DESCRIPTIONThe pkcs7 command processes PKCS#7 files in DER or PEM format. COMMAND OPTIONS
-inform DER|PEM This specifies the input format. DER format is DER encoded
PKCS#7 v1.5 structure.PEM (the default) is a base64 encoded version
of the DER form with header and footer lines.
-outform DER|PEM This specifies the output format, the options have the same
meaning as the -inform option.
-in filename This specifies the input filename to read from or standard
input if this option is not specified.
-out filename specifies the output filename to write to or standard output
by default.
-print_certs prints out any certificates or CRLs contained in the file.
They are preceded by their subject and issuer names in one line
format.
-text prints out certificates details in full rather than just subject
and issuer names.
-noout don't output the encoded version of the PKCS#7 structure (or
certificates is -print_certs is set).
-engine id specifying an engine (by it's unique id string) will cause
req to attempt to obtain a functional reference to the specified
engine, thus initialising it if needed. The engine will then be
set as the default for all available algorithms.
EXAMPLESConvert a PKCS#7 file from PEM to DER:
openssl pkcs7 -in file.pem -outform DER -out file.der
RESTRICTIONSThere is no option to print out all the fields of a PKCS#7
file.
This PKCS#7 routines only understand PKCS#7 v 1.5 as specified
in RFC2315 they cannot currently parse, for example, the new CMS
as described in RFC2630.
HP Open Source Security for OpenVMS Volume 2:... 
OpenSSL Command Line Interface (CLI) Reference
