# Interface X509KeyManager

All Superinterfaces:
  `KeyManager`

All Known Implementing Classes:
  `X509ExtendedKeyManager`

public interface X509KeyManager extends KeyManager
Instances of this interface manage which X509 certificate-based key pairs are used to authenticate the local side of a secure socket.

During secure socket negotiations, implementations call methods in this interface to:

- determine the set of aliases that are available for negotiations based on the criteria presented,
- select the best alias based on the criteria presented, and
- obtain the corresponding key material for given aliases.

Note: the X509ExtendedKeyManager should be used in favor of this class.

Since:
  1.4

- ## Method Summary

  Modifier and Type
  Method
  Description
  `String`
  `chooseClientAlias(String[] keyType, Principal[] issuers, Socket socket)`
  Choose an alias to authenticate the client side of a secure socket given the public key type and the list of certificate issuer authorities recognized by the peer (if any).
  `String`
  `chooseServerAlias(String keyType, Principal[] issuers, Socket socket)`
  Choose an alias to authenticate the server side of a secure socket given the public key type and the list of certificate issuer authorities recognized by the peer (if any).
  `X509Certificate[]`
  `getCertificateChain(String alias)`
  Returns the certificate chain associated with the given alias.
  `String[]`
  `getClientAliases(String keyType, Principal[] issuers)`
  Get the matching aliases for authenticating the client side of a secure socket given the public key type and the list of certificate issuer authorities recognized by the peer (if any).
  `PrivateKey`
  `getPrivateKey(String alias)`
  Returns the key associated with the given alias.
  `String[]`
  `getServerAliases(String keyType, Principal[] issuers)`
  Get the matching aliases for authenticating the server side of a secure socket given the public key type and the list of certificate issuer authorities recognized by the peer (if any).

- ## Method Details

  - ### getClientAliases

    String[] getClientAliases(String keyType, Principal[] issuers)
    Get the matching aliases for authenticating the client side of a secure socket given the public key type and the list of certificate issuer authorities recognized by the peer (if any).
    Parameters:
      `keyType` - the key algorithm type name
      `issuers` - the list of acceptable CA issuer subject names, or null if it does not matter which issuers are used.
    Returns:
      an array of the matching alias names, or null if there were no matches.

  - ### chooseClientAlias

    String chooseClientAlias(String[] keyType, Principal[] issuers, Socket socket)
    Choose an alias to authenticate the client side of a secure socket given the public key type and the list of certificate issuer authorities recognized by the peer (if any).
    Parameters:
      `keyType` - the key algorithm type name(s), ordered with the most-preferred key type first.
      `issuers` - the list of acceptable CA issuer subject names or null if it does not matter which issuers are used.
      `socket` - the socket to be used for this connection. This parameter can be null, which indicates that implementations are free to select an alias applicable to any socket.
    Returns:
      the alias name for the desired key, or null if there are no matches.

  - ### getServerAliases

    String[] getServerAliases(String keyType, Principal[] issuers)
    Get the matching aliases for authenticating the server side of a secure socket given the public key type and the list of certificate issuer authorities recognized by the peer (if any).
    Parameters:
      `keyType` - the key algorithm type name
      `issuers` - the list of acceptable CA issuer subject names or null if it does not matter which issuers are used.
    Returns:
      an array of the matching alias names, or null if there were no matches.

  - ### chooseServerAlias

    String chooseServerAlias(String keyType, Principal[] issuers, Socket socket)
    Choose an alias to authenticate the server side of a secure socket given the public key type and the list of certificate issuer authorities recognized by the peer (if any).
    Parameters:
      `keyType` - the key algorithm type name.
      `issuers` - the list of acceptable CA issuer subject names or null if it does not matter which issuers are used.
      `socket` - the socket to be used for this connection. This parameter can be null, which indicates that implementations are free to select an alias applicable to any socket.
    Returns:
      the alias name for the desired key, or null if there are no matches.

  - ### getCertificateChain

    X509Certificate[] getCertificateChain(String alias)
    Returns the certificate chain associated with the given alias.
    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 alias can't be found.

  - ### getPrivateKey

    PrivateKey getPrivateKey(String alias)
    Returns the key associated with the given alias.
    Parameters:
      `alias` - the alias name
    Returns:
      the requested key, or null if the alias can't be found.