Module java.base
Package java.security

Class 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

    • Constructor Detail

      • KeyStore

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

    • Method Detail

      • getInstance

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

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

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

        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,
                                   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.

      • 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).

      • 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

      • 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