PKCS12(1) OpenSSL PKCS12(1)
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.
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).
-cacerts
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
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 "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 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 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 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 bug from other implementations (MSIE or Netscape) could 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)
0.9.7l 2001-09-06 PKCS12(1)
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