code: function(cert) {
        var sAttr = cert.issuer.attributes;
  
        for(var i = 0; i < msg.recipients.length; ++i) {
          var r = msg.recipients[i];
          var rAttr = r.issuer;
  
          if(r.serialNumber !== cert.serialNumber) {
            continue;
          }
  
          if(rAttr.length !== sAttr.length) {
            continue;
          }
  
          var match = true;
          for(var j = 0; j < sAttr.length; ++j) {
            if(rAttr[j].type !== sAttr[j].type ||
              rAttr[j].value !== sAttr[j].value) {
              match = false;
              break;
            }
          }
  
          if(match) {
            return r;
          }
        }
  
        return null;
      }
docs: Find recipient by X.509 certificate's issuer.
  
  @param cert the certificate with the issuer to look for.
  
  @return the recipient object.