public
  
  
  
  class
  CertificateFactory
  
    extends Object
  
  
  
  
  
  
| java.lang.Object | |
| ↳ | java.security.cert.CertificateFactory | 
This class defines the functionality of a certificate factory, which is
 used to generate certificate, certification path (CertPath)
 and certificate revocation list (CRL) objects from their encodings.
 
For encodings consisting of multiple certificates, use
 generateCertificates when you want to
 parse a collection of possibly unrelated certificates. Otherwise,
 use generateCertPath when you want to generate
 a CertPath (a certificate chain) and subsequently
 validate it with a CertPathValidator.
 
A certificate factory for X.509 must return certificates that are an
 instance of java.security.cert.X509Certificate, and CRLs
 that are an instance of java.security.cert.X509CRL.
 
The following example reads a file with Base64 encoded certificates,
 which are each bounded at the beginning by -----BEGIN CERTIFICATE-----, and
 bounded at the end by -----END CERTIFICATE-----. We convert the
 FileInputStream (which does not support mark
 and reset) to a BufferedInputStream (which
 supports those methods), so that each call to
 generateCertificate consumes only one certificate, and the
 read position of the input stream is positioned to the next certificate in
 the file:
 FileInputStream fis = new FileInputStream(filename);
 BufferedInputStream bis = new BufferedInputStream(fis);
 CertificateFactory cf = CertificateFactory.getInstance("X.509");
 while (bis.available() > 0) {
    Certificate cert = cf.generateCertificate(bis);
    System.out.println(cert.toString());
 }
 
 The following example parses a PKCS#7-formatted certificate reply stored in a file and extracts all the certificates from it:
 FileInputStream fis = new FileInputStream(filename);
 CertificateFactory cf = CertificateFactory.getInstance("X.509");
 Collection c = cf.generateCertificates(fis);
 Iterator i = c.iterator();
 while (i.hasNext()) {
    Certificate cert = (Certificate)i.next();
    System.out.println(cert);
 }
 
  Android provides the following CertificateFactory types:
 
| Name | Supported (API Levels) | 
|---|---|
| X.509 | 1+ | 
CertPath encodings:
 | Name | Supported (API Levels) | 
|---|---|
| PKCS7 | 1+ | 
| PkiPath | 1+ | 
| Protected constructors | |
|---|---|
| 
      CertificateFactory(CertificateFactorySpi certFacSpi, Provider provider, String type)
      Creates a CertificateFactory object of the given type, and encapsulates the given provider implementation (SPI object) in it. | |
| Public methods | |
|---|---|
| 
        
        
        
        final
        
        CRL | 
      generateCRL(InputStream inStream)
      Generates a certificate revocation list (CRL) object and initializes it
 with the data read from the input stream  | 
| 
        
        
        
        final
        
        Collection<? extends CRL> | 
      generateCRLs(InputStream inStream)
      Returns a (possibly empty) collection view of the CRLs read
 from the given input stream  | 
| 
        
        
        
        final
        
        CertPath | 
      generateCertPath(List<? extends Certificate> certificates)
      Generates a  | 
| 
        
        
        
        final
        
        CertPath | 
      generateCertPath(InputStream inStream)
      Generates a  | 
| 
        
        
        
        final
        
        CertPath | 
      generateCertPath(InputStream inStream, String encoding)
      Generates a  | 
| 
        
        
        
        final
        
        Certificate | 
      generateCertificate(InputStream inStream)
      Generates a certificate object and initializes it with
 the data read from the input stream  | 
| 
        
        
        
        final
        
        Collection<? extends Certificate> | 
      generateCertificates(InputStream inStream)
      Returns a (possibly empty) collection view of the certificates read
 from the given input stream  | 
| 
        
        
        
        final
        
        Iterator<String> | 
      getCertPathEncodings()
      Returns an iteration of the  | 
| 
        
        
        static
        final
        
        CertificateFactory | 
      getInstance(String type)
      Returns a certificate factory object that implements the specified certificate type. | 
| 
        
        
        static
        final
        
        CertificateFactory | 
      getInstance(String type, String provider)
      Returns a certificate factory object for the specified certificate type. | 
| 
        
        
        static
        final
        
        CertificateFactory | 
      getInstance(String type, Provider provider)
      Returns a certificate factory object for the specified certificate type. | 
| 
        
        
        
        final
        
        Provider | 
      getProvider()
      Returns the provider of this certificate factory. | 
| 
        
        
        
        final
        
        String | 
      getType()
      Returns the name of the certificate type associated with this certificate factory. | 
| Inherited methods | |
|---|---|
|  From
class 
  
    java.lang.Object
  
 | |
CertificateFactory (CertificateFactorySpi certFacSpi, Provider provider, String type)
Creates a CertificateFactory object of the given type, and encapsulates the given provider implementation (SPI object) in it.
| Parameters | |
|---|---|
| certFacSpi | CertificateFactorySpi:
          the provider implementation. | 
| provider | Provider:
          the provider. | 
| type | String:
          the certificate type. | 
CRL generateCRL (InputStream inStream)
Generates a certificate revocation list (CRL) object and initializes it
 with the data read from the input stream inStream.
 
In order to take advantage of the specialized CRL format
 supported by this certificate factory,
 the returned CRL object can be typecast to the corresponding
 CRL class. For example, if this certificate
 factory implements X.509 CRLs, the returned CRL object
 can be typecast to the X509CRL class.
 
Note that if the given input stream does not support
 mark and
 reset, this method will
 consume the entire input stream. Otherwise, each call to this
 method consumes one CRL and the read position of the input stream
 is positioned to the next available byte after the inherent
 end-of-CRL marker. If the data in the
 input stream does not contain an inherent end-of-CRL marker (other
 than EOF) and there is trailing data after the CRL is parsed, a
 CRLException is thrown.
| Parameters | |
|---|---|
| inStream | InputStream:
          an input stream with the CRL data. | 
| Returns | |
|---|---|
| CRL | a CRL object initialized with the data from the input stream. | 
| Throws | |
|---|---|
| CRLException | on parsing errors. | 
Collection<? extends CRL> generateCRLs (InputStream inStream)
Returns a (possibly empty) collection view of the CRLs read
 from the given input stream inStream.
 
In order to take advantage of the specialized CRL format
 supported by this certificate factory, each element in
 the returned collection view can be typecast to the corresponding
 CRL class. For example, if this certificate
 factory implements X.509 CRLs, the elements in the returned
 collection can be typecast to the X509CRL class.
 
In the case of a certificate factory for X.509 CRLs,
 inStream may contain a sequence of DER-encoded CRLs.
 In addition, inStream may contain a PKCS#7 CRL
 set. This is a PKCS#7 SignedData object, with the only
 significant field being crls. In particular, the
 signature and the contents are ignored. This format allows multiple
 CRLs to be downloaded at once. If no CRLs are present,
 an empty collection is returned.
 
Note that if the given input stream does not support
 mark and
 reset, this method will
 consume the entire input stream.
| Parameters | |
|---|---|
| inStream | InputStream:
          the input stream with the CRLs. | 
| Returns | |
|---|---|
| Collection<? extends CRL> | a (possibly empty) collection view of java.security.cert.CRL objects initialized with the data from the input stream. | 
| Throws | |
|---|---|
| CRLException | on parsing errors. | 
CertPath generateCertPath (List<? extends Certificate> certificates)
Generates a CertPath object and initializes it with
 a List of Certificates.
 
 The certificates supplied must be of a type supported by the
 CertificateFactory. They will be copied out of the supplied
 List object.
| Parameters | |
|---|---|
| certificates | List:
          aListofCertificates | 
| Returns | |
|---|---|
| CertPath | a CertPathinitialized with the supplied list of
   certificates | 
| Throws | |
|---|---|
| CertificateException | if an exception occurs | 
CertPath generateCertPath (InputStream inStream)
Generates a CertPath object and initializes it with
 the data read from the InputStream inStream. The data
 is assumed to be in the default encoding. The name of the default
 encoding is the first element of the Iterator returned by
 the getCertPathEncodings method.
| Parameters | |
|---|---|
| inStream | InputStream:
          anInputStreamcontaining the data | 
| Returns | |
|---|---|
| CertPath | a CertPathinitialized with the data from theInputStream | 
| Throws | |
|---|---|
| CertificateException | if an exception occurs while decoding | 
CertPath generateCertPath (InputStream inStream, String encoding)
Generates a CertPath object and initializes it with
 the data read from the InputStream inStream. The data
 is assumed to be in the specified encoding. See
 the CertPath Encodings section in the 
 Java Cryptography Architecture Standard Algorithm Name Documentation
 for information about standard encoding names and their formats.
| Parameters | |
|---|---|
| inStream | InputStream:
          anInputStreamcontaining the data | 
| encoding | String:
          the encoding used for the data | 
| Returns | |
|---|---|
| CertPath | a CertPathinitialized with the data from theInputStream | 
| Throws | |
|---|---|
| CertificateException | if an exception occurs while decoding or the encoding requested is not supported | 
Certificate generateCertificate (InputStream inStream)
Generates a certificate object and initializes it with
 the data read from the input stream inStream.
 
In order to take advantage of the specialized certificate format
 supported by this certificate factory,
 the returned certificate object can be typecast to the corresponding
 certificate class. For example, if this certificate
 factory implements X.509 certificates, the returned certificate object
 can be typecast to the X509Certificate class.
 
In the case of a certificate factory for X.509 certificates, the
 certificate provided in inStream must be DER-encoded and
 may be supplied in binary or printable (Base64) encoding. If the
 certificate is provided in Base64 encoding, it must be bounded at
 the beginning by -----BEGIN CERTIFICATE-----, and must be bounded at
 the end by -----END CERTIFICATE-----.
 
Note that if the given input stream does not support
 mark and
 reset, this method will
 consume the entire input stream. Otherwise, each call to this
 method consumes one certificate and the read position of the
 input stream is positioned to the next available byte after
 the inherent end-of-certificate marker. If the data in the input stream
 does not contain an inherent end-of-certificate marker (other
 than EOF) and there is trailing data after the certificate is parsed, a
 CertificateException is thrown.
| Parameters | |
|---|---|
| inStream | InputStream:
          an input stream with the certificate data. | 
| Returns | |
|---|---|
| Certificate | a certificate object initialized with the data from the input stream. | 
| Throws | |
|---|---|
| CertificateException | on parsing errors. | 
Collection<? extends Certificate> generateCertificates (InputStream inStream)
Returns a (possibly empty) collection view of the certificates read
 from the given input stream inStream.
 
In order to take advantage of the specialized certificate format
 supported by this certificate factory, each element in
 the returned collection view can be typecast to the corresponding
 certificate class. For example, if this certificate
 factory implements X.509 certificates, the elements in the returned
 collection can be typecast to the X509Certificate class.
 
In the case of a certificate factory for X.509 certificates,
 inStream may contain a sequence of DER-encoded certificates
 in the formats described for
 generateCertificate.
 In addition, inStream may contain a PKCS#7 certificate
 chain. This is a PKCS#7 SignedData object, with the only
 significant field being certificates. In particular, the
 signature and the contents are ignored. This format allows multiple
 certificates to be downloaded at once. If no certificates are present,
 an empty collection is returned.
 
Note that if the given input stream does not support
 mark and
 reset, this method will
 consume the entire input stream.
| Parameters | |
|---|---|
| inStream | InputStream:
          the input stream with the certificates. | 
| Returns | |
|---|---|
| Collection<? extends Certificate> | a (possibly empty) collection view of java.security.cert.Certificate objects initialized with the data from the input stream. | 
| Throws | |
|---|---|
| CertificateException | on parsing errors. | 
Iterator<String> getCertPathEncodings ()
Returns an iteration of the CertPath encodings supported
 by this certificate factory, with the default encoding first. See
 the CertPath Encodings section in the 
 Java Cryptography Architecture Standard Algorithm Name Documentation
 for information about standard encoding names and their formats.
 
 Attempts to modify the returned Iterator via its
 remove method result in an
 UnsupportedOperationException.
| Returns | |
|---|---|
| Iterator<String> | an Iteratorover the names of the supportedCertPathencodings (asStrings) | 
CertificateFactory getInstance (String type)
Returns a certificate factory object that implements the specified certificate type.
This method traverses the list of registered security Providers, starting with the most preferred Provider. A new CertificateFactory object encapsulating the CertificateFactorySpi 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.
| Parameters | |
|---|---|
| type | String:
          the name of the requested certificate type.
 See the CertificateFactory section in the 
 Java Cryptography Architecture Standard Algorithm Name Documentation
 for information about standard certificate types. | 
| Returns | |
|---|---|
| CertificateFactory | a certificate factory object for the specified type. | 
| Throws | |
|---|---|
| CertificateException | if no Provider supports a CertificateFactorySpi implementation for the specified type. | 
See also:
CertificateFactory getInstance (String type, String provider)
Returns a certificate factory object for the specified certificate type.
A new CertificateFactory object encapsulating the CertificateFactorySpi implementation from the specified provider is returned. The specified provider must be registered in the security provider list.
 Note that the list of registered providers may be retrieved via
 the Security.getProviders() method.
| Parameters | |
|---|---|
| type | String:
          the certificate type.
 See the CertificateFactory section in the 
 Java Cryptography Architecture Standard Algorithm Name Documentation
 for information about standard certificate types. | 
| provider | String:
          the name of the provider. | 
| Returns | |
|---|---|
| CertificateFactory | a certificate factory object for the specified type. | 
| Throws | |
|---|---|
| CertificateException | if a CertificateFactorySpi implementation for the specified algorithm is not available from the specified provider. | 
| NoSuchProviderException | if the specified provider is not registered in the security provider list. | 
| IllegalArgumentException | if the provider name is null or empty. | 
See also:
CertificateFactory getInstance (String type, Provider provider)
Returns a certificate factory object for the specified certificate type.
A new CertificateFactory object encapsulating the CertificateFactorySpi 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 | String:
          the certificate type.
 See the CertificateFactory section in the 
 Java Cryptography Architecture Standard Algorithm Name Documentation
 for information about standard certificate types. | 
| provider | Provider:
          the provider. | 
| Returns | |
|---|---|
| CertificateFactory | a certificate factory object for the specified type. | 
| Throws | |
|---|---|
| CertificateException | if a CertificateFactorySpi implementation for the specified algorithm is not available from the specified Provider object. | 
| IllegalArgumentException | if the provideris
          null. | 
See also:
Provider getProvider ()
Returns the provider of this certificate factory.
| Returns | |
|---|---|
| Provider | the provider of this certificate factory. | 
String getType ()
Returns the name of the certificate type associated with this certificate factory.
| Returns | |
|---|---|
| String | the name of the certificate type associated with this certificate factory. |