keytool(1)keytool(1)Name
keytool - Key and Certificate Management Tool
Manages a keystore (database) of cryptographic keys, X.509 certificate
chains, and trusted certificates.
SYNOPSIS
keytool [ commands ]
The keytool command interface has changed in Java SE 6. See the Changes
Section for a detailed description. Note that previously defined com‐
mands are still supported.
DESCRIPTION
keytool is a key and certificate management utility. It allows users to
administer their own public/private key pairs and associated certifi‐
cates for use in self-authentication (where the user authenticates him‐
self/herself to other users/services) or data integrity and authentica‐
tion services, using digital signatures. It also allows users to cache
the public keys (in the form of certificates) of their communicating
peers.
A certificate is a digitally signed statement from one entity (person,
company, etc.), saying that the public key (and some other information)
of some other entity has a particular value. (See Certificates.) When
data is digitally signed, the signature can be verified to check the
data integrity and authenticity. Integrity means that the data has not
been modified or tampered with, and authenticity means the data indeed
comes from whoever claims to have created and signed it.
keytool also enables users to administer secret keys used in symmetric
encryption/decryption (e.g. DES).
keytool stores the keys and certificates in a keystore.
COMMAND AND OPTION NOTES
The various commands and their options are listed and described below.
Note:
o All command and option names are preceded by a minus sign (-).
o The options for each command may be provided in any order.
o All items not italicized or in braces or square brackets are
required to appear as is.
o Braces surrounding an option generally signify that a default
value will be used if the option is not specified on the command
line. Braces are also used around the -v, -rfc, and -J options,
which only have meaning if they appear on the command line (that
is, they don't have any "default" values other than not existing).
o Brackets surrounding an option signify that the user is prompted
for the value(s) if the option is not specified on the command
line. (For a -keypass option, if you do not specify the option on
the command line, keytool will first attempt to use the keystore
password to recover the private/secret key, and if this fails,
will then prompt you for the private/secret key password.)
o Items in italics (option values) represent the actual values that
must be supplied. For example, here is the format of the -print‐
cert command:
keytool -printcert {-file cert_file} {-v}
When specifying a -printcert command, replace cert_file with the
actual file name, as in:
keytool -printcert -file VScert.cer
o Option values must be quoted if they contain a blank (space).
o The -help command is the default. Thus, the command line
keytool
is equivalent to
keytool -help
Option Defaults
Below are the defaults for various option values.
-alias "mykey"
-keyalg
"DSA" (when using -genkeypair)
"DES" (when using -genseckey)
-keysize
2048 (when using -genkeypair and -keyalg is "RSA")
1024 (when using -genkeypair and -keyalg is "DSA")
256 (when using -genkeypair and -keyalg is "EC")
56 (when using -genseckey and -keyalg is "DES")
168 (when using -genseckey and -keyalg is "DESede")
-validity 90
-keystore the file named .keystore in the user's home directory
-storetype the value of the "keystore.type" property in the security properties file,
which is returned by the static getDefaultType method in
java.security.KeyStore
-file stdin if reading, stdout if writing
-protected false
In generating a public/private key pair, the signature algorithm
(-sigalg option) is derived from the algorithm of the underlying pri‐
vate key:
o If the underlying private key is of type "DSA", the -sigalg option
defaults to "SHA1withDSA"
o If the underlying private key is of type "RSA", the -sigalg option
defaults to "SHA256withRSA".
o If the underlying private key is of type "EC", the -sigalg option
defaults to "SHA256withECDSA".
Please consult the Java Cryptography Architecture API Specification &
Reference @
http://docs.oracle.com/javase/7/docs/technotes/guides/secu‐
rity/crypto/CryptoSpec.html#AppA for a full list of -keyalg and -sigalg
you can choose from.
Common Options
The -v option can appear for all commands except -help. If it appears,
it signifies "verbose" mode; more information will be provided in the
output.
There is also a -Jjavaoption option that may appear for any command. If
it appears, the specified javaoption string is passed through directly
to the Java interpreter. This option should not contain any spaces. It
is useful for adjusting the execution environment or memory usage. For
a list of possible interpreter options, type java -h or java -X at the
command line.
These options may appear for all commands operating on a keystore:
-storetype storetype
This qualifier specifies the type of keystore to be instantiated.
-keystore keystore
The keystore location.
If the JKS storetype is used and a keystore file does not yet exist,
then certain keytool commands may result in a new keystore file
being created. For example, if keytool -genkeypair is invoked and
the -keystore option is not specified, the default keystore file
named .keystore in the user's home directory will be created if it
does not already exist. Similarly, if the -keystore ks_file option
is specified but ks_file does not exist, then it will be created
Note that the input stream from the -keystore option is passed to
the KeyStore.load method. If NONE is specified as the URL, then a
null stream is passed to the KeyStore.load method. NONE should be
specified if the KeyStore is not file-based (for example, if it
resides on a hardware token device).
-storepass[:env|:file] argument
The password which is used to protect the integrity of the keystore.
If the modifier env or file is not specified, then the password has
the value argument, which must be at least 6 characters long. Other‐
wise, the password is retrieved as follows:
o env: Retrieve the password from the environment variable named
argument
o file: Retrieve the password from the file named argument
Note: All other options that require passwords, such as -keypass,
-srckeypass, -destkeypass -srcstorepass, and -deststorepass, accept
the env and file modifiers. (Remember to separate the password
option and the modifier with a colon, (:).)
The password must be provided to all commands that access the key‐
store contents. For such commands, if a -storepass option is not
provided at the command line, the user is prompted for it.
When retrieving information from the keystore, the password is
optional; if no password is given, the integrity of the retrieved
information cannot be checked and a warning is displayed.
-providerName provider_name
Used to identify a cryptographic service provider's name when listed
in the security properties file.
-providerClass provider_class_name
Used to specify the name of cryptographic service provider's master
class file when the service provider is not listed in the security
properties file.
-providerArg provider_arg
Used in conjunction with -providerClass. Represents an optional
string input argument for the constructor of provider_class_name.
-protected
Either true or false. This value should be specified as true if a
password must be given via a protected authentication path such as a
dedicated PIN reader.
Note: Since there are two keystores involved in -importkeystore com‐
mand, two options, namely, -srcprotected and -destprotected are pro‐
vided for the source keystore and the destination keystore respec‐
tively.
-ext {name{:critical}{=value}}
Denotes an X.509 certificate extension. The option can be used in
-genkeypair and -gencert to embed extensions into the certificate
generated, or in -certreq to show what extensions are requested in
the certificate request. The option can appear multiple times. name
can be a supported extension name (see below) or an arbitrary OID
number. value, if provided, denotes the parameter for the extension;
if omitted, denotes the default value (if defined) of the extension
or the extension requires no parameter. The :critical modifier, if
provided, means the extension's isCritical attribute is true; other‐
wise, false. You may use :c in place of :critical.
Currently keytool supports these named extensions (case-insensitive):
For name as OID, value is the HEX dumped DER encoding of the extnValue
for the extension excluding the OCTET STRING type and length bytes. Any
extra character other than standard HEX numbers (0-9, a-f, A-F) are
ignored in the HEX string. Therefore, both "01:02:03:04" and "01020304"
are accepted as identical values. If there is no value, the extension
has an empty value field then.
A special name 'honored', used in -gencert only, denotes how the exten‐
sions included in the certificate request should be honored. The value
for this name is a comma separated list of "all" (all requested exten‐
sions are honored), "name{:[critical|non-critical]}" (the named exten‐
sion is honored, but using a different isCritical attribute) and
"-name" (used with all, denotes an exception). Requested extensions are
not honored by default.
If, besides the -ext honored option, another named or OID -ext option
is provided, this extension will be added to those already honored.
However, if this name (or OID) also appears in the honored value, its
value and criticality overrides the one in the request.
The subjectKeyIdentifier extension is always created. For non
self-signed certificates, the authorityKeyIdentifier is always created.
Note: Users should be aware that some combinations of extensions (and
other certificate fields) may not conform to the Internet standard. See
Warning Regarding Certificate Conformance for details.
COMMANDS
Creating or Adding Data to the Keystore
-gencert {-rfc} {-infile infile} {-outfile outfile} {-alias alias}
{-sigalg sigalg} {-dname dname} {-startdate startdate {-ext ext}*
{-validity valDays} [-keypass keypass] {-keystore keystore}
[-storepass storepass] {-storetype storetype} {-providername
provider_name} {-providerClass provider_class_name {-providerArg
provider_arg}} {-v} {-protected} {-Jjavaoption}
Generates a certificate as a response to a certificate request file
(which can be created by the keytool -certreq command). The command
reads the request from infile (if omitted, from the standard input),
signs it using alias's private key, and output the X.509 certificate
into outfile (if omitted, to the standard output). If -rfc is speci‐
fied, output format is BASE64-encoded PEM; otherwise, a binary DER
is created.
sigalg specifies the algorithm that should be used to sign the cer‐
tificate. startdate is the start time/date that the certificate is
valid. valDays tells the number of days for which the certificate
should be considered valid.
If dname is provided, it's used as the subject of the generated cer‐
tificate. Otherwise, the one from the certificate request is used.
ext shows what X.509 extensions will be embedded in the certificate.
Read Common Options for the grammar of -ext.
The -gencert command enables you to create certificate chains. The
following example creates a certificate, e1, that contains three
certificates in its certificate chain.
The following commands creates four key pairs named ca, ca1, ca2,
and e1:
keytool -alias ca -dname CN=CA -genkeypair
keytool -alias ca1 -dname CN=CA -genkeypair
keytool -alias ca2 -dname CN=CA -genkeypair
keytool -alias e1 -dname CN=E1 -genkeypair
The following two commands create a chain of signed certificates; ca
signs ca1 and ca1 signs ca2, all of which are self-issued:
keytool -alias ca1 -certreq | keytool -alias ca -gencert -ext san=dns:ca1 | keytool -alias ca1 -importcert
keytool -alias ca2 -certreq | $KT -alias ca1 -gencert -ext san=dns:ca2 | $KT -alias ca2 -importcert
The following command creates the certificate e1 and stores it in
the file e1.cert, which is signed by ca2. As a result, e1 should
contain ca, ca1, and ca2 in its certificate chain:
keytool -alias e1 -certreq | keytool -alias ca2 -gencert > e1.cert
-genkeypair {-alias alias} {-keyalg keyalg} {-keysize keysize}
{-sigalg sigalg} [-dname dname] [-keypass keypass] {-startdate
value} {-ext ext}* {-validity valDays} {-storetype storetype} {-key‐
store keystore} [-storepass storepass] {-providerClass
provider_class_name {-providerArg provider_arg}} {-v} {-protected}
{-Jjavaoption}
Generates a key pair (a public key and associated private key).
Wraps the public key into an X.509 v3 self-signed certificate, which
is stored as a single-element certificate chain. This certificate
chain and the private key are stored in a new keystore entry identi‐
fied by alias.
keyalg specifies the algorithm to be used to generate the key pair,
and keysize specifies the size of each key to be generated. sigalg
specifies the algorithm that should be used to sign the self-signed
certificate; this algorithm must be compatible with keyalg.
dname specifies the X.500 Distinguished Name to be associated with
alias, and is used as the issuer and subject fields in the
self-signed certificate. If no distinguished name is provided at the
command line, the user will be prompted for one.
keypass is a password used to protect the private key of the gener‐
ated key pair. If no password is provided, the user is prompted for
it. If you press RETURN at the prompt, the key password is set to
the same password as that used for the keystore. keypass must be at
least 6 characters long.
startdate specifies the issue time of the certificate, also known as
the "Not Before" value of the X.509 certificate's Validity field.
The option value can be set in one of these two forms:
1. ([+-]nnn[ymdHMS])+
2. [yyyy/mm/dd] [HH:MM:SS]
With the first form, the issue time is shifted by the specified
value from the current time. The value is a concatenation of a
sequence of sub values. Inside each sub value, the plus sign ("+")
means shifting forward, and the minus sign ("-") means shifting
backward. The time to be shifted is nnn units of years, months,
days, hours, minutes, or seconds (denoted by a single character of
"y", "m", "d", "H", "M", or "S" respectively). The exact value of
the issue time is calculated using the java.util.GregorianCalen‐
dar.add(int field, int amount) method on each sub value, from left
to right. For example, by specifying "-startdate -1y+1m-1d", the
issue time will be:
Calendar c = new GregorianCalendar();
c.add(Calendar.YEAR, -1);
c.add(Calendar.MONTH, 1);
c.add(Calendar.DATE, -1);
return c.getTime()
With the second form, the user sets the exact issue time in two
parts, year/month/day and hour:minute:second (using the local time
zone). The user may provide only one part, which means the other
part is the same as the current date (or time). User must provide
the exact number of digits as shown in the format definition (pad‐
ding with 0 if shorter). When both the date and time are provided,
there is one (and only one) space character between the two parts.
The hour should always be provided in 24 hour format.
When the option is not provided, the start date is the current time.
The option can be provided at most once.
valDays specifies the number of days (starting at the date specified
by -startdate, or the current date if -startdate is not specified)
for which the certificate should be considered valid.
This command was named -genkey in previous releases. This old name
is still supported in this release and will be supported in future
releases, but for clarity the new name, -genkeypair, is preferred
going forward.
-genseckey {-alias alias} {-keyalg keyalg} {-keysize keysize} [-key‐
pass keypass] {-storetype storetype} {-keystore keystore}
[-storepass storepass] {-providerClass provider_class_name
{-providerArg provider_arg}} {-v} {-protected} {-Jjavaoption}
Generates a secret key and stores it in a new KeyStore.SecretKeyEn‐
try identified by alias.
keyalg specifies the algorithm to be used to generate the secret
key, and keysize specifies the size of the key to be generated. key‐
pass is a password used to protect the secret key. If no password is
provided, the user is prompted for it. If you press RETURN at the
prompt, the key password is set to the same password as that used
for the keystore. keypass must be at least 6 characters long.
-importcert {-alias alias} {-file cert_file} [-keypass keypass]
{-noprompt} {-trustcacerts} {-storetype storetype} {-keystore key‐
store} [-storepass storepass] {-providerName provider_name}
{-providerClass provider_class_name {-providerArg provider_arg}}
{-v} {-protected} {-Jjavaoption}
Reads the certificate or certificate chain (where the latter is sup‐
plied in a PKCS#7 formatted reply or a sequence of X.509 certifi‐
cates) from the file cert_file, and stores it in the keystore entry
identified by alias. If no file is given, the certificate or cer‐
tificate chain is read from stdin.
keytool can import X.509 v1, v2, and v3 certificates, and PKCS#7
formatted certificate chains consisting of certificates of that
type. The data to be imported must be provided either in binary
encoding format, or in printable encoding format (also known as
Base64 encoding) as defined by the Internet RFC 1421 standard. In
the latter case, the encoding must be bounded at the beginning by a
string that starts with "-----BEGIN", and bounded at the end by a
string that starts with "-----END".
You import a certificate for two reasons:
1. to add it to the list of trusted certificates, or
2. to import a certificate reply received from a CA as the result
of submitting a Certificate Signing Request (see the -certreq
command) to that CA.
Which type of import is intended is indicated by the value of the
-alias option:
1. If the alias does not point to a key entry, then keytool
assumes you are adding a trusted certificate entry. In this
case, the alias should not already exist in the keystore. If
the alias does already exist, then keytool outputs an error,
since there is already a trusted certificate for that alias,
and does not import the certificate.
2. If the alias points to a key entry, then keytool assumes you
are importing a certificate reply.
Importing a New Trusted Certificate
Before adding the certificate to the keystore, keytool tries to ver‐
ify it by attempting to construct a chain of trust from that cer‐
tificate to a self-signed certificate (belonging to a root CA),
using trusted certificates that are already available in the key‐
store.
If the -trustcacerts option has been specified, additional certifi‐
cates are considered for the chain of trust, namely the certificates
in a file named "cacerts".
If keytool fails to establish a trust path from the certificate to
be imported up to a self-signed certificate (either from the key‐
store or the "cacerts" file), the certificate information is printed
out, and the user is prompted to verify it, e.g., by comparing the
displayed certificate fingerprints with the fingerprints obtained
from some other (trusted) source of information, which might be the
certificate owner himself/herself. Be very careful to ensure the
certificate is valid prior to importing it as a "trusted" certifi‐
cate! -- see WARNING Regarding Importing Trusted Certificates. The
user then has the option of aborting the import operation. If the
-noprompt option is given, however, there will be no interaction
with the user. Importing a Certificate Reply
When importing a certificate reply, the certificate reply is vali‐
dated using trusted certificates from the keystore, and optionally
using the certificates configured in the "cacerts" keystore file (if
the -trustcacerts option was specified).
The methods of determining whether the certificate reply is trusted
are described in the following:
o If the reply is a single X.509 certificate, keytool attempts to
establish a trust chain, starting at the certificate reply and
ending at a self-signed certificate (belonging to a root CA).
The certificate reply and the hierarchy of certificates used to
authenticate the certificate reply form the new certificate
chain of alias. If a trust chain cannot be established, the
certificate reply is not imported. In this case, keytool does
not print out the certificate and prompt the user to verify it,
because it is very hard (if not impossible) for a user to
determine the authenticity of the certificate reply.
o If the reply is a PKCS#7 formatted certificate chain or a
sequence of X.509 certificates, the chain is ordered with the
user certificate first followed by zero or more CA certifi‐
cates. If the chain ends with a self-signed root CA certificate
and -trustcacerts option was specified, keytool will attempt to
match it with any of the trusted certificates in the keystore
or the "cacerts" keystore file. If the chain does not end with
a self-signed root CA certificate and the -trustcacerts option
was specified, keytool will try to find one from the trusted
certificates in the keystore or the "cacerts" keystore file and
add it to the end of the chain. If the certificate is not found
and -noprompt option is not specified, the information of the
last certificate in the chain is printed out, and the user is
prompted to verify it.
If the public key in the certificate reply matches the user's public
key already stored with under alias, the old certificate chain is
replaced with the new certificate chain in the reply. The old chain
can only be replaced if a valid keypass, the password used to pro‐
tect the private key of the entry, is supplied. If no password is
provided, and the private key password is different from the key‐
store password, the user is prompted for it.
This command was named -import in previous releases. This old name
is still supported in this release and will be supported in future
releases, but for clarify the new name, -importcert, is preferred
going forward.
-importkeystore -srckeystore srckeystore -destkeystore destkeystore
{-srcstoretype srcstoretype} {-deststoretype deststoretype} [-src‐
storepass srcstorepass] [-deststorepass deststorepass] {-srcpro‐
tected} {-destprotected} {-srcalias srcalias {-destalias destalias}
[-srckeypass srckeypass] [-destkeypass destkeypass] } {-noprompt}
{-srcProviderName src_provider_name} {-destProviderName
dest_provider_name} {-providerClass provider_class_name {-provider‐
Arg provider_arg}} {-v} {-protected} {-Jjavaoption}
Imports a single entry or all entries from a source keystore to a
destination keystore.
When the srcalias option is provided, the command imports the single
entry identified by the alias to the destination keystore. If a des‐
tination alias is not provided with destalias, then srcalias is used
as the destination alias. If the source entry is protected by a
password, srckeypass will be used to recover the entry. If srckey‐
pass is not provided, then keytool will attempt to use srcstorepass
to recover the entry. If srcstorepass is either not provided or is
incorrect, the user will be prompted for a password. The destination
entry will be protected using destkeypass. If destkeypass is not
provided, the destination entry will be protected with the source
entry password.
If the srcalias option is not provided, then all entries in the
source keystore are imported into the destination keystore. Each
destination entry will be stored under the alias from the source
entry. If the source entry is protected by a password, srcstorepass
will be used to recover the entry. If srcstorepass is either not
provided or is incorrect, the user will be prompted for a password.
If a source keystore entry type is not supported in the destination
keystore, or if an error occurs while storing an entry into the des‐
tination keystore, the user will be prompted whether to skip the
entry and continue, or to quit. The destination entry will be pro‐
tected with the source entry password.
If the destination alias already exists in the destination keystore,
the user is prompted to either overwrite the entry, or to create a
new entry under a different alias name.
Note that if -noprompt is provided, the user will not be prompted
for a new destination alias. Existing entries will automatically be
overwritten with the destination alias name. Finally, entries that
can not be imported are automatically skipped and a warning is out‐
put.
-printcertreq {-file file}
Prints the content of a PKCS #10 format certificate request, which
can be generated by the keytool -certreq command. The command reads
the request from file; if omitted, from the standard input.
Exporting Data
-certreq {-alias alias} {-dname dname} {-sigalg sigalg} {-file
certreq_file} [-keypass keypass] {-storetype storetype} {-keystore
keystore} [-storepass storepass] {-providerName provider_name}
{-providerClass provider_class_name {-providerArg provider_arg}}
{-v} {-protected} {-Jjavaoption}
Generates a Certificate Signing Request (CSR), using the PKCS#10
format.
A CSR is intended to be sent to a certificate authority (CA). The CA
will authenticate the certificate requestor (usually off-line) and
will return a certificate or certificate chain, used to replace the
existing certificate chain (which initially consists of a
self-signed certificate) in the keystore.
The private key associated with alias is used to create the PKCS#10
certificate request. In order to access the private key, the appro‐
priate password must be provided, since private keys are protected
in the keystore with a password. If keypass is not provided at the
command line, and is different from the password used to protect the
integrity of the keystore, the user is prompted for it. If dname is
provided, it's used as the subject in the CSR. Otherwise, the X.500
Distinguished Name associated with alias is used.
sigalg specifies the algorithm that should be used to sign the CSR.
The CSR is stored in the file certreq_file. If no file is given, the
CSR is output to stdout.
Use the importcert command to import the response from the CA.
-exportcert {-alias alias} {-file cert_file} {-storetype storetype}
{-keystore keystore} [-storepass storepass] {-providerName
provider_name} {-providerClass provider_class_name {-providerArg
provider_arg}} {-rfc} {-v} {-protected} {-Jjavaoption}
Reads (from the keystore) the certificate associated with alias, and
stores it in the file cert_file.
If no file is given, the certificate is output to stdout.
The certificate is by default output in binary encoding, but will
instead be output in the printable encoding format, as defined by
the Internet RFC 1421 standard, if the -rfc option is specified.
If alias refers to a trusted certificate, that certificate is out‐
put. Otherwise, alias refers to a key entry with an associated cer‐
tificate chain. In that case, the first certificate in the chain is
returned. This certificate authenticates the public key of the
entity addressed by alias.
This command was named -export in previous releases. This old name
is still supported in this release and will be supported in future
releases, but for clarify the new name, -exportcert, is preferred
going forward.
Displaying Data
-list {-alias alias} {-storetype storetype} {-keystore keystore}
[-storepass storepass] {-providerName provider_name} {-providerClass
provider_class_name {-providerArg provider_arg}} {-v | -rfc} {-pro‐
tected} {-Jjavaoption}
Prints (to stdout) the contents of the keystore entry identified by
alias. If no alias is specified, the contents of the entire keystore
are printed.
This command by default prints the SHA1 fingerprint of a certifi‐
cate. If the -v option is specified, the certificate is printed in
human-readable format, with additional information such as the
owner, issuer, serial number, and any extensions. If the -rfc option
is specified, certificate contents are printed using the printable
encoding format, as defined by the Internet RFC 1421 standard
You cannot specify both -v and -rfc.
-printcert {-file cert_file | -sslserver host[:port]} {-jarfile
JAR_file {-rfc} {-v} {-Jjavaoption}
Reads the certificate from the file cert_file, the SSL server
located at host:port, or the signed JAR file JAR_file (with the
option -jarfile and prints its contents in a human-readable format.
When no port is specified, the standard HTTPS port 443 is assumed.
Note that -sslserver and -file options cannot be provided at the
same time. Otherwise, an error is reported. If neither option is
given, the certificate is read from stdin.
If -rfc is specified, keytool prints the certificate in PEM mode as
defined by the Internet RFC 1421 standard.
If the certificate is read from a file or stdin, it may be either
binary encoded or in printable encoding format, as defined by the
Internet RFC 1421 standard
If the SSL server is behind a firewall, -J-Dhttps.proxyHost=proxy‐
host and -J-Dhttps.proxyPort=proxyport can be specified on the com‐
mand line for proxy tunneling. See the JSSE Reference Guide @
http://docs.oracle.com/javase/7/docs/technotes/guides/secu‐
rity/jsse/JSSERefGuide.html for more information.
Note: This option can be used independently of a keystore.
-printcrl -file crl_ {-v}
Reads the certificate revocation list (CRL) from the file crl_file.
A Certificate Revocation List (CRL) is a list of digital certifi‐
cates which have been revoked by the Certificate Authority (CA) that
issued them. The CA generates crl_file.
Note: This option can be used independently of a keystore.
Managing the Keystore
-storepasswd [-new new_storepass] {-storetype storetype} {-keystore
keystore} [-storepass storepass] {-providerName provider_name}
{-providerClass provider_class_name {-providerArg provider_arg}}
{-v} {-Jjavaoption}
Changes the password used to protect the integrity of the keystore
contents. The new password is new_storepass, which must be at least
6 characters long.
-keypasswd {-alias alias} [-keypass old_keypass] [-new new_keypass]
{-storetype storetype} {-keystore keystore} [-storepass storepass]
{-providerName provider_name} {-providerClass provider_class_name
{-providerArg provider_arg}} {-v} {-Jjavaoption}
Changes the password under which the private/secret key identified
by alias is protected, from old_keypass to new_keypass, which must
be at least 6 characters long.
If the -keypass option is not provided at the command line, and the
key password is different from the keystore password, the user is
prompted for it.
If the -new option is not provided at the command line, the user is
prompted for it.
-delete [-alias alias] {-storetype storetype} {-keystore keystore}
[-storepass storepass] {-providerName provider_name} {-providerClass
provider_class_name {-providerArg provider_arg}} {-v} {-protected}
{-Jjavaoption}
Deletes from the keystore the entry identified by alias. The user is
prompted for the alias, if no alias is provided at the command line.
-changealias {-alias alias} [-destalias destalias] [-keypass key‐
pass] {-storetype storetype} {-keystore keystore} [-storepass
storepass] {-providerName provider_name} {-providerClass
provider_class_name {-providerArg provider_arg}} {-v} {-protected}
{-Jjavaoption}
Move an existing keystore entry from the specified alias to a new
alias, destalias. If no destination alias is provided, the command
will prompt for one. If the original entry is protected with an
entry password, the password can be supplied via the "-keypass"
option. If no key password is provided, the storepass (if given)
will be attempted first. If that attempt fails, the user will be
prompted for a password.
Getting Help
-help
Lists the basic commands and their options.
For more information about a specific command, enter the following,
where command_name is the name of the command:
keytool -command_name -help
EXAMPLES
Suppose you want to create a keystore for managing your public/private
key pair and certificates from entities you trust.
Generating Your Key Pair
The first thing you need to do is create a keystore and generate the
key pair. You could use a command such as the following:
keytool -genkeypair -dname "cn=Mark Jones, ou=Java, o=Oracle, c=US"
-alias business -keypass <new password for private key> -keystore /working/mykeystore
-storepass <new password for keystore> -validity 180
(Please note: This must be typed as a single line. Multiple lines are
used in the examples just for legibility purposes.)
This command creates the keystore named "mykeystore" in the "working"
directory (assuming it doesn't already exist), and assigns it the pass‐
word specified by <new password for keystore>. It generates a pub‐
lic/private key pair for the entity whose "distinguished name" has a
common name of "Mark Jones", organizational unit of "Java", organiza‐
tion of "Oracle" and two-letter country code of "US". It uses the
default "DSA" key generation algorithm to create the keys, both 1024
bits long.
It creates a self-signed certificate (using the default "SHA1withDSA"
signature algorithm) that includes the public key and the distinguished
name information. This certificate will be valid for 180 days, and is
associated with the private key in a keystore entry referred to by the
alias "business". The private key is assigned the password specified by
<new password for private key>.
The command could be significantly shorter if option defaults were
accepted. As a matter of fact, no options are required; defaults are
used for unspecified options that have default values, and you are
prompted for any required values. Thus, you could simply have the fol‐
lowing:
keytool -genkeypair
In this case, a keystore entry with alias "mykey" is created, with a
newly-generated key pair and a certificate that is valid for 90 days.
This entry is placed in the keystore named ".keystore" in your home
directory. (The keystore is created if it doesn't already exist.) You
will be prompted for the distinguished name information, the keystore
password, and the private key password.
The rest of the examples assume you executed the -genkeypair command
without options specified, and that you responded to the prompts with
values equal to those given in the first -genkeypair command, above
(for example, a distinguished name of "cn=Mark Jones, ou=Java, o=Ora‐
cle, c=US").
Requesting a Signed Certificate from a Certification Authority
So far all we've got is a self-signed certificate. A certificate is
more likely to be trusted by others if it is signed by a Certification
Authority (CA). To get such a signature, you first generate a Certifi‐
cate Signing Request (CSR), via the following:
keytool -certreq -file MarkJ.csr
This creates a CSR (for the entity identified by the default alias
"mykey") and puts the request in the file named "MarkJ.csr". Submit
this file to a CA, such as VeriSign, Inc. The CA will authenticate you,
the requestor (usually off-line), and then will return a certificate,
signed by them, authenticating your public key. (In some cases, they
will actually return a chain of certificates, each one authenticating
the public key of the signer of the previous certificate in the chain.)
Importing a Certificate for the CA
You need to replace your self-signed certificate with a certificate
chain, where each certificate in the chain authenticates the public key
of the signer of the previous certificate in the chain, up to a "root"
CA.
Before you import the certificate reply from a CA, you need one or more
"trusted certificates" in your keystore or in the cacerts keystore file
(which is described in importcert command):
o If the certificate reply is a certificate chain, you just need the
top certificate of the chain (that is, the "root" CA certificate
authenticating that CA's public key).
o If the certificate reply is a single certificate, you need a cer‐
tificate for the issuing CA (the one that signed it), and if that
certificate is not self-signed, you need a certificate for its
signer, and so on, up to a self-signed "root" CA certificate.
The "cacerts" keystore file ships with several VeriSign root CA cer‐
tificates, so you probably won't need to import a VeriSign certificate
as a trusted certificate in your keystore. But if you request a signed
certificate from a different CA, and a certificate authenticating that
CA's public key hasn't been added to "cacerts", you will need to import
a certificate from the CA as a "trusted certificate".
A certificate from a CA is usually either self-signed, or signed by
another CA (in which case you also need a certificate authenticating
that CA's public key). Suppose company ABC, Inc., is a CA, and you
obtain a file named "ABCCA.cer" that is purportedly a self-signed cer‐
tificate from ABC, authenticating that CA's public key.
Be very careful to ensure the certificate is valid prior to importing
it as a "trusted" certificate! View it first (using the keytool -print‐
cert command, or the keytool -importcert command without the -noprompt
option), and make sure that the displayed certificate fingerprint(s)
match the expected ones. You can call the person who sent the certifi‐
cate, and compare the fingerprint(s) that you see with the ones that
they show (or that a secure public key repository shows). Only if the
fingerprints are equal is it guaranteed that the certificate has not
been replaced in transit with somebody else's (for example, an
attacker's) certificate. If such an attack took place, and you did not
check the certificate before you imported it, you would end up trusting
anything the attacker has signed.
If you trust that the certificate is valid, then you can add it to your
keystore via the following:
keytool -importcert -alias abc -file ABCCA.cer
This creates a "trusted certificate" entry in the keystore, with the
data from the file "ABCCA.cer", and assigns the alias "abc" to the
entry.
Importing the Certificate Reply from the CA
Once you've imported a certificate authenticating the public key of the
CA you submitted your certificate signing request to (or there is
already such a certificate in the "cacerts" file), you can import the
certificate reply and thereby replace your self-signed certificate with
a certificate chain. This chain is the one returned by the CA in
response to your request (if the CA reply is a chain), or one con‐
structed (if the CA reply is a single certificate) using the certifi‐
cate reply and trusted certificates that are already available in the
keystore where you import the reply or in the "cacerts" keystore file.
For example, suppose you sent your certificate signing request to
VeriSign. You can then import the reply via the following, which
assumes the returned certificate is named "VSMarkJ.cer":
keytool -importcert -trustcacerts -file VSMarkJ.cer
Exporting a Certificate Authenticating Your Public Key
Suppose you have used the jarsigner(1) tool to sign a Java ARchive
(JAR) file. Clients that want to use the file will want to authenticate
your signature.
One way they can do this is by first importing your public key certifi‐
cate into their keystore as a "trusted" entry. You can export the cer‐
tificate and supply it to your clients. As an example, you can copy
your certificate to a file named MJ.cer via the following, assuming the
entry is aliased by "mykey":
keytool -exportcert -alias mykey -file MJ.cer
Given that certificate, and the signed JAR file, a client can use the
jarsigner tool to authenticate your signature.
Importing Keystore
The command "importkeystore" is used to import an entire keystore into
another keystore, which means all entries from the source keystore,
including keys and certificates, are all imported to the destination
keystore within a single command. You can use this command to import
entries from a different type of keystore. During the import, all new
entries in the destination keystore will have the same alias names and
protection passwords (for secret keys and private keys). If keytool has
difficulties recover the private keys or secret keys from the source
keystore, it will prompt you for a password. If it detects alias dupli‐
cation, it will ask you for a new one, you can specify a new alias or
simply allow keytool to overwrite the existing one.
For example, to import entries from a normal JKS type keystore key.jks
into a PKCS #11 type hardware based keystore, you can use the command:
keytool -importkeystore
-srckeystore key.jks -destkeystore NONE
-srcstoretype JKS -deststoretype PKCS11
-srcstorepass <source keystore password> -deststorepass <destination keystore password>
The importkeystore command can also be used to import a single entry
from a source keystore to a destination keystore. In this case, besides
the options you see in the above example, you need to specify the alias
you want to import. With the srcalias option given, you can also spec‐
ify the destination alias name in the command line, as well as protec‐
tion password for a secret/private key and the destination protection
password you want. The following command demonstrates this:
keytool -importkeystore
-srckeystore key.jks -destkeystore NONE
-srcstoretype JKS -deststoretype PKCS11
-srcstorepass <source keystore password> -deststorepass <destination keystore password>
-srcalias myprivatekey -destalias myoldprivatekey
-srckeypass <source entry password> -destkeypass <destination entry password>
-noprompt
Generating Certificates for a Typical SSL Server
The following are keytool commands to generate keypairs and certifi‐
cates for three entities, namely, Root CA (root), Intermediate CA (ca),
and SSL server (server). Ensure that you store all the certificates in
the same keystore. In these examples, it is recommended that you spec‐
ify RSA as the key algorithm.
keytool -genkeypair -keystore root.jks -alias root -ext bc:c
keytool -genkeypair -keystore ca.jks -alias ca -ext bc:c
keytool -genkeypair -keystore server.jks -alias server
keytool -keystore root.jks -alias root -exportcert -rfc > root.pem
keytool -storepass <storepass> -keystore ca.jks -certreq -alias ca | keytool -storepass <storepass> -keystore root.jks -gencert -alias root -ext BC=0 -rfc > ca.pem
keytool -keystore ca.jks -importcert -alias ca -file ca.pem
keytool -storepass <storepass> -keystore server.jks -certreq -alias server | keytool -storepass <storepass> -keystore ca.jks -gencert -alias ca -ext ku:c=dig,kE -rfc > server.pem
cat root.pem ca.pem server.pem | keytool -keystore server.jks -importcert -alias server
TERMINOLOGY and WARNINGS
KeyStore
A keystore is a storage facility for cryptographic keys and certifi‐
cates.
o KeyStore Entries
Keystores may have different types of entries. The two most applica‐
ble entry types for keytool include:
1. key entries - each holds very sensitive cryptographic key
information, which is stored in a protected format to prevent
unauthorized access. Typically, a key stored in this type of
entry is a secret key, or a private key accompanied by the
certificate "chain" for the corresponding public key. The key‐
tool can handle both types of entries, while the jarsigner
tool only handle the latter type of entry, that is private
keys and their associated certificate chains.
2. trusted certificate entries - each contains a single public
key certificate belonging to another party. It is called a
"trusted certificate" because the keystore owner trusts that
the public key in the certificate indeed belongs to the iden‐
tity identified by the "subject" (owner) of the certificate.
The issuer of the certificate vouches for this, by signing the
certificate.
o KeyStore Aliases
All keystore entries (key and trusted certificate entries) are
accessed via unique aliases.
An alias is specified when you add an entity to the keystore using
the -genseckey command to generate a secret key, -genkeypair command
to generate a key pair (public and private key) or the -importcert
command to add a certificate or certificate chain to the list of
trusted certificates. Subsequent keytool commands must use this same
alias to refer to the entity.
For example, suppose you use the alias duke to generate a new pub‐
lic/private key pair and wrap the public key into a self-signed cer‐
tificate (see Certificate Chains) via the following command:
keytool -genkeypair -alias duke -keypass dukekeypasswd
This specifies an initial password of "dukekeypasswd" required by
subsequent commands to access the private key associated with the
alias duke. If you later want to change duke's private key password,
you use a command like the following:
keytool -keypasswd -alias duke -keypass dukekeypasswd -new newpass
This changes the password from "dukekeypasswd" to "newpass".
Please note: A password should not actually be specified on a com‐
mand line or in a script unless it is for testing purposes, or you
are on a secure system. If you don't specify a required password
option on a command line, you will be prompted for it.
o KeyStore Implementation
The KeyStore class provided in the java.security package supplies
well-defined interfaces to access and modify the information in a
keystore. It is possible for there to be multiple different concrete
implementations, where each implementation is that for a particular
type of keystore.
Currently, two command-line tools (keytool and jarsigner) and a
GUI-based tool named Policy Tool make use of keystore implementa‐
tions. Since KeyStore is publicly available, users can write addi‐
tional security applications that use it.
There is a built-in default implementation, provided by Oracle. It
implements the keystore as a file, utilizing a proprietary keystore
type (format) named "JKS". It protects each private key with its
individual password, and also protects the integrity of the entire
keystore with a (possibly different) password.
Keystore implementations are provider-based. More specifically, the
application interfaces supplied by KeyStore are implemented in terms
of a "Service Provider Interface" (SPI). That is, there is a corre‐
sponding abstract KeystoreSpi class, also in the java.security pack‐
age, which defines the Service Provider Interface methods that
"providers" must implement. (The term "provider" refers to a package
or a set of packages that supply a concrete implementation of a sub‐
set of services that can be accessed by the Java Security API.)
Thus, to provide a keystore implementation, clients must implement a
"provider" and supply a KeystoreSpi subclass implementation, as
described in How to Implement a Provider for the Java Cryptography
Architecture @
http://docs.oracle.com/javase/7/docs/technotes/guides/secu‐
rity/crypto/HowToImplAProvider.html.
Applications can choose different types of keystore implementations
from different providers, using the "getInstance" factory method
supplied in the KeyStore class. A keystore type defines the storage
and data format of the keystore information, and the algorithms used
to protect private/secret keys in the keystore and the integrity of
the keystore itself. Keystore implementations of different types are
not compatible.
keytool works on any file-based keystore implementation. (It treats
the keystore location that is passed to it at the command line as a
filename and converts it to a FileInputStream, from which it loads
the keystore information.) The jarsigner and policytool tools, on
the other hand, can read a keystore from any location that can be
specified using a URL.
For keytool and jarsigner, you can specify a keystore type at the
command line, via the -storetype option. For Policy Tool, you can
specify a keystore type via the "Keystore" menu.
If you don't explicitly specify a keystore type, the tools choose a
keystore implementation based simply on the value of the key‐
store.type property specified in the security properties file. The
security properties file is called java.security, and it resides in
the security properties directory, java.home/lib/security, where
java.home is the runtime environment's directory (the jre directory
in the SDK or the top-level directory of the Java 2 Runtime Environ‐
ment).
Each tool gets the keystore.type value and then examines all the
currently-installed providers until it finds one that implements
keystores of that type. It then uses the keystore implementation
from that provider.
The KeyStore class defines a static method named getDefaultType that
lets applications and applets retrieve the value of the key‐
store.type property. The following line of code creates an instance
of the default keystore type (as specified in the keystore.type
property):
KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
The default keystore type is "jks" (the proprietary type of the key‐
store implementation provided by Oracle). This is specified by the
following line in the security properties file:
keystore.type=jks
To have the tools utilize a keystore implementation other than the
default, you can change that line to specify a different keystore
type.
For example, if you have a provider package that supplies a keystore
implementation for a keystore type called "pkcs12", change the line
to
keystore.type=pkcs12
Note: case doesn't matter in keystore type designations. For exam‐
ple, "JKS" would be considered the same as "jks".
Certificate
A certificate (also known as a public-key certificate) is a digitally
signed statement from one entity (the issuer), saying that the public
key (and some other information) of another entity (the subject) has
some specific value.
o Certificate Terms
Public Keys
These are numbers associated with a particular entity, and are
intended to be known to everyone who needs to have trusted inter‐
actions with that entity. Public keys are used to verify signa‐
tures.
Digitally Signed
If some data is digitally signed it has been stored with the
"identity" of an entity, and a signature that proves that entity
knows about the data. The data is rendered unforgeable by signing
with the entity's private key.
Identity
A known way of addressing an entity. In some systems the identity
is the public key, in others it can be anything from a Unix UID
to an Email address to an X.509 Distinguished Name.
Signature
A signature is computed over some data using the private key of
an entity (the signer, which in the case of a certificate is also
known as the issuer).
Private Keys
These are numbers, each of which is supposed to be known only to
the particular entity whose private key it is (that is, it's sup‐
posed to be kept secret). Private and public keys exist in pairs
in all public key cryptography systems (also referred to as "pub‐
lic key crypto systems"). In a typical public key crypto system,
such as DSA, a private key corresponds to exactly one public key.
Private keys are used to compute signatures.
Entity
An entity is a person, organization, program, computer, business,
bank, or something else you are trusting to some degree.
Basically, public key cryptography requires access to users' public
keys. In a large-scale networked environment it is impossible to
guarantee that prior relationships between communicating entities
have been established or that a trusted repository exists with all
used public keys. Certificates were invented as a solution to this
public key distribution problem. Now a Certification Authority (CA)
can act as a trusted third party. CAs are entities (for example,
businesses) that are trusted to sign (issue) certificates for other
entities. It is assumed that CAs will only create valid and reliable
certificates, as they are bound by legal agreements. There are many
public Certification Authorities, such as VeriSign @
http://www.verisign.com/, Thawte @
http://www.thawte.com/, Entrust @
http://www.entrust.com/, and so on. You can also run your own Certi‐
fication Authority using products such as Microsoft Certificate
Server or the Entrust CA product for your organization.
Using keytool, it is possible to display, import, and export cer‐
tificates. It is also possible to generate self-signed certificates.
keytool currently handles X.509 certificates.
o X.509 Certificates
The X.509 standard defines what information can go into a certifi‐
cate, and describes how to write it down (the data format). All the
data in a certificate is encoded using two related standards called
ASN.1/DER. Abstract Syntax Notation 1 describes data. The Definite
Encoding Rules describe a single way to store and transfer that
data.
All X.509 certificates have the following data, in addition to the
signature:
Version
This identifies which version of the X.509 standard applies to
this certificate, which affects what information can be specified
in it. Thus far, three versions are defined. keytool can import
and export v1, v2, and v3 certificates. It generates v3 certifi‐
cates.
X.509 Version 1 has been available since 1988, is widely
deployed, and is the most generic.
X.509 Version 2 introduced the concept of subject and issuer
unique identifiers to handle the possibility of reuse of subject
and/or issuer names over time. Most certificate profile documents
strongly recommend that names not be reused, and that certifi‐
cates should not make use of unique identifiers. Version 2 cer‐
tificates are not widely used.
X.509 Version 3 is the most recent (1996) and supports the notion
of extensions, whereby anyone can define an extension and include
it in the certificate. Some common extensions in use today are:
KeyUsage (limits the use of the keys to particular purposes such
as "signing-only") and AlternativeNames (allows other identities
to also be associated with this public key, e.g. DNS names, Email
addresses, IP addresses). Extensions can be marked critical to
indicate that the extension should be checked and enforced/used.
For example, if a certificate has the KeyUsage extension marked
critical and set to "keyCertSign" then if this certificate is
presented during SSL communication, it should be rejected, as the
certificate extension indicates that the associated private key
should only be used for signing certificates and not for SSL use.
Serial Number
The entity that created the certificate is responsible for
assigning it a serial number to distinguish it from other cer‐
tificates it issues. This information is used in numerous ways,
for example when a certificate is revoked its serial number is
placed in a Certificate Revocation List (CRL).
Signature Algorithm Identifier
This identifies the algorithm used by the CA to sign the certifi‐
cate.
Issuer Name
The X.500 Distinguished Name of the entity that signed the cer‐
tificate. This is normally a CA. Using this certificate implies
trusting the entity that signed this certificate. (Note that in
some cases, such as root or top-level CA certificates, the issuer
signs its own certificate.)
Validity Period
Each certificate is valid only for a limited amount of time. This
period is described by a start date and time and an end date and
time, and can be as short as a few seconds or almost as long as a
century. The validity period chosen depends on a number of fac‐
tors, such as the strength of the private key used to sign the
certificate or the amount one is willing to pay for a certifi‐
cate. This is the expected period that entities can rely on the
public value, if the associated private key has not been compro‐
mised.
Subject Name
The name of the entity whose public key the certificate identi‐
fies. This name uses the X.500 standard, so it is intended to be
unique across the Internet. This is the X.500 Distinguished Name
(DN) of the entity, for example,
CN=Java Duke, OU=Java Software Division, O=Oracle Corporation, C=US
(These refer to the subject's Common Name, Organizational Unit,
Organization, and Country.)
Subject Public Key Information
This is the public key of the entity being named, together with
an algorithm identifier which specifies which public key crypto
system this key belongs to and any associated key parameters.
o Certificate Chains
keytool can create and manage keystore "key" entries that each con‐
tain a private key and an associated certificate "chain". The first
certificate in the chain contains the public key corresponding to
the private key.
When keys are first generated (see the -genkeypair command), the
chain starts off containing a single element, a self-signed certifi‐
cate. A self-signed certificate is one for which the issuer (signer)
is the same as the subject (the entity whose public key is being
authenticated by the certificate). Whenever the -genkeypair command
is called to generate a new public/private key pair, it also wraps
the public key into a self-signed certificate.
Later, after a Certificate Signing Request (CSR) has been generated
(see the -certreq command) and sent to a Certification Authority
(CA), the response from the CA is imported (see -importcert), and
the self-signed certificate is replaced by a chain of certificates.
At the bottom of the chain is the certificate (reply) issued by the
CA authenticating the subject's public key. The next certificate in
the chain is one that authenticates the CA's public key.
In many cases, this is a self-signed certificate (that is, a cer‐
tificate from the CA authenticating its own public key) and the last
certificate in the chain. In other cases, the CA may return a chain
of certificates. In this case, the bottom certificate in the chain
is the same (a certificate signed by the CA, authenticating the pub‐
lic key of the key entry), but the second certificate in the chain
is a certificate signed by a different CA, authenticating the public
key of the CA you sent the CSR to. Then, the next certificate in the
chain will be a certificate authenticating the second CA's key, and
so on, until a self-signed "root" certificate is reached. Each cer‐
tificate in the chain (after the first) thus authenticates the pub‐
lic key of the signer of the previous certificate in the chain.
Many CAs only return the issued certificate, with no supporting
chain, especially when there is a flat hierarchy (no intermediates
CAs). In this case, the certificate chain must be established from
trusted certificate information already stored in the keystore.
A different reply format (defined by the PKCS#7 standard) also
includes the supporting certificate chain, in addition to the issued
certificate. Both reply formats can be handled by keytool.
The top-level (root) CA certificate is self-signed. However, the
trust into the root's public key does not come from the root cer‐
tificate itself (anybody could generate a self-signed certificate
with the distinguished name of say, the VeriSign root CA!), but from
other sources like a newspaper. The root CA public key is widely
known. The only reason it is stored in a certificate is because this
is the format understood by most tools, so the certificate in this
case is only used as a "vehicle" to transport the root CA's public
key. Before you add the root CA certificate to your keystore, you
should view it (using the -printcert option) and compare the dis‐
played fingerprint with the well-known fingerprint (obtained from a
newspaper, the root CA's Web page, etc.).
o The cacerts Certificates File
A certificates file named "cacerts" resides in the security proper‐
ties directory, java.home/lib/security, where java.home is the run‐
time environment's directory (the jre directory in the SDK or the
top-level directory of the Java 2 Runtime Environment).
The "cacerts" file represents a system-wide keystore with CA cer‐
tificates. System administrators can configure and manage that file
using keytool, specifying "jks" as the keystore type. The "cacerts"
keystore file ships with a default set of root CA certificates; list
them with the following command:
keytool -list -keystore java.home/lib/security/cacerts
The initial password of the "cacerts" keystore file is "changeit".
System administrators should change that password and the default
access permission of that file upon installing the SDK.
IMPORTANT: Verify Your cacerts File: Since you trust the CAs in the
cacerts file as entities for signing and issuing certificates to
other entities, you must manage the cacerts file carefully. The cac‐
erts file should contain only certificates of the CAs you trust. It
is your responsibility to verify the trusted root CA certificates
bundled in the cacerts file and make your own trust decisions. To
remove an untrusted CA certificate from the cacerts file, use the
delete option of the keytool command. You can find the cacerts file
in the JRE installation directory. Contact your system administrator
if you do not have permission to edit this file.
o The Internet RFC 1421 Certificate Encoding Standard
Certificates are often stored using the printable encoding format
defined by the Internet RFC 1421 standard, instead of their binary
encoding. This certificate format, also known as "Base 64 encoding",
facilitates exporting certificates to other applications by email or
through some other mechanism.
Certificates read by the -importcert and -printcert commands can be
in either this format or binary encoded.
The -exportcert command by default outputs a certificate in binary
encoding, but will instead output a certificate in the printable
encoding format, if the -rfc option is specified.
The -list command by default prints the SHA1 fingerprint of a cer‐
tificate. If the -v option is specified, the certificate is printed
in human-readable format, while if the -rfc option is specified, the
certificate is output in the printable encoding format.
In its printable encoding format, the encoded certificate is bounded
at the beginning by
-----BEGIN CERTIFICATE-----
and at the end by
-----END CERTIFICATE-----
X.500 Distinguished Names
X.500 Distinguished Names are used to identify entities, such as those
which are named by the subject and issuer (signer) fields of X.509 cer‐
tificates. keytool supports the following subparts:
o commonName - common name of a person, e.g., "Susan Jones"
o organizationUnit - small organization (e.g., department or divi‐
sion) name, e.g., "Purchasing"
o organizationName - large organization name, e.g., "ABCSystems,
Inc."
o localityName - locality (city) name, e.g., "Palo Alto"
o stateName - state or province name, e.g., "California"
o country - two-letter country code, e.g., "CH"
When supplying a distinguished name string as the value of a -dname
option, as for the -genkeypair command, the string must be in the fol‐
lowing format:
CN=cName, OU=orgUnit, O=org, L=city, S=state, C=countryCode
where all the italicized items represent actual values and the above
keywords are abbreviations for the following:
CN=commonName
OU=organizationUnit
O=organizationName
L=localityName
S=stateName
C=country
A sample distinguished name string is
CN=Mark Smith, OU=Java, O=Oracle, L=Cupertino, S=California, C=US
and a sample command using such a string is
keytool -genkeypair -dname "CN=Mark Smith, OU=Java, O=Oracle, L=Cupertino,
S=California, C=US" -alias mark
Case does not matter for the keyword abbreviations. For example, "CN",
"cn", and "Cn" are all treated the same.
Order matters; each subcomponent must appear in the designated order.
However, it is not necessary to have all the subcomponents. You may use
a subset, for example:
CN=Steve Meier, OU=Java, O=Oracle, C=US
If a distinguished name string value contains a comma, the comma must
be escaped by a "\" character when you specify the string on a command
line, as in
cn=Peter Schuster, ou=Java\, Product Development, o=Oracle, c=US
It is never necessary to specify a distinguished name string on a com‐
mand line. If it is needed for a command, but not supplied on the com‐
mand line, the user is prompted for each of the subcomponents. In this
case, a comma does not need to be escaped by a "\".
WARNING Regarding Importing Trusted Certificates
IMPORTANT: Be sure to check a certificate very carefully before import‐
ing it as a trusted certificate!
View it first (using the -printcert command, or the -importcert command
without the -noprompt option), and make sure that the displayed cer‐
tificate fingerprint(s) match the expected ones. For example, suppose
someone sends or emails you a certificate, and you put it in a file
named /tmp/cert. Before you consider adding the certificate to your
list of trusted certificates, you can execute a -printcert command to
view its fingerprints, as in
keytool -printcert -file /tmp/cert
Owner: CN=ll, OU=ll, O=ll, L=ll, S=ll, C=ll
Issuer: CN=ll, OU=ll, O=ll, L=ll, S=ll, C=ll
Serial Number: 59092b34
Valid from: Thu Sep 25 18:01:13 PDT 1997 until: Wed Dec 24 17:01:13 PST 1997
Certificate Fingerprints:
MD5: 11:81:AD:92:C8:E5:0E:A2:01:2E:D4:7A:D7:5F:07:6F
SHA1: 20:B6:17:FA:EF:E5:55:8A:D0:71:1F:E8:D6:9D:C0:37:13:0E:5E:FE
SHA256: 90:7B:70:0A:EA:DC:16:79:92:99:41:FF:8A:FE:EB:90:
17:75:E0:90:B2:24:4D:3A:2A:16:A6:E4:11:0F:67:A4
Then call or otherwise contact the person who sent the certificate, and
compare the fingerprint(s) that you see with the ones that they show.
Only if the fingerprints are equal is it guaranteed that the certifi‐
cate has not been replaced in transit with somebody else's (for exam‐
ple, an attacker's) certificate. If such an attack took place, and you
did not check the certificate before you imported it, you would end up
trusting anything the attacker has signed (for example, a JAR file with
malicious class files inside).
Note: it is not required that you execute a -printcert command prior to
importing a certificate, since before adding a certificate to the list
of trusted certificates in the keystore, the -importcert command prints
out the certificate information and prompts you to verify it. You then
have the option of aborting the import operation. Note, however, this
is only the case if you invoke the -importcert command without the
-noprompt option. If the -noprompt option is given, there is no inter‐
action with the user.
Warning Regarding Passwords
Most commands operating on a keystore require the store password. Some
commands require a private/secret key password.
Passwords can be specified on the command line (in the -storepass and
-keypass options, respectively). However, a password should not be
specified on a command line or in a script unless it is for testing
purposes, or you are on a secure system.
If you don't specify a required password option on a command line, you
will be prompted for it.
Warning Regarding Certificate Conformance
The Internet standard RFC 5280 @
http://tools.ietf.org/rfc/rfc5280.txt has defined a profile on conform‐
ing X.509 certificates, which includes what values and value combina‐
tions are valid for certificate fields and extensions. keytool has not
enforced all these rules so it can generate certificates which do not
conform to the standard, and these certificates might be rejected by
JRE or other applications. Users should make sure that they provide the
correct options for -dname, -ext, etc.
SEE ALSO
o jar(1) tool documentation
o jarsigner(1) tool documentation
o the Security @
http://docs.oracle.com/javase/tutorial/security/index.html trail
of the Java Tutorial @
http://docs.oracle.com/javase/tutorial/ for examples of the use of
keytool
CHANGES
The command interface for keytool changed in Java SE 6.
keytool no longer displays password input when entered by users. Since
password input can no longer be viewed when entered, users will be
prompted to re-enter passwords any time a password is being set or
changed (for example, when setting the initial keystore password, or
when changing a key password).
Some commands have simply been renamed, and other commands deemed obso‐
lete are no longer listed in this document. All previous commands (both
renamed and obsolete) are still supported in this release and will con‐
tinue to be supported in future releases. The following summarizes all
of the changes made to the keytool command interface:
Renamed commands:
o -export, renamed to -exportcert
o -genkey, renamed to -genkeypair
o -import, renamed to -importcert
Commands deemed obsolete and no longer documented:
o -keyclone @
http://java.sun.com/j2se/1.5.0/docs/tooldocs/windows/key‐
tool.html#keycloneCmd
o -identitydb @
http://java.sun.com/j2se/1.5.0/docs/tooldocs/windows/key‐
tool.html#identitydbCmd
o -selfcert @
http://java.sun.com/j2se/1.5.0/docs/tooldocs/windows/key‐
tool.html#selfcertCmd
16 Mar 2012 keytool(1)
