pkcs12 - PKCS#12 file utility
SYNOPSIS
openssl pkcs12 [-export] [-chain] [-inkey filename]
[-certfile filename] [-name name] [-caname name] [-in
filename] [-out filename] [-noout] [-nomacver] [-nocerts]
[-clcerts] [-cacerts] [-nokeys] [-info] [-des] [-des3]
[-idea] [-nodes] [-noiter] [-maciter] [-twopass]
[-descert] [-certpbe] [-keypbe] [-keyex] [-keysig]
[-password arg] [-passin arg] [-passout arg] [-rand
file(s)]
DESCRIPTION
The pkcs12 command allows PKCS#12 files (sometimes
referred to as PFX files) to be created and parsed.
PKCS#12 files are used by several programs including
Netscape, MSIE and MS Outlook.
COMMAND OPTIONS
There are a lot of options the meaning of some depends of
whether a PKCS#12 file is being created or parsed. By
default a PKCS#12 file is parsed a PKCS#12 file can be
created by using the -export option (see below).
PARSING OPTIONS
-in filename
This specifies filename of the PKCS#12 file to be
parsed. Standard input is used by default.
-out filename
The filename to write certificates and private keys
to, standard output by default. They are all written
in PEM format.
-pass arg, -passin arg
the PKCS#12 file (i.e. input file) password source.
For more information about the format of arg see the
PASS PHRASE ARGUMENTS section in openssl(1).
-passout arg
pass phrase source to encrypt any outputed private
keys with. For more information about the format of
arg see the PASS PHRASE ARGUMENTS section in
openssl(1).
-noout
this option inhibits output of the keys and
certificates to the output file version of the PKCS#12
file.
-clcerts
only output client certificates (not CA certificates).
only output CA certificates (not client certificates).
-nocerts
no certificates at all will be output.
-nokeys
no private keys will be output.
-info
output additional information about the PKCS#12 file
structure, algorithms used and iteration counts.
-des
use DES to encrypt private keys before outputting.
-des3
use triple DES to encrypt private keys before
outputting, this is the default.
-idea
use IDEA to encrypt private keys before outputting.
-nodes
don't encrypt the private keys at all.
-nomacver
don't attempt to verify the integrity MAC before
reading the file.
-twopass
prompt for separate integrity and encryption
passwords: most software always assumes these are the
same so this option will render such PKCS#12 files
unreadable.
FILE CREATION OPTIONS
-export
This option specifies that a PKCS#12 file will be
created rather than parsed.
-out filename
This specifies filename to write the PKCS#12 file to.
Standard output is used by default.
-in filename
The filename to read certificates and private keys
from, standard input by default. They must all be in
PEM format. The order doesn't matter but one private
key and its corresponding certificate should be
present. If additional certificates are present they
will also be included in the PKCS#12 file.
file to read private key from. If not present then a
private key must be present in the input file.
-name friendlyname
This specifies the "friendly name" for the certificate
and private key. This name is typically displayed in
list boxes by software importing the file.
-certfile filename
A filename to read additional certificates from.
-caname friendlyname
This specifies the "friendly name" for other
certificates. This option may be used multiple times
to specify names for all certificates in the order
they appear. Netscape ignores friendly names on other
certificates whereas MSIE displays them.
-pass arg, -passout arg
the PKCS#12 file (i.e. output file) password source.
For more information about the format of arg see the
PASS PHRASE ARGUMENTS section in openssl(1).
-passin password
pass phrase source to decrypt any input private keys
with. For more information about the format of arg see
the PASS PHRASE ARGUMENTS section in openssl(1).
-chain
if this option is present then an attempt is made to
include the entire certificate chain of the user
certificate. The standard CA store is used for this
search. If the search fails it is considered a fatal
error.
-descert
encrypt the certificate using triple DES, this may
render the PKCS#12 file unreadable by some "export
grade" software. By default the private key is
encrypted using triple DES and the certificate using
40 bit RC2.
-keypbe alg, -certpbe alg
these options allow the algorithm used to encrypt the
private key and certificates to be selected. Although
any PKCS#5 v1.5 or PKCS#12 algorithms can be selected
it is advisable only to use PKCS#12 algorithms. See
the list in the NOTES section for more information.
-keyex|-keysig
specifies that the private key is to be used for key
exchange or just signing. This option is only
interpreted by MSIE and similar MS software. Normally
keys to be used for encryption purposes but arbitrary
length keys for signing. The -keysig option marks the
key for signing only. Signing only keys can be used
for S/MIME signing, authenticode (ActiveX control
signing) and SSL client authentication, however due
to a bug only MSIE 5.0 and later support the use of
signing only keys for SSL client authentication.
-nomaciter, -noiter
these options affect the iteration counts on the MAC
and key algorithms. Unless you wish to produce files
compatible with MSIE 4.0 you should leave these
options alone.
To discourage attacks by using large dictionaries of
common passwords the algorithm that derives keys from
passwords can have an iteration count applied to it:
this causes a certain part of the algorithm to be
repeated and slows it down. The MAC is used to check
the file integrity but since it will normally have the
same password as the keys and certificates it could
also be attacked. By default both MAC and encryption
iteration counts are set to 2048, using these options
the MAC and encryption iteration counts can be set to
1, since this reduces the file security you should not
use these options unless you really have to. Most
software supports both MAC and key iteration counts.
MSIE 4.0 doesn't support MAC iteration counts so it
needs the -nomaciter option.
-maciter
This option is included for compatibility with
previous versions, it used to be needed to use MAC
iterations counts but they are now used by default.
-rand file(s)
a file or files containing random data used to seed
the random number generator, or an EGD socket (see
RAND_egd(3)). Multiple files can be specified
separated by a OS-dependent character. The separator
is ; for MS-Windows, , for OpenVMS, and : for all
others.
NOTES
Although there are a large number of options most of them
are very rarely used. For PKCS#12 file parsing only -in
and -out need to be used for PKCS#12 file creation -export
and -name are also used.
If none of the -clcerts, -cacerts or -nocerts options are
present then all certificates will be output in the order
they appear in the input PKCS#12 files. There is no
guarantee that the first certificate present is the one
requires a private key and certificate and assumes the
first certificate in the file is the one corresponding to
the private key: this may not always be the case. Using
the -clcerts option will solve this problem by only
outputing the certificate corresponding to the private
key. If the CA certificates are required then they can be
output to a separate file using the -nokeys -cacerts
options to just output CA certificates.
The -keypbe and -certpbe algorithms allow the precise
encryption algorithms for private keys and certificates to
be specified. Normally the defaults are fine but
occasionally software can't handle triple DES encrypted
private keys, then the option -keypbe PBE-SHA1-RC2-40 can
be used to reduce the private key encryption to 40 bit
RC2. A complete description of all algorithms is contained
in the pkcs8 manual page.
EXAMPLES
Parse a PKCS#12 file and output it to a file:
openssl pkcs12 -in file.p12 -out file.pem
Output only client certificates to a file:
openssl pkcs12 -in file.p12 -clcerts -out file.pem
Don't encrypt the private key:
openssl pkcs12 -in file.p12 -out file.pem -nodes
Print some info about a PKCS#12 file:
openssl pkcs12 -in file.p12 -info -noout
Create a PKCS#12 file:
openssl pkcs12 -export -in file.pem -out file.p12 -name "My Certificate"
Include some extra certificates:
openssl pkcs12 -export -in file.pem -out file.p12 -name "My Certificate" \
-certfile othercerts.pem
BUGS
Some would argue that the PKCS#12 standard is one big bug
:-)
Versions of OpenSSL before 0.9.6a had a bug in the PKCS#12
key generation routines. Under rare circumstances this
could produce a PKCS#12 file encrypted with an invalid
key. As a result some PKCS#12 files which triggered this
not be decrypted by OpenSSL and similarly OpenSSL could
produce PKCS#12 files which could not be decrypted by
other implementations. The chances of producing such a
file are relatively small: less than 1 in 256.
A side effect of fixing this bug is that any old invalidly
encrypted PKCS#12 files cannot no longer be parsed by the
fixed version. Under such circumstances the pkcs12 utility
will report that the MAC is OK but fail with a decryption
error when extracting private keys.
This problem can be resolved by extracting the private
keys and certificates from the PKCS#12 file using an older
version of OpenSSL and recreating the PKCS#12 file from
the keys and certificates using a newer version of
OpenSSL. For example:
old-openssl -in bad.p12 -out keycerts.pem
openssl -in keycerts.pem -export -name "My PKCS#12 file" -out fixed.p12
SEE ALSO
pkcs8(1)
Man(1) output converted with
man2html