Java™ Platform
Standard Ed. 6

java.security
Class KeyStore

java.lang.Object
  extended by java.security.KeyStore

public class KeyStore
extends Object

This class represents a storage facility for cryptographic keys and certificates.

A KeyStore manages different types of entries. Each type of entry implements the KeyStore.Entry interface. Three basic KeyStore.Entry implementations are provided:

Each entry in a keystore is identified by an "alias" string. In the case of private keys and their associated certificate chains, these strings distinguish among the different ways in which the entity may authenticate itself. For example, the entity may authenticate itself using different certificate authorities, or using different public key algorithms.

Whether aliases are case sensitive is implementation dependent. In order to avoid problems, it is recommended not to use aliases in a KeyStore that only differ in case.

Whether keystores are persistent, and the mechanisms used by the keystore if it is persistent, are not specified here. This allows use of a variety of techniques for protecting sensitive (e.g., private or secret) keys. Smart cards or other integrated cryptographic engines (SafeKeyper) are one option, and simpler mechanisms such as files may also be used (in a variety of formats).

Typical ways to request a KeyStore object include relying on the default type and providing a specific keystore type.

Before a keystore can be accessed, it must be loaded.

    KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());

    // get user password and file input stream
    char[] password = getPassword();

    java.io.FileInputStream fis = null;
    try {
        fis = new java.io.FileInputStream("keyStoreName");
        ks.load(fis, password);
    } finally {
        if (fis != null) {
            fis.close();
        }
    }
 
To create an empty keystore using the above load method, pass null as the InputStream argument.

Once the keystore has been loaded, it is possible to read existing entries from the keystore, or to write new entries into the keystore:

    // get my private key
    KeyStore.PrivateKeyEntry pkEntry = (KeyStore.PrivateKeyEntry)
        ks.getEntry("privateKeyAlias", password);
    PrivateKey myPrivateKey = pkEntry.getPrivateKey();

    // save my secret key
    javax.crypto.SecretKey mySecretKey;
    KeyStore.SecretKeyEntry skEntry =
        new KeyStore.SecretKeyEntry(mySecretKey);
    ks.setEntry("secretKeyAlias", skEntry, 
        new KeyStore.PasswordProtection(password));

    // store away the keystore
    java.io.FileOutputStream fos = null;
    try {
        fos = new java.io.FileOutputStream("newKeyStoreName");
        ks.store(fos, password);
    } finally {
        if (fos != null) {
            fos.close();
        }
    }
 
Note that although the same password may be used to load the keystore, to protect the private key entry, to protect the secret key entry, and to store the keystore (as is shown in the sample code above), different passwords or other protection parameters may also be used.

Since:
1.2
See Also:
PrivateKey, SecretKey, Certificate

Nested Class Summary
static class KeyStore.Builder
          A description of a to-be-instantiated KeyStore object.
static class KeyStore.CallbackHandlerProtection
          A ProtectionParameter encapsulating a CallbackHandler.
static interface KeyStore.Entry
          A marker interface for KeyStore entry types.
static interface KeyStore.LoadStoreParameter
          A marker interface for KeyStore load and store parameters.
static class KeyStore.PasswordProtection
          A password-based implementation of ProtectionParameter.
static class KeyStore.PrivateKeyEntry
          A KeyStore entry that holds a PrivateKey and corresponding certificate chain.
static interface KeyStore.ProtectionParameter
          A marker interface for keystore protection parameters.
static class KeyStore.SecretKeyEntry
          A KeyStore entry that holds a SecretKey.
static class KeyStore.TrustedCertificateEntry
          A KeyStore entry that holds a trusted Certificate.
 
Constructor Summary
protected KeyStore(KeyStoreSpi keyStoreSpi, Provider provider, String type)
          Creates a KeyStore object of the given type, and encapsulates the given provider implementation (SPI object) in it.
 
Method Summary
 Enumeration<String> aliases()
          Lists all the alias names of this keystore.
 boolean containsAlias(String alias)
          Checks if the given alias exists in this keystore.
 void deleteEntry(String alias)
          Deletes the entry identified by the given alias from this keystore.
 boolean entryInstanceOf(String alias, Class<? extends KeyStore.Entry> entryClass)
          Determines if the keystore Entry for the specified alias is an instance or subclass of the specified entryClass.
 Certificate getCertificate(String alias)
          Returns the certificate associated with the given alias.
 String getCertificateAlias(Certificate cert)
          Returns the (alias) name of the first keystore entry whose certificate matches the given certificate.
 Certificate[] getCertificateChain(String alias)
          Returns the certificate chain associated with the given alias.
 Date getCreationDate(String alias)
          Returns the creation date of the entry identified by the given alias.
static String getDefaultType()
          Returns the default keystore type as specified in the Java security properties file, or the string "jks" (acronym for "Java keystore") if no such property exists.
 KeyStore.Entry getEntry(String alias, KeyStore.ProtectionParameter protParam)
          Gets a keystore Entry for the specified alias with the specified protection parameter.
static KeyStore getInstance(String type)
          Returns a keystore object of the specified type.
static KeyStore getInstance(String type, Provider provider)
          Returns a keystore object of the specified type.
static KeyStore getInstance(String type, String provider)
          Returns a keystore object of the specified type.
 Key getKey(String alias, char[] password)
          Returns the key associated with the given alias, using the given password to recover it.
 Provider getProvider()
          Returns the provider of this keystore.
 String getType()
          Returns the type of this keystore.
 boolean isCertificateEntry(String alias)
          Returns true if the entry identified by the given alias was created by a call to setCertificateEntry, or created by a call to setEntry with a TrustedCertificateEntry.
 boolean isKeyEntry(String alias)
          Returns true if the entry identified by the given alias was created by a call to setKeyEntry, or created by a call to setEntry with a PrivateKeyEntry or a SecretKeyEntry.
 void load(InputStream stream, char[] password)
          Loads this KeyStore from the given input stream.
 void load(KeyStore.LoadStoreParameter param)
          Loads this keystore using the given LoadStoreParameter.
 void setCertificateEntry(String alias, Certificate cert)
          Assigns the given trusted certificate to the given alias.
 void setEntry(String alias, KeyStore.Entry entry, KeyStore.ProtectionParameter protParam)
          Saves a keystore Entry under the specified alias.
 void setKeyEntry(String alias, byte[] key, Certificate[] chain)
          Assigns the given key (that has already been protected) to the given alias.
 void setKeyEntry(String alias, Key key, char[] password, Certificate[] chain)
          Assigns the given key to the given alias, protecting it with the given password.
 int size()
          Retrieves the number of entries in this keystore.
 void store(KeyStore.LoadStoreParameter param)
          Stores this keystore using the given LoadStoreParameter.
 void store(OutputStream stream, char[] password)
          Stores this keystore to the given output stream, and protects its integrity with the given password.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

KeyStore

protected KeyStore(KeyStoreSpi keyStoreSpi,
                   Provider provider,
                   String type)
Creates a KeyStore object of the given type, and encapsulates the given provider implementation (SPI object) in it.

Parameters:
keyStoreSpi - the provider implementation.
provider - the provider.
type - the keystore type.
Method Detail

getInstance

public static KeyStore getInstance(String type)
                            throws KeyStoreException
Returns a keystore object of the specified type.

This method traverses the list of registered security Providers, starting with the most preferred Provider. A new KeyStore object encapsulating the KeyStoreSpi implementation from the first Provider that supports the specified type is returned.

Note that the list of registered providers may be retrieved via the Security.getProviders() method.

Parameters:
type - the type of keystore. See Appendix A in the Java Cryptography Architecture API Specification & Reference for information about standard keystore types.
Returns:
a keystore object of the specified type.
Throws:
KeyStoreException - if no Provider supports a KeyStoreSpi implementation for the specified type.
See Also:
Provider

getInstance

public static KeyStore getInstance(String type,
                                   String provider)
                            throws KeyStoreException,
                                   NoSuchProviderException
Returns a keystore object of the specified type.

A new KeyStore object encapsulating the KeyStoreSpi implementation from the specified provider is returned. The specified provider must be registered in the security provider list.

Note that the list of registered providers may be retrieved via the Security.getProviders() method.

Parameters:
type - the type of keystore. See Appendix A in the Java Cryptography Architecture API Specification & Reference for information about standard keystore types.
provider - the name of the provider.
Returns:
a keystore object of the specified type.
Throws:
KeyStoreException - if a KeyStoreSpi implementation for the specified type is not available from the specified provider.
NoSuchProviderException - if the specified provider is not registered in the security provider list.
IllegalArgumentException - if the provider name is null or empty.
See Also:
Provider

getInstance

public static KeyStore getInstance(String type,
                                   Provider provider)
                            throws KeyStoreException
Returns a keystore object of the specified type.

A new KeyStore object encapsulating the KeyStoreSpi implementation from the specified Provider object is returned. Note that the specified Provider object does not have to be registered in the provider list.

Parameters:
type - the type of keystore. See Appendix A in the Java Cryptography Architecture API Specification & Reference for information about standard keystore types.
provider - the provider.
Returns:
a keystore object of the specified type.
Throws:
KeyStoreException - if KeyStoreSpi implementation for the specified type is not available from the specified Provider object.
IllegalArgumentException - if the specified provider is null.
Since:
1.4
See Also:
Provider

getDefaultType

public static final String getDefaultType()
Returns the default keystore type as specified in the Java security properties file, or the string "jks" (acronym for "Java keystore") if no such property exists. The Java security properties file is located in the file named <JAVA_HOME>/lib/security/java.security. <JAVA_HOME> refers to the value of the java.home system property, and specifies the directory where the JRE is installed.

The default keystore type can be used by applications that do not want to use a hard-coded keystore type when calling one of the getInstance methods, and want to provide a default keystore type in case a user does not specify its own.

The default keystore type can be changed by setting the value of the "keystore.type" security property (in the Java security properties file) to the desired keystore type.

Returns:
the default keystore type as specified in the Java security properties file, or the string "jks" if no such property exists.

getProvider

public final Provider getProvider()
Returns the provider of this keystore.

Returns:
the provider of this keystore.

getType

public final String getType()
Returns the type of this keystore.

Returns:
the type of this keystore.

getKey

public final Key getKey(String alias,
                        char[] password)
                 throws KeyStoreException,
                        NoSuchAlgorithmException,
                        UnrecoverableKeyException
Returns the key associated with the given alias, using the given password to recover it. The key must have been associated with the alias by a call to setKeyEntry, or by a call to setEntry with a PrivateKeyEntry or SecretKeyEntry.

Parameters:
alias - the alias name
password - the password for recovering the key
Returns:
the requested key, or null if the given alias does not exist or does not identify a key-related entry.
Throws:
KeyStoreException - if the keystore has not been initialized (loaded).
NoSuchAlgorithmException - if the algorithm for recovering the key cannot be found
UnrecoverableKeyException - if the key cannot be recovered (e.g., the given password is wrong).

getCertificateChain

public final Certificate[] getCertificateChain(String alias)
                                        throws KeyStoreException
Returns the certificate chain associated with the given alias. The certificate chain must have been associated with the alias by a call to setKeyEntry, or by a call to setEntry with a PrivateKeyEntry.

Parameters:
alias - the alias name
Returns:
the certificate chain (ordered with the user's certificate first and the root certificate authority last), or null if the given alias does not exist or does not contain a certificate chain
Throws:
KeyStoreException - if the keystore has not been initialized (loaded).

getCertificate

public final Certificate getCertificate(String alias)
                                 throws KeyStoreException
Returns the certificate associated with the given alias.

If the given alias name identifies an entry created by a call to setCertificateEntry, or created by a call to setEntry with a TrustedCertificateEntry, then the trusted certificate contained in that entry is returned.

If the given alias name identifies an entry created by a call to setKeyEntry, or created by a call to setEntry with a PrivateKeyEntry, then the first element of the certificate chain in that entry is returned.

Parameters:
alias - the alias name
Returns:
the certificate, or null if the given alias does not exist or does not contain a certificate.
Throws:
KeyStoreException - if the keystore has not been initialized (loaded).

getCreationDate

public final Date getCreationDate(String alias)
                           throws KeyStoreException
Returns the creation date of the entry identified by the given alias.

Parameters:
alias - the alias name
Returns:
the creation date of this entry, or null if the given alias does not exist
Throws:
KeyStoreException - if the keystore has not been initialized (loaded).

setKeyEntry

public final void setKeyEntry(String alias,
                              Key key,
                              char[] password,
                              Certificate[] chain)
                       throws KeyStoreException
Assigns the given key to the given alias, protecting it with the given password.

If the given key is of type java.security.PrivateKey, it must be accompanied by a certificate chain certifying the corresponding public key.

If the given alias already exists, the keystore information associated with it is overridden by the given key (and possibly certificate chain).

Parameters:
alias - the alias name
key - the key to be associated with the alias
password - the password to protect the key
chain - the certificate chain for the corresponding public key (only required if the given key is of type java.security.PrivateKey).
Throws:
KeyStoreException - if the keystore has not been initialized (loaded), the given key cannot be protected, or this operation fails for some other reason

setKeyEntry

public final void setKeyEntry(String alias,
                              byte[] key,
                              Certificate[] chain)
                       throws KeyStoreException
Assigns the given key (that has already been protected) to the given alias.

If the protected key is of type java.security.PrivateKey, it must be accompanied by a certificate chain certifying the corresponding public key. If the underlying keystore implementation is of type jks, key must be encoded as an EncryptedPrivateKeyInfo as defined in the PKCS #8 standard.

If the given alias already exists, the keystore information associated with it is overridden by the given key (and possibly certificate chain).

Parameters:
alias - the alias name
key - the key (in protected format) to be associated with the alias
chain - the certificate chain for the corresponding public key (only useful if the protected key is of type java.security.PrivateKey).
Throws:
KeyStoreException - if the keystore has not been initialized (loaded), or if this operation fails for some other reason.

setCertificateEntry

public final void setCertificateEntry(String alias,
                                      Certificate cert)
                               throws KeyStoreException
Assigns the given trusted certificate to the given alias.

If the given alias identifies an existing entry created by a call to setCertificateEntry, or created by a call to setEntry with a TrustedCertificateEntry, the trusted certificate in the existing entry is overridden by the given certificate.

Parameters:
alias - the alias name
cert - the certificate
Throws:
KeyStoreException - if the keystore has not been initialized, or the given alias already exists and does not identify an entry containing a trusted certificate, or this operation fails for some other reason.

deleteEntry

public final void deleteEntry(String alias)
                       throws KeyStoreException
Deletes the entry identified by the given alias from this keystore.

Parameters:
alias - the alias name
Throws:
KeyStoreException - if the keystore has not been initialized, or if the entry cannot be removed.

aliases

public final Enumeration<String> aliases()
                                  throws KeyStoreException
Lists all the alias names of this keystore.

Returns:
enumeration of the alias names
Throws:
KeyStoreException - if the keystore has not been initialized (loaded).

containsAlias

public final boolean containsAlias(String alias)
                            throws KeyStoreException
Checks if the given alias exists in this keystore.

Parameters:
alias - the alias name
Returns:
true if the alias exists, false otherwise
Throws:
KeyStoreException - if the keystore has not been initialized (loaded).

size

public final int size()
               throws KeyStoreException
Retrieves the number of entries in this keystore.

Returns:
the number of entries in this keystore
Throws:
KeyStoreException - if the keystore has not been initialized (loaded).

isKeyEntry

public final boolean isKeyEntry(String alias)
                         throws KeyStoreException
Returns true if the entry identified by the given alias was created by a call to setKeyEntry, or created by a call to setEntry with a PrivateKeyEntry or a SecretKeyEntry.

Parameters:
alias - the alias for the keystore entry to be checked
Returns:
true if the entry identified by the given alias is a key-related entry, false otherwise.
Throws:
KeyStoreException - if the keystore has not been initialized (loaded).

isCertificateEntry

public final boolean isCertificateEntry(String alias)
                                 throws KeyStoreException
Returns true if the entry identified by the given alias was created by a call to setCertificateEntry, or created by a call to setEntry with a TrustedCertificateEntry.

Parameters:
alias - the alias for the keystore entry to be checked
Returns:
true if the entry identified by the given alias contains a trusted certificate, false otherwise.
Throws:
KeyStoreException - if the keystore has not been initialized (loaded).

getCertificateAlias

public final String getCertificateAlias(Certificate cert)
                                 throws KeyStoreException
Returns the (alias) name of the first keystore entry whose certificate matches the given certificate.

This method attempts to match the given certificate with each keystore entry. If the entry being considered was created by a call to setCertificateEntry, or created by a call to setEntry with a TrustedCertificateEntry, then the given certificate is compared to that entry's certificate.

If the entry being considered was created by a call to setKeyEntry, or created by a call to setEntry with a PrivateKeyEntry, then the given certificate is compared to the first element of that entry's certificate chain.

Parameters:
cert - the certificate to match with.
Returns:
the alias name of the first entry with a matching certificate, or null if no such entry exists in this keystore.
Throws:
KeyStoreException - if the keystore has not been initialized (loaded).

store

public final void store(OutputStream stream,
                        char[] password)
                 throws KeyStoreException,
                        IOException,
                        NoSuchAlgorithmException,
                        CertificateException
Stores this keystore to the given output stream, and protects its integrity with the given password.

Parameters:
stream - the output stream to which this keystore is written.
password - the password to generate the keystore integrity check
Throws:
KeyStoreException - if the keystore has not been initialized (loaded).
IOException - if there was an I/O problem with data
NoSuchAlgorithmException - if the appropriate data integrity algorithm could not be found
CertificateException - if any of the certificates included in the keystore data could not be stored

store

public final void store(KeyStore.LoadStoreParameter param)
                 throws KeyStoreException,
                        IOException,
                        NoSuchAlgorithmException,
                        CertificateException
Stores this keystore using the given LoadStoreParameter.

Parameters:
param - the LoadStoreParameter that specifies how to store the keystore, which may be null
Throws:
IllegalArgumentException - if the given LoadStoreParameter input is not recognized
KeyStoreException - if the keystore has not been initialized (loaded)
IOException - if there was an I/O problem with data
NoSuchAlgorithmException - if the appropriate data integrity algorithm could not be found
CertificateException - if any of the certificates included in the keystore data could not be stored
Since:
1.5

load

public final void load(InputStream stream,
                       char[] password)
                throws IOException,
                       NoSuchAlgorithmException,
                       CertificateException
Loads this KeyStore from the given input stream.

A password may be given to unlock the keystore (e.g. the keystore resides on a hardware token device), or to check the integrity of the keystore data. If a password is not given for integrity checking, then integrity checking is not performed.

In order to create an empty keystore, or if the keystore cannot be initialized from a stream, pass null as the stream argument.

Note that if this keystore has already been loaded, it is reinitialized and loaded again from the given input stream.

Parameters:
stream - the input stream from which the keystore is loaded, or null
password - the password used to check the integrity of the keystore, the password used to unlock the keystore, or null
Throws:
IOException - if there is an I/O or format problem with the keystore data, if a password is required but not given, or if the given password was incorrect. If the error is due to a wrong password, the cause of the IOException should be an UnrecoverableKeyException
NoSuchAlgorithmException - if the algorithm used to check the integrity of the keystore cannot be found
CertificateException - if any of the certificates in the keystore could not be loaded

load

public final void load(KeyStore.LoadStoreParameter param)
                throws IOException,
                       NoSuchAlgorithmException,
                       CertificateException
Loads this keystore using the given LoadStoreParameter.

Note that if this KeyStore has already been loaded, it is reinitialized and loaded again from the given parameter.

Parameters:
param - the LoadStoreParameter that specifies how to load the keystore, which may be null
Throws:
IllegalArgumentException - if the given LoadStoreParameter input is not recognized
IOException - if there is an I/O or format problem with the keystore data. If the error is due to an incorrect ProtectionParameter (e.g. wrong password) the cause of the IOException should be an UnrecoverableKeyException
NoSuchAlgorithmException - if the algorithm used to check the integrity of the keystore cannot be found
CertificateException - if any of the certificates in the keystore could not be loaded
Since:
1.5

getEntry

public final KeyStore.Entry getEntry(String alias,
                                     KeyStore.ProtectionParameter protParam)
                              throws NoSuchAlgorithmException,
                                     UnrecoverableEntryException,
                                     KeyStoreException
Gets a keystore Entry for the specified alias with the specified protection parameter.

Parameters:
alias - get the keystore Entry for this alias
protParam - the ProtectionParameter used to protect the Entry, which may be null
Returns:
the keystore Entry for the specified alias, or null if there is no such entry
Throws:
NullPointerException - if alias is null
NoSuchAlgorithmException - if the algorithm for recovering the entry cannot be found
UnrecoverableEntryException - if the specified protParam were insufficient or invalid
UnrecoverableKeyException - if the entry is a PrivateKeyEntry or SecretKeyEntry and the specified protParam does not contain the information needed to recover the key (e.g. wrong password)
KeyStoreException - if the keystore has not been initialized (loaded).
Since:
1.5
See Also:
setEntry(String, KeyStore.Entry, KeyStore.ProtectionParameter)

setEntry

public final void setEntry(String alias,
                           KeyStore.Entry entry,
                           KeyStore.ProtectionParameter protParam)
                    throws KeyStoreException
Saves a keystore Entry under the specified alias. The protection parameter is used to protect the Entry.

If an entry already exists for the specified alias, it is overridden.

Parameters:
alias - save the keystore Entry under this alias
entry - the Entry to save
protParam - the ProtectionParameter used to protect the Entry, which may be null
Throws:
NullPointerException - if alias or entry is null
KeyStoreException - if the keystore has not been initialized (loaded), or if this operation fails for some other reason
Since:
1.5
See Also:
getEntry(String, KeyStore.ProtectionParameter)

entryInstanceOf

public final boolean entryInstanceOf(String alias,
                                     Class<? extends KeyStore.Entry> entryClass)
                              throws KeyStoreException
Determines if the keystore Entry for the specified alias is an instance or subclass of the specified entryClass.

Parameters:
alias - the alias name
entryClass - the entry class
Returns:
true if the keystore Entry for the specified alias is an instance or subclass of the specified entryClass, false otherwise
Throws:
NullPointerException - if alias or entryClass is null
KeyStoreException - if the keystore has not been initialized (loaded)
Since:
1.5

Java™ Platform
Standard Ed. 6

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