/* _ _ ** _ __ ___ ___ __| | ___ ___| | mod_ssl ** | '_ ` _ \ / _ \ / _` | / __/ __| | Apache Interface to OpenSSL ** | | | | | | (_) | (_| | \__ \__ \ | www.modssl.org ** |_| |_| |_|\___/ \__,_|___|___/___/_| ftp.modssl.org ** |_____| ** ssl_engine_rand.c ** Random Number Generator Seeding */ /* ==================================================================== * Copyright (c) 1998-2005 Ralf S. Engelschall. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following * disclaimer in the documentation and/or other materials * provided with the distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by * Ralf S. Engelschall for use in the * mod_ssl project (http://www.modssl.org/)." * * 4. The names "mod_ssl" must not be used to endorse or promote * products derived from this software without prior written * permission. For written permission, please contact * rse@engelschall.com. * * 5. Products derived from this software may not be called "mod_ssl" * nor may "mod_ssl" appear in their names without prior * written permission of Ralf S. Engelschall. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by * Ralf S. Engelschall for use in the * mod_ssl project (http://www.modssl.org/)." * * THIS SOFTWARE IS PROVIDED BY RALF S. ENGELSCHALL ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RALF S. ENGELSCHALL OR * HIS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== */ /* ``The generation of random numbers is too important to be left to chance.'' */ #include "mod_ssl.h" /* _________________________________________________________________ ** ** Support for better seeding of SSL library's RNG ** _________________________________________________________________ */ static int ssl_rand_choosenum(int, int); static int ssl_rand_feedfp(pool *, FILE *, int); int ssl_rand_seed(server_rec *s, pool *p, ssl_rsctx_t nCtx, char *prefix) { SSLModConfigRec *mc; array_header *apRandSeed; ssl_randseed_t *pRandSeeds; ssl_randseed_t *pRandSeed; unsigned char stackdata[256]; int nReq, nDone; FILE *fp; int i, n, l; time_t t; pid_t pid; int m; mc = myModConfig(); nReq = 0; nDone = 0; apRandSeed = mc->aRandSeed; pRandSeeds = (ssl_randseed_t *)apRandSeed->elts; for (i = 0; i < apRandSeed->nelts; i++) { pRandSeed = &pRandSeeds[i]; if (pRandSeed->nCtx == nCtx) { nReq += pRandSeed->nBytes; if (pRandSeed->nSrc == SSL_RSSRC_FILE) { /* * seed in contents of an external file */ #ifdef WIN32 if ((fp = ap_pfopen(p, pRandSeed->cpPath, "rb")) == NULL) #else if ((fp = ap_pfopen(p, pRandSeed->cpPath, "r")) == NULL) #endif continue; nDone += ssl_rand_feedfp(p, fp, pRandSeed->nBytes); ap_pfclose(p, fp); } else if (pRandSeed->nSrc == SSL_RSSRC_EXEC) { /* * seed in contents generated by an external program */ if ((fp = ssl_util_ppopen(s, p, ap_psprintf(p, "%s %d", pRandSeed->cpPath, pRandSeed->nBytes))) == NULL) continue; nDone += ssl_rand_feedfp(p, fp, pRandSeed->nBytes); ssl_util_ppclose(s, p, fp); } #if SSL_LIBRARY_VERSION >= 0x00905100 else if (pRandSeed->nSrc == SSL_RSSRC_EGD) { /* * seed in contents provided by the external * Entropy Gathering Daemon (EGD) */ #if SSL_LIBRARY_VERSION >= 0x00906000 if ((n = RAND_egd_bytes(pRandSeed->cpPath, pRandSeed->nBytes)) == -1) #else if ((n = RAND_egd(pRandSeed->cpPath)) == -1) #endif continue; nDone += n; } #endif else if (pRandSeed->nSrc == SSL_RSSRC_BUILTIN) { /* * seed in the current time (usually just 4 bytes) */ t = time(NULL); l = sizeof(time_t); RAND_seed((unsigned char *)&t, l); nDone += l; /* * seed in the current process id (usually just 4 bytes) */ pid = getpid(); l = sizeof(pid_t); RAND_seed((unsigned char *)&pid, l); nDone += l; /* * seed in some current state of the run-time stack (128 bytes) */ n = ssl_rand_choosenum(0, sizeof(stackdata)-128-1); RAND_seed(stackdata+n, 128); nDone += 128; /* * seed in extract data from the current scoreboard */ if (ap_scoreboard_image != NULL && SCOREBOARD_SIZE > 16) { if ((m = ((SCOREBOARD_SIZE / 2) - 1)) > 1024) m = 1024; n = ssl_rand_choosenum(0, m); RAND_seed(((unsigned char *)ap_scoreboard_image)+n, m); nDone += m; } } } } ssl_log(s, SSL_LOG_INFO, "%sSeeding PRNG with %d bytes of entropy", prefix, nDone); #if SSL_LIBRARY_VERSION >= 0x00905100 if (RAND_status() == 0) ssl_log(s, SSL_LOG_WARN, "%sPRNG still contains insufficient entropy!", prefix); #endif return nDone; } #define BUFSIZE 8192 static int ssl_rand_feedfp(pool *p, FILE *fp, int nReq) { int nDone; unsigned char caBuf[BUFSIZE]; int nBuf; int nRead; int nTodo; nDone = 0; nRead = BUFSIZE; nTodo = nReq; while (1) { if (nReq > 0) nRead = (nTodo < BUFSIZE ? nTodo : BUFSIZE); if ((nBuf = (int)fread(caBuf, 1, nRead, fp)) <= 0) break; RAND_seed(caBuf, nBuf); nDone += nBuf; if (nReq > 0) { nTodo -= nBuf; if (nTodo <= 0) break; } } return nDone; } static int ssl_rand_choosenum(int l, int h) { int i; char buf[50]; srand((unsigned int)time(NULL)); ap_snprintf(buf, sizeof(buf), "%.0f", (((double)(rand()%RAND_MAX)/RAND_MAX)*(h-l))); i = atoi(buf)+1; if (i < l) i = l; if (i > h) i = h; return i; }