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swcipher.cpp

/******************************************************************************
 *  swcipher.cpp   - code for class 'SWCipher'- a driver class that provides
 *                              cipher utilities.
 */

#include <string.h>
#include <stdlib.h>
#include <swcipher.h>


/******************************************************************************
 * SWCipher Constructor - Initializes data for instance of SWCipher
 *
 */

SWCipher::SWCipher(unsigned char *key) {
        master.initialize(key, strlen((char *)key));
        buf = 0;
}


/******************************************************************************
 * SWCipher Destructor - Cleans up instance of SWCipher
 */

SWCipher::~SWCipher()
{
        if (buf)
                free(buf);
}


char *SWCipher::Buf(const char *ibuf, unsigned int ilen)
{
        if (ibuf) {
        
                if (buf)
                        free(buf);

                if (!ilen) {
                        len = strlen(buf);
                        ilen = len + 1;
                }
                else len = ilen;

                buf = (char *) malloc(ilen);
                memcpy(buf, ibuf, ilen);
                cipher = false;
        }

        Decode();

        return buf;
}


char *SWCipher::cipherBuf(unsigned int *ilen, const char *ibuf)
{
        if (ibuf) {
        
                if (buf)
                        free(buf);
                        
                buf = (char *) malloc(*ilen);
                memcpy(buf, ibuf, *ilen);
                len = *ilen;
                cipher = true;
        }

        Encode();

        *ilen = (short)len;
        return buf;
}


/******************************************************************************
 * SWCipher::Encode     - This function "encodes" the input stream into the
 *                                              output stream.
 *                                              The GetChars() and SendChars() functions are
 *                                              used to separate this method from the actual
 *                                              i/o.
 */

void SWCipher::Encode(void)
{
        if (!cipher) {
                work = master;
                for (int i = 0; i < len; i++)
                        buf[i] = work.encrypt(buf[i]);
                cipher = true;
        }
}


/******************************************************************************
 * SWCipher::Decode     - This function "decodes" the input stream into the
 *                                              output stream.
 *                                              The GetChars() and SendChars() functions are
 *                                              used to separate this method from the actual
 *                                              i/o.
 */

void SWCipher::Decode(void)
{
        if (cipher) {
                work = master;
                for (int i = 0; i < len; i++)
                        buf[i] = work.decrypt(buf[i]);
                cipher = false;
        }
}


/******************************************************************************
 * SWCipher::setCipherKey       - setter for a new CipherKey
 *
 */

void SWCipher::setCipherKey(const char *ikey) {
        unsigned char *key = (unsigned char *)ikey;
        master.initialize(key, strlen((char *)key));
}

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