Module java.base
Package java.security.cert

## Class PKIXBuilderParameters

- java.lang.Object
- - java.security.cert.PKIXParameters
  - - java.security.cert.PKIXBuilderParameters

- All Implemented Interfaces:
    `Cloneable`, `CertPathParameters`

      public class PKIXBuilderParameters
      extends PKIXParameters

  Parameters used as input for the PKIX `CertPathBuilder` algorithm.

  A PKIX `CertPathBuilder` uses these parameters to `build` a `CertPath` which has been validated according to the PKIX certification path validation algorithm.

  To instantiate a `PKIXBuilderParameters` object, an application must specify one or more most-trusted CAs as defined by the PKIX certification path validation algorithm. The most-trusted CA can be specified using one of two constructors. An application can call `PKIXBuilderParameters(Set, CertSelector)`, specifying a `Set` of `TrustAnchor` objects, each of which identifies a most-trusted CA. Alternatively, an application can call `PKIXBuilderParameters(KeyStore, CertSelector)`, specifying a `KeyStore` instance containing trusted certificate entries, each of which will be considered as a most-trusted CA.

  In addition, an application must specify constraints on the target certificate that the `CertPathBuilder` will attempt to build a path to. The constraints are specified as a `CertSelector` object. These constraints should provide the `CertPathBuilder` with enough search criteria to find the target certificate. Minimal criteria for an `X509Certificate` usually include the subject name and/or one or more subject alternative names. If enough criteria is not specified, the `CertPathBuilder` may throw a `CertPathBuilderException`.

  Concurrent Access

  Unless otherwise specified, the methods defined in this class are not thread-safe. Multiple threads that need to access a single object concurrently should synchronize amongst themselves and provide the necessary locking. Multiple threads each manipulating separate objects need not synchronize.

  Since:
    1.4
  See Also:
    `CertPathBuilder`

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `PKIXBuilderParameters​(KeyStore keystore, CertSelector targetConstraints)` | Creates an instance of `PKIXBuilderParameters` that populates the set of most-trusted CAs from the trusted certificate entries contained in the specified `KeyStore`.
    `PKIXBuilderParameters​(Set<TrustAnchor> trustAnchors, CertSelector targetConstraints)` | Creates an instance of `PKIXBuilderParameters` with the specified `Set` of most-trusted CAs.

  - ### Method Summary

    Modifier and Type | Method | Description
    --- | --- | ---
    `int` | `getMaxPathLength()` | Returns the value of the maximum number of intermediate non-self-issued certificates that may exist in a certification path.
    `void` | `setMaxPathLength​(int maxPathLength)` | Sets the value of the maximum number of non-self-issued intermediate certificates that may exist in a certification path.
    `String` | `toString()` | Returns a formatted string describing the parameters.

    - ### Methods declared in class java.security.cert.PKIXParameters

      `addCertPathChecker, addCertStore, clone, getCertPathCheckers, getCertStores, getDate, getInitialPolicies, getPolicyQualifiersRejected, getSigProvider, getTargetCertConstraints, getTrustAnchors, isAnyPolicyInhibited, isExplicitPolicyRequired, isPolicyMappingInhibited, isRevocationEnabled, setAnyPolicyInhibited, setCertPathCheckers, setCertStores, setDate, setExplicitPolicyRequired, setInitialPolicies, setPolicyMappingInhibited, setPolicyQualifiersRejected, setRevocationEnabled, setSigProvider, setTargetCertConstraints, setTrustAnchors`

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

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

- - ### Constructor Detail

    - #### PKIXBuilderParameters

          public PKIXBuilderParameters​(Set<TrustAnchor> trustAnchors,
                                       CertSelector targetConstraints)
                                throws InvalidAlgorithmParameterException

      Creates an instance of `PKIXBuilderParameters` with the specified `Set` of most-trusted CAs. Each element of the set is a `TrustAnchor`.

      Note that the `Set` is copied to protect against subsequent modifications.

      Parameters:
        `trustAnchors` - a `Set` of `TrustAnchor`s
        `targetConstraints` - a `CertSelector` specifying the constraints on the target certificate
      Throws:
        `InvalidAlgorithmParameterException` - if `trustAnchors` is empty `(trustAnchors.isEmpty() == true)`
        `NullPointerException` - if `trustAnchors` is `null`
        `ClassCastException` - if any of the elements of `trustAnchors` are not of type `java.security.cert.TrustAnchor`

    - #### PKIXBuilderParameters

          public PKIXBuilderParameters​(KeyStore keystore,
                                       CertSelector targetConstraints)
                                throws KeyStoreException,
                                       InvalidAlgorithmParameterException

      Creates an instance of `PKIXBuilderParameters` that populates the set of most-trusted CAs from the trusted certificate entries contained in the specified `KeyStore`. Only keystore entries that contain trusted `X509Certificate`s are considered; all other certificate types are ignored.
      Parameters:
        `keystore` - a `KeyStore` from which the set of most-trusted CAs will be populated
        `targetConstraints` - a `CertSelector` specifying the constraints on the target certificate
      Throws:
        `KeyStoreException` - if `keystore` has not been initialized
        `InvalidAlgorithmParameterException` - if `keystore` does not contain at least one trusted certificate entry
        `NullPointerException` - if `keystore` is `null`

  - ### Method Detail

    - #### setMaxPathLength

          public void setMaxPathLength​(int maxPathLength)

      Sets the value of the maximum number of non-self-issued intermediate certificates that may exist in a certification path. A certificate is self-issued if the DNs that appear in the subject and issuer fields are identical and are not empty. Note that the last certificate in a certification path is not an intermediate certificate, and is not included in this limit. Usually the last certificate is an end entity certificate, but it can be a CA certificate. A PKIX `CertPathBuilder` instance must not build paths longer than the length specified.

      A value of 0 implies that the path can only contain a single certificate. A value of -1 implies that the path length is unconstrained (i.e. there is no maximum). The default maximum path length, if not specified, is 5. Setting a value less than -1 will cause an exception to be thrown.

      If any of the CA certificates contain the `BasicConstraintsExtension`, the value of the `pathLenConstraint` field of the extension overrides the maximum path length parameter whenever the result is a certification path of smaller length.

      Parameters:
        `maxPathLength` - the maximum number of non-self-issued intermediate certificates that may exist in a certification path
      Throws:
        `InvalidParameterException` - if `maxPathLength` is set to a value less than -1
      See Also:
        `getMaxPathLength()`

    - #### getMaxPathLength

          public int getMaxPathLength()

      Returns the value of the maximum number of intermediate non-self-issued certificates that may exist in a certification path. See the `setMaxPathLength(int)` method for more details.
      Returns:
        the maximum number of non-self-issued intermediate certificates that may exist in a certification path, or -1 if there is no limit
      See Also:
        `setMaxPathLength(int)`

    - #### toString

          public String toString()

      Returns a formatted string describing the parameters.
      Overrides:
        `toString` in class `PKIXParameters`
      Returns:
        a formatted string describing the parameters