Rsa Chilkat2 Java Reference Documentation

Rsa

Current Version: 11.7.0

Markdown version of this page for AI tools (v 11.7.0) · all AI docs

Chilkat.Rsa

Encrypt, decrypt, sign, verify, and generate RSA keys.

Use Chilkat.Rsa when an application needs direct RSA cryptographic operations. It can encrypt data with a public key, decrypt with a private key, create RSA signatures, verify signatures, sign precomputed hashes, verify signed hashes, and generate RSA key pairs. It also works with keys supplied directly as PrivateKey or PublicKey objects, or indirectly through certificates.

RSA encryption

Encrypt data with a public key for workflows where only the matching private key should be able to decrypt the result.

RSA decryption

Decrypt RSA-encrypted data using a private key, including keys loaded directly or accessed through a certificate.

Sign and verify data

Create and verify RSA signatures over data using the hash algorithm and padding mode required by the application or protocol.

Sign precomputed hashes

Sign or verify already-computed message digests when the hashing step is performed separately or by another component.

Generate RSA keys

Generate RSA key pairs for applications that need new public/private key material.

Certificate-backed keys

Use RSA keys associated with certificates, including non-exportable private keys in smart cards, USB tokens, Windows stores, or Apple Keychain.

Common pattern: Load or generate the RSA key material, configure the padding, hash, charset, and encoding options needed by the protocol, then call the method matching the operation: encrypt, decrypt, sign, verify, sign-hash, or verify-hash. Use Chilkat.Rsa for direct RSA operations; use higher-level classes such as Crypt2, Jws, Jwt, or Mime when the RSA operation is part of a larger format or protocol.

For an extended overview, see Rsa Class Overview.

Object Creation

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Rsa;

try (Rsa rsa = new Rsa()) {
    // ... use rsa ...
} catch (ChilkatException e) {
    System.out.println(e.getMessage());          // "Rsa.someMethod failed: <reason>"
    System.out.println(e.getLastErrorText());    // the full log of the failed call
}

public Rsa()

Creates the underlying native Chilkat object. The native library (chilkat2java) is loaded the first time any Chilkat2 object is created; see the README in the download for where it is looked for (-Dchilkat2.library.path, a classpath resource, or java.library.path).

public void close()

Releases the native object (Rsa is AutoCloseable, so try-with-resources calls it). Calling it again does nothing; any other method or property accessor called afterwards throws IllegalStateException. An object that is never closed is freed by a background cleaner once it becomes unreachable, but the garbage collector does not see native memory, so closing is the normal path. Objects returned by methods are owned by the caller too.

public boolean isClosed()

Returns true once close() has been called.

Errors

A method that fails throws ChilkatException, an unchecked exception carrying getClassName(), getMethodName(), getReason() (one line, also in the message) and getLastErrorText() (the full log, captured at the moment of the failure). The object remains usable. Methods that look something up and find nothing return null instead of throwing (each such method says so), and methods that answer a question (hasMember, isUnlocked, ...) return a plain boolean. Property accessors do not throw for Chilkat reasons.

A null string or object argument throws NullPointerException naming the parameter (except where a method documents that null is accepted), and a string containing U+0000 throws IllegalArgumentException.

Use an object from one thread at a time; it may be handed from one thread to another. The one cross-thread operation is setting setAbortCurrent(true) on an object that is busy in another thread (on the classes that have AbortCurrent). Unlocking: call new Global().unlockBundle("...") once at startup.

Properties

Charset

// read/write
String getCharset()
void setCharset(String value)

This property specifies the character encoding used to represent text as bytes for encryption, decryption, signing, and signature validation. By default, it uses the computer's ANSI charset, such as Windows-1252 for locales like the United States, United Kingdom, Western Europe, Australia, and New Zealand.

Most applications are advised to set this property to UTF-8. Chilkat plans to change its default to UTF-8 in a future major version to align with current standards. The current default of ANSI stems from a time when UTF-8 was not widely adopted.

More Information and Examples

How Charset Affects RSA ANSI Charset Explained Charset Considerations when RSA Encrypting Strings

Rsa Chilkat2 Java Reference Documentation

Rsa

Current Version: 11.7.0

Encrypt, decrypt, sign, verify, and generate RSA keys.

RSA encryption

RSA decryption

Sign and verify data

Sign precomputed hashes

Generate RSA keys

Certificate-backed keys

Object Creation

Errors

Properties

Charset

DebugLogFilePath

EncodingMode

LastErrorHtml

LastErrorText

LastErrorXml

LastMethodSuccess

LittleEndian

NoUnpad

NumBits

OaepHash

OaepLabel

OaepMgfHash

PkcsPadding

PssSaltLen

UncommonOptions

VerboseLogging

Version

Methods

DecryptBd

DecryptStringENC

EncryptBd

EncryptStringENC

GenKey

SetX509Cert

SignBd

SignHashENC

SignRawBd

SignStringENC

SnkToXml

UsePrivateKey

UsePublicKey

VerifyBd

VerifyHashENC

VerifyRawBd

VerifyStringENC