summaryrefslogtreecommitdiffstats
path: root/modules/ssl/ssl_engine_rand.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--modules/ssl/ssl_engine_rand.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/modules/ssl/ssl_engine_rand.c b/modules/ssl/ssl_engine_rand.c
new file mode 100644
index 0000000..4e1a9c1
--- /dev/null
+++ b/modules/ssl/ssl_engine_rand.c
@@ -0,0 +1,177 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* _ _
+ * _ __ ___ ___ __| | ___ ___| | mod_ssl
+ * | '_ ` _ \ / _ \ / _` | / __/ __| | Apache Interface to OpenSSL
+ * | | | | | | (_) | (_| | \__ \__ \ |
+ * |_| |_| |_|\___/ \__,_|___|___/___/_|
+ * |_____|
+ * ssl_engine_rand.c
+ * Random Number Generator Seeding
+ */
+ /* ``The generation of random
+ numbers is too important
+ to be left to chance.'' */
+
+#include "ssl_private.h"
+
+/* _________________________________________________________________
+**
+** Support for better seeding of SSL library's RNG
+** _________________________________________________________________
+*/
+
+static int ssl_rand_choosenum(int, int);
+static int ssl_rand_feedfp(apr_pool_t *, apr_file_t *, int);
+
+int ssl_rand_seed(server_rec *s, apr_pool_t *p, ssl_rsctx_t nCtx, char *prefix)
+{
+ SSLModConfigRec *mc;
+ apr_array_header_t *apRandSeed;
+ ssl_randseed_t *pRandSeeds;
+ ssl_randseed_t *pRandSeed;
+ unsigned char stackdata[256];
+ int nDone;
+ apr_file_t *fp;
+ int i, n, l;
+
+ mc = myModConfig(s);
+ 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) {
+ if (pRandSeed->nSrc == SSL_RSSRC_FILE) {
+ /*
+ * seed in contents of an external file
+ */
+ if (apr_file_open(&fp, pRandSeed->cpPath,
+ APR_READ, APR_OS_DEFAULT, p) != APR_SUCCESS)
+ continue;
+ nDone += ssl_rand_feedfp(p, fp, pRandSeed->nBytes);
+ apr_file_close(fp);
+ }
+ else if (pRandSeed->nSrc == SSL_RSSRC_EXEC) {
+ const char *cmd = pRandSeed->cpPath;
+ const char **argv = apr_palloc(p, sizeof(char *) * 3);
+ /*
+ * seed in contents generated by an external program
+ */
+ argv[0] = cmd;
+ argv[1] = apr_itoa(p, pRandSeed->nBytes);
+ argv[2] = NULL;
+
+ if ((fp = ssl_util_ppopen(s, p, cmd, argv)) == NULL)
+ continue;
+ nDone += ssl_rand_feedfp(p, fp, pRandSeed->nBytes);
+ ssl_util_ppclose(s, p, fp);
+ }
+#ifdef HAVE_RAND_EGD
+ else if (pRandSeed->nSrc == SSL_RSSRC_EGD) {
+ /*
+ * seed in contents provided by the external
+ * Entropy Gathering Daemon (EGD)
+ */
+ if ((n = RAND_egd(pRandSeed->cpPath)) == -1)
+ continue;
+ nDone += n;
+ }
+#endif
+ else if (pRandSeed->nSrc == SSL_RSSRC_BUILTIN) {
+ struct {
+ time_t t;
+ pid_t pid;
+ } my_seed;
+
+ /*
+ * seed in the current time (usually just 4 bytes)
+ */
+ my_seed.t = time(NULL);
+
+ /*
+ * seed in the current process id (usually just 4 bytes)
+ */
+ my_seed.pid = mc->pid;
+
+ l = sizeof(my_seed);
+ RAND_seed((unsigned char *)&my_seed, 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;
+
+ }
+ }
+ }
+ ap_log_error(APLOG_MARK, APLOG_TRACE2, 0, s,
+ "%sSeeding PRNG with %d bytes of entropy", prefix, nDone);
+
+ if (RAND_status() == 0)
+ ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s, APLOGNO(01990)
+ "%sPRNG still contains insufficient entropy!", prefix);
+
+ return nDone;
+}
+
+#define BUFSIZE 8192
+
+static int ssl_rand_feedfp(apr_pool_t *p, apr_file_t *fp, int nReq)
+{
+ apr_size_t nDone;
+ unsigned char caBuf[BUFSIZE];
+ apr_size_t nBuf;
+ apr_size_t nRead;
+ apr_size_t nTodo;
+
+ nDone = 0;
+ nRead = BUFSIZE;
+ nTodo = nReq;
+ while (1) {
+ if (nReq > 0)
+ nRead = (nTodo < BUFSIZE ? nTodo : BUFSIZE);
+ nBuf = nRead;
+ if (apr_file_read(fp, caBuf, &nBuf) != APR_SUCCESS)
+ 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];
+
+ apr_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;
+}
+