KeyStore (Java SE 14 & JDK 14)
Description: declaration: module: java.base, package: java.security, class: KeyStore
Keywords: java.security.KeyStore class

Module java.base
Package java.security

# 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.ProtectionParameter protParam =
            new KeyStore.PasswordProtection(password);

        // 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
        try (FileOutputStream fos = new FileOutputStream("newKeyStoreName")) {
            ks.store(fos, password);
        }

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:
  `PrivateKey`, `SecretKey`, `Certificate`

- ## Nested Class Summary

  Nested Classes
  Modifier and Type | Class | Description
  --- | --- | ---
  `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

  Constructors
  Modifier | Constructor | Description
  --- | --- | ---
  `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

  Modifier and Type | Method | Description
  --- | --- | ---
  `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 by the `keystore.type` security property, 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​(File file, char[] password)` | Returns a loaded keystore object of the appropriate keystore type.
  `static KeyStore` | `getInstance​(File file, KeyStore.LoadStoreParameter param)` | Returns a loaded keystore object of the appropriate keystore type.
  `static KeyStore` | `getInstance​(String type)` | Returns a keystore object of the specified type.
  `static KeyStore` | `getInstance​(String type, String provider)` | Returns a keystore object of the specified type.
  `static KeyStore` | `getInstance​(String type, Provider 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​(OutputStream stream, char[] password)` | Stores this keystore to the given output stream, and protects its integrity with the given password.
  `void` | `store​(KeyStore.LoadStoreParameter param)` | Stores this keystore using the given `LoadStoreParameter`.

  ### Methods declared in class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## 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 than 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:
      `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 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:
      `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 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:
      `Provider`

  - ### getDefaultType

    public static final String getDefaultType()
    Returns the default keystore type as specified by the `keystore.type` security property, or the string "jks" (acronym for "Java keystore") 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 "jks" if no such property exists.
    See Also:
      `security properties`

  - ### 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 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
    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

  - ### 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`.
      `SecurityException` - if a security manager exists and its `SecurityManager.checkRead(java.io.FileDescriptor)` method denies read access to the specified file.
    Since:
      9
    See Also:
      `Provider`

  - ### 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`.
      `SecurityException` - if a security manager exists and its `SecurityManager.checkRead(java.io.FileDescriptor)` method denies read access to the specified file.
    Since:
      9
    See Also:
      `Provider`