Class KeyStore

java.lang.Object
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:

  • KeyStore.PrivateKeyEntry

    This type of entry holds a cryptographic PrivateKey, which is optionally stored in a protected format to prevent unauthorized access. It is also accompanied by a certificate chain for the corresponding public key.

    Private keys and certificate chains are used by a given entity for self-authentication. Applications for this authentication include software distribution organizations which sign JAR files as part of releasing and/or licensing software.

  • KeyStore.SecretKeyEntry

    This type of entry holds a cryptographic SecretKey, which is optionally stored in a protected format to prevent unauthorized access.

  • KeyStore.TrustedCertificateEntry

    This type of entry contains a single public key Certificate belonging to another party. It is called a trusted certificate because the keystore owner trusts that the public key in the certificate indeed belongs to the identity identified by the subject (owner) of the certificate.

    This type of entry can be used to authenticate other parties.

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 specifying an existing keystore file, relying on the default type and providing a specific keystore type.

  • To specify an existing keystore file: 
        // get keystore password
    char[] password = getPassword();

    // probe the keystore file and load the keystore entries
    KeyStore ks = KeyStore.getInstance(new File("keyStoreName"), password);
    The system will probe the specified file to determine its keystore type and return a keystore implementation with its entries already loaded. When this approach is used there is no need to call the keystore's load method.
  • To rely on the default type: 
        KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
    The system will return a keystore implementation for the default type.
  • To provide a specific keystore type: 
          KeyStore ks = KeyStore.getInstance("JKS");
    The system will return the most preferred implementation of the specified keystore type available in the environment.

Before a keystore can be accessed, it must be loaded (unless it was already loaded during instantiation). 

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

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

    try (FileInputStream fis = new FileInputStream("keyStoreName")) {
        ks.load(fis, password);
    }
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: 

    KeyStore.PasswordProtection protParam =
        new KeyStore.PasswordProtection(password);
    try (FileOutputStream fos = new FileOutputStream("newKeyStoreName")) {
        // get my private key
        KeyStore.PrivateKeyEntry pkEntry = (KeyStore.PrivateKeyEntry)
            ks.getEntry("privateKeyAlias", protParam);
        PrivateKey myPrivateKey = pkEntry.getPrivateKey();

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

        // store away the keystore
        ks.store(fos, password);
    } finally {
        protParam.destroy();
    }
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.

Every implementation of the Java platform is required to support the following standard KeyStore type:

  • PKCS12
This type is described in the KeyStore section of the Java Security Standard Algorithm Names Specification. Consult the release documentation for your implementation to see if any other types are supported.
Since:
1.2
See Also:

  • Constructor Details

    • 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 Details

    • 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.

      Implementation Note:
      The JDK Reference Implementation additionally uses the jdk.security.provider.preferred Security property to determine the preferred provider order for the specified algorithm. This may be different from the order of providers returned by Security.getProviders().
      Parameters:
      type - the type of keystore. See the KeyStore section in the Java Security Standard Algorithm Names Specification 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
      NullPointerException - if type is null
      See Also:

    • 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 the KeyStore section in the Java Security Standard Algorithm Names Specification for information about standard keystore types.
      provider - the name of the provider.
      Returns:
      a keystore object of the specified type
      Throws:
      IllegalArgumentException - if the provider name is null or empty
      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
      NullPointerException - if type is null
      See Also:

    • 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 the KeyStore section in the Java Security Standard Algorithm Names Specification for information about standard keystore types.
      provider - the provider.
      Returns:
      a keystore object of the specified type
      Throws:
      IllegalArgumentException - if the specified provider is null
      KeyStoreException - if KeyStoreSpi implementation for the specified type is not available from the specified Provider object
      NullPointerException - if type is null
      Since:
      1.4
      See Also:

    • getDefaultType

      public static final String getDefaultType()
      Returns the default keystore type as specified by the keystore.type security property, or the string "pkcs12" if no such property exists.

      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 to the desired keystore type.

      Returns:
      the default keystore type as specified by the keystore.type security property, or the string "pkcs12" if no such property exists.
      See Also:

    • 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.

    • getAttributes

      public final Set<KeyStore.Entry.Attribute> getAttributes(String alias) throws KeyStoreException
      Retrieves the attributes associated with the given alias.
      Parameters:
      alias - the alias name
      Returns:
      an unmodifiable Set of attributes. This set is empty if the KeyStoreSpi implementation has not overridden KeyStoreSpi.engineGetAttributes(String), or the given alias does not exist, or there are no attributes associated with the alias. This set may also be empty for PrivateKeyEntry or SecretKeyEntry entries that contain protected attributes and are only available through the KeyStore.Entry.getAttributes() method after the entry is extracted.
      Throws:
      KeyStoreException - if the keystore has not been initialized (loaded).
      NullPointerException - if alias is null
      Since:
      18

    • 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 followed by zero or more certificate authorities), 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. May be null if the keystore does not support or require an 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
      UnsupportedOperationException - if this operation is not supported
      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

      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:

    • 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

    • getInstance

      public static final KeyStore getInstance(File file, char[] password) throws KeyStoreException, IOException, NoSuchAlgorithmException, CertificateException
      Returns a loaded keystore object of the appropriate keystore type. First the keystore type is determined by probing the specified file. Then a keystore object is instantiated and loaded using the data from that file.

      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.

      This method traverses the list of registered security providers, starting with the most preferred provider. For each KeyStoreSpi implementation supported by a provider, it invokes the engineProbe method to determine if it supports the specified keystore. A new KeyStore object is returned that encapsulates the KeyStoreSpi implementation from the first provider that supports the specified file.

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

      Parameters:
      file - the keystore file
      password - the keystore password, which may be null
      Returns:
      a keystore object loaded with keystore data
      Throws:
      KeyStoreException - if no provider supports a KeyStoreSpi implementation for the specified keystore file.
      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.
      IllegalArgumentException - if file does not exist or does not refer to a normal file.
      NullPointerException - if file is null.
      Since:
      9
      See Also:

    • getInstance

      public static final KeyStore getInstance(File file, KeyStore.LoadStoreParameter param) throws KeyStoreException, IOException, NoSuchAlgorithmException, CertificateException
      Returns a loaded keystore object of the appropriate keystore type. First the keystore type is determined by probing the specified file. Then a keystore object is instantiated and loaded using the data from that file. A LoadStoreParameter may be supplied which specifies how to unlock the keystore data or perform an integrity check.

      This method traverses the list of registered security providers, starting with the most preferred provider. For each KeyStoreSpi implementation supported by a provider, it invokes the engineProbe method to determine if it supports the specified keystore. A new KeyStore object is returned that encapsulates the KeyStoreSpi implementation from the first provider that supports the specified file.

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

      Parameters:
      file - the keystore file
      param - the LoadStoreParameter that specifies how to load the keystore, which may be null
      Returns:
      a keystore object loaded with keystore data
      Throws:
      KeyStoreException - if no provider supports a KeyStoreSpi implementation for the specified keystore file.
      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.
      IllegalArgumentException - if file does not exist or does not refer to a normal file, or if param is not recognized.
      NullPointerException - if file is null.
      Since:
      9
      See Also: