.pem
Defined in RFC's 1421 through 1424, this is a container format that may include just the public certificate (such as with Apache installs, and CA certificate files /etc/ssl/certs), or may include an entire certificate chain including public key, private key, and root certificates. Confusingly, it may also encode a CSR (e.g. as used here) as the PKCS10 format can be translated into PEM. The name is from Privacy Enhanced Mail (PEM), a failed method for secure email but the container format it used lives on, and is a base64 translation of the x509 ASN.1 keys.

.key
This is a PEM formatted file containing just the private-key of a specific certificate and is merely a conventional name and not a standardized one. In Apache installs, this frequently resides in /etc/ssl/private. The rights on these files are very important, and some programs will refuse to load these certificates if they are set wron

.pkcs12 .pfx .p12
Originally defined by RSA in the Public-Key Cryptography Standards, the "12" variant was enhanced by Microsoft. This is a passworded container format that contains both public and private certificate pairs. Unlike .pem files, this container is fully encrypted. Openssl can turn this into a .pem file with both public and private keys: openssl pkcs12 -in file-to-convert.p12 -out converted-file.pem -nodes

.der
A way to encode ASN.1 syntax in binary, a .pem file is just a Base64 encoded .der file. OpenSSL can convert these to .pem (openssl x509 -inform der -in to-convert.der -out converted.pem). Windows sees these as Certificate files. By default, Windows will export certificates as .DER formatted files with a different extension. Like...

.cert .cer .crt
A .pem (or rarely .der) formatted file with a different extension, one that is recognized by Windows Explorer as a certificate, which .pem is not.

.p7b
Defined in RFC 2315, this is a format used by windows for certificate interchange. Java understands these natively. Unlike .pem style certificates, this format has a defined way to include certification-path certificates

.crl
A certificate revocation list. Certificate Authorities produce these as a way to de-authorize certificates before expiration. You can sometimes download them from CA websites

مراحل راه اندازی وب سرور امن wamp در ویندوز :
http://www.phpjoel.com/2011/04/07/installing-ssl-using-openssl-on-a-wamp-localhost/

#security #webserver #malware #botnet #DOS