This chapter demonstrates how to generate an RSA based OpenPGP key pair with OpenPGP Library for Java.

• Java Generate Rsa 2048 Keys
• Java Generate Rsa 2048 Key Download
• Java Generate Rsa 2048 Key Download

Usage Guide - RSA Encryption and Decryption Online. In the first section of this tool, you can generate public or private keys. To do so, select the RSA key size among 515, 1024, 2048 and 4096 bit click on the button. Dummy tools to generate RSA 2048 key pair, to encrypt strings with pub key and also decrypt string with private keys - RSAKeyGenMain.java.

When we create an OpenPGP key pair, a few parameters must be passed. These include:

• Encryption key size in bytes (recommended between 1024 and 3072)
• User ID
• key algorithm (RSA or ELGAMAL)
• private key password
• list of preferred compression algorithms
• list of preferred signature hash algorithms
• list of preferred symmetric encryption algorithms
• key expiration date (optional)

One note regarding the naming convention for the User ID parameter. The original PGP(r) software is delimiting the email in the User ID with < and > like : “Richard C. <richard.c@site.com>”

An overloaded method exists that accepts key expiration date as a last parameter.

Table of Contents

1. Key generation with a KeyStore

2. Key generation directly

3. Exception handling

1. Key generation example

After the key pair is generated usually we will export the public key and send it to our partners.

Below is a screenshot of the generated key properties when we open it with PGP (r) 10:

2. Key generation directly

We can avoid the use of a KeyStore class and generate a key pair in the memory in a PGPKeyPair object. In that case we also have to export it afterwards.

3. Exception Handling

The key pair generation methods simply throw com.didisoft.pgp.PGPException in case the key generation fails.

Summary

This chapter demonstrated how to generate an RSA OpenPGP key pair with DidiSoft OpenPGP Library for Java.

The KeyPairGenerator class is used to generate pairs of public and private keys. Key pair generators are constructed using the getInstance factory methods (static methods that return instances of a given class).

A Key pair generator for a particular algorithm creates a public/private key pair that can be used with this algorithm. It also associates algorithm-specific parameters with each of the generated keys.

Java Generate Rsa 2048 Keys

There are two ways to generate a key pair: in an algorithm-independent manner, and in an algorithm-specific manner. The only difference between the two is the initialization of the object:

Java Generate Rsa 2048 Key Download

• Algorithm-Independent Initialization

  All key pair generators share the concepts of a keysize and a source of randomness. The keysize is interpreted differently for different algorithms (e.g., in the case of the DSA algorithm, the keysize corresponds to the length of the modulus). There is an initialize method in this KeyPairGenerator class that takes these two universally shared types of arguments. There is also one that takes just a keysize argument, and uses the SecureRandom implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation of SecureRandom, a system-provided source of randomness is used.)

  Since no other parameters are specified when you call the above algorithm-independent initialize methods, it is up to the provider what to do about the algorithm-specific parameters (if any) to be associated with each of the keys.

  If the algorithm is the DSA algorithm, and the keysize (modulus size) is 512, 768, or 1024, then the Sun provider uses a set of precomputed values for the p, q, and g parameters. If the modulus size is not one of the above values, the Sun provider creates a new set of parameters. /openssl-generate-private-key-and-csr-as-pem.html. Other providers might have precomputed parameter sets for more than just the three modulus sizes mentioned above. Still others might not have a list of precomputed parameters at all and instead always create new parameter sets.

• Algorithm-Specific Initialization

  For situations where a set of algorithm-specific parameters already exists (e.g., so-called community parameters in DSA), there are two initialize methods that have an AlgorithmParameterSpec argument. One also has a SecureRandom argument, while the the other uses the SecureRandom implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation of SecureRandom, a system-provided source of randomness is used.)

In case the client does not explicitly initialize the KeyPairGenerator (via a call to an initialize method), each provider must supply (and document) a default initialization. For example, the Sun provider uses a default modulus size (keysize) of 1024 bits.

Note that this class is abstract and extends from KeyPairGeneratorSpi for historical reasons. Application developers should only take notice of the methods defined in this KeyPairGenerator class; all the methods in the superclass are intended for cryptographic service providers who wish to supply their own implementations of key pair generators.

Every implementation of the Java platform is required to support the following standard KeyPairGenerator algorithms and keysizes in parentheses:

• DiffieHellman (1024)
• DSA (1024)
• RSA (1024, 2048)

Java Generate Rsa 2048 Key Download

These algorithms are described in the KeyPairGenerator section of the Java Cryptography Architecture Standard Algorithm Name Documentation. Consult the release documentation for your implementation to see if any other algorithms are supported.