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Edit File: RsaSha1.php

<?php

namespace Eher\OAuth\SignatureMethod;

/**
 * The RSA-SHA1 signature method uses the RSASSA-PKCS1-v1_5 signature algorithm as defined in
 * [RFC3447] section 8.2 (more simply known as PKCS#1), using SHA-1 as the hash function for
 * EMSA-PKCS1-v1_5. It is assumed that the Consumer has provided its RSA public key in a
 * verified way to the Service Provider, in a manner which is beyond the scope of this
 * specification.
 *   - Chapter 9.3 ("RSA-SHA1")
 */
abstract class RsaSha1 extends SignatureMethod {
  public function get_name() {
    return "RSA-SHA1";
  }

// Up to the SP to implement this lookup of keys. Possible ideas are:
  // (1) do a lookup in a table of trusted certs keyed off of consumer
  // (2) fetch via http using a url provided by the requester
  // (3) some sort of specific discovery code based on request
  //
  // Either way should return a string representation of the certificate
  protected abstract function fetch_public_cert(&$request);

// Up to the SP to implement this lookup of keys. Possible ideas are:
  // (1) do a lookup in a table of trusted certs keyed off of consumer
  //
  // Either way should return a string representation of the certificate
  protected abstract function fetch_private_cert(&$request);

public function build_signature($request, $consumer, $token) {
    $base_string = $request->get_signature_base_string();
    $request->base_string = $base_string;

// Fetch the private key cert based on the request
    $cert = $this->fetch_private_cert($request);

// Pull the private key ID from the certificate
    $privatekeyid = openssl_get_privatekey($cert);

// Sign using the key
    $ok = openssl_sign($base_string, $signature, $privatekeyid);

// Release the key resource
    openssl_free_key($privatekeyid);

return base64_encode($signature);
  }

public function check_signature($request, $consumer, $token, $signature) {
    $decoded_sig = base64_decode($signature);

$base_string = $request->get_signature_base_string();

// Fetch the public key cert based on the request
    $cert = $this->fetch_public_cert($request);

// Pull the public key ID from the certificate
    $publickeyid = openssl_get_publickey($cert);

// Check the computed signature against the one passed in the query
    $ok = openssl_verify($base_string, $decoded_sig, $publickeyid);

// Release the key resource
    openssl_free_key($publickeyid);

return $ok == 1;
  }
}

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