What is the difference between a cer, pvk, and pfx file?
EDIT:
Also, which files do I keep and which am I expected to give to my counter-parties?
+1
A:
I actually came across something like this not too long ago... check it out over on msdn (see the first answer)
in summary:
.cer - certificate stored in the X.509 standard format. This certificate contains information about the certificate's owner... along with public and private keys.
.pvk - files are used to store private keys for code signing. You can also create a certificate based on .pvk private key file.
.pfx - stands for personal exchange format. It is used to exchange public and private objects in a single file. A pfx file can be created from .cer file. Can also be used to create a Software Publisher Certificate.
I summarized the info from the page based on the suggestion from the comments.
Ryan Ferretti
2010-02-18 22:01:22
I would recommend quoting or summarizing the linked content in addition to the link itself. That way you both give proper credit and protect us from losing the information the next time MS redesigns their site.
Jonathan Allen
2010-02-18 22:06:42
I've seen that link, but I it doesn't fully answer the question.
Jonathan Allen
2010-02-18 22:08:33
Also, some of the information in the link is wrong. For example, you can't extract a private key from a certificate. Obviously.
erickson
2010-02-18 22:08:43
+3
A:
Windows uses .cer extension for an X.509 certificate. These can be in "binary" (ASN.1 DER), or it can be encoded with Base-64 and have a header and footer applied (PEM); Windows will recognize either. To verify the integrity of a certificate, you have to have check its signature using the issuer's public key... which is, in turn, another certificate.
Windows uses .pfx for a PKCS #12 file. This file can contain a variety of cryptographic information, including certificates, certificate chains, root authority certificates, and private keys. Its contents can be cryptographically protected (with passwords) to keep private keys private and preserve the integrity of root certificates.
Windows uses .pvk for a private key file. I'm not sure what standard (if any) Windows follows for these. Hopefully they are PKCS #8 encoded keys.
You should never disclose your private key. These are contained in .pfx and .pvk files.
Generally, you only exchange your certificate (.cer) and the certificates of any intermediate issuers (i.e., the certificates of all of your CAs, except the root CA) with other parties.
erickson
2010-02-18 22:09:28