Webbots, Spiders, and Screen Scrapers

Local Certificates

Corporate networks sometimes use local certificates to authenticate both client and server. In the vast majority of cases, however, there is no need for a local certificate—in fact, I have never been in a situation that required one. However, PHP/CURL supports local encryption certificates, and it's important to configure them even if you don't use them. Versions 7.10 and later of cURL assume that a local certificate is used and will not download any web page if the local certificate isn't defined.^[65] This is counterintuitive since local certificates are seldom used; therefore, LIB_http—the library this book uses to fetch web pages and submit forms—assumes that there is no local encryption certificate and configures PHP/CURL ...