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<h1>keytool - Key and Certificate Management Tool</h1>
<blockquote>
<p>Manages a keystore (database) of private keys and their associated X.509
certificate chains authenticating the corresponding public keys. Also manages
certificates from trusted entities. </p>
</blockquote>
<h2>SYNOPSIS</h2>
<blockquote>
<pre><strong>keytool</strong> [ <a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#Commands">commands</a> ]
</pre>
</blockquote>
<h2>DESCRIPTION</h2>
<blockquote>
<p><b>keytool</b> 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 the user authenticates
himself/herself to other users/services) or data integrity and authentication
services, using digital signatures. It also allows users to cache the public
keys (in the form of certificates) of their communicating peers. </p>
<p>A <i>certificate</i> 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
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#Certificates">
Certificates</a>.) When data is digitally signed, the signature can be
verified to check the data integrity and authenticity. <i>Integrity</i> means
that the data has not been modified or tampered with, and <i>authenticity</i>
means the data indeed comes from whoever claims to have created and signed it.
</p>
<p><b>keytool</b> stores the keys and certificates in a so-called <i>keystore</i>.
The default
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#KeystoreImplementation">
keystore implementation</a> implements the keystore as a file. It protects
private keys with a password. </p>
<p>The
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/jarsigner.html">
<b>jarsigner</b></a> tool uses information from a keystore to generate or
verify digital signatures for Java ARchive (JAR) files. (A JAR file packages
class files, images, sounds, and/or other digital data in a single file). <b>
jarsigner</b> verifies the digital signature of a JAR file, using the
certificate that comes with it (it is included in the signature block file of
the JAR file), and then checks whether or not the public key of that
certificate is &quot;trusted&quot;, i.e., is contained in the specified keystore. </p>
<p>Please note: the <b>keytool</b> and <b>jarsigner</b> tools completely
replace the <b>javakey</b> tool provided in JDK 1.1. These new tools provide
more features than <b>javakey</b>, including the ability to protect the
keystore and private keys with passwords, and the ability to verify signatures
in addition to generating them. The new keystore architecture replaces the
identity database that <b>javakey</b> created and managed. It is possible to
import the information from an identity database into a keystore, via the
<code>-identitydb</code> <b>keytool</b> command. </p>
<h3>Keystore Entries</h3>
<blockquote>
<p>There are two different types of entries in a keystore: </p>
<ol>
<li><b>key entries</b> - 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
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#CertChains">
certificate &quot;chain&quot;</a> for the corresponding public key. The <b>keytool</b>
and <b>jarsigner</b> tools only handle the latter type of entry, that is
private keys and their associated certificate chains.<p>&nbsp;</li>
<li><b>trusted certificate entries</b> - each contains a single public key
certificate belonging to another party. It is called a &quot;trusted
certificate&quot; because the keystore owner trusts that the public key in the
certificate indeed belongs to the identity identified by the &quot;subject&quot;
(owner) of the certificate. The issuer of the certificate vouches for
this, by signing the certificate. </li>
</ol>
</blockquote>
<h3>Keystore Aliases</h3>
<blockquote>
<p>All keystore entries (key and trusted certificate entries) are accessed
via unique <i>aliases</i>. Aliases are case-insensitive; the aliases <code>
Hugo</code> and <code>hugo</code> would refer to the same keystore entry.
</p>
<p>An alias is specified when you add an entity to the keystore using the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#genkeyCmd">
-genkey</a> command to generate a key pair (public and private key) or the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#importCmd">
-import</a> command to add a certificate or certificate chain to the list of
trusted certificates. Subsequent <b>keytool</b> commands must use this same
alias to refer to the entity. </p>
<p>For example, suppose you use the alias <tt>duke</tt> to generate a new
public/private key pair and wrap the public key into a self-signed
certificate (see
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#CertChains">
Certificate Chains</a>) via the following command: </p>
<pre> keytool -genkey -alias duke -keypass dukekeypasswd
</pre>
<p>This specifies an inital password of &quot;dukekeypasswd&quot; required by
subsequent commands to access the private key assocated with the alias <code>
duke</code>. If you later want to change duke's private key password, you
use a command like the following: </p>
<pre> keytool -keypasswd -alias duke -keypass dukekeypasswd -new newpass
</pre>
<p>This changes the password from &quot;dukekeypasswd&quot; to &quot;newpass&quot;. </p>
<p>Please note: A password should not actually 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. When typing in a password at the password
prompt, the password is currently echoed (displayed exactly as typed), so be
careful not to type it in front of anyone. </p>
</blockquote>
<h3><a name="KeystoreLoc">Keystore Location</a></h3>
<blockquote>
<p>Each <b>keytool</b> command has a <code>-keystore</code> option for
specifying the name and location of the persistent keystore file for the
keystore managed by <b>keytool</b>. The keystore is by default stored in a
file named <i>.keystore</i> in the user's home directory, as determined by
the &quot;user.home&quot; system property. Given user name <i>uName</i>, the &quot;user.home&quot;
property value defaults to </p>
<pre>C:\Winnt\Profiles\uName on multi-user Windows NT systems
C:\Windows\Profiles\uName on multi-user Windows 95 systems
C:\Windows on single-user Windows 95 systems
</pre>
<p>Thus, if the user name is &quot;cathy&quot;, &quot;user.home&quot; defaults to </p>
<pre>C:\Winnt\Profiles\cathy on multi-user Windows NT systems
C:\Windows\Profiles\cathy on multi-user Windows 95 systems
</pre>
</blockquote>
<h3>Keystore Creation</h3>
<blockquote>
<p>A keystore is created whenever you use a
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#genkeyCmd">
-genkey</a>,
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#importCmd">
-import</a>, or
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#identitydbCmd">
-identitydb</a> command to add data to a keystore that doesn't yet exist.
</p>
<p>More specifically, if you specify, in the <code>-keystore</code> option,
a keystore that doesn't yet exist, that keystore will be created. </p>
<p>If you don't specify a <code>-keystore</code> option, the default
keystore is a file named <code>.keystore</code> in your home directory. If
that file does not yet exist, it will be created. </p>
</blockquote>
<h3><a name="KeystoreImplementation">Keystore Implementation</a></h3>
<blockquote>
<p>The <code>KeyStore</code> class provided in the <code>java.security</code>
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
<i>type</i> of keystore. </p>
<p>Currently, two command-line tools (<b>keytool</b> and <b>jarsigner</b>)
and a GUI-based tool named <b>Policy Tool</b> make use of keystore
implementations. Since <code>KeyStore</code> is publicly available, JDK
users can write additional security applications that use it. </p>
<p>There is a built-in default implementation, provided by Sun Microsystems.
It implements the keystore as a file, utilizing a proprietary keystore type
(format) named &quot;JKS&quot;. It protects each private key with its individual
password, and also protects the integrity of the entire keystore with a
(possibly different) password. </p>
<p>Keystore implementations are provider-based. More specifically, the
application interfaces supplied by <code>KeyStore</code> are implemented in
terms of a &quot;Service Provider Interface&quot; (SPI). That is, there is a
corresponding abstract <code>KeystoreSpi</code> class, also in the <code>
java.security</code> package, which defines the Service Provider Interface
methods that &quot;providers&quot; must implement. (The term &quot;provider&quot; 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.) Thus, to
provide a keystore implementation, clients must implement a &quot;provider&quot; and
supply a KeystoreSpi subclass implementation, as described in
<a href="http://download.oracle.com/javase/1.3/docs/guide/security/HowToImplAProvider.html">
How to Implement a Provider for the Java Cryptography Architecture</a>. </p>
<p>Applications can choose different <i>types</i> of keystore
implementations from different providers, using the &quot;getInstance&quot; factory
method supplied in the <code>KeyStore</code> class. A keystore type defines
the storage and data format of the keystore information, and the algorithms
used to protect private keys in the keystore and the integrity of the
keystore itself. Keystore implementations of different types are not
compatible. </p>
<p><b>keytool</b> works on any file-based keystore implementation. (It
treats the keytore 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 <b>jarsigner</b> and <b>policytool</b> tools, on
the other hand, can read a keystore from any location that can be specified
using a URL. </p>
<p>For <b>keytool</b> and <b>jarsigner</b>, you can specify a keystore type
at the command line, via the <i>-storetype</i> option. For <b>Policy Tool</b>,
you can specify a keystore type via the &quot;Change Keystore&quot; command in the
Edit menu. </p>
<p>If you don't explicitly specify a keystore type, the tools choose a
keystore implementation based simply on the value of the <code>keystore.type</code>
property specified in the security properties file. The security properties
file is called <tt>java.security</tt>, and it resides in the JDK security
properties directory, <code><i>java.home</i>\lib\security</code>, where <i>
java.home</i> is the runtime environment's directory (the <tt>jre</tt>
directory in the SDK or the top-level directory of the Java 2 Runtime
Environment). </p>
<p>Each tool gets the <code>keystore.type</code> 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. </p>
<p>The <code>KeyStore</code> class defines a static method named <code>
getDefaultType</code> that lets applications and applets retrieve the value
of the <code>keystore.type</code> property. The following line of code
creates an instance of the default keystore type (as specified in the <code>
keystore.type</code> property): </p>
<pre> KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
</pre>
<p>The default keystore type is &quot;jks&quot; (the proprietary type of the keystore
implementation provided by Sun). This is specified by the following line in
the security properties file: </p>
<pre> keystore.type=jks
</pre>
<p>To have the tools utilize a keystore implementation other than the
default, you can change that line to specify a different keystore type. </p>
<p>For example, if you have a provider package that supplies a keystore
implementation for a keystore type called &quot;pkcs12&quot;, change the line to </p>
<pre> keystore.type=pkcs12
</pre>
<p>Note: case doesn't matter in keystore type designations. For example, &quot;JKS&quot;
would be considered the same as &quot;jks&quot;. </p>
</blockquote>
<h3><a name="DefaultAlgs">Supported Algorithms and Key Sizes</a></h3>
<blockquote>
<p><b>keytool</b> allows users to specify any key pair generation and
signature algorithm supplied by any of the registered cryptographic service
providers. That is, the <i>keyalg</i> and <i>sigalg</i> options for various
commands must be supported by a provider implementation. The default key
pair generation algorithm is &quot;DSA&quot;. The signature algorithm is derived from
the algorithm of the underlying private key: If the underlying private key
is of type &quot;DSA&quot;, the default signature algorithm is &quot;SHA1withDSA&quot;, and if
the underlying private key is of type &quot;RSA&quot;, the default signature algorithm
is &quot;MD5withRSA&quot;. </p>
<p>When generating a DSA key pair, the key size must be in the range from
512 to 1024 bits, and must be a multiple of 64. The default key size for any
algorithm is 1024 bits. </p>
</blockquote>
<h3><a name="Certificates">Certificates</a></h3>
<blockquote>
<p>A <b>certificate</b> (also known as a <b>public-key certificate</b>) is a
digitally signed statement from one entity (the <i>issuer</i>), saying that
the public key (and some other information) of another entity (the <i>
subject</i>) has some specific value. </p>
<p>Let us expand on some of the key terms used in this sentence: </p>
<dl>
<dt><i>Public Keys</i> </dt>
<dd>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. </dd>
<dt><i>Digitally Signed</i> </dt>
<dd>If some data is <i>digitally signed</i> it has been stored with the
&quot;identity&quot; 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. </dd>
<dt><i>Identity</i> </dt>
<dd>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. </dd>
<dt><i>Signature</i> </dt>
<dd>A signature is computed over some data using the private key of an
entity (the <i>signer</i>, which in the case of a certificate is also
known as the <i>issuer</i>). </dd>
<dt><i>Private Keys</i> </dt>
<dd>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 supposed to be
kept secret). Private and public keys exist in pairs in all public key
cryptography systems (also referred to as &quot;public key crypto systems&quot;). 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.
</dd>
<dt><i>Entity</i> </dt>
<dd>An entity is a person, organization, program, computer, business,
bank, or something else you are trusting to some degree. </dd>
</dl>
<p>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
<i>Certification Authority</i> (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
<a href="http://www.verisign.com">VeriSign</a>,
<a href="http://www.thawte.com">Thawte</a>, <a href="http://www.entrust.com">
Entrust</a>, and so on. You can also run your own Certification Authority
using products such as the Netscape/Microsoft Certificate Servers or the
Entrust CA product for your organization. </p>
<p>Using <b>keytool</b>, it is possible to display, import, and export
certificates. It is also possible to generate self-signed certificates. </p>
<p><b>keytool</b> currently handles X.509 certificates. </p>
<h3><a name="DName">X.509 Certificates</a></h3>
<blockquote>
<p>The X.509 standard defines what information can go into a certificate,
and describes how to write it down (the data format). All X.509
certificates have the following data, in addition to the signature: </p>
<dl>
<dt><b>Version</b> </dt>
<dd>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. <b>keytool</b> can import and export
v1, v2, and v3 certificates. It generates v1 certificates. </dd>
<dt><b>Serial Number</b> </dt>
<dd>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). </dd>
<dt><b>Signature Algorithm Identifier</b> </dt>
<dd>This identifies the algorithm used by the CA to sign the
certificate. </dd>
<dt><b>Issuer Name</b> </dt>
<dd>The
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#DName">
X.500 Distinguished Name</a> of the entity that signed the certificate.
This is normally a CA. Using this certificate implies trusting the
entity that signed this certificate. (Note that in some cases, such as
<i>root or top-level</i> CA certificates, the issuer signs its own
certificate.) </dd>
<dt><b>Validity Period</b> </dt>
<dd>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, if the associated private
key has not been compromised. </dd>
<dt><b>Subject Name</b> </dt>
<dd>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
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#DName">
X.500 Distinguished Name</a> (DN) of the entity, for example,
<pre> CN=Java Duke, OU= Division, O=Sun Microsystems Inc, C=US
</pre>
<p>(These refer to the subject's Common Name, Organizational Unit,
Organization, and Country.) </dd>
<dt><b>Subject Public Key Information</b> </dt>
<dd>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. </dd>
</dl>
<p><i>X.509 Version 1</i> has been available since 1988, is widely
deployed, and is the most generic. </p>
<p><i>X.509 Version 2</i> 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 certificates should not make
use of unique identifiers. Version 2 certificates are not widely used. </p>
<p><i>X.509 Version 3</i> 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: <i>
KeyUsage</i> (limits the use of the keys to particular purposes such as
&quot;signing-only&quot;) and <i>AlternativeNames</i> (allows other identities to
also be associated with this public key, e.g. DNS names, Email addresses,
IP addresses). Extensions can be marked <i>critical</i> 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 &quot;keyCertSign&quot;
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. </p>
<p>All the data in a certificate is encoded using two related standards
called ASN.1/DER. <i>Abstract Syntax Notation 1</i> describes data. The <i>
Definite Encoding Rules</i> describe a single way to store and transfer
that data. </p>
</blockquote>
<h4><a name="DName">X.500 Distinguished Names</a></h4>
<blockquote>
<p>X.500 Distinguished Names are used to identify entities, such as those
which are named by the <code>subject</code> and <code>issuer</code>
(signer) fields of X.509 certificates. <b>keytool</b> supports the
following subparts: </p>
<ul>
<li><i>commonName</i> - common name of a person, e.g., &quot;Susan Jones&quot;<p>&nbsp;</li>
<li><i>organizationUnit</i> - small organization (e.g, department or
division) name, e.g., &quot;Purchasing&quot;<p>&nbsp;</li>
<li><i>organizationName</i> - large organization name, e.g., &quot;ABCSystems,
Inc.&quot;<p>&nbsp;</li>
<li><i>localityName</i> - locality (city) name, e.g., &quot;Palo Alto&quot;<p>&nbsp;</li>
<li><i>stateName</i> - state or province name, e.g., &quot;California&quot;<p>&nbsp;</li>
<li><i>country</i> - two-letter country code, e.g., &quot;CH&quot;<p>&nbsp;</li>
</ul>
<p>When supplying a distinguished name string as the value of a <code>-dname</code>
option, as for the <code>-genkey</code> or <code>-selfcert</code>
commands, the string must be in the following format: </p>
<pre>CN=<i>cName</i>, OU=<i>orgUnit</i>, O=<i>org</i>, L=<i>city</i>, S=<i>state</i>, C=<i>countryCode</i>
</pre>
<p>where all the italicized items represent actual values and the above
keywords are abbreviations for the following: </p>
<pre> CN=commonName
OU=organizationUnit
O=organizationName
L=localityName
S=stateName
C=country
</pre>
<p>A sample distinguished name string is </p>
<pre>CN=Mark Smith, OU=JavaSoft, O=Sun, L=Cupertino, S=California, C=US
</pre>
<p>and a sample command using such a string is </p>
<pre>keytool -genkey -dname &quot;CN=Mark Smith, OU=JavaSoft, O=Sun, L=Cupertino,
S=California, C=US&quot; -alias mark
</pre>
<p>Case does not matter for the keyword abbreviations. For example, &quot;CN&quot;,
&quot;cn&quot;, and &quot;Cn&quot; are all treated the same. </p>
<p>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: </p>
<pre>CN=Steve Meier, OU=SunSoft, O=Sun, C=US
</pre>
<p>If a distinguished name string value contains a comma, the comma must
be escaped by a &quot;\&quot; character when you specify the string on a command
line, as in </p>
<pre> cn=peter schuster, o=Sun Microsystems\, Inc., o=sun, c=us
</pre>
<p>It is never necessary to specify a distinguished name string on a
command line. If it 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 does not need to be escaped by a &quot;\&quot;. </p>
</blockquote>
<h4><a name="EncodeCertificate">The Internet RFC 1421 Certificate Encoding
Standard</a></h4>
<blockquote>
<p>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 &quot;Base 64 encoding&quot;,
facilitates exporting certificates to other applications by email or
through some other mechanism. </p>
<p>Certificates read by the <code>-import</code> and <code>-printcert</code>
commands can be in either this format or binary encoded. </p>
<p>The <code>-export</code> command by default outputs a certificate in
binary encoding, but will instead output a certificate in the printable
encoding format, if the <code>-rfc</code> option is specified. </p>
<p>The <code>-list</code> command by default prints the MD5 fingerprint of
a certificate. If the <code>-v</code> option is specified, the certificate
is printed in human-readable format, while if the <code>-rfc</code> option
is specified, the certificate is output in the printable encoding format.
</p>
<p>In its printable encoding format, the encoded certificate is bounded at
the beginning by </p>
<pre>-----BEGIN CERTIFICATE-----
</pre>
<p>and at the end by </p>
<pre>-----END CERTIFICATE-----
</pre>
</blockquote>
<h3><a name="CertChains">Certificate Chains</a></h3>
<blockquote>
<p><b>keytool</b> can create and manage keystore &quot;key&quot; entries that each
contain a private key and an associated certificate &quot;chain&quot;. The first
certificate in the chain contains the public key corresponding to the
private key. </p>
<p>When keys are first generated (see the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#genkeyCmd">
-genkey</a> command), the chain starts off containing a single element, a
<i>self-signed certificate</i>. 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 <code>-genkey</code>
command is called to generate a new public/private key pair, it also wraps
the public key into a self-signed certificate. </p>
<p>Later, after a Certificate Signing Request (CSR) has been generated
(see the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#certreqCmd">
-certreq</a> command) and sent to a Certification Authority (CA), the
response from the CA is imported (see
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#importCmd">
-import</a>), 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 <i>CA</i>'s public key. </p>
<p>In many cases, this is a self-signed certificate (that is, a
certificate 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 public key of the
key entry), but the second certificate in the chain is a certificate
signed by a <i>different</i> 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 &quot;root&quot; certificate is reached. Each certificate in the chain
(after the first) thus authenticates the public key of the signer of the
previous certificate in the chain. </p>
<p>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. </p>
<p>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 <b>keytool</b>. </p>
<p>The top-level (root) CA certificate is self-signed. However, the trust
into the root's public key does not come from the root certificate 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 &quot;vehicle&quot; to
transport the root CA's public key. Before you add the root CA certificate
to your keystore, you should view it (using the <code>-printcert</code>
option) and compare the displayed fingerprint with the well-known
fingerprint (obtained from a newspaper, the root CA's webpage, etc.). </p>
</blockquote>
<h4><a name="ImportCertificate">Importing Certificates</a></h4>
<blockquote>
<p>To import a certificate from a file, use the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#importCmd">
-import</a> command, as in </p>
<pre> keytool -import -alias joe -file jcertfile.cer
</pre>
<p>This sample command imports the certificate(s) in the file <i>
jcertfile.cer</i> and stores it in the keystore entry identified by the
alias <i>joe</i>. </p>
<p>You import a certificate for two reasons: </p>
<ol>
<li>to add it to the list of trusted certificates, or<p>&nbsp;</li>
<li>to import a certificate reply received from a CA as the result of
submitting a Certificate Signing Request (see the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#certreqCmd">
-certreq</a> command) to that CA. </li>
</ol>
<p>Which type of import is intended is indicated by the value of the <code>
-alias</code> option. If the alias exists in the database, and identifies
an entry with a private key, then it is assumed you want to import a
certificate reply. <b>keytool</b> checks whether the public key in the
certificate reply matches the public key stored with the alias, and exits
if they are different. If the alias identifies the other type of keystore
entry, the certificate will not be imported. If the alias does not exist,
then it will be created and associated with the imported certificate. </p>
<h4><a name="TrustedCertWarning">WARNING Regarding Importing Trusted
Certificates</a></h4>
<blockquote>
<p>IMPORTANT: Be sure to check a certificate very carefully before
importing it as a trusted certificate! </p>
<p>View it first (using the <code>-printcert</code> command, or the
<code>-import command</code> without the <code>-noprompt</code> option),
and make sure that the displayed certificate fingerprint(s) match the
expected ones. For example, suppose someone sends or emails you a
certificate, and you put it in a file named <code>/tmp/cert</code>.
Before you consider adding the certificate to your list of trusted
certificates, you can execute a <code>-printcert</code> command to view
its fingerprints, as in </p>
<pre> 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
</pre>
<p>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
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 (for example, a JAR file
with malicious class files inside). </p>
<p>Note: it is not required that you execute a <code>-printcert</code>
command prior to importing a certificate, since before adding a
certificate to the list of trusted certificates in the keystore, the
<code>-import</code> 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
<code>-import</code> command without the <code>-noprompt</code> option.
If the <code>-noprompt</code> option is given, there is no interaction
with the user. </p>
</blockquote>
</blockquote>
<h4><a name="ExportCertificate">Exporting Certificates</a></h4>
<blockquote>
<p>To export a certificate to a file, use the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#exportCmd">
-export</a> command, as in </p>
<pre> keytool -export -alias jane -file janecertfile.cer
</pre>
<p>This sample command exports <code>jane</code>'s certificate to the file
<i>janecertfile.cer</i>. That is, if <code>jane</code> is the alias for a
key entry, the command exports the certificate at the bottom of the
certificate chain in that keystore entry. This is the certificate that
authenticates <code>jane</code>'s public key. </p>
<p>If, instead, <code>jane</code> is the alias for a trusted certificate
entry, then that trusted certificate is exported. </p>
</blockquote>
<h4><a name="DisplayCertificate">Displaying Certificates</a></h4>
<blockquote>
<p>To print out the contents of a keystore entry, use the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#listCmd">
-list</a> command, as in </p>
<pre> keytool -list -alias joe
</pre>
<p>If you don't specify an alias, as in </p>
<pre> keytool -list
</pre>
<p>the contents of the entire keystore are printed. </p>
<p>To display the contents of a certificate stored in a file, use the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#printcertCmd">
-printcert</a> command, as in </p>
<pre> keytool -printcert -file certfile.cer
</pre>
<p>This displays information about the certificate stored in the file
<code>certfile.cer</code>. </p>
<p>Note: This works independently of a keystore, i.e., you do <i>not</i>
need a keystore in order to display a certificate that's stored in a file.
</p>
</blockquote>
<h4><a name="CertificateGeneration">Generating a self-signed certificate</a></h4>
<blockquote>
<p>A <i>self-signed certificate</i> 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 <code>-genkey</code>
command is called to generate a new public/private key pair, it also wraps
the public key into a self-signed certificate. </p>
<p>You may occasionally wish to generate a new self-signed certificate.
For example, you may want to use the same key pair under a different
identity (distinguished name). For example, suppose you change
departments. You can then: </p>
<ol>
<li>copy (clone) the original key entry. See
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#keycloneCmd">
-keyclone</a>.<p>&nbsp;</li>
<li>generate a new self-signed certificate for the cloned entry, using
your new distinguished name. See below.<p>&nbsp;</li>
<li>generate a Certificate Signing Requests for the cloned entry, and
import the reply certificate or certificate chain. See the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#-certreqCmd">
-certreq</a> and
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#importCmd">
-import</a> commands.<p>&nbsp;</li>
<li>delete the original (now obsolete) entry. See
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#deleteCmd">
-delete</a>.<p>&nbsp;</li>
</ol>
<p>To generate a self-signed certificate, use the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#selfcertCmd">
-selfcert</a> command, as in </p>
<pre> keytool -selfcert -alias dukeNew -keypass b92kqmp
-dname &quot;cn=Duke Smith, ou=Purchasing, o=BlueSoft, c=US&quot;
</pre>
<p>The generated certificate is stored as a single-element certificate
chain in the keystore entry identified by the specified alias (in this
case &quot;dukeNew&quot;), where it replaces the existing certificate chain. </p>
</blockquote>
</blockquote>
</blockquote>
<h2><a name="CommandNotes">COMMAND AND OPTION NOTES</a></h2>
<blockquote>
<p>The various commands and their options are listed and described
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#Commands">
below</a> . Note: </p>
<ul>
<li>All command and option names are preceded by a minus sign (-).<p>&nbsp;</li>
<li>The options for each command may be provided in any order.<p>&nbsp;</li>
<li>All items not italicized or in braces or square brackets are required to
appear as is.<p>&nbsp;</li>
<li>Braces surrounding an option generally signify that a
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#OptionDefaults">
default</a> value will be used if the option is not specified on the command
line. Braces are also used around the <code>-v</code>, <code>-rfc</code>,
and <code>-J</code> options, which only have meaning if they appear on the
command line (that is, they don't have any &quot;default&quot; values other than not
existing).<p>&nbsp;</li>
<li>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 <code>-keypass</code>
option, if you do not specify the option on the command line, <b>keytool</b>
will first attempt to use the keystore password to recover the private key,
and if this fails, will then prompt you for the private key password.)<p>&nbsp;</li>
<li>Items in italics (option values) represent the actual values that must
be supplied. For example, here is the format of the <code>-printcert</code>
command:
<pre> keytool -printcert {-file <i>cert_file</i>} {-v}
</pre>
<p>When specifying a <code>-printcert</code> command, replace <i>cert_file</i>
with the actual file name, as in: </p>
<pre> keytool -printcert -file VScert.cer
</pre>
<p>&nbsp;</li>
<li>Option values must be quoted if they contain a blank (space).<p>&nbsp;</li>
<li>The <code>-help</code> command is the default. Thus, the command line
<pre> keytool
</pre>
<p>is equivalent to </p>
<pre> keytool -help
</pre>
</li>
</ul>
<h3><a name="OptionDefaults">Option Defaults</a></h3>
<blockquote>
<p>Below are the defaults for various option values. </p>
<pre>-alias &quot;mykey&quot;
-keyalg &quot;DSA&quot;
-keysize 1024
-validity 90
-keystore <i>the file named .keystore in the user's home directory</i>
-file <i>stdin if reading, stdout if writing</i>
</pre>
<p>The signature algorithm (<i>-sigalg</i> option) is derived from the
algorithm of the underlying private key: If the underlying private key is of
type &quot;DSA&quot;, the <i>-sigalg</i> option defaults to &quot;SHA1withDSA&quot;, and if the
underlying private key is of type &quot;RSA&quot;, <i>-sigalg</i> defaults to
&quot;MD5withRSA&quot;. </p>
</blockquote>
<h3><a name="OptionsInAll">Options that Appear for Most Commands</a></h3>
<blockquote>
<p>The <code>-v</code> option can appear for all commands except <code>-help</code>.
If it appears, it signifies &quot;verbose&quot; mode; detailed certificate information
will be output. </p>
<p>There is also a <code>-J<i>javaoption</i></code> option that may appear
for any command. If it appears, the specified <i>javaoption</i> string is
passed through directly to the Java interpreter. (<b>keytool</b> is actually
a &quot;wrapper&quot; around the 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 <code>java -h</code>
or <code>java -X</code> at the command line. </p>
<p>These options may appear for all commands operating on a keystore: </p>
<dl>
<dt><code>-storetype <i>storetype</i></code> </dt>
<dd>This qualifier specifies the type of keystore to be instantiated. The
default keystore type is the one that is specified as the value of the &quot;keystore.type&quot;
property in the security properties file, which is returned by the static
<code>getDefaultType</code> method in <code>java.security.KeyStore</code>.
<p>&nbsp;</dd>
<dt><code>-keystore <i>keystore</i></code> </dt>
<dd>The keystore (database file) location. Defaults to the file <em>.keystore</em>
in the user's home directory, as determined by the &quot;user.home&quot; system
property, whose value is described in
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#KeystoreLoc">
Keystore Location</a>.
<p>&nbsp;</dd>
<dt><code>-storepass <i>storepass</i></code> </dt>
<dd>The password which is used to protect the integrity of the keystore.
<p><em>storepass</em> must be at least 6 characters long. It must be
provided to all commands that access the keystore contents. For such
commands, if a <code>-storepass</code> option is not provided at the
command line, the user is prompted for it. </p>
<p>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. </p>
<p>Be careful with passwords - see
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#PasswordWarning">
Warning Regarding Passwords</a>. </p>
<p>&nbsp;</dd>
<dt><code>-provider <i>provider-class-name</i></code> </dt>
<dd>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.<p>&nbsp;</dd>
</dl>
</blockquote>
<h3><a name="PasswordWarning">Warning Regarding Passwords</a></h3>
<blockquote>
<p>Most commands operating on a keystore require the store password. Some
commands require a private key password. </p>
<p>Passwords can be specified on the command line (in the <code>-storepass</code>
and <code>-keypass</code> 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. </p>
<p>If you don't specify a required password option on a command line, you
will be prompted for it. When typing in a password at the password prompt,
the password is currently echoed (displayed exactly as typed), so be careful
not to type it in front of anyone. </p>
</blockquote>
</blockquote>
<h2><a name="Commands">COMMANDS</a></h2>
<blockquote>
<p>See also the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#CommandNotes">
Command and Option Notes</a>. </p>
<h3>Adding Data to the Keystore</h3>
<blockquote>
<dl>
<dt><code><b><font size="+1"><a name="genkeyCmd">-genkey </a></font></b>
{-alias <i>alias</i>} {-keyalg <i>keyalg</i>} {-keysize <i>keysize</i>} {-sigalg
<i>sigalg</i>} [-dname <i>dname</i>] [-keypass <i>keypass</i>] {-validity
<i>valDays</i>} {-storetype <i>storetype</i>} {-keystore <i>keystore</i>}
[-storepass <i>storepass</i>] [-provider <i>provider_class_name</i>] {-v}
{-J<i>javaoption</i>}</code> </dt>
<dd>Generates a key pair (a public key and associated private key). Wraps
the public key into an X.509 v1 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 identified by <em>alias</em>.
<p><em>keyalg</em> specifies the algorithm to be used to generate the key
pair, and <em>keysize</em> specifies the size of each key to be generated.
<em>sigalg</em> specifies the algorithm that should be used to sign the
self-signed certificate; this algorithm must be compatible with <em>keyalg</em>.
See
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#DefaultAlgs">
Supported Algorithms and Key Sizes</a>. </p>
<p><em>dname</em> specifies the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#DName">
X.500 Distinguished Name</a> to be associated with <em>alias</em>, and is
used as the <code>issuer</code> and <code>subject</code> fields in the
self-signed certificate. If no distinguished name is provided at the
command line, the user will be prompted for one. </p>
<p><em>keypass</em> is a password used to protect the private key of the
generated 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. <em>keypass</em> must be at least
6 characters long. Be careful with passwords - see
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#PasswordWarning">
Warning Regarding Passwords</a>. </p>
<p><em>valDays</em> tells the number of days for which the certificate
should be considered valid.</p>
<p>&nbsp;</dd>
<dt><code><b><font size="+1"><a name="importCmd">-import </a></font></b>
{-alias <i>alias</i>} {-file <i>cert_file</i>} [-keypass <i>keypass</i>]
{-noprompt} {-trustcacerts} {-storetype <i>storetype</i>} {-keystore <i>
keystore</i>} [-storepass <i>storepass</i>] [-provider <i>
provider_class_name</i>] {-v} {-J<i>javaoption</i>}</code> </dt>
<dd>Reads the certificate or certificate chain (where the latter is
supplied in a PKCS#7 formatted reply) from the file <i>cert_file</i>, and
stores it in the keystore entry identified by <i>alias</i>. If no file is
given, the certificate or PKCS#7 reply is read from stdin. <b>keytool</b>
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
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#EncodeCertificate">
Internet RFC 1421 standard</a>. In the latter case, the encoding must be
bounded at the beginning by a string that starts with &quot;-----BEGIN&quot;, and
bounded at the end by a string that starts with &quot;-----END&quot;.
<p>When importing a <b>new trusted certificate</b>, <i>alias</i> must not
yet exist in the keystore. Before adding the certificate to the keystore,
<b>keytool</b> tries to verify 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. </p>
<p>If the <code>-trustcacerts</code> option has been specified, additional
certificates are considered for the chain of trust, namely the
certificates in a file named <b>&quot;cacerts&quot;</b>, which resides in the JDK
security properties directory, <code><i>java.home</i>\lib\security</code>,
where <i>java.home</i> is the runtime environment's directory (the <tt>jre</tt>
directory in the SDK or the top-level directory of the Java 2 Runtime
Environment). The &quot;cacerts&quot; file represents a system-wide keystore with CA
certificates. System administrators can configure and manage that file
using <b>keytool</b>, specifying &quot;jks&quot; as the keystore type. The &quot;cacerts&quot;
keystore file ships with five VeriSign root CA certificates with the
following X.500 distinguished names: </p>
<pre>1. OU=Class 1 Public Primary Certification Authority, O=&quot;VeriSign, Inc.&quot;,
C=US
2. OU=Class 2 Public Primary Certification Authority, O=&quot;VeriSign,
Inc.&quot;, C=US
3. OU=Class 3 Public Primary Certification Authority,
O=&quot;VeriSign, Inc.&quot;, C=US
4. OU=Class 4 Public Primary Certification
Authority, O=&quot;VeriSign, Inc.&quot;, C=US
5. OU=Secure Server Certification
Authority, O=&quot;RSA Data Security, Inc.&quot;, C=US
</pre>
<p>The initial password of the &quot;cacerts&quot; keystore file is &quot;changeit&quot;.
System administrators should change that password and the default access
permission of that file upon installing the JDK. </p>
<p>If <b>keytool</b> fails to establish a trust path from the certificate
to be imported up to a self-signed certificate (either from the keystore
or the &quot;cacerts&quot; 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 &quot;trusted&quot; certificate! -- see
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#TrustedCertWarning">
WARNING Regarding Importing Trusted Certificates</a>. The user then has
the option of aborting the import operation. If the <code>-noprompt</code>
option is given, however, there will be no interaction with the user. </p>
<p>When importing a <b>certificate reply</b>, the certificate reply is
validated using trusted certificates from the keystore, and optionally
using the certificates configured in the &quot;cacerts&quot; keystore file (if the
<code>-trustcacerts</code> option was specified). </p>
<p>If the reply is a single X.509 certificate, <b>keytool</b> 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 <i>alias</i>. </p>
<p>If the reply is a PKCS#7 formatted certificate chain, the chain is
first ordered (with the user certificate first and the self-signed root CA
certificate last), before <b>keytool</b> attempts to match the root CA
certificate provided in the reply with any of the trusted certificates in
the keystore or the &quot;cacerts&quot; keystore file (if the <code>-trustcacerts</code>
option was specified). If no match can be found, the information of the
root CA certificate 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 root CA itself. The user then has the option of
aborting the import operation. If the <code>-noprompt</code> option is
given, however, there will be no interaction with the user. </p>
<p>The new certificate chain of <i>alias</i> replaces the old certificate
chain associated with this entry. The old chain can only be replaced if a
valid <i>keypass</i>, 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. Be careful with passwords - see
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#PasswordWarning">
Warning Regarding Passwords</a>. </p>
<p>&nbsp;</dd>
<dt><code><b><font size="+1"><a name="selfcertCmd">-selfcert </a></font>
</b>{-alias <i>alias</i>} {-sigalg <i>sigalg</i>} {-dname <i>dname</i>}
{-validity <i>valDays</i>} [-keypass <i>keypass</i>] {-storetype <i>
storetype</i>} {-keystore <i>keystore</i>} [-storepass <i>storepass</i>]
[-provider <i>provider_class_name</i>] {-v} {-J<i>javaoption</i>}</code>
</dt>
<dd>Generates an X.509 v1 self-signed certificate, using keystore
information including the private key and public key associated with <em>
alias</em>. If <i>dname</i> is supplied at the command line, it is used as
the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#DName">
X.500 Distinguished Name</a> for both the <code>issuer</code> and <code>
subject</code> of the certificate. Otherwise, the X.500 Distinguished Name
associated with <em>alias</em> (at the bottom of its existing certificate
chain) is used.
<p>The generated certificate is stored as a single-element certificate
chain in the keystore entry identified by <em>alias</em>, where it
replaces the existing certificate chain. </p>
<p><em>sigalg</em> specifies the algorithm that should be used to sign the
certificate. See
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#DefaultAlgs">
Supported Algorithms and Key Sizes</a>. </p>
<p>In order to access the private key, the appropriate password must be
provided, since private keys are protected in the keystore with a
password. If <em>keypass</em> 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. Be careful with passwords - see
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#PasswordWarning">
Warning Regarding Passwords</a>. </p>
<p><em>valDays</em> tells the number of days for which the certificate
should be considered valid.</p>
<p>&nbsp;</dd>
<dt><code><b><font size="+1"><a name="identitydbCmd">-identitydb </a>
</font></b>{-file <i>idb_file</i>} {-storetype <i>storetype</i>} {-keystore
<i>keystore</i>} [-storepass <i>storepass</i>] [-provider <i>
provider_class_name</i>] {-v} {-J<i>javaoption</i>}</code> </dt>
<dd>Reads the JDK 1.1.x-style identity database from the file <em>idb_file</em>,
and adds its entries to the keystore. If no file is given, the identity
database is read from stdin. If a keystore does not exist, it is created.
<p>Only identity database entries (&quot;identities&quot;) that were marked as
trusted will be imported in the keystore. All other identities will be
ignored. For each trusted identity, a keystore entry will be created. The
identity's name is used as the &quot;alias&quot; for the keystore entry. </p>
<p>The private keys from trusted identities will all be encrypted under
the same password, <i>storepass</i>. This is the same password that is
used to protect the keystore's integrity. Users can later assign
individual passwords to those private keys by using the &quot;-keypasswd&quot; <b>
keytool</b> command option. </p>
<p>An identity in an identity database may hold more than one certificate,
each certifying the same public key. But a keystore key entry for a
private key has that private key and a single &quot;certificate chain&quot;
(initially just a single certificate), where the first certificate in the
chain contains the public key corresponding to the private key. When
importing the information from an identity, only the first certificate of
the identity is stored in the keystore. This is because an identity's name
in an identity database is used as the alias for its corresponding
keystore entry, and alias names are unique within a keystore, </dd>
</dl>
<p>&nbsp;</p>
</blockquote>
<h3>Exporting Data</h3>
<blockquote>
<dl>
<dt><code><b><font size="+1"><a name="certreqCmd">-certreq </a></font></b>
{-alias <i>alias</i>} {-sigalg <i>sigalg</i>} {-file <i>certreq_file</i>}
[-keypass <i>keypass</i>] {-storetype <i>storetype</i>} {-keystore <i>
keystore</i>} [-storepass <i>storepass</i>] [-provider <i>
provider_class_name</i>] {-v} {-J<i>javaoption</i>}</code> </dt>
<dd>Generates a Certificate Signing Request (CSR), using the PKCS#10
format.
<p>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. </p>
<p>The private key and X.500 Distinguished Name associated with <em>alias</em>
are used to create the PKCS#10 certificate request. In order to access the
private key, the appropriate password must be provided, since private keys
are protected in the keystore with a password. If <em>keypass</em> 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.</p>
<p>Be careful with passwords - see
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#PasswordWarning">
Warning Regarding Passwords</a>. </p>
<p><em>sigalg</em> specifies the algorithm that should be used to sign the
CSR. See
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#DefaultAlgs">
Supported Algorithms and Key Sizes</a>. </p>
<p>The CSR is stored in the file <em>certreq_file</em>. If no file is
given, the CSR is output to stdout. </p>
<p>Use the <em>import</em> command to import the response from the CA.</p>
<p>&nbsp;</dd>
<dt><code><b><font size="+1"><a name="exportCmd">-export </a></font></b>
{-alias <i>alias</i>} {-file <i>cert_file</i>} {-storetype <i>storetype</i>}
{-keystore <i>keystore</i>} [-storepass <i>storepass</i>] [-provider <i>
provider_class_name</i>] {-rfc} {-v} {-J<i>javaoption</i>}</code> </dt>
<dd>Reads (from the keystore) the certificate associated with <em>alias</em>,
and stores it in the file <em>cert_file</em>.
<p>If no file is given, the certificate is output to stdout. </p>
<p>The certificate is by default output in binary encoding, but will
instead be output in the printable encoding format, as defined by the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#EncodeCertificate">
Internet RFC 1421 standard</a>, if the <code>-rfc</code> option is
specified. </p>
<p>If <i>alias</i> refers to a trusted certificate, that certificate is
output. Otherwise, <i>alias</i> 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 <i>alias</i>.</p>
<p>&nbsp;</dd>
</dl>
</blockquote>
<h3>Displaying Data</h3>
<blockquote>
<dl>
<dt><code><b><font size="+1"><a name="listCmd">-list </a></font></b>
{-alias <i>alias</i>} {-storetype <i>storetype</i>} {-keystore <i>keystore</i>}
[-storepass <i>storepass</i>] [-provider <i>provider_class_name</i>] {-v |
-rfc} {-J<i>javaoption</i>}</code> </dt>
<dd>Prints (to stdout) the contents of the keystore entry identified by <i>
alias</i>. If no alias is specified, the contents of the entire keystore
are printed.
<p>This command by default prints the MD5 fingerprint of a certificate. If
the <code>-v</code> option is specified, the certificate is printed in
human-readable format, with additional information such as the owner,
issuer, and serial number. If the <code>-rfc</code> option is specified,
certificate contents are printed using the printable encoding format, as
defined by the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#EncodeCertificate">
Internet RFC 1421 standard</a> </p>
<p>You cannot specify both <code>-v</code> and <code>-rfc</code>. </p>
<p>&nbsp;</dd>
<dt><code><b><font size="+1"><a name="printcertCmd">-printcert </a></font>
</b><a name="printcertCmd">{-file <i>cert_file</i>} {-v} {-J<i>javaoption</i>}</a></code>
</dt>
<dd><a name="printcertCmd">Reads the certificate from the file <em>
cert_file</em>, and prints its contents in a human-readable format. If no
file is given, the certificate is read from stdin. </a>
<p><a name="printcertCmd">The certificate may be either binary encoded or
in printable encoding format, as defined by the </a>
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#EncodeCertificate">
Internet RFC 1421 standard</a>. </p>
<p>Note: This option can be used independently of a keystore.</p>
<p>&nbsp;</dd>
</dl>
</blockquote>
<h3>Managing the Keystore</h3>
<blockquote>
<dl>
<dt><code><b><font size="+1"><a name="keycloneCmd">-keyclone </a></font>
</b>{-alias <i>alias</i>} [-dest <i>dest_alias</i>] [-keypass <i>keypass</i>]
[-new <i>new_keypass</i>] {-storetype <i>storetype</i>} {-keystore <i>
keystore</i>} [-storepass <i>storepass</i>] [-provider <i>
provider_class_name</i>] {-v} {-J<i>javaoption</i>}</code> </dt>
<dd>Creates a new keystore entry, which has the same private key and
certificate chain as the original entry.
<p>The original entry is identified by <em>alias</em> (which defaults to &quot;mykey&quot;
if not provided). The new (destination) entry is identified by <em>
dest_alias</em>. If no destination alias is supplied at the command line,
the user is prompted for it. </p>
<p>If the private key password is different from the keystore password,
then the entry will only be cloned if a valid <i>keypass</i> is supplied.
This is the password used to protect the private key associated with <i>
alias</i>. If no key password is supplied at the command line, and the
private key password is different from the keystore password, the user is
prompted for it. The private key in the cloned entry may be protected with
a different password, if desired. If no <code>-new</code> option is
supplied at the command line, the user is prompted for the new entry's
password (and may choose to let it be the same as for the cloned entry's
private key). </p>
<p>Be careful with passwords - see
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#PasswordWarning">
Warning Regarding Passwords</a>. </p>
<p>This command can be used to establish multiple certificate chains
corresponding to a given key pair, or for backup purposes.</p>
<p>&nbsp;</dd>
<dt><code><b><font size="+1">-storepasswd </font></b>[-new <i>
new_storepass</i>] {-storetype <i>storetype</i>} {-keystore <i>keystore</i>}
[-storepass <i>storepass</i>] [-provider <i>provider_class_name</i>] {-v}
{-J<i>javaoption</i>}</code> </dt>
<dd>Changes the password used to protect the integrity of the keystore
contents. The new password is <em>new_storepass</em>, which must be at
least 6 characters long.<p>Be careful with passwords - see
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#PasswordWarning">
Warning Regarding Passwords</a>.</p>
<p>&nbsp;</dd>
<dt><code><b><font size="+1">-keypasswd </font></b>{-alias <i>alias</i>}
[-keypass <i>old_keypass</i>] [-new <i>new_keypass</i>] {-storetype <i>
storetype</i>} {-keystore <i>keystore</i>} [-storepass <i>storepass</i>]
[-provider <i>provider_class_name</i>] {-v} {-J<i>javaoption</i>}</code>
</dt>
<dd>Changes the password under which the private key identified by <em>
alias</em> is protected, from <em>old_keypass</em> to <em>new_keypass</em>.
<p>If the <code>-keypass</code> option is not provided at the command
line, and the private key password is different from the keystore
password, the user is prompted for it. </p>
<p>If the <code>-new</code> option is not provided at the command line,
the user is prompted for it.</p>
<p>&nbsp;</p>
<p>Be careful with passwords - see
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#PasswordWarning">
Warning Regarding Passwords</a>.</p>
<p>&nbsp;</dd>
<dt><code><b><font size="+1"><a name="deleteCmd">-delete </a></font></b>
[-alias <i>alias</i>] {-storetype <i>storetype</i>} {-keystore <i>keystore</i>}
[-storepass <i>storepass</i>] [-provider <i>provider_class_name</i>] {-v}
{-J<i>javaoption</i>}</code> </dt>
<dd>Deletes from the keystore the entry identified by <em>alias</em>. The
user is prompted for the alias, if no alias is provided at the command
line.<p>&nbsp;</dd>
</dl>
</blockquote>
<h3>Getting Help</h3>
<blockquote>
<dl>
<dt><code><b><font size="+1">-help </font></b></code></dt>
<dd>Lists all the commands and their options.<p>&nbsp;</dd>
</dl>
</blockquote>
</blockquote>
<h2><a name="EXAMPLES">EXAMPLES</a></h2>
<blockquote>
<p>Suppose you want to create a keystore for managing your public/private key
pair and certificates from entities you trust. </p>
<h3>Generating Your Key Pair</h3>
<blockquote>
<p>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: </p>
<pre> keytool -genkey -dname &quot;cn=Mark Jones, ou=JavaSoft, o=Sun, c=US&quot;
-alias business -keypass kpi135 -keystore C:\working\mykeystore
-storepass ab987c -validity 180
</pre>
<p>(Please note: This must be typed as a single line. Multiple lines are
used in the examples just for legibility purposes.) </p>
<p>This command creates the keystore named &quot;mykeystore&quot; in the &quot;working&quot;
directory on the C drive (assuming it doesn't already exist), and assigns it
the password &quot;ab987c&quot;. It generates a public/private key pair for the entity
whose &quot;distinguished name&quot; has a common name of &quot;Mark Jones&quot;, organizational
unit of &quot;JavaSoft&quot;, organization of &quot;Sun&quot; and two-letter country code of
&quot;US&quot;. It uses the default &quot;DSA&quot; key generation algorithm to create the keys,
both 1024 bits long. </p>
<p>It creates a self-signed certificate (using the default &quot;SHA1withDSA&quot;
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
&quot;business&quot;. The private key is assigned the password &quot;kpi135&quot;. </p>
<p>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 following: </p>
<pre> keytool -genkey
</pre>
<p>In this case, a keystore entry with alias &quot;mykey&quot; 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 &quot;.keystore&quot; 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. </p>
<p>The rest of the examples assume you executed the <code>-genkey</code>
command without options specified, and that you responded to the prompts
with values equal to those given in the first <code>-genkey</code> command,
above (a private key password of &quot;kpi135&quot;, etc.) </p>
</blockquote>
<h3>Requesting a Signed Certificate from a Certification Authority</h3>
<blockquote>
<p>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 Certificate Signing
Request (CSR), via the following: </p>
<pre> keytool -certreq -file MarkJ.csr
</pre>
<p>This creates a CSR (for the entity identified by the default alias &quot;mykey&quot;)
and puts the request in the file named &quot;MarkJ.csr&quot;. 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.) </p>
</blockquote>
<h3>Importing a Certificate for the CA</h3>
<blockquote>
<p>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 &quot;root&quot; CA. </p>
<p>Before you import the certificate reply from a CA, you need one or more
&quot;trusted certificates&quot; in your keystore or in the <code>cacerts</code>
keystore file (which is described in
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/keytool.html#importCmd">
import command</a>): </p>
<ul>
<li>If the certificate reply is a certificate chain, you just need the top
certificate of the chain (that is, the &quot;root&quot; CA certificate
authenticating that CA's public key).<p>&nbsp;</li>
<li>If the certificate reply is a single certificate, you need a
certificate 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 &quot;root&quot; CA certificate. </li>
</ul>
<p>The &quot;cacerts&quot; keystore file ships with five VeriSign root CA
certificates, 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 &quot;cacerts&quot;, you will need to import a
certificate from the CA as a &quot;trusted certificate&quot;. </p>
<p>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 &quot;ABCCA.cer&quot; that is purportedly a self-signed certificate from ABC,
authenticating that CA's public key. </p>
<p>Be very careful to ensure the certificate is valid prior to importing it
as a &quot;trusted&quot; certificate! View it first (using the <b>keytool</b> <code>-printcert</code>
command, or the <b>keytool</b> <code>-import</code> command without the
<code>-noprompt</code> option), and make sure that the displayed certificate
fingerprint(s) match the expected ones. You can call the person who sent the
certificate, 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. </p>
<p>If you trust that the certificate is valid, then you can add it to your
keystore via the following: </p>
<pre> keytool -import -alias abc -file ABCCA.cer
</pre>
<p>This creates a &quot;trusted certificate&quot; entry in the keystore, with the data
from the file &quot;ABCCA.cer&quot;, and assigns the alias &quot;abc&quot; to the entry. </p>
</blockquote>
<h3>Importing the Certificate Reply from the CA</h3>
<blockquote>
<p>Once you've imported a certificate authenticating the public key of the
CA you submitted your certificate signing request to (or there's already
such a certificate in the &quot;cacerts&quot; 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 constructed (if the CA reply is a
single certificate) using the certificate reply and trusted certificates
that are already available in the keystore where you import the reply or in
the &quot;cacerts&quot; keystore file. </p>
<p>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 &quot;VSMarkJ.cer&quot;: </p>
<pre> keytool -import -trustcacerts -file VSMarkJ.cer
</pre>
</blockquote>
<h3>Exporting a Certificate Authenticating Your Public Key</h3>
<blockquote>
<p>Suppose you have used the
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/jarsigner.html">
jarsigner</a> tool to sign a Java ARchive (JAR) file. Clients that want to
use the file will want to authenticate your signature. </p>
<p>One way they can do this is by first importing your public key
certificate into their keystore as a &quot;trusted&quot; entry. You can export the
certificate and supply it to your clients. As an example, you can copy your
certificate to a file named <code>MJ.cer</code> via the following, assuming
the entry is aliased by &quot;mykey&quot;: </p>
<pre> keytool -export -alias mykey -file MJ.cer
</pre>
<p>Given that certificate, and the signed JAR file, a client can use the <b>
jarsigner</b> tool to authenticate your signature. </p>
</blockquote>
<h3>Changing Your Distinguished Name but Keeping your Key Pair</h3>
<blockquote>
<p>Suppose your distinguished name changes, for example because you have
changed departments or moved to a different city. If desired, you may still
use the public/private key pair you've previously used, and yet update your
distinguished name. For example, suppose your name is Susan Miller, and you
created your initial key entry with the alias <code>sMiller</code> and the
distinguished name </p>
<pre> &quot;cn=Susan Miller, ou=Finance Department, o=BlueSoft, c=us&quot;
</pre>
<p>Suppose you change from the Finance Department to the Accounting
Department. You can still use the previously-generated public/private key
pair and yet update your distinguished name by doing the following. First,
copy (clone) your key entry: </p>
<pre> keytool -keyclone -alias sMiller -dest sMillerNew
</pre>
<p>(This prompts for the store password and for the initial and destination
private key passwords, since they aren't provided at the command line.) Now
you need to change the certificate chain associated with the copy, so that
the first certificate in the chain uses your different distinguished name.
Start by generating a self-signed certificate with the appropriate name: </p>
<pre> keytool -selfcert -alias sMillerNew
-dname &quot;cn=Susan Miller, ou=Accounting Department, o=BlueSoft, c=us&quot;
</pre>
<p>Then generate a Certificate Signing Request based on the information in
this new certificate: </p>
<pre> keytool -certreq -alias sMillerNew
</pre>
<p>When you get the CA certificate reply, import it: </p>
<pre> keytool -import -alias sMillerNew -file VSSMillerNew.cer
</pre>
<p>After importing the certificate reply, you may want to remove the initial
key entry that used your old distinguished name: </p>
<pre> keytool -delete -alias sMiller
</pre>
</blockquote>
</blockquote>
<h2>SEE ALSO</h2>
<blockquote>
<ul>
<li>
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/jar.html">
jar</a> tool documentation</li>
<li>
<a href="http://download.oracle.com/javase/1.3/docs/tooldocs/win32/jarsigner.html">
jarsigner</a> tool documentation</li>
<li>the
<a href="http://java.sun.com/docs/books/tutorial/security1.2/index.html"><b>
Security</b></a> trail of the
<a href="http://java.sun.com/docs/books/tutorial/index.html"><b>Java
Tutorial</b></a> for examples of the use of <b>keytool</b> </li>
</ul>
</blockquote>
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affiliates.</a> All rights reserved.</font></td>
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