Implement the Function in C using Function parameters are void cbc_enc_three_blo
ID: 3600766 • Letter: I
Question
Implement the Function in C using
Function parameters are
void cbc_enc_three_blocks(char block1[8],char block2[8], char block3[8], char IV[8],keysched *ks)
{
// You write this code
}
Definition 5.1.2 Cipher block chaining mode (CBC) Let e) be a block cipher of block size b; let x, and y, be bit strings of length b; and IV be a nonce of length b. Encryption (first block): yi -ez(xi IV) Encryption (general block): y,-ek(xiyi-1), i22Explanation / Answer
import java.util.NoSuchElementException; /** * The {@code BST} class represents an ordered symbol table of generic * key-value pairs. * It supports the usual put, get, contains, * delete, size, and is-empty methods. * It also provides ordered methods for finding the minimum, * maximum, floor, select, ceiling. * It also provides a keys method for iterating over all of the keys. * A symbol table implements the associative array abstraction: * when associating a value with a key that is already in the symbol table, * the convention is to replace the old value with the new value. * Unlike {@link java.util.Map}, this class uses the convention that * values cannot be {@code null}—setting the * value associated with a key to {@code null} is equivalent to deleting the key * from the symbol table. ** This implementation uses an (unbalanced) binary search tree. It requires that * the key type implements the {@code Comparable} interface and calls the * {@code compareTo()} and method to compare two keys. It does not call either * {@code equals()} or {@code hashCode()}. * The put, contains, remove, minimum, * maximum, ceiling, floor, select, and * rank operations each take * linear time in the worst case, if the tree becomes unbalanced. * The size, and is-empty operations take constant time. * Construction takes constant time. *
* For additional documentation, see Section 3.2 of * Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne. * For other implementations, see {@link ST}, {@link BinarySearchST}, * {@link SequentialSearchST}, {@link RedBlackBST}, * {@link SeparateChainingHashST}, and {@link LinearProbingHashST}, * * @author Robert Sedgewick * @author Kevin Wayne */ public class BST { private Node root; // root of BST private class Node { private Key key; // sorted by key private Value val; // associated data private Node left, right; // left and right subtrees private int size; // number of nodes in subtree public Node(Key key, Value val, int size) { this.key = key; this.val = val; this.size = size; } } /** * Initializes an empty symbol table. */ public BST() { } /** * Returns true if this symbol table is empty. * @return {@code true} if this symbol table is empty; {@code false} otherwise */ public boolean isEmpty() { return size() == 0; } /** * Returns the number of key-value pairs in this symbol table. * @return the number of key-value pairs in this symbol table */ public int size() { return size(root); } // return number of key-value pairs in BST rooted at x private int size(Node x) { if (x == null) return 0; else return x.size; } /** * Does this symbol table contain the given key? * * @param key the key * @return {@code true} if this symbol table contains {@code key} and * {@code false} otherwise * @throws IllegalArgumentException if {@code key} is {@code null} */ public boolean contains(Key key) { if (key == null) throw new IllegalArgumentException("argument to contains() is null"); return get(key) != null; } /** * Returns the value associated with the given key. * * @param key the key * @return the value associated with the given key if the key is in the symbol table * and {@code null} if the key is not in the symbol table * @throws IllegalArgumentException if {@code key} is {@code null} */ public Value get(Key key) { return get(root, key); } private Value get(Node x, Key key) { if (key == null) throw new IllegalArgumentException("calls get() with a null key"); if (x == null) return null; int cmp = key.compareTo(x.key); if (cmp < 0) return get(x.left, key); else if (cmp > 0) return get(x.right, key); else return x.val; } /** * Inserts the specified key-value pair into the symbol table, overwriting the old * value with the new value if the symbol table already contains the specified key. * Deletes the specified key (and its associated value) from this symbol table * if the specified value is {@code null}. * * @param key the key * @param val the value * @throws IllegalArgumentException if {@code key} is {@code null} */ public void put(Key key, Value val) { if (key == null) throw new IllegalArgumentException("calls put() with a null key"); if (val == null) { delete(key); return; } root = put(root, key, val); assert check(); } private Node put(Node x, Key key, Value val) { if (x == null) return new Node(key, val, 1); int cmp = key.compareTo(x.key); if (cmp < 0) x.left = put(x.left, key, val); else if (cmp > 0) x.right = put(x.right, key, val); else x.val = val; x.size = 1 + size(x.left) + size(x.right); return x; } /** * Removes the smallest key and associated value from the symbol table. * * @throws NoSuchElementException if the symbol table is empty */ public void deleteMin() { if (isEmpty()) throw new NoSuchElementException("Symbol table underflow"); root = deleteMin(root); assert check(); } private Node deleteMin(Node x) { if (x.left == null) return x.right; x.left = deleteMin(x.left); x.size = size(x.left) + size(x.right) + 1; return x; } /** * Removes the largest key and associated value from the symbol table. * * @throws NoSuchElementException if the symbol table is empty */ public void deleteMax() { if (isEmpty()) throw new NoSuchElementException("Symbol table underflow"); root = deleteMax(root); assert check(); } private Node deleteMax(Node x) { if (x.right == null) return x.left; x.right = deleteMax(x.right); x.size = size(x.left) + size(x.right) + 1; return x; } /** * Removes the specified key and its associated value from this symbol table * (if the key is in this symbol table). * * @param key the key * @throws IllegalArgumentException if {@code key} is {@code null} */ public void delete(Key key) { if (key == null) throw new IllegalArgumentException("calls delete() with a null key"); root = delete(root, key); assert check(); } private Node delete(Node x, Key key) { if (x == null) return null; int cmp = key.compareTo(x.key); if (cmp < 0) x.left = delete(x.left, key); else if (cmp > 0) x.right = delete(x.right, key); else { if (x.right == null) return x.left; if (x.left == null) return x.right; Node t = x; x = min(t.right); x.right = deleteMin(t.right); x.left = t.left; } x.size = size(x.left) + size(x.right) + 1; return x; } /** * Returns the smallest key in the symbol table. * * @return the smallest key in the symbol table * @throws NoSuchElementException if the symbol table is empty */ public Key min() { if (isEmpty()) throw new NoSuchElementException("calls min() with empty symbol table"); return min(root).key; } private Node min(Node x) { if (x.left == null) return x; else return min(x.left); } /** * Returns the largest key in the symbol table. * * @return the largest key in the symbol table * @throws NoSuchElementException if the symbol table is empty */ public Key max() { if (isEmpty()) throw new NoSuchElementException("calls max() with empty symbol table"); return max(root).key; } private Node max(Node x) { if (x.right == null) return x; else return max(x.right); } /** * Returns the largest key in the symbol table less than or equal to {@code key}. * * @param key the key * @return the largest key in the symbol table less than or equal to {@code key} * @throws NoSuchElementException if there is no such key * @throws IllegalArgumentException if {@code key} is {@code null} */ public Key floor(Key key) { if (key == null) throw new IllegalArgumentException("argument to floor() is null"); if (isEmpty()) throw new NoSuchElementException("calls floor() with empty symbol table"); Node x = floor(root, key); if (x == null) return null; else return x.key; } private Node floor(Node x, Key key) { if (x == null) return null; int cmp = key.compareTo(x.key); if (cmp == 0) return x; if (cmp < 0) return floor(x.left, key); Node t = floor(x.right, key); if (t != null) return t; else return x; } public Key floor2(Key key) { return floor2(root, key, null); } private Key floor2(Node x, Key key, Key best) { if (x == null) return best; int cmp = key.compareTo(x.key); if (cmp < 0) return floor2(x.left, key, best); else if (cmp > 0) return floor2(x.right, key, x.key); else return x.key; }