When sending an invoice in PDF format, it is useful (in some countries obligatory) to sign this PDF digitally.
Of course, I could create a self-signed certificate via OpenSSL, but a warning "could not verify certificate" in the PDF rather reduces trust than increases it. Of course, this is absolutely correct as anyone could create self-signed certificates in any name.
No problem, I thought. I have an SSL certificate signed by RapidSSL, signed by CACert and OpenSSL allows me to convert this to a PKCS#12 certificate file http://support.citrix.com/article/CTX106630.
Probably it is bold to expect that the same instance valid for signing SSL certificates would also be valid for my PDF documents. So Adobe Acrobat shows the same message again that it cannot verify the certificate.
Well, then someone probably sells certificates that are signed by some authority that is trusted by Adobe Acrobat by default. However, I simply can't find the right search term in Google to locate appropriate offers.
Therefore my question: Did I think completely wrong in one point or another? And: What must I watch for at the certificate vendors when I need a certificate that Adobe Acrobat likes?