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 | -aes128 | -aes192
| -aes256 | -camellia128 | -camellia192 | -camellia256 | -nodes] [
-noiter] [
-maciter | -nomaciter | -nomac] [
-twopass] [
-descert] [
-certpbe cipher] [
-keypbe cipher] [
-macalg digest] [
-keyex] [
-keysig] [
-password
arg] [
-passin arg] [
-passout arg] [
-rand file(s)]
[
-CAfile file] [
-CApath dir] [
-CSP name]
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.
- -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 outputted private keys with. For more
information about the format of arg see the PASS PHRASE
ARGUMENTS section in openssl(1).
- -password arg
- With -export, -password is equivalent to -passout. Otherwise, -password is
equivalent to -passin.
- -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.
- -aes128, -aes192, -aes256
- use AES to encrypt private keys before outputting.
- -camellia128, -camellia192, -camellia256
- use Camellia 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. Any PKCS#5 v1.5 or PKCS#12 PBE algorithm name
can be used (see NOTES section for more information). If a cipher
name (as output by the list-cipher-algorithms command is specified
then it is used with PKCS#5 v2.0. For interoperability reasons it is
advisable to only use PKCS#12 algorithms.
- -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.
- -macalg digest
- specify the MAC digest algorithm. If not included them SHA1 will be
used.
- -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.
- -nomac
- don't attempt to provide the MAC integrity.
- -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.
- -CAfile file
- CA storage as a file.
- -CApath dir
- CA storage as a directory. This directory must be a standard certificate
directory: that is a hash of each subject name (using x509 -hash)
should be linked to each certificate.
- -CSP name
- write name as a Microsoft CSP name.
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)