keytool(1) JDK Commands keytool(1)
NAME
keytool - a key and certificate management utility
SYNOPSIS
keytool [commands]
commands
Commands for keytool include the following:
o -certreq: Generates a certificate request
o -changealias: Changes an entry's alias
o -delete: Deletes an entry
o -exportcert: Exports certificate
o -genkeypair: Generates a key pair
o -genseckey: Generates a secret key
o -gencert: Generates a certificate from a certificate request
o -importcert: Imports a certificate or a certificate chain
o -importpass: Imports a password
o -importkeystore: Imports one or all entries from another
keystore
o -keypasswd: Changes the key password of an entry
o -list: Lists entries in a keystore
o -printcert: Prints the content of a certificate
o -printcertreq: Prints the content of a certificate request
o -printcrl: Prints the content of a Certificate Revocation List
(CRL) file
o -storepasswd: Changes the store password of a keystore
o -showinfo: Displays security-related information
o -version: Prints the program version
See Commands and Options for a description of these commands with
their options.
DESCRIPTION
The keytool command is a key and certificate management utility. It
enables users to administer their own public/private key pairs and
associated certificates for use in self-authentication (where a user
authenticates themselves to other users and services) or data integrity
and authentication services, by using digital signatures. The keytool
command also enables 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, and so on), which says that the public key (and some other
information) of some other entity has a particular value. When data is
digitally signed, the signature can be verified to check the data
integrity and authenticity. Integrity means that the data hasn't been
modified or tampered with, and authenticity means that the data comes
from the individual who claims to have created and signed it.
The keytool command also enables users to administer secret keys and
passphrases used in symmetric encryption and decryption (Data Encryption
Standard). It can also display other security-related information.
The keytool command stores the keys and certificates in a keystore.
The keytool command uses the jdk.certpath.disabledAlgorithms and
jdk.security.legacyAlgorithms security properties to determine which
algorithms are considered a security risk. It emits warnings when
disabled or legacy algorithms are being used. The
jdk.certpath.disabledAlgorithms and jdk.security.legacyAlgorithms
security properties are defined in the java.security file (located in the
JDK's $JAVA_HOME/conf/security directory).
COMMAND AND OPTION NOTES
The following notes apply to the descriptions in Commands and Options:
o All command and option names are preceded by a hyphen sign (-).
o Only one command can be provided.
o Options for each command can be provided in any order.
o There are two kinds of options, one is single-valued which should be
only provided once. If a single-valued option is provided multiple
times, the value of the last one is used. The other type is
multi-valued, which can be provided multiple times and all values are
used. The only multi-valued option currently supported is the -ext
option used to generate X.509v3 certificate extensions.
o All items not italicized or in braces ({ }) or brackets ([ ]) are
required to appear as is.
o Braces surrounding an option signify that a default value is used when
the option isn't specified on the command line. Braces are also used
around the -v, -rfc, and -J options, which have meaning only when they
appear on the command line. They don't have any default values.
o Brackets surrounding an option signify that the user is prompted for
the values when the option isn't specified on the command line. For
the -keypass option, if you don't specify the option on the command
line, then the keytool command first attempts to use the keystore
password to recover the private/secret key. If this attempt fails,
then the keytool command prompts 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 -printcert
command:
keytool -printcert {-file cert_file} {-v}
When you specify a -printcert command, replace cert_file with the
actual file name, as follows: keytool -printcert -file VScert.cer
o Option values must be enclosed in quotation marks when they contain a
blank (space).
COMMANDS AND OPTIONS
The keytool commands and their options can be grouped by the tasks that
they perform.
Commands for Creating or Adding Data to the Keystore:
o -gencert
o -genkeypair
o -genseckey
o -importcert
o -importpass
Commands for Importing Contents from Another Keystore:
o -importkeystore
Commands for Generating a Certificate Request:
o -certreq
Commands for Exporting Data:
o -exportcert
Commands for Displaying Data:
o -list
o -printcert
o -printcertreq
o -printcrl
Commands for Managing the Keystore:
o -storepasswd
o -keypasswd
o -delete
o -changealias
Commands for Displaying Security-related Information:
o -showinfo
Commands for Displaying Program Version:
o -version
COMMANDS FOR CREATING OR ADDING DATA TO THE KEYSTORE
-gencert
The following are the available options for the -gencert command:
o {-rfc}: Output in RFC (Request For Comment) style
o {-infile infile}: Input file name
o {-outfile outfile}: Output file name
o {-alias alias}: Alias name of the entry to process
o {-sigalg sigalg}: Signature algorithm name
o {-dname dname}: Distinguished name
o {-startdate startdate}: Certificate validity start date and time
o {-ext ext}*: X.509 extension
o {-validity days}: Validity number of days
o [-keypass arg]: Key password
o {-keystore keystore}: Keystore name
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Adds a security provider
by name (such as SunPKCS11) with an optional configure argument.
The value of the security provider is the name of a security
provider that is defined in a module.
For example,
keytool -addprovider SunPKCS11 -providerarg some.cfg ...
Note:
For compatibility reasons, the SunPKCS11 provider can still be
loaded with -providerclass sun.security.pkcs11.SunPKCS11 even if
it is now defined in a module. This is the only module included
in the JDK that needs a configuration, and therefore the most
widely used with the -providerclass option. For legacy security
providers located on classpath and loaded by reflection,
-providerclass should still be used.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument.
For example, if MyProvider is a legacy provider loaded via
reflection,
keytool -providerclass com.example.MyProvider ...
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
o {-protected}: Password provided through a protected mechanism
Use the -gencert command to generate a certificate as a response
to a certificate request file (which can be created by the keytool
-certreq command). The command reads the request either from
infile or, if omitted, from the standard input, signs it by using
the alias's private key, and outputs the X.509 certificate into
either outfile or, if omitted, to the standard output. When -rfc
is specified, the output format is Base64-encoded PEM; otherwise,
a binary DER is created.
The -sigalg value specifies the algorithm that should be used to
sign the certificate. The startdate argument is the start time
and date that the certificate is valid. The days argument tells
the number of days for which the certificate should be considered
valid.
When dname is provided, it is used as the subject of the generated
certificate. Otherwise, the one from the certificate request is
used.
The -ext value shows what X.509 extensions will be embedded in the
certificate. Read Common Command Options for the grammar of -ext.
The -gencert option 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 -keyalg rsa
keytool -alias ca1 -dname CN=CA -genkeypair -keyalg rsa
keytool -alias ca2 -dname CN=CA -genkeypair -keyalg rsa
keytool -alias e1 -dname CN=E1 -genkeypair -keyalg rsa
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 |
keytool -alias ca1 -gencert -ext san=dns:ca2 |
keytool -alias ca2 -importcert
The following command creates the certificate e1 and stores it in
the e1.cert file, 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
The following are the available options for the -genkeypair
command:
o {-alias alias}: Alias name of the entry to process
o -keyalg alg: Key algorithm name
o {-keysize size}: Key bit size
o {-groupname name}: Group name. For example, an Elliptic Curve
name.
o {-sigalg alg}: Signature algorithm name
o {-signer alias}: Signer alias
o [-signerkeypass arg]: Signer key password
o [-dname name]: Distinguished name
o {-startdate date}: Certificate validity start date and time
o {-ext value}*: X.509 extension
o {-validity days}: Validity number of days
o [-keypass arg]: Key password
o {-keystore keystore}: Keystore name
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg] }: Add security
provider by fully qualified class name with an optional
configure argument.
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
o {-protected}: Password provided through a protected mechanism
Use the -genkeypair command to generate a key pair (a public key
and associated private key). When the -signer option is not
specified, the public key is wrapped in an X.509 v3 self-signed
certificate and stored as a single-element certificate chain.
When the -signer option is specified, a new certificate is
generated and signed by the designated signer and stored as a
multiple-element certificate chain (containing the generated
certificate itself, and the signer's certificate chain). The
certificate chain and private key are stored in a new keystore
entry that is identified by its alias.
The -keyalg value specifies the algorithm to be used to generate
the key pair. The -keysize value specifies the size of each key
to be generated. The -groupname value specifies the named group
(for example, the standard or predefined name of an Elliptic
Curve) of the key to be generated.
When a -keysize value is provided, it will be used to initialize a
KeyPairGenerator object using the initialize(int keysize) method.
When a -groupname value is provided, it will be used to initialize
a KeyPairGenerator object using the
initialize(AlgorithmParameterSpec params) method where params is
new NamedParameterSpec(groupname).
Only one of -groupname and -keysize can be specified. If an
algorithm has multiple named groups that have the same key size,
the -groupname option should usually be used. In this case, if
-keysize is specified, it's up to the security provider to
determine which named group is chosen when generating a key pair.
The -sigalg value specifies the algorithm that should be used to
sign the certificate. This algorithm must be compatible with the
-keyalg value.
The -signer value specifies the alias of a PrivateKeyEntry for the
signer that already exists in the keystore. This option is used
to sign the certificate with the signer's private key. This is
especially useful for key agreement algorithms (i.e. the -keyalg
value is XDH, X25519, X448, or DH) as these keys cannot be used
for digital signatures, and therefore a self-signed certificate
cannot be created.
The -signerkeypass value specifies the password of the signer's
private key. It can be specified if the private key of the signer
entry is protected by a password different from the store
password.
The -dname value specifies the X.500 Distinguished Name to be
associated with the value of -alias. If the -signer option is not
specified, the issuer and subject fields of the self-signed
certificate are populated with the specified distinguished name.
If the -signer option is specified, the subject field of the
certificate is populated with the specified distinguished name and
the issuer field is populated with the subject field of the
signer's certificate. If a distinguished name is not provided at
the command line, then the user is prompted for one.
The value of -keypass is a password used to protect the private
key of the generated key pair. If a password is not provided,
then the user is prompted for it. If you press the Return key at
the prompt, then the key password is set to the same password as
the keystore password. The -keypass value must have at least six
characters.
The value of -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:
([+-]nnn[ymdHMS])+
[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 subvalues. Inside each subvalue, the plus sign (+)
means shift forward, and the minus sign (-) means shift 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 by using the java.util.GregorianCalendar.add(int field,
int amount) method on each subvalue, from left to right. For
example, the issue time can be specified by:
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 can provide only one part, which means the other
part is the same as the current date (or time). The user must
provide the exact number of digits shown in the format definition
(padding with 0 when shorter). When both 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 isn't provided, the start date is the current
time. The option can only be provided one time.
The value of date specifies the number of days (starting at the
date specified by -startdate, or the current date when -startdate
isn't specified) for which the certificate should be considered
valid.
-genseckey
The following are the available options for the -genseckey
command:
o {-alias alias}: Alias name of the entry to process
o [-keypass arg]: Key password
o -keyalg alg: Key algorithm name
o {-keysize size}: Key bit size
o {-keystore keystore}: Keystore name
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument.
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
o {-protected}: Password provided through a protected mechanism
Use the -genseckey command to generate a secret key and store it
in a new KeyStore.SecretKeyEntry identified by alias.
The value of -keyalg specifies the algorithm to be used to
generate the secret key, and the value of -keysize specifies the
size of the key that is generated. The -keypass value is a
password that protects the secret key. If a password is not
provided, then the user is prompted for it. If you press the
Return key at the prompt, then the key password is set to the same
password that is used for the -keystore. The -keypass value must
contain at least six characters.
-importcert
The following are the available options for the -importcert
command:
o {-noprompt}: Do not prompt
o {-trustcacerts}: Trust certificates from cacerts
o {-protected}: Password is provided through protected mechanism
o {-alias alias}: Alias name of the entry to process
o {-file file}: Input file name
o [-keypass arg]: Key password
o {-keystore keystore}: Keystore name
o {-cacerts}: Access the cacerts keystore
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument.
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
Use the -importcert command to read the certificate or certificate
chain (where the latter is supplied in a PKCS#7 formatted reply or
in a sequence of X.509 certificates) from -file file, and store it
in the keystore entry identified by -alias. If -file file is not
specified, then the certificate or certificate chain is read from
stdin.
The keytool command 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: To add it to the list of
trusted certificates, and to import a certificate reply received
from a certificate authority (CA) as the result of submitting a
Certificate Signing Request (CSR) to that CA. See the -certreq
command in Commands for Generating a Certificate Request.
The type of import is indicated by the value of the -alias option.
If the alias doesn't point to a key entry, then the keytool
command assumes you are adding a trusted certificate entry. In
this case, the alias shouldn't already exist in the keystore. If
the alias does exist, then the keytool command outputs an error
because a trusted certificate already exists for that alias, and
doesn't import the certificate. If -alias points to a key entry,
then the keytool command assumes that you're importing a
certificate reply.
-importpass
The following are the available options for the -importpass
command:
o {-alias alias}: Alias name of the entry to process
o [-keypass arg]: Key password
o {-keyalg alg}: Key algorithm name
o {-keysize size}: Key bit size
o {-keystore keystore}: Keystore name
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument.
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
o {-protected}: Password provided through a protected mechanism
Use the -importpass command to imports a passphrase and store it
in a new KeyStore.SecretKeyEntry identified by -alias. The
passphrase may be supplied via the standard input stream;
otherwise the user is prompted for it. The -keypass option
provides a password to protect the imported passphrase. If a
password is not provided, then the user is prompted for it. If
you press the Return key at the prompt, then the key password is
set to the same password as that used for the keystore. The
-keypass value must contain at least six characters.
COMMANDS FOR IMPORTING CONTENTS FROM ANOTHER KEYSTORE
-importkeystore
The following are the available options for the -importkeystore
command:
o -srckeystore keystore: Source keystore name
o {-destkeystore keystore}: Destination keystore name
o {-srcstoretype type}: Source keystore type
o {-deststoretype type}: Destination keystore type
o [-srcstorepass arg]: Source keystore password
o [-deststorepass arg]: Destination keystore password
o {-srcprotected}: Source keystore password protected
o {-destprotected}: Destination keystore password protected
o {-srcprovidername name}: Source keystore provider name
o {-destprovidername name}: Destination keystore provider name
o {-srcalias alias}: Source alias
o {-destalias alias}: Destination alias
o [-srckeypass arg]: Source key password
o [-destkeypass arg]: Destination key password
o {-noprompt}: Do not prompt
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
Note:
This is the first line of all options:
-srckeystore keystore -destkeystore keystore
Use the -importkeystore command to import a single entry or all
entries from a source keystore to a destination keystore.
Note:
If you do not specify -destkeystore when using the keytool
-importkeystore command, then the default keystore used is
$HOME/.keystore.
When the -srcalias option is provided, the command imports the
single entry identified by the alias to the destination keystore.
If a destination alias isn't provided with -destalias, then
-srcalias is used as the destination alias. If the source entry
is protected by a password, then -srckeypass is used to recover
the entry. If -srckeypass isn't provided, then the keytool
command attempts to use -srcstorepass to recover the entry. If
-srcstorepass is not provided or is incorrect, then the user is
prompted for a password. The destination entry is protected with
-destkeypass. If -destkeypass isn't provided, then the
destination entry is protected with the source entry password.
For example, most third-party tools require storepass and keypass
in a PKCS #12 keystore to be the same. To create a PKCS#12
keystore for these tools, always specify a -destkeypass that is
the same as -deststorepass.
If the -srcalias option isn't provided, then all entries in the
source keystore are imported into the destination keystore. Each
destination entry is stored under the alias from the source entry.
If the source entry is protected by a password, then -srcstorepass
is used to recover the entry. If -srcstorepass is not provided or
is incorrect, then the user is prompted for a password. If a
source keystore entry type isn't supported in the destination
keystore, or if an error occurs while storing an entry into the
destination keystore, then the user is prompted either to skip the
entry and continue or to quit. The destination entry is protected
with the source entry password.
If the destination alias already exists in the destination
keystore, then the user is prompted either to overwrite the entry
or to create a new entry under a different alias name.
If the -noprompt option is provided, then the user isn't prompted
for a new destination alias. Existing entries are overwritten
with the destination alias name. Entries that can't be imported
are skipped and a warning is displayed.
COMMANDS FOR GENERATING A CERTIFICATE REQUEST
-certreq
The following are the available options for the -certreq command:
o {-alias alias}: Alias name of the entry to process
o {-sigalg alg}: Signature algorithm name
o {-file file}: Output file name
o [ -keypass arg]: Key password
o {-keystore keystore}: Keystore name
o {-dname name}: Distinguished name
o {-ext value}: X.509 extension
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument.
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
o {-protected}: Password provided through a protected mechanism
Use the -certreq command to generate a Certificate Signing Request
(CSR) using the PKCS #10 format.
A CSR is intended to be sent to a CA. The CA authenticates the
certificate requestor (usually offline) and returns a certificate
or certificate chain to replace the existing certificate chain
(initially a self-signed certificate) in the keystore.
The private key associated with alias is used to create the PKCS
#10 certificate request. To access the private key, the correct
password must be provided. If -keypass isn't provided at the
command line and is different from the password used to protect
the integrity of the keystore, then the user is prompted for it.
If -dname is provided, then it is used as the subject in the CSR.
Otherwise, the X.500 Distinguished Name associated with alias is
used.
The -sigalg value specifies the algorithm that should be used to
sign the CSR.
The CSR is stored in the -file file. If a file is not specified,
then the CSR is output to -stdout.
Use the -importcert command to import the response from the CA.
COMMANDS FOR EXPORTING DATA
-exportcert
The following are the available options for the -exportcert
command:
o {-rfc}: Output in RFC style
o {-alias alias}: Alias name of the entry to process
o {-file file}: Output file name
o {-keystore keystore}: Keystore name
o {-cacerts}: Access the cacerts keystore
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg] }: Add security
provider by fully qualified class name with an optional
configure argument.
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
o {-protected}: Password provided through a protected mechanism
Use the -exportcert command to read a certificate from the
keystore that is associated with -alias alias and store it in the
-file file. When a file is not specified, the certificate is
output to stdout.
By default, the certificate is output in binary encoding. If the
-rfc option is specified, then the output in the printable
encoding format defined by the Internet RFC 1421 Certificate
Encoding Standard.
If -alias refers to a trusted certificate, then that certificate
is output. Otherwise, -alias refers to a key entry with an
associated certificate chain. In that case, the first certificate
in the chain is returned. This certificate authenticates the
public key of the entity addressed by -alias.
COMMANDS FOR DISPLAYING DATA
-list The following are the available options for the -list command:
o {-rfc}: Output in RFC style
o {-alias alias}: Alias name of the entry to process
o {-keystore keystore}: Keystore name
o {-cacerts}: Access the cacerts keystore
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg] }: Add security
provider by fully qualified class name with an optional
configure argument.
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
o {-protected}: Password provided through a protected mechanism
Use the -list command to print the contents of the keystore entry
identified by -alias to stdout. If -alias alias is not specified,
then the contents of the entire keystore are printed.
By default, this command prints the SHA-256 fingerprint of a
certificate. If the -v option is specified, then 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, then the certificate contents are
printed by using the printable encoding format, as defined by the
Internet RFC 1421 Certificate Encoding Standard.
Note:
You can't specify both -v and -rfc in the same command.
Otherwise, an error is reported.
-printcert
The following are the available options for the -printcert
command:
o {-rfc}: Output in RFC style
o {-file cert_file}: Input file name
o {-sslserver server[:port]}:: Secure Sockets Layer (SSL) server
host and port
o {-jarfile JAR_file}: Signed .jar file
o {-keystore keystore}: Keystore name
o {-trustcacerts}: Trust certificates from cacerts
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument.
o {-providerpath list}: Provider classpath
o {-protected}: Password is provided through protected mechanism
o {-v}: Verbose output
Use the -printcert command to read and print the certificate from
-file cert_file, the SSL server located at -sslserver
server[:port], or the signed JAR file specified by -jarfile
JAR_file. It prints its contents in a human-readable format.
When a port is not specified, the standard HTTPS port 443 is
assumed.
Note:
The -sslserver and -file options can't be provided in the same
command. Otherwise, an error is reported. If you don't specify
either option, then the certificate is read from stdin.
When-rfc is specified, the keytool command prints the certificate
in PEM mode as defined by the Internet RFC 1421 Certificate
Encoding standard.
If the certificate is read from a file or stdin, then it might be
either binary encoded or in printable encoding format, as defined
by the RFC 1421 Certificate Encoding standard.
If the SSL server is behind a firewall, then the
-J-Dhttps.proxyHost=proxyhost and -J-Dhttps.proxyPort=proxyport
options can be specified on the command line for proxy tunneling.
Note:
This command can be used independently of a keystore. This
command does not check for the weakness of a certificate's
signature algorithm if it is a trusted certificate in the user
keystore (specified by -keystore) or in the cacerts keystore (if
-trustcacerts is specified).
-printcertreq
The following are the available options for the -printcertreq
command:
o {-file file}: Input file name
o {-v}: Verbose output
Use the -printcertreq command to print the contents of a PKCS #10
format certificate request, which can be generated by the keytool
-certreq command. The command reads the request from file. If
there is no file, then the request is read from the standard
input.
-printcrl
The following are the available options for the -printcrl command:
o {-file crl}: Input file name
o {-keystore keystore}: Keystore name
o {-trustcacerts}: Trust certificates from cacerts
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument.
o {-providerpath list}: Provider classpath
o {-protected}: Password is provided through protected mechanism
o {-v}: Verbose output
Use the -printcrl command to read the Certificate Revocation List
(CRL) from -file crl . A CRL is a list of the digital
certificates that were revoked by the CA that issued them. The CA
generates the crl file.
Note:
This command can be used independently of a keystore. This
command attempts to verify the CRL using a certificate from the
user keystore (specified by -keystore) or the cacerts keystore (if
-trustcacerts is specified), and will print out a warning if it
cannot be verified.
COMMANDS FOR MANAGING THE KEYSTORE
-storepasswd
The following are the available options for the -storepasswd
command:
o [-new arg]: New password
o {-keystore keystore}: Keystore name
o {-cacerts}: Access the cacerts keystore
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument.
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
Use the -storepasswd command to change the password used to
protect the integrity of the keystore contents. The new password
is set by -new arg and must contain at least six characters.
-keypasswd
The following are the available options for the -keypasswd
command:
o {-alias alias}: Alias name of the entry to process
o [-keypass old_keypass]: Key password
o [-new new_keypass]: New password
o {-keystore keystore}: Keystore name
o {-storepass arg}: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument.
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
Use the -keypasswd command to change the password (under which
private/secret keys identified by -alias are protected) from
-keypass old_keypass to -new new_keypass. The password value must
contain at least six characters.
If the -keypass option isn't provided at the command line and the
-keypass password is different from the keystore password
(-storepass arg), then the user is prompted for it.
If the -new option isn't provided at the command line, then the
user is prompted for it.
-delete
The following are the available options for the -delete command:
o [-alias alias]: Alias name of the entry to process
o {-keystore keystore}: Keystore name
o {-cacerts}: Access the cacerts keystore
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument.
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
o {-protected}: Password provided through a protected mechanism
Use the -delete command to delete the -alias alias entry from the
keystore. When not provided at the command line, the user is
prompted for the alias.
-changealias
The following are the available options for the -changealias
command:
o {-alias alias}: Alias name of the entry to process
o [-destalias alias]: Destination alias
o [-keypass arg]: Key password
o {-keystore keystore}: Keystore name
o {-cacerts}: Access the cacerts keystore
o [-storepass arg]: Keystore password
o {-storetype type}: Keystore type
o {-providername name}: Provider name
o {-addprovider name [-providerarg arg]}: Add security provider by
name (such as SunPKCS11) with an optional configure argument.
o {-providerclass class [-providerarg arg]}: Add security provider
by fully qualified class name with an optional configure
argument.
o {-providerpath list}: Provider classpath
o {-v}: Verbose output
o {-protected}: Password provided through a protected mechanism
Use the -changealias command to move an existing keystore entry
from -alias alias to a new -destalias alias. If a destination
alias is not provided, then the command prompts you for one. If
the original entry is protected with an entry password, then the
password can be supplied with the -keypass option. If a key
password is not provided, then the -storepass (if provided) is
attempted first. If the attempt fails, then the user is prompted
for a password.
COMMANDS FOR DISPLAYING SECURITY-RELATED INFORMATION
-showinfo
The following are the available options for the -showinfo command:
o {-tls}: Displays TLS configuration information
o {-v}: Verbose output
Use the -showinfo command to display various security-related
information. The -tls option displays TLS configurations, such as
the list of enabled protocols and cipher suites.
COMMANDS FOR DISPLAYING PROGRAM VERSION
You can use -version to print the program version of keytool.
COMMANDS FOR DISPLAYING HELP INFORMATION
You can use --help to display a list of keytool commands or to display
help information about a specific keytool command.
o To display a list of keytool commands, enter:
keytool --help
o To display help information about a specific keytool command, enter:
keytool -<command> --help
COMMON COMMAND OPTIONS
The -v option can appear for all commands except --help. When the -v
option appears, it signifies verbose mode, which means that more
information is provided in the output.
The -Joption argument can appear for any command. When the -Joption is
used, the specified option string is passed directly to the Java
interpreter. This option doesn't contain any spaces. It's useful for
adjusting the execution environment or memory usage. For a list of
possible interpreter options, enter java -h or java -X at the command
line.
These options can 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 doesn't yet
exist, then certain keytool commands can result in a new keystore
file being created. For example, if keytool -genkeypair is called
and the -keystore option isn't specified, the default keystore
file named .keystore is created in the user's home directory if it
doesn't already exist. Similarly, if the -keystore ks_file option
is specified but ks_file doesn't exist, then it is created. For
more information on the JKS storetype, see the KeyStore
Implementation section in KeyStore aliases.
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 isn't file-based. For example, when the
keystore resides on a hardware token device.
-cacerts cacerts
Operates on the cacerts keystore . This option is equivalent to
-keystore path_to_cacerts -storetype type_of_cacerts. An error is
reported if the -keystore or -storetype option is used with the
-cacerts option.
-storepass [:env | :file ] argument
The password that is used to protect the integrity of the
keystore.
If the modifier env or file isn't specified, then the password has
the value argument, which must contain at least six characters.
Otherwise, 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
keystore contents. For such commands, when the -storepass option
isn't provided at the command line, the user is prompted for it.
When retrieving information from the keystore, the password is
optional. If a password is not specified, then the integrity of
the retrieved information can't be verified and a warning is
displayed.
-providername name
Used to identify a cryptographic service provider's name when
listed in the security properties file.
-addprovider name
Used to add a security provider by name (such as SunPKCS11) .
-providerclass class
Used to specify the name of a cryptographic service provider's
master class file when the service provider isn't listed in the
security properties file.
-providerpath list
Used to specify the provider classpath.
-providerarg arg
Used with the -addprovider or -providerclass option to represent
an optional string input argument for the constructor of class
name.
-protected=true|false
Specify this value as true when a password must be specified by
way of a protected authentication path, such as a dedicated PIN
reader. Because there are two keystores involved in the
-importkeystore command, the following two options, -srcprotected
and -destprotected, are provided for the source keystore and the
destination keystore respectively.
-ext {name{:critical} {=value}}
Denotes an X.509 certificate extension. The option can be used in
-genkeypair and -gencert to embed extensions into the generated
certificate, or in -certreq to show what extensions are requested
in the certificate request. The option can appear multiple times.
The name argument can be a supported extension name (see Supported
Named Extensions) or an arbitrary OID number. The value argument,
when provided, denotes the argument for the extension. When value
is omitted, the default value of the extension or the extension
itself requires no argument. The :critical modifier, when
provided, means the extension's isCritical attribute is true;
otherwise, it is false. You can use :c in place of :critical.
-conf file
Specifies a pre-configured options file.
PRE-CONFIGURED OPTIONS FILE
A pre-configured options file is a Java properties file that can be
specified with the -conf option. Each property represents the default
option(s) for a keytool command using "keytool.command_name" as the
property name. A special property named "keytool.all" represents the
default option(s) applied to all commands. A property value can include
${prop} which will be expanded to the system property associated with it.
If an option value includes white spaces inside, it should be surrounded
by quotation marks (" or '). All property names must be in lower case.
When keytool is launched with a pre-configured options file, the value
for "keytool.all" (if it exists) is prepended to the keytool command line
first, with the value for the command name (if it exists) comes next, and
the existing options on the command line at last. For a single-valued
option, this allows the property for a specific command to override the
"keytool.all" value, and the value specified on the command line to
override both. For multiple-valued options, all of them will be used by
keytool.
For example, given the following file named preconfig:
# A tiny pre-configured options file
keytool.all = -keystore ${user.home}/ks
keytool.list = -v
keytool.genkeypair = -keyalg rsa
keytool -conf preconfig -list is identical to
keytool -keystore ~/ks -v -list
keytool -conf preconfig -genkeypair -alias me is identical to
keytool -keystore ~/ks -keyalg rsa -genkeypair -alias me
keytool -conf preconfig -genkeypair -alias you -keyalg ec is identical to
keytool -keystore ~/ks -keyalg rsa -genkeypair -alias you -keyalg
ec
which is equivalent to
keytool -keystore ~/ks -genkeypair -alias you -keyalg ec
because -keyalg is a single-valued option and the ec value specified on
the command line overrides the preconfigured options file.
EXAMPLES OF OPTION VALUES
The following examples show the defaults for various option values:
-alias "mykey"
-keysize
2048 (when using -genkeypair and -keyalg is "DSA")
3072 (when using -genkeypair and -keyalg is "RSA", "RSASSA-PSS", or "DH")
384 (when using -genkeypair and -keyalg is "EC")
56 (when using -genseckey and -keyalg is "DES")
168 (when using -genseckey and -keyalg is "DESede")
-groupname
ed25519 (when using -genkeypair and -keyalg is "EdDSA", key size is 255)
x25519 (when using -genkeypair and -keyalg is "XDH", key size is 255)
-validity 90
-keystore <the file named .keystore in the user's home directory>
-destkeystore <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
When generating a certificate or a certificate request, the default
signature algorithm (-sigalg option) is derived from the algorithm of the
underlying private key to provide an appropriate level of security
strength as follows:
Default Signature Algorithms
keyalg key size default sigalg
-------------------------------------------
DSA any size SHA256withDSA
RSA < 624 SHA256withRSA (key
size is too small
for using SHA-384)
<= 7680 SHA384withRSA
> 7680 SHA512withRSA
EC < 512 SHA384withECDSA
>= 512 SHA512withECDSA
RSASSA-PSS < 624 RSASSA-PSS (with
SHA-256, key size
is too small for
using SHA-384)
<= 7680 RSASSA-PSS (with
SHA-384)
> 7680 RSASSA-PSS (with
SHA-512)
EdDSA 255 Ed25519
448 Ed448
Ed25519 255 Ed25519
Ed448 448 Ed448
o The key size, measured in bits, corresponds to the size of the private
key. This size is determined by the value of the -keysize or
-groupname options or the value derived from a default setting.
o An RSASSA-PSS signature algorithm uses a MessageDigest algorithm as its
hash and MGF1 algorithms.
o If neither a default -keysize or -groupname is defined for an
algorithm, the security provider will choose a default setting.
Note:
To improve out of the box security, default keysize, groupname, and
signature algorithm names are periodically updated to stronger values
with each release of the JDK. If interoperability with older releases of
the JDK is important, make sure that the defaults are supported by those
releases. Alternatively, you can use the -keysize, -groupname, or
-sigalg options to override the default values at your own risk.
SUPPORTED NAMED EXTENSIONS
The keytool command supports these named extensions. The names aren't
case-sensitive.
BC or BasicConstraints
Values:
The full form is ca:{true|false}[,pathlen:len] or len, which is
short for ca:true,pathlen:len.
When len is omitted, the resulting value is ca:true.
KU or KeyUsage
Values:
usage(, usage)*
usage can be one of the following:
o digitalSignature
o nonRepudiation (contentCommitment)
o keyEncipherment
o dataEncipherment
o keyAgreement
o keyCertSign
o cRLSign
o encipherOnly
o decipherOnly
Provided there is no ambiguity, the usage argument can be
abbreviated with the first few letters (such as dig for
digitalSignature) or in camel-case style (such as dS for
digitalSignature or cRLS for cRLSign). The usage values are
case-sensitive.
EKU or ExtendedKeyUsage
Values:
usage(, usage)*
usage can be one of the following:
o anyExtendedKeyUsage
o serverAuth
o clientAuth
o codeSigning
o emailProtection
o timeStamping
o OCSPSigning
o Any OID string
Provided there is no ambiguity, the usage argument can be
abbreviated with the first few letters or in camel-case style.
The usage values are case-sensitive.
SAN or SubjectAlternativeName
Values:
type:value(, type:value)*
type can be one of the following:
o EMAIL
o URI
o DNS
o IP
o OID
The value argument is the string format value for the type.
IAN or IssuerAlternativeName
Values:
Same as SAN or SubjectAlternativeName.
SIA or SubjectInfoAccess
Values:
method:location-type:location-value(,
method:location-type:location-value)*
method can be one of the following:
o timeStamping
o caRepository
o Any OID
The location-type and location-value arguments can be any
type:value supported by the SubjectAlternativeName extension.
AIA or AuthorityInfoAccess
Values:
Same as SIA or SubjectInfoAccess.
The method argument can be one of the following:
o ocsp
o caIssuers
o Any OID
When name is OID, the value is the hexadecimal dumped Definite Encoding
Rules (DER) encoding of the extnValue for the extension excluding the
OCTET STRING type and length bytes. Other than standard hexadecimal
numbers (0-9, a-f, A-F), any extra characters are ignored in the HEX
string. Therefore, both 01:02:03:04 and 01020304 are accepted as
identical values. When there is no value, the extension has an empty
value field.
A special name honored, used only in -gencert, denotes how the extensions
included in the certificate request should be honored. The value for
this name is a comma-separated list of all (all requested extensions are
honored), name{:[critical|non-critical]} (the named extension is honored,
but it uses a different isCritical attribute), and -name (used with all,
denotes an exception). Requested extensions aren't honored by default.
If, besides the-ext honored option, another named or OID -ext option is
provided, this extension is added to those already honored. However, if
this name (or OID) also appears in the honored value, then its value and
criticality override that in the request. If an extension of the same
type is provided multiple times through either a name or an OID, only the
last extension is used.
The subjectKeyIdentifier extension is always created. For
non-self-signed certificates, the authorityKeyIdentifier is created.
CAUTION:
Users should be aware that some combinations of extensions (and other
certificate fields) may not conform to the Internet standard. See
Certificate Conformance Warning.
EXAMPLES OF TASKS IN CREATING A KEYSTORE
The following examples describe the sequence actions in creating a
keystore for managing public/private key pairs and certificates from
trusted entities.
o Generating the Key Pair
o Requesting a Signed Certificate from a CA
o Importing a Certificate for the CA
o Importing the Certificate Reply from the CA
o Exporting a Certificate That Authenticates the Public Key
o Importing the Keystore
o Generating Certificates for an SSL Server
GENERATING THE KEY PAIR
Create a keystore and then generate the key pair.
You can enter the command as a single line such as the following:
keytool -genkeypair -dname "cn=myname, ou=mygroup, o=mycompany,
c=mycountry" -alias business -keyalg rsa -keypass password
-keystore /working/mykeystore -storepass password -validity 180
The command creates the keystore named mykeystore in the working
directory (provided it doesn't already exist), and assigns it the
password specified by -keypass. It generates a public/private key pair
for the entity whose distinguished name is myname, mygroup, mycompany,
and a two-letter country code of mycountry. It uses the RSA key
generation algorithm to create the keys; both are 3072 bits.
The command uses the default SHA384withRSA signature algorithm to create
a self-signed certificate that includes the public key and the
distinguished name information. The certificate is valid for 180 days,
and is associated with the private key in a keystore entry referred to by
-alias business. The private key is assigned the password specified by
-keypass.
The command is significantly shorter when the option defaults are
accepted. In this case, only -keyalg is required, and the defaults are
used for unspecified options that have default values. You are prompted
for any required values. You could have the following:
keytool -genkeypair -keyalg rsa
In this case, a keystore entry with the alias mykey is created, with a
newly generated key pair and a certificate that is valid for 90 days.
This entry is placed in your home directory in a keystore named .keystore
. .keystore is created if it doesn't already exist. You are prompted
for the distinguished name information, the keystore password, and the
private key password.
Note:
The rest of the examples assume that you responded to the prompts with
values equal to those specified in the first -genkeypair command. For
example, a distinguished name of cn=myname, ou=mygroup, o=mycompany,
c=mycountry.
REQUESTING A SIGNED CERTIFICATE FROM A CA
Note:
Generating the key pair created a self-signed certificate; however, a
certificate is more likely to be trusted by others when it is signed by a
CA.
To get a CA signature, complete the following process:
1. Generate a CSR:
keytool -certreq -file myname.csr
This creates a CSR for the entity identified by the default alias
mykey and puts the request in the file named myname.csr.
2. Submit myname.csr to a CA, such as DigiCert.
The CA authenticates you, the requestor (usually offline), and returns a
certificate, signed by them, authenticating your public key. In some
cases, the CA returns 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
To import a certificate for the CA, complete the following process:
1. Before you import the certificate reply from a CA, you need one or
more trusted certificates either in your keystore or in the cacerts
keystore file. See -importcert in Commands.
o If the certificate reply is a certificate chain, then you need the
top certificate of the chain. The root CA certificate that
authenticates the public key of the CA.
o If the certificate reply is a single certificate, then you need a
certificate for the issuing CA (the one that signed it). If that
certificate isn't self-signed, then you need a certificate for its
signer, and so on, up to a self-signed root CA certificate.
The cacerts keystore ships with a set of root certificates issued by
the CAs of the Oracle Java Root Certificate program
[https://www.oracle.com/java/technologies/javase/carootcertsprogram.html].
If you request a signed certificate from a CA, and a certificate
authenticating that CA's public key hasn't been added to cacerts,
then you must import a certificate from that CA as a trusted
certificate.
A certificate from a CA is usually self-signed or signed by another
CA. If it is signed by another CA, you need a certificate that
authenticates that CA's public key.
For example, you have obtained a X.cer file from a company that is a
CA and the file is supposed to be a self-signed certificate that
authenticates that CA's public key. Before you import it as a
trusted certificate, you should ensure that the certificate is valid
by:
1. Viewing it with the keytool -printcert command or the keytool
-importcert command without using the -noprompt option. Make sure
that the displayed certificate fingerprints match the expected
fingerprints.
2. Calling the person who sent the certificate, and comparing the
fingerprints that you see with the ones that they show or that a
secure public key repository shows.
Only when the fingerprints are equal is it assured that the
certificate wasn't replaced in transit with somebody else's
certificate (such as an attacker's certificate). If such an attack
takes place, and you didn't check the certificate before you imported
it, then you would be trusting anything that the attacker signed.
2. Replace the 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.
If you trust that the certificate is valid, then you can add it to
your keystore by entering the following command:
keytool -importcert -alias alias -file *X*.cer`
This command creates a trusted certificate entry in the keystore from
the data in the CA certificate file and assigns the values of the
alias to the entry.
IMPORTING THE CERTIFICATE REPLY FROM THE CA
After you import a certificate that authenticates the public key of the
CA that 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 replace your self-signed certificate with a
certificate chain.
The certificate chain is one of the following:
o Returned by the CA when the CA reply is a chain.
o Constructed when the CA reply is a single certificate. This
certificate chain is constructed by using the certificate reply and
trusted certificates available either in the keystore where you import
the reply or in the cacerts keystore file.
For example, if you sent your certificate signing request to DigiCert,
then you can import their reply by entering the following command:
Note:
In this example, the returned certificate is named DCmyname.cer.
keytool -importcert -trustcacerts -file DCmyname.cer
EXPORTING A CERTIFICATE THAT AUTHENTICATES THE PUBLIC KEY
Note:
If you used the jarsigner command to sign a Java Archive (JAR) file, then
clients that use the file will want to authenticate your signature.
One way that clients can authenticate you is by importing your public key
certificate into their keystore as a trusted entry. You can then export
the certificate and supply it to your clients.
For example:
1. Copy your certificate to a file named myname.cer by entering the
following command:
Note:
In this example, the entry has an alias of mykey.
keytool -exportcert -alias mykey -file myname.cer
2. With the certificate and the signed JAR file, a client can use the
jarsigner command to authenticate your signature.
IMPORTING THE KEYSTORE
Use the importkeystore command to import an entire keystore into another
keystore. This imports all entries from the source keystore, including
keys and certificates, to the destination keystore with 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 the keytool command can't recover the private keys
or secret keys from the source keystore, then it prompts you for a
password. If it detects alias duplication, then it asks you for a new
alias, and you can specify a new alias or simply allow the keytool
command to overwrite the existing one.
For example, import entries from a typical JKS type keystore key.jks into
a PKCS #11 type hardware-based keystore, by entering the following
command:
keytool -importkeystore -srckeystore key.jks -destkeystore NONE
-srcstoretype JKS -deststoretype PKCS11 -srcstorepass password
-deststorepass 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 used in the previous example, you need to specify the alias
you want to import. With the -srcalias option specified, you can also
specify the destination alias name, protection password for a secret or
private key, and the destination protection password you want as follows:
keytool -importkeystore -srckeystore key.jks -destkeystore NONE
-srcstoretype JKS -deststoretype PKCS11 -srcstorepass password
-deststorepass password -srcalias myprivatekey -destalias
myoldprivatekey -srckeypass password -destkeypass password
-noprompt
GENERATING CERTIFICATES FOR AN SSL SERVER
The following are keytool commands used to generate key pairs and
certificates for three entities:
o Root CA (root)
o Intermediate CA (ca)
o SSL server (server)
Ensure that you store all the certificates in the same keystore.
keytool -genkeypair -keystore root.jks -alias root -ext bc:c -keyalg rsa
keytool -genkeypair -keystore ca.jks -alias ca -ext bc:c -keyalg rsa
keytool -genkeypair -keystore server.jks -alias server -keyalg rsa
keytool -keystore root.jks -alias root -exportcert -rfc > root.pem
keytool -storepass password -keystore ca.jks -certreq -alias ca |
keytool -storepass password -keystore root.jks
-gencert -alias root -ext BC=0 -rfc > ca.pem
keytool -keystore ca.jks -importcert -alias ca -file ca.pem
keytool -storepass password -keystore server.jks -certreq -alias server |
keytool -storepass password -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
TERMS
Keystore
A keystore is a storage facility for cryptographic keys and
certificates.
Keystore entries
Keystores can have different types of entries. The two most
applicable entry types for the keytool command include the
following:
Key entries: Each entry 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. See
Certificate Chains. The keytool command can handle both types of
entries, while the jarsigner tool only handles the latter type of
entry, that is private keys and their associated certificate
chains.
Trusted certificate entries: Each entry contains a single public
key certificate that belongs to another party. The entry is
called a trusted certificate because the keystore owner trusts
that the public key in the certificate belongs to the identity
identified by the subject (owner) of the certificate. The issuer
of the certificate vouches for this, by signing the certificate.
Keystore aliases
All keystore entries (key and trusted certificate entries) are
accessed by way of unique aliases.
An alias is specified when you add an entity to the keystore with
the -genseckey command to generate a secret key, the -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, you can use the alias duke to generate a new
public/private key pair and wrap the public key into a self-signed
certificate with the following command. See Certificate Chains.
keytool -genkeypair -alias duke -keyalg rsa -keypass passwd
This example specifies an initial passwd 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, use a
command such as the following:
keytool -keypasswd -alias duke -keypass passwd -new
newpasswd
This changes the initial passwd to newpasswd. A password
shouldn't 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, then
you are prompted for it.
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) make use
of keystore implementations. Because the KeyStore class is
public, users can write additional security applications that use
it.
In JDK 9 and later, the default keystore implementation is PKCS12.
This is a cross platform keystore based on the RSA PKCS12 Personal
Information Exchange Syntax Standard. This standard is primarily
meant for storing or transporting a user's private keys,
certificates, and miscellaneous secrets. There is another
built-in implementation, provided by Oracle. It implements the
keystore as a file with 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
corresponding abstract KeystoreSpi class, also in the
java.security package, 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 subset of services that can be
accessed by the Java Security API. To provide a keystore
implementation, clients must implement a provider and supply a
KeystoreSpi subclass implementation, as described in Steps to
Implement and Integrate a Provider.
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. Keystore
implementations of different types aren't compatible.
The keytool command works on any file-based keystore
implementation. It treats the keystore location that is passed to
it at the command line as a file name and converts it to a
FileInputStream, from which it loads the keystore information.
The jarsigner commands can read a keystore from any location that
can be specified with a URL.
For keytool and jarsigner, you can specify a keystore type at the
command line, with the -storetype option.
If you don't explicitly specify a keystore type, then the tools
choose a keystore implementation based on the value of the
keystore.type property specified in the security properties file.
The security properties file is called java.security, and resides
in the security properties directory:
o Linux and macOS: java.home/lib/security
o Windows: java.home\lib\security
Each tool gets the keystore.type value and then examines all the
currently installed providers until it finds one that implements a
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 retrieve the value of
the keystore.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 pkcs12, which is a cross-platform
keystore based on the RSA PKCS12 Personal Information Exchange
Syntax Standard. This is specified by the following line in the
security properties file:
keystore.type=pkcs12
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 want to use the Oracle's jks keystore
implementation, then change the line to the following:
keystore.type=jks
Note:
Case doesn't matter in keystore type designations. For example,
JKS would be considered the same as jks.
Certificate
A certificate (or 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. The following terms are related to
certificates:
o Public Keys: These are numbers associated with a particular
entity, and are intended to be known to everyone who needs to
have trusted interactions with that entity. Public keys are
used to verify signatures.
o Digitally Signed: If some data is digitally signed, then it is
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.
o Identity: A known way of addressing an entity. In some systems,
the identity is the public key, and in others it can be anything
from an Oracle Solaris UID to an email address to an X.509
distinguished name.
o 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.
o 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 is supposed to be kept secret). Private and public
keys exist in pairs in all public key cryptography systems (also
referred to as public 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.
o Entity: An entity is a person, organization, program, computer,
business, bank, or something else you are trusting to some
degree.
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 were
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 such as
businesses that are trusted to sign (issue) certificates for other
entities. It is assumed that CAs only create valid and reliable
certificates because they are bound by legal agreements. There
are many public Certification Authorities, such as DigiCert,
Comodo, Entrust, and so on.
You can also run your own Certification Authority using products
such as Microsoft Certificate Server or the Entrust CA product for
your organization. With the keytool command, it is possible to
display, import, and export certificates. It is also possible to
generate self-signed certificates.
The keytool command currently handles X.509 certificates.
X.509 Certificates
The X.509 standard defines what information can go into a
certificate and describes how to write it down (the data format).
All the data in a certificate is encoded with 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:
o 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. The
keytool command can import and export v1, v2, and v3
certificates. It generates v3 certificates.
o X.509 Version 1 has been available since 1988, is widely
deployed, and is the most generic.
o X.509 Version 2 introduced the concept of subject and issuer
unique identifiers to handle the possibility of reuse of
subject or issuer names over time. Most certificate profile
documents strongly recommend that names not be reused and that
certificates shouldn't make use of unique identifiers.
Version 2 certificates aren't widely used.
o X.509 Version 3 is the most recent (1996) and supports the
notion of extensions where anyone can define an extension and
include it in the certificate. Some common extensions 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, for
example. DNS names, email addresses, IP addresses).
Extensions can be marked critical to indicate that the
extension should be checked and enforced or used. For
example, if a certificate has the KeyUsage extension marked
critical and set to keyCertSign, then when this certificate is
presented during SSL communication, it should be rejected
because the certificate extension indicates that the
associated private key should only be used for signing
certificates and not for SSL use.
o Serial number: The entity that created the certificate is
responsible for assigning it a serial number to distinguish it
from other certificates 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).
o Signature algorithm identifier: This identifies the algorithm
used by the CA to sign the certificate.
o Issuer name: The X.500 Distinguished Name of the entity that
signed the certificate. This is typically a CA. Using this
certificate implies trusting the entity that signed this
certificate. In some cases, such as root or top-level CA
certificates, the issuer signs its own certificate.
o 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 factors, such as the strength of
the private key used to sign the certificate, or the amount one
is willing to pay for a certificate. This is the expected
period that entities can rely on the public value, when the
associated private key has not been compromised.
o Subject name: The name of the entity whose public key the
certificate identifies. 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 (CN), organizational
unit (OU), organization (O), and country (C).
o Subject public key information: This is the public key of the
entity being named with an algorithm identifier that specifies
which public key crypto system this key belongs to and any
associated key parameters.
Certificate Chains
The keytool command can create and manage keystore key entries
that each contain a private key and an associated certificate
chain. The first certificate in the chain contains the public key
that corresponds to the private key.
When keys are first generated, the chain usually starts off
containing a single element, a self-signed certificate. See
-genkeypair in Commands. A self-signed certificate is one for
which the issuer (signer) is the same as the subject. The subject
is the entity whose public key is being authenticated by the
certificate. When the -genkeypair command is called to generate a
new public/private key pair, it also wraps the public key into a
self-signed certificate (unless the -signer option is specified).
Later, after a Certificate Signing Request (CSR) was generated
with the -certreq command and sent to a Certification Authority
(CA), the response from the CA is imported with -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, which is a
certificate from the CA authenticating its own public key, and the
last certificate in the chain. In other cases, the CA might
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 public key of the key entry), but the
second certificate in the chain is a certificate signed by a
different CA that authenticates the public key of the CA you sent
the CSR to. The next certificate in the chain is a certificate
that authenticates the second CA's key, and so on, until a
self-signed root certificate is reached. Each certificate in the
chain (after the first) authenticates the public 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)
includes the supporting certificate chain in addition to the
issued certificate. Both reply formats can be handled by the
keytool command.
The top-level (root) CA certificate is self-signed. However, the
trust into the root's public key doesn't come from the root
certificate itself, but from other sources such as a newspaper.
This is because anybody could generate a self-signed certificate
with the distinguished name of, for example, the DigiCert root CA.
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 with the
-printcert option and compare the displayed fingerprint with the
well-known fingerprint obtained from a newspaper, the root CA's
Web page, and so on.
cacerts Certificates File
A certificates file named cacerts resides in the security
properties directory:
o Linux and macOS: JAVA_HOME/lib/security
o Windows: JAVA_HOME\lib\security
The cacerts file represents a system-wide keystore with CA
certificates. System administrators can configure and manage that
file with the keytool command by specifying jks as the keystore
type. The cacerts keystore file ships with a default set of root
CA certificates. For Linux, macOS, and Windows, you can list the
default certificates with the following command:
keytool -list -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.
Note:
It is important to verify your cacerts file. Because 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 cacerts 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 JDK's $JAVA_HOME/lib/security directory.
Contact your system administrator if you don't have permission to
edit this file.
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 Base64 encoding,
makes it easy to export 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, when the -rfc option is specified.
The -list command by default prints the SHA-256 fingerprint of a
certificate. If the -v option is specified, then the certificate
is printed in human-readable format. If the -rfc option is
specified, then the certificate is output in the printable
encoding format.
In its printable encoding format, the encoded certificate is
bounded at the beginning and end by the following text:
-----BEGIN CERTIFICATE-----
encoded certificate goes here.
-----END CERTIFICATE-----
X.500 Distinguished Names
X.500 Distinguished Names are used to identify entities, such as
those that are named by the subject and issuer (signer) fields of
X.509 certificates. The keytool command supports the following
subparts:
o commonName: The common name of a person such as Susan Jones.
o organizationUnit: The small organization (such as department or
division) name. For example, Purchasing.
o localityName: The locality (city) name, for example, Palo Alto.
o stateName: State or province name, for example, California.
o country: Two-letter country code, for example, CH.
When you supply a distinguished name string as the value of a
-dname option, such as for the -genkeypair command, the string
must be in the following format:
CN=cName, OU=orgUnit, O=org, L=city, S=state, C=countryCode
All the following items represent actual values and the previous
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
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
-keyalg rsa
Case doesn't 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 isn't necessary to have all the subcomponents.
You can use a subset, for example:
CN=Smith, OU=Java, O=Oracle, C=US
If a distinguished name string value contains a comma, then the
comma must be escaped by a backslash (\) character when you
specify the string on a command line, as in:
cn=Jack, ou=Java\, Product Development, o=Oracle, c=US
It is never necessary to specify a distinguished name string on a
command line. When the distinguished name is needed for a
command, but not supplied on the command line, the user is
prompted for each of the subcomponents. In this case, a comma
doesn't need to be escaped by a backslash (\).
WARNINGS
IMPORTING TRUSTED CERTIFICATES WARNING
Important: Be sure to check a certificate very carefully before importing
it as a trusted certificate.
Windows Example:
View the certificate first with the -printcert command or the -importcert
command without the -noprompt option. Ensure that the displayed
certificate fingerprints match the expected ones. For example, suppose
someone sends or emails you a certificate that 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 follows:
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 Jun 24 18:01:13 PDT 2016 until: Wed Jun 23 17:01:13 PST 2016
Certificate Fingerprints:
SHA-1: 20:B6:17:FA:EF:E5:55:8A:D0:71:1F:E8:D6:9D:C0:37:13:0E:5E:FE
SHA-256: 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
Linux Example:
View the certificate first with the -printcert command or the -importcert
command without the -noprompt option. Ensure that the displayed
certificate fingerprints match the expected ones. For example, suppose
someone sends or emails you a certificate that 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 follows:
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 Jun 24 18:01:13 PDT 2016 until: Wed Jun 23 17:01:13 PST 2016
Certificate Fingerprints:
SHA-1: 20:B6:17:FA:EF:E5:55:8A:D0:71:1F:E8:D6:9D:C0:37:13:0E:5E:FE
SHA-256: 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 fingerprints that you see with the ones that they show. Only
when the fingerprints are equal is it guaranteed that the certificate
wasn't replaced in transit with somebody else's certificate such as an
attacker's certificate. If such an attack took place, and you didn't
check the certificate before you imported it, then you would be trusting
anything the attacker signed, for example, a JAR file with malicious
class files inside.
Note:
It isn't required that you execute a -printcert command before importing
a certificate. This is because before you add 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 can
then stop the import operation. However, you can do this only when you
call the -importcert command without the -noprompt option. If the
-noprompt option is specified, then there is no interaction with the
user.
PASSWORDS WARNING
Most commands that operate 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.
However, a password shouldn't be specified on a command line or in a
script unless it is for testing, or you are on a secure system. When you
don't specify a required password option on a command line, you are
prompted for it.
CERTIFICATE CONFORMANCE WARNING
Internet X.509 Public Key Infrastructure Certificate and Certificate
Revocation List (CRL) Profile [https://tools.ietf.org/rfc/rfc5280.txt]
defined a profile on conforming X.509 certificates, which includes what
values and value combinations are valid for certificate fields and
extensions.
The keytool command doesn't enforce all of these rules so it can generate
certificates that don't conform to the standard, such as self-signed
certificates that would be used for internal testing purposes.
Certificates that don't conform to the standard might be rejected by the
JDK or other applications. Users should ensure that they provide the
correct options for -dname, -ext, and so on.
IMPORT A NEW TRUSTED CERTIFICATE
Before you add the certificate to the keystore, the keytool command
verifies it by attempting to construct a chain of trust from that
certificate to a self-signed certificate (belonging to a root CA), using
trusted certificates that are already available in the keystore.
If the -trustcacerts option was specified, then additional certificates
are considered for the chain of trust, namely the certificates in a file
named cacerts.
If the keytool command fails to establish a trust path from the
certificate to be imported up to a self-signed certificate (either from
the keystore or the cacerts file), then the certificate information is
printed, and the user is prompted to verify it by comparing the displayed
certificate fingerprints with the fingerprints obtained from some other
(trusted) source of information, which might be the certificate owner.
Be very careful to ensure the certificate is valid before importing it as
a trusted certificate. The user then has the option of stopping the
import operation. If the -noprompt option is specified, then there is no
interaction with the user.
IMPORT A CERTIFICATE REPLY
When you import a certificate reply, the certificate reply is validated
with trusted certificates from the keystore, and optionally, the
certificates configured in the cacerts keystore file when the
-trustcacerts option is specified.
The methods of determining whether the certificate reply is trusted are
as follows:
o If the reply is a single X.509 certificate, then the keytool command
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 is used to
authenticate the certificate reply from the new certificate chain of
aliases. If a trust chain can't be established, then the certificate
reply isn't imported. In this case, the keytool command doesn't print
the certificate and prompt the user to verify it, because it is very
difficult 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, then the chain is ordered with the user certificate
first followed by zero or more CA certificates. If the chain ends with
a self-signed root CA certificate and the-trustcacerts option was
specified, the keytool command attempts to match it with any of the
trusted certificates in the keystore or the cacerts keystore file. If
the chain doesn't end with a self-signed root CA certificate and the
-trustcacerts option was specified, the keytool command tries 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
isn't found and the -noprompt option isn't specified, the information
of the last certificate in the chain is printed, 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 alias, then the old certificate chain is replaced
with the new certificate chain in the reply. The old chain can only be
replaced with a valid keypass, and so the password used to protect the
private key of the entry is supplied. If no password is provided, and
the private key password is different from the keystore password, the
user is prompted for it.
This command was named -import in earlier releases. This old name is
still supported in this release. The new name, -importcert, is
preferred.
JDK 27.0.1 2026 keytool(1)
openjdk27-zulu 27.30.107 - Generated Tue Oct 27 08:59:52 CDT 2026