vmcms.c

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/****************************************************************************
*                                                                           *
*                       VM/CMS Randomness-Gathering Code                    *
*                         Copyright Peter Gutmann 1999                      *
*                                                                           *
****************************************************************************/

/* This module is part of the cryptlib continuously seeded pseudorandom
   number generator.  For usage conditions, see random.c.

   This code represents a template for randomness-gathering only and will
   need to be modified to provide OS-specific randomness.  In its current
   form it does not provide any usable entropy and should not be used as an
   entropy source */

/* General includes */

#include "crypt.h"

/* OS-specific includes */

void fastPoll( void )
    {
    MESSAGE_DATA msgData;
    time_t timeStamp = time( NULL );

    /* There's not much we can do under VM */
    setMessageData( &msgData, &timeStamp, sizeof( time_t ) );
    krnlSendMessage( SYSTEM_OBJECT_HANDLE, IMESSAGE_SETATTRIBUTE_S, &msgData,
                     CRYPT_IATTRIBUTE_ENTROPY );
    }

void slowPoll( void )
    {
    MESSAGE_DATA msgData;
    BYTE buffer[ 128 ];
    int quality = 1, total = 128;

    /* Kludge something here */
    setMessageData( &msgData, buffer, total );
    krnlSendMessage( SYSTEM_OBJECT_HANDLE, IMESSAGE_SETATTRIBUTE_S, &msgData,
                     CRYPT_IATTRIBUTE_ENTROPY );
    zeroise( buffer, sizeof( buffer ) );
    krnlSendMessage( SYSTEM_OBJECT_HANDLE, IMESSAGE_SETATTRIBUTE, &quality,
                     CRYPT_IATTRIBUTE_ENTROPY_QUALITY );
    }