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lib/Amazon/PAApi5/Signature.pm  view on Meta::CPAN

package Amazon::PAApi5::Signature;
use strict;
use warnings;
use Carp qw/croak/;
use POSIX qw/strftime/;
use Digest::SHA qw/sha256_hex hmac_sha256 hmac_sha256_hex/;
use Class::Accessor::Lite (
    rw  => [qw/
        access_key
        secret_key
        payload
        resource_path
        operation
        host
        region
        aws_headers
        str_signed_header
    /],
    ro  => [qw/
        service
        http_method
        hmac_algorithm
        aws4_request
        x_amz_date
        current_date
    /],
);

our $VERSION = '0.05';

sub new {
    my $class      = shift;
    my $access_key = shift or croak 'access_key is required';
    my $secret_key = shift or croak 'secret_key is required';
    my $payload    = shift or croak 'payload is required';
    my $opt        = shift || {};

    my $operation     = $opt->{operation} || 'SearchItems';
    my $resource_path = $opt->{resource_path} ? $opt->{resource_path} : '/paapi5/' . lc($operation);

    return bless {
        access_key     => $access_key,
        secret_key     => $secret_key,
        payload        => $payload,
        resource_path  => $resource_path,
        operation      => $operation,
        host           => $opt->{host}           || 'webservices.amazon.com',
        region         => $opt->{region}         || 'us-east-1',
        service        => $opt->{service}        || 'ProductAdvertisingAPI',
        http_method    => $opt->{http_method}    || 'POST',
        hmac_algorithm => $opt->{hmac_algorithm} || 'AWS4-HMAC-SHA256',
        aws4_request   => $opt->{aws4_request}   || 'aws4_request',
        x_amz_date     => $class->_get_time_stamp,
        current_date   => $class->_get_date,
        aws_headers    => {},
        str_signed_header => '',
    }, $class;
}

sub req_url {
    my ($self) = @_;

    return sprintf("https://%s%s", $self->host, $self->resource_path);
}

sub _prepare_canonical_url {
    my ($self) = @_;

    my $canonical_url = $self->http_method . "\n";

    $canonical_url .= $self->resource_path . "\n\n";

    my $signed_headers = '';
    for my $key (grep { $_ !~ m!content-type! } sort keys %{$self->aws_headers}) {
        $signed_headers .=  lc($key) . ';';
        $canonical_url .= lc($key) . ':' . $self->aws_headers->{$key} . "\n";
    }

    $canonical_url .= "\n";

    $self->str_signed_header(substr($signed_headers, 0, -1)); # remove ';'
    $canonical_url .= $self->str_signed_header . "\n";

    $canonical_url .= sha256_hex($self->payload);

    return $canonical_url;
}

sub _prepare_string_to_sign {
    my ($self, $canonical_url) = @_;

    return join("\n",
        $self->hmac_algorithm,
        $self->x_amz_date,
        join('/', $self->current_date, $self->region, $self->service, $self->aws4_request),
        sha256_hex($canonical_url),
    );
}

sub _calculate_signature {
    my ($self, $string_to_sign) = @_;