- base64_decode: documentation ( source)
- print_r: documentation ( source)
<?php
$signature = 'gX7owAGRQzq/m/uF9jK5vKtrBnRbvSNe8czOuFzBxGUtVku/9AB8uv1IUBtAsL8jxSv/w/LJdgwZZo4UVvfJSoRJhpvlN5sSsiw2b99WCsLCcndWSWpWPdFU3xmNvs6R0j45F5yc6YWlRp/S0tLxKpGyx+okKQJMDVB3Zxg2muw=';
$base_string = 'POST&http%3A%2F%2F203.189.106.178%2Fapi%2FC07_1103_WorldmapView&oauth_consumer_key%3Ddmm%26oauth_nonce%3D6d095a6736d5874e9c22a61f2729117c%26oauth_signature_method%3DRSA-SHA1%26oauth_timestamp%3D1407993732%26oauth_token%3D%26oauth_version%3D1.0%26opensocial_app_id%3D987930%26opensocial_app_url%3Dhttp%253A%252F%252F203.189.106.178%252Fgadget%252Fgadget.xml%26opensocial_owner_id%3D9498293%26opensocial_viewer_id%3D9498293%26params%3D%257B%2522spotId%2522%253A%25220%2522%252C%2522callback%2522%253A%2522C07_1103_WorldmapView%2522%252C%2522screenId%2522%253A%25220301%2522%252C%2522authNumber%2522%253A348%252C%2522userId%2522%253A10000000%252C%2522dmmId%2522%253A%25229498293%2522%252C%2522ajax%2522%253A1%257D%26xoauth_public_key%3Dhttp%253A%252F%252Fsbx-osapi.dmm.com%252Fsbx_public_0609.crt%26xoauth_signature_publickey%3Dhttp%253A%252F%252Fsbx-osapi.dmm.com%252Fsbx_public_0609.crt';
$decoded_sig = base64_decode($signature);
$cert = <<< KEY
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
KEY;
$publickeyid = openssl_get_publickey($cert);
$ok = openssl_verify($base_string, $decoded_sig, $publickeyid);
openssl_free_key($publickeyid);
print_r($ok);