Mojo::JSON->false, errors => [{message => $_->error, path => $c->req->url->path_query}]}; |
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$data = {header => {"WWW-Authenticate" => "Where is Koha API authentication publicly instructed?"}}; |
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$statusCode = 401; |
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} |
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elsif ($_->isa('Koha::Exception::UnknownProgramState')){ |
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$error = {valid => Mojo::JSON->false, errors => [{message => $_->error, path => $c->req->url->path_query}]}; |
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$data = {}; |
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$statusCode = 500; |
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} |
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|
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} |
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|
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}; |
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return ($error, $data, $statusCode); |
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} |
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|
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=head check_key_auth |
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|
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my $auth_ok = check_key_auth($c, $opObj); |
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|
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For authentication to succeed, the client have to send 3 custom HTTP |
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headers: |
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- X-Koha-Username: userid of borrower |
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- X-Koha-Timestamp: timestamp of the request |
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- X-Koha-Signature: signature of the request |
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|
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The signature is a HMAC-SHA256 hash of several elements of the request, |
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separated by spaces: |
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- HTTP method (uppercase) |
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- URL path and query string |
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- username |
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- timestamp of the request |
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|
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The server then tries to rebuild the signature with each user's API key. |
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If one matches the received X-Koha-Signature, then authentication is |
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almost OK. |
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|
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To avoid requests to be replayed, the last request's timestamp is stored |
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in database and the authentication succeeds only if the stored timestamp |
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is lesser than X-Koha-Timestamp. |
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|
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|
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There is also an "anonymous" mode if X-Koha-* headers are not set. |
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Anonymous mode differ from authenticated mode in one thing: if user is |
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authenticated, the corresponding Koha::Borrower object is stored in |
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Mojolicious stash, so it can easily be retrieved by controllers. |
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Controllers then have the responsibility of what to do if user is |
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authenticated or not. |
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|
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@PARAM1 Mojolicious::Controller |
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@PARAM2 Reference to HASH, the "Operation Object" from Swagger2.0 specification, |
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matching the given "Path Item Object"'s HTTP Verb. |
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@RETURNS Integer, 1 if authentication succeeded, otherwise throws exceptions. |
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@THROWS Koha::Exception::BadAuthenticationToken from _check_key_auth_api_key() |
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@THROWS Koha::Exception::NoPermission if borrower has no Koha permission to access the resource |
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@THROWS Koha::Exception::UnknownProgramState if authentication system malfunctions; |
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=cut |
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|
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sub check_key_auth { |
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my ($c, $opObj) = @_; |
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my $req_username = $c->req->headers->header('X-Koha-Username'); |
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my $req_timestamp = $c->req->headers->header('X-Koha-Timestamp'); |
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my $req_signature = $c->req->headers->header('X-Koha-Signature'); |
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my $req_method = $c->req->method; |
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my $req_url = '/' . $c->req->url->path_query; |
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|
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my $borrower = Koha::Borrowers->find({userid => $req_username}); |
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|
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#If the resource requires specific permissions, a strong authentication must be given. |
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if ($opObj->{"x-koha-permission"}) { |
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#Does key authentication fail? |
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_check_key_auth_api_key($c, $borrower); |
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|
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#Strong auth OK, Are there enough permissions? |
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my ($failedPermission, $borrowerPermissions) = C4::Auth::haspermission($borrower, $opObj->{"x-koha-permission"}); |
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unless ($borrowerPermissions) { #Permissions are lacking. |
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my @permTokens = %$failedPermission if (ref $failedPermission eq 'HASH'); |
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my $failedPermissionString = (@permTokens) ? $permTokens[0].' => '.$permTokens[1] : "Permission unknown"; |
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Koha::Exception::NoPermission->throw(error => "No Koha permission to access this resource. Permission '$failedPermissionString' required."); |
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} |
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|
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# Authentication succeeded, store authenticated user in stash |
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$c->stash('user', $borrower); |
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return 1; |
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} |
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#No special permissions needed, try anon auth, and then strong auth. |
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else { |
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# "Anonymous" mode |
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if (_check_key_auth_anonymous($c)) { |
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return 'ANON'; |
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} |
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_check_key_auth_api_key($c, $borrower); |
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|
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# Authentication succeeded, store authenticated user in stash |
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$c->stash('user', $borrower); |
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return 1; |
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} |
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|
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#If we reach this point there is something wrong. NEVER default to auth OK |
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Koha::Exception::UnknownProgramState->throw(error => "Failure when authenticating. Unknown authentication state."); |
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} |
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|
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=head _check_key_auth_anonymous |
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|
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@PARAM1, Mojolicious::Controller |
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@RETURNS, Int, 2, if anonymous authentication |
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undef, if no anonymous authentication. |
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=cut |
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|
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sub _check_key_auth_anonymous { |
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my ($c) = @_; |
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my $req_username = $c->req->headers->header('X-Koha-Username'); |
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my $req_timestamp = $c->req->headers->header('X-Koha-Timestamp'); |
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my $req_signature = $c->req->headers->header('X-Koha-Signature'); |
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|
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return 2 |
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unless ( defined($req_username) |
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or defined($req_timestamp) |
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or defined($req_signature) ); |
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return undef; |
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} |
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|
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=head _check_key_auth_api_key |
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|
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unless (_check_key_auth_api_key($c, $borrower)) { |
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return; |
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} |
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|
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@PARAM1 Mojolicious::Controller |
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@PARAM2 Koha::Borrower |
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@RETURNS Int, 1, if api authentication succeeded |
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undef, authentication failed |
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@THROWS Koha::Exception::BadAuthenticationToken if borrower: |
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has no API keys, |
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signatures do not match, |
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given timestamp is stale |
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=cut |
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|
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sub _check_key_auth_api_key { |
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my ($c, $borrower) = @_; |
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my $req_username = $c->req->headers->header('X-Koha-Username'); |
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my $req_timestamp = $c->req->headers->header('X-Koha-Timestamp'); |
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my $req_signature = $c->req->headers->header('X-Koha-Signature'); |
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my $req_method = $c->req->method; |
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my $req_url = '/' . $c->req->url->path_query; |
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|
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my @apikeys = Koha::ApiKeys->search({ |
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borrowernumber => $borrower->borrowernumber, |
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active => 1, |
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}); |
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Koha::Exception::BadAuthenticationToken->throw(error => "User has no API keys") unless @apikeys; |
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|
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my $message = "$req_method $req_url $req_username $req_timestamp"; |
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my $signature = ''; |
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foreach my $apikey (@apikeys) { |
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$signature = hmac_sha256_hex($message, $apikey->api_key); |
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|
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last if $signature eq $req_signature; |
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} |
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|
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unless ($signature eq $req_signature) { |
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Koha::Exception::BadAuthenticationToken->throw(error => "API key authentication failed"); |
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} |
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|
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my $api_timestamp = Koha::ApiTimestamps->find($borrower->borrowernumber); |
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my $timestamp = $api_timestamp ? $api_timestamp->timestamp : 0; |
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unless ($timestamp < $req_timestamp) { |
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Koha::Exception::BadAuthenticationToken->throw(error => "Bad X-Koha-Timestamp, expected '$timestamp'"); |
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} |
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|
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unless ($api_timestamp) { |
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$api_timestamp = new Koha::ApiTimestamp; |
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$api_timestamp->borrowernumber($borrower->borrowernumber); |
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} |
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$api_timestamp->timestamp($req_timestamp); |
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$api_timestamp->store; |
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|
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return 1; |
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} |
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|
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return 1; |