OpenSL pkcs12(1openssl)
NAME
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.
COMAND 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 PAS
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 PAS 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).
-cacerts
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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.
-inkey filename
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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 PAS
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 PAS 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
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"export grade" software will only allow 512 bit RSA 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 SL
client authentication, however due to a bug only MSIE
5.0 and later support the use of signing only keys for
SL 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
RANDegd(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
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guarantee that the first certificate present is the one
corresponding to the private key. Certain software which
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 outputting
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 OpenSL before 0.9.6a had a bug in the PKCS#12
key generation routines. Under rare circumstances this could
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produce a PKCS#12 file encrypted with an invalid key. As a
result some PKCS#12 files which triggered this bug from
other implementations (MSIE or Netscape) could not be
decrypted by OpenSL and similarly OpenSL 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 OpenSL and recreating the PKCS#12 file from the
keys and certificates using a newer version of OpenSL. 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)
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