본문 바로가기

카테고리 없음

Java Generate Key Pair Programmatically



The KeyPairGenerator class is used to generate pairs of public and private keys. Key pair generators are constructed using the
  1. It lacked one particular feature - it couldn't put a private key of a key pair in a certificate store. When you try to import a generated self-signed certificate and a key pair into a certificate store, a private key is always lost in the process and you can't export it with the certificate later.
  2. I would like to generate a key pair and insert it into a Java KeyStore programmatically. I can use the command line to do exactly what I want, but how to do that using Java code? Here is the command.

The Java KeyPairGenerator class (java.security.KeyPairGenerator) is used to generate asymmetric encryption / decryption key pairs. An asymmetric key pair consists of two keys. The first key is typically used to encrypt data. The second key which is used to decrypt data encrypted with the first key. Public Key, Private Key Type Key Pairs.

https://admelcomdi.tistory.com/4. The /dev/random source is a special file that serves as a blocking pseudorandom number generator which allows access to environmental noise collected from device drivers and other sources.

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.

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 Key Pair Programmatically
  • 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. 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. The sims 3 seasons key generator free. 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.)

Generate Key Code

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.

Java Generate Key Pair Programmatically Windows 10

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:

Java Generate Key Pair Programmatically
  • DiffieHellman (1024)
  • DSA (1024)
  • RSA (1024, 2048)
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.