Validate X.509 (SSL) certificates, implemented PHP only.
Licensed under The MIT license.
iTune Store Receipt have Certificate(DER).
But PHP's openssl doesn't support Certificate Path Validation(Certificate Chain).
This Library support Certificate Path Validation.
e.g.
Root CA: /C=US/O=Apple Inc./OU=Apple Certification Authority/CN=Apple Root CA
Intermidiate CA: /C=US/O=Apple Inc./OU=Apple Certification Authority/CN=Apple iTunes Store Certification Authority
Leaf CA: /CN=PurchaseReceiptCertificate/OU=Apple iTunes Store/O=Apple Inc./C=US
But This Library doesn't support full validation.