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 Details

### 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 Details

### 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