# KeyStoreSpi

public abstract class **KeyStoreSpi** extends [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html)  
This class defines the *Service Provider Interface* (**SPI** )
for the `KeyStore` class.
All the abstract methods in this class must be implemented by each
cryptographic service provider who wishes to supply the implementation
of a keystore for a particular keystore type.

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.html`

### Public Constructor Summary

|---|---|
|   | [KeyStoreSpi](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#KeyStoreSpi())() |

### Public Method Summary

|---|---|
| abstract [Enumeration](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Enumeration.html)\<[String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html)\> | [engineAliases](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineAliases())() Lists all the alias names of this keystore. |
| abstract boolean | [engineContainsAlias](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineContainsAlias(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias) Checks if the given alias exists in this keystore. |
| abstract void | [engineDeleteEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineDeleteEntry(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias) Deletes the entry identified by the given alias from this keystore. |
| boolean | [engineEntryInstanceOf](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineEntryInstanceOf(java.lang.String,%20java.lang.Class<?%20extends%20java.security.KeyStore.Entry>))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, [Class](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html)\<? extends [KeyStore.Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.Entry.html)\> entryClass) Determines if the keystore `Entry` for the specified `alias` is an instance or subclass of the specified `entryClass`. |
| abstract [Certificate](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html) | [engineGetCertificate](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineGetCertificate(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias) Returns the certificate associated with the given alias. |
| abstract [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [engineGetCertificateAlias](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineGetCertificateAlias(java.security.cert.Certificate))([Certificate](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html) cert) Returns the (alias) name of the first keystore entry whose certificate matches the given certificate. |
| abstract [Certificate\[\]](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html) | [engineGetCertificateChain](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineGetCertificateChain(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias) Returns the certificate chain associated with the given alias. |
| abstract [Date](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Date.html) | [engineGetCreationDate](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineGetCreationDate(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias) Returns the creation date of the entry identified by the given alias. |
| [KeyStore.Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.Entry.html) | [engineGetEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineGetEntry(java.lang.String,%20java.security.KeyStore.ProtectionParameter))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, [KeyStore.ProtectionParameter](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.ProtectionParameter.html) protParam) Gets a `KeyStore.Entry` for the specified alias with the specified protection parameter. |
| abstract [Key](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Key.html) | [engineGetKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineGetKey(java.lang.String,%20char[]))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, char\[\] password) Returns the key associated with the given alias, using the given password to recover it. |
| abstract boolean | [engineIsCertificateEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineIsCertificateEntry(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) 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`. |
| abstract boolean | [engineIsKeyEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineIsKeyEntry(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) 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 | [engineLoad](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineLoad(java.security.KeyStore.LoadStoreParameter))([KeyStore.LoadStoreParameter](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.LoadStoreParameter.html) param) Loads the keystore using the given `KeyStore.LoadStoreParameter`. |
| abstract void | [engineLoad](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineLoad(java.io.InputStream,%20char[]))([InputStream](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html) stream, char\[\] password) Loads the keystore from the given input stream. |
| abstract void | [engineSetCertificateEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineSetCertificateEntry(java.lang.String,%20java.security.cert.Certificate))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, [Certificate](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html) cert) Assigns the given certificate to the given alias. |
| void | [engineSetEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineSetEntry(java.lang.String,%20java.security.KeyStore.Entry,%20java.security.KeyStore.ProtectionParameter))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, [KeyStore.Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.Entry.html) entry, [KeyStore.ProtectionParameter](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.ProtectionParameter.html) protParam) Saves a `KeyStore.Entry` under the specified alias. |
| abstract void | [engineSetKeyEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineSetKeyEntry(java.lang.String,%20java.security.Key,%20char[],%20java.security.cert.Certificate[]))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, [Key](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Key.html) key, char\[\] password, [Certificate\[\]](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html) chain) Assigns the given key to the given alias, protecting it with the given password. |
| abstract void | [engineSetKeyEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineSetKeyEntry(java.lang.String,%20byte[],%20java.security.cert.Certificate[]))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, byte\[\] key, [Certificate\[\]](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html) chain) Assigns the given key (that has already been protected) to the given alias. |
| abstract int | [engineSize](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineSize())() Retrieves the number of entries in this keystore. |
| void | [engineStore](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineStore(java.security.KeyStore.LoadStoreParameter))([KeyStore.LoadStoreParameter](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.LoadStoreParameter.html) param) Stores this keystore using the given `KeyStore.LoadStoreParmeter`. |
| abstract void | [engineStore](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreSpi.html#engineStore(java.io.OutputStream,%20char[]))([OutputStream](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/OutputStream.html) stream, char\[\] password) Stores this keystore to the given output stream, and protects its integrity with the given password. |

### Inherited Method Summary

From class [java.lang.Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html)

|---|---|
| [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [clone](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#clone())() Creates and returns a copy of this `Object`. |
| boolean | [equals](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#equals(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) obj) Compares this instance with the specified object and indicates if they are equal. |
| void | [finalize](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#finalize())() Invoked when the garbage collector has detected that this instance is no longer reachable. |
| final [Class](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html)\<?\> | [getClass](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#getClass())() Returns the unique instance of `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html` that represents this object's class. |
| int | [hashCode](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#hashCode())() Returns an integer hash code for this object. |
| final void | [notify](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notify())() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| final void | [notifyAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notifyAll())() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [toString](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#toString())() Returns a string containing a concise, human-readable description of this object. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long,%20int))(long timeout, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long))(long timeout) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait())() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object. |

## Public Constructors

#### public
**KeyStoreSpi**
()

<br />

## Public Methods

#### public abstract [Enumeration](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Enumeration.html)\<[String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html)\>
**engineAliases**
()

Lists all the alias names of this keystore.

##### Returns

- enumeration of the alias names

#### public abstract boolean
**engineContainsAlias**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias)

Checks if the given alias exists in this keystore.

##### Parameters

| alias | the alias name |
|---|---|

##### Returns

- true if the alias exists, false otherwise

#### public abstract void
**engineDeleteEntry**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias)

Deletes the entry identified by the given alias from this keystore.

##### Parameters

| alias | the alias name |
|---|---|

##### Throws

| [KeyStoreException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreException.html) | if the entry cannot be removed. |
|---|---|

#### public boolean
**engineEntryInstanceOf**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, [Class](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html)\<? extends [KeyStore.Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.Entry.html)\> entryClass)

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

#### public abstract [Certificate](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html)
**engineGetCertificate**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias)

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
(if a chain exists) 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.

#### public abstract [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html)
**engineGetCertificateAlias**
([Certificate](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html) cert)

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 matching certificate, or null if no such entry exists in this keystore.

#### public abstract [Certificate\[\]](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html)
**engineGetCertificateChain**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias)

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

#### public abstract [Date](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Date.html)
**engineGetCreationDate**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias)

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

#### public [KeyStore.Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.Entry.html)
**engineGetEntry**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, [KeyStore.ProtectionParameter](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.ProtectionParameter.html) protParam)

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

| [KeyStoreException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreException.html) | if the operation failed |
| [NoSuchAlgorithmException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/NoSuchAlgorithmException.html) | if the algorithm for recovering the entry cannot be found |
| [UnrecoverableEntryException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/UnrecoverableEntryException.html) | if the specified `protParam` were insufficient or invalid |
| [UnrecoverableKeyException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/UnrecoverableKeyException.html) | 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) |
|---|---|

#### public abstract [Key](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Key.html)
**engineGetKey**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, char\[\] password)

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

| [NoSuchAlgorithmException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/NoSuchAlgorithmException.html) | if the algorithm for recovering the key cannot be found |
| [UnrecoverableKeyException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/UnrecoverableKeyException.html) | if the key cannot be recovered (e.g., the given password is wrong). |
|---|---|

#### public abstract boolean
**engineIsCertificateEntry**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) 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`.

##### 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.

#### public abstract boolean
**engineIsKeyEntry**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) 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`.

##### 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, false otherwise.

#### public void
**engineLoad**
([KeyStore.LoadStoreParameter](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.LoadStoreParameter.html) param)

Loads the keystore using the given
`KeyStore.LoadStoreParameter`.

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

##### Parameters

| param | the `KeyStore.LoadStoreParameter` that specifies how to load the keystore, which may be `null` |
|---|---|

##### Throws

| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) | if the given `KeyStore.LoadStoreParameter` input is not recognized |
| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | 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 `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Throwable.html#getCause()` of the `IOException` should be an `UnrecoverableKeyException` |
| [NoSuchAlgorithmException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/NoSuchAlgorithmException.html) | if the algorithm used to check the integrity of the keystore cannot be found |
| [CertificateException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/CertificateException.html) | if any of the certificates in the keystore could not be loaded |
|---|---|

#### public abstract void
**engineLoad**
([InputStream](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/InputStream.html) stream, char\[\] password)

Loads the 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.

##### 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](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | 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 `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Throwable.html#getCause()` of the `IOException` should be an `UnrecoverableKeyException` |
| [NoSuchAlgorithmException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/NoSuchAlgorithmException.html) | if the algorithm used to check the integrity of the keystore cannot be found |
| [CertificateException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/CertificateException.html) | if any of the certificates in the keystore could not be loaded |
|---|---|

#### public abstract void
**engineSetCertificateEntry**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, [Certificate](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html) cert)

Assigns the given 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](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreException.html) | if the given alias already exists and does not identify an entry containing a trusted certificate, or this operation fails for some other reason. |
|---|---|

#### public void
**engineSetEntry**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, [KeyStore.Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.Entry.html) entry, [KeyStore.ProtectionParameter](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.ProtectionParameter.html) protParam)

Saves a `KeyStore.Entry` under the specified alias.
The specified 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

| [KeyStoreException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreException.html) | if this operation fails |
|---|---|

#### public abstract void
**engineSetKeyEntry**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, [Key](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Key.html) key, char\[\] password, [Certificate\[\]](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html) chain)

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](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreException.html) | if the given key cannot be protected, or this operation fails for some other reason |
|---|---|

#### public abstract void
**engineSetKeyEntry**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) alias, byte\[\] key, [Certificate\[\]](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/Certificate.html) chain)

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 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](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStoreException.html) | if this operation fails. |
|---|---|

#### public abstract int
**engineSize**
()

Retrieves the number of entries in this keystore.

##### Returns

- the number of entries in this keystore

#### public void
**engineStore**
([KeyStore.LoadStoreParameter](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyStore.LoadStoreParameter.html) param)

Stores this keystore using the given
`KeyStore.LoadStoreParmeter`.

##### Parameters

| param | the `KeyStore.LoadStoreParmeter` that specifies how to store the keystore, which may be `null` |
|---|---|

##### Throws

| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) | if the given `KeyStore.LoadStoreParmeter` input is not recognized |
| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | if there was an I/O problem with data |
| [NoSuchAlgorithmException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/NoSuchAlgorithmException.html) | if the appropriate data integrity algorithm could not be found |
| [CertificateException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/CertificateException.html) | if any of the certificates included in the keystore data could not be stored |
|---|---|

#### public abstract void
**engineStore**
([OutputStream](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/OutputStream.html) stream, char\[\] password)

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

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | if there was an I/O problem with data |
| [NoSuchAlgorithmException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/NoSuchAlgorithmException.html) | if the appropriate data integrity algorithm could not be found |
| [CertificateException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/cert/CertificateException.html) | if any of the certificates included in the keystore data could not be stored |
|---|---|