JRE 8 rt.jar is the JAR file for JRE 8 RT (Runtime) libraries. JRE (Java Runtime) 8 is the runtime environment included in JDK 8. JRE 8 rt.jar libraries are divided into 6 packages:

com.* - Internal Oracle and Sun Microsystems libraries
java.* - Standard Java API libraries.
javax.* - Extended Java API libraries.
jdk.* -  JDK supporting libraries.
org.* - Third party libraries.
sun.* - Old libraries developed by Sun Microsystems.

JAR File Information:

Directory of C:\fyicenter\jdk-1.8.0_191\jre\lib
      63,596,151 rt.jar

Here is the list of Java classes of the java.* package in JRE 1.8.0_191 rt.jar. Java source codes are also provided.

⏎ java/security/spec/RSAPrivateKeySpec.java

/*
 * Copyright (c) 1998, 2001, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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package java.security.spec;

import java.math.BigInteger;

/**
 * This class specifies an RSA private key.
 *
 * @author Jan Luehe
 *
 *
 * @see java.security.Key
 * @see java.security.KeyFactory
 * @see KeySpec
 * @see PKCS8EncodedKeySpec
 * @see RSAPublicKeySpec
 * @see RSAPrivateCrtKeySpec
 */

public class RSAPrivateKeySpec implements KeySpec {

    private BigInteger modulus;
    private BigInteger privateExponent;

    /**
     * Creates a new RSAPrivateKeySpec.
     *
     * @param modulus the modulus
     * @param privateExponent the private exponent
     */
    public RSAPrivateKeySpec(BigInteger modulus, BigInteger privateExponent) {
        this.modulus = modulus;
        this.privateExponent = privateExponent;
    }

    /**
     * Returns the modulus.
     *
     * @return the modulus
     */
    public BigInteger getModulus() {
        return this.modulus;
    }

    /**
     * Returns the private exponent.
     *
     * @return the private exponent
     */
    public BigInteger getPrivateExponent() {
        return this.privateExponent;
    }
}

⏎ java/security/spec/RSAPrivateKeySpec.java

Or download all of them as a single archive file:

File name: jre-rt-java-1.8.0_191-src.zip
File size: 6664831 bytes
Release date: 2018-10-28
Download 

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