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- /* Copyright (C) 2002-2003 RealVNC Ltd. All Rights Reserved.
- *
- * This is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This software is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this software; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
- * USA.
- */
-
- #include <rdr/RandomStream.h>
- #include <rdr/Exception.h>
- #include <time.h>
- #include <stdlib.h>
- #ifndef WIN32
- #include <unistd.h>
- #include <errno.h>
- #else
- #define getpid() GetCurrentProcessId()
- #endif
-
- using namespace rdr;
-
- const int DEFAULT_BUF_LEN = 256;
-
- unsigned int RandomStream::seed;
-
- RandomStream::RandomStream()
- : offset(0)
- {
- ptr = end = start = new U8[DEFAULT_BUF_LEN];
-
- #ifdef WIN32
- provider = 0;
- if (!CryptAcquireContext(&provider, 0, 0, PROV_RSA_FULL, 0)) {
- if (GetLastError() == NTE_BAD_KEYSET) {
- if (!CryptAcquireContext(&provider, 0, 0, PROV_RSA_FULL, CRYPT_NEWKEYSET)) {
- fprintf(stderr, "RandomStream: unable to create keyset\n");
- provider = 0;
- }
- } else {
- fprintf(stderr, "RandomStream: unable to acquire context\n");
- provider = 0;
- }
- }
- if (!provider) {
- #else
- fp = fopen("/dev/urandom", "r");
- if (!fp)
- fp = fopen("/dev/random", "r");
- if (!fp) {
- #endif
- fprintf(stderr,"RandomStream: warning: no OS supplied random source - using rand()\n");
- seed += (unsigned int) time(0) + getpid() + getpid() * 987654 + rand();
- srand(seed);
- }
- }
-
- RandomStream::~RandomStream() {
- delete [] start;
-
- #ifdef WIN32
- if (provider) {
- CryptReleaseContext(provider, 0);
- }
- #else
- if (fp) fclose(fp);
- #endif
- }
-
- int RandomStream::pos() {
- return offset + ptr - start;
- }
-
- int RandomStream::overrun(int itemSize, int nItems, bool wait) {
- if (itemSize > DEFAULT_BUF_LEN)
- throw Exception("RandomStream overrun: max itemSize exceeded");
-
- if (end - ptr != 0)
- memmove(start, ptr, end - ptr);
-
- end -= ptr - start;
- offset += ptr - start;
- ptr = start;
-
- int length = start + DEFAULT_BUF_LEN - end;
-
- #ifdef WIN32
- if (provider) {
- if (!CryptGenRandom(provider, length, (U8*)end))
- throw rdr::SystemException("unable to CryptGenRandom", GetLastError());
- end += length;
- #else
- if (fp) {
- int n = fread((U8*)end, length, 1, fp);
- if (n != 1)
- throw rdr::SystemException("reading /dev/urandom or /dev/random failed",
- errno);
- end += length;
- #endif
- } else {
- for (int i=0; i<length; i++)
- *(U8*)end++ = (int) (256.0*rand()/(RAND_MAX+1.0));
- }
-
- if (itemSize * nItems > end - ptr)
- nItems = (end - ptr) / itemSize;
-
- return nItems;
- }
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