java.security.KeyFactory - Reading Encoded Keys

This section describes the java.security.KeyFactory class, which allows you to convert key spec objects back to key objects. Full process of reading and converting encoded key files back to key objects are also provided.

In the previous chapter, we learned how to write keys into files as encoded byte strings generated by the java.security.Key.getEncoded() method. Now we want to learn how to read those encoded type strings back and convert them into keys using 3 classes: java.security.spec.PKCS8EncodedKeySpec, java.security.spec.X509EncodedKeySpec, and java.security.KeyFactory.

PKCS8EncodedKeySpec and X509EncodedKeySpec classes are described in the previous section. Here is a quick description of the KeyFactory class.

java.security.KeyFactory - A class to convert keys between Key objects and EncodedKeySpec objects. Major methods offered:

getInstance() - Returns a KeyFactory object of the specified algorithm and the specified security package provider. If not specified, the default security package provider will be used.

generatePrivate() - Generates a PrivateKey object based on the specified EncodedKeySpec object, and returns it.

generatePublic() - Generates a PublicKey object based on the specified EncodedKeySpec object, and returns it.

getKeySpec() - Converts a Key object to an EncodedKeySpec object, and returns it.

getAlgorithm() - Returns the algorithm name of this object.

getProvider() - Returns the provider as a provider object of this object.

To read an encoded byte string and convert it back a key, you need to follow these steps:

See the next section on how to write a sample program.

Last update: 2014.

Table of Contents

 About This JDK Tutorial Book

 Downloading and Installing JDK 1.8.0 on Windows

 Downloading and Installing JDK 1.7.0 on Windows

 Downloading and Installing JDK 1.6.2 on Windows

 Java Date-Time API

 Date, Time and Calendar Classes

 Date and Time Object and String Conversion

 Number Object and Numeric String Conversion

 Locales, Localization Methods and Resource Bundles

 Calling and Importing Classes Defined in Unnamed Packages

 HashSet, Vector, HashMap and Collection Classes

 Character Set Encoding Classes and Methods

 Character Set Encoding Maps

 Encoding Conversion Programs for Encoded Text Files

 Socket Network Communication

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 DOM (Document Object Model) - API for XML Files

 SAX (Simple API for XML)

 DTD (Document Type Definition) - XML Validation

 XSD (XML Schema Definition) - XML Validation

 XSL (Extensible Stylesheet Language)

 Message Digest Algorithm Implementations in JDK

 Private key and Public Key Pair Generation

PKCS#8/X.509 Private/Public Encoding Standards

 What Is Key Encoding?

 PKCS#8 and X.509 Key Encoding Classes

java.security.KeyFactory - Reading Encoded Keys

 JcaKeyFactoryTest.java - Key Factory Test Program

 Reading DSA Private and Public Key Files

 Reading RSA Private and Public Key Files

 Digital Signature Algorithm and Sample Program

 "keytool" Commands and "keystore" Files

 KeyStore and Certificate Classes

 Secret Key Generation and Management

 Cipher - Secret Key Encryption and Decryption

 The SSL (Secure Socket Layer) Protocol

 SSL Socket Communication Testing Programs

 SSL Client Authentication

 HTTPS (Hypertext Transfer Protocol Secure)

 Outdated Tutorials

 References

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