Fully implement callback sources, and add a test program to test it.

bin/tests/.cvsignore

@@ -10,6 +10,7 @@ db_test
 dispatch_tcp_test
 dispatch_test
 entropy_test
+entropy2_test
 fsaccess_test
 gxba_test
 gxbn_test

bin/tests/Makefile.in

@@ -50,6 +50,7 @@ XTARGETS =	adb_test \
 		dispatch_tcp_test \
 		dispatch_test \
 		entropy_test \
+		entropy2_test \
 		gxba_test \
 		gxbn_test \
 		hash_test \
@@ -90,6 +91,7 @@ SRCS =		adb_test.c \
 		dispatch_tcp_test.c \
 		dispatch_test.c \
 		entropy_test.c \
+		entropy2_test.c \
 		gxba_test.c \
 		gxbn_test.c \
 		hash_test.c \
@@ -171,6 +173,10 @@ entropy_test: entropy_test.@O@ ${ISCDEPLIBS}
 	${LIBTOOL} ${CC} ${CFLAGS} -o $@ entropy_test.@O@ \
 		${ISCLIBS} ${LIBS}
 
+entropy2_test: entropy2_test.@O@ ${ISCDEPLIBS}
+	${LIBTOOL} ${CC} ${CFLAGS} -o $@ entropy2_test.@O@ \
+		${ISCLIBS} ${LIBS}
+
 sock_test: sock_test.@O@ ${ISCDEPLIBS}
 	${LIBTOOL} ${CC} ${CFLAGS} -o $@ sock_test.@O@ \
 		${ISCLIBS} ${LIBS}

bin/tests/entropy2_test.c

@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 2000  Internet Software Consortium.
+ * 
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
+ * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
+ * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+ * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+ * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ */
+
+#include <isc/entropy.h>
+#include <isc/mem.h>
+#include <isc/util.h>
+#include <isc/string.h>
+
+#include <stdio.h>
+
+static void
+hex_dump(const char *msg, void *data, unsigned int length) {
+        unsigned int len;
+	unsigned char *base;
+	isc_boolean_t first = ISC_TRUE;
+
+	base = data;
+
+        printf("DUMP of %d bytes:  %s\n\t", length, msg);
+        for (len = 0 ; len < length ; len++) {
+                if (len % 16 == 0 && !first)
+			printf("\n\t");
+                printf("%02x ", base[len]);
+		first = ISC_FALSE;
+        }
+        printf("\n");
+}
+
+static void
+CHECK(const char *msg, isc_result_t result) {
+	if (result != ISC_R_SUCCESS) {
+		printf("FAILURE:  %s:  %s\n", msg, isc_result_totext(result));
+		exit(1);
+	}
+}
+
+static isc_result_t
+start(isc_entropysource_t *source, void *arg, isc_boolean_t blocking)
+{
+	printf("start called, non-blocking mode.\n");
+
+	return (ISC_R_SUCCESS);
+}
+
+static void
+stop(isc_entropysource_t *source, void *arg) {
+	printf("stop called\n");
+}
+
+/*
+ * This function is by no way a good one to actually add entropy into
+ * the system.  It is intended to fool the entropy system into beliving
+ * there are actual bits from us.
+ */
+static isc_result_t
+get(isc_entropysource_t *source, void *arg, isc_boolean_t blocking) {
+	isc_result_t result;
+	static isc_uint32_t val = 1;
+	static int count = 0;
+
+	/*
+	 * Here, we should check to see if we are in blocking mode or not.
+	 * If we will block and the application asked us not to,
+	 * we should return an error instead, rather than block.
+	 */
+	if (!blocking) {
+		count++;
+		if (count > 6)
+			return (ISC_R_NOENTROPY);
+	}
+
+	do {
+		if (val == 0)
+			val = 0x12345678;
+		val <<= 3;
+		val %= 100000;
+
+		result = isc_entropy_addcallbacksample(source, val, 0);
+	} while (result == ISC_R_SUCCESS);
+
+	return (result);
+}
+
+int
+main(int argc, char **argv) {
+	isc_mem_t *mctx;
+	unsigned char buffer[512];
+	isc_entropy_t *ent;
+	isc_entropysource_t *source;
+	unsigned int returned;
+	unsigned int flags;
+	isc_result_t result;
+
+	UNUSED(argc);
+	UNUSED(argv);
+
+	mctx = NULL;
+	CHECK("isc_mem_create()",
+	      isc_mem_create(0, 0, &mctx));
+
+	ent = NULL;
+	CHECK("isc_entropy_create()",
+	      isc_entropy_create(mctx, &ent));
+
+	isc_entropy_stats(ent, stderr);
+
+	source = NULL;
+	result = isc_entropy_createcallbacksource(ent, start, get, stop, NULL,
+						  &source);
+	CHECK("isc_entropy_createcallbacksource()", result);
+
+	fprintf(stderr,
+		"Reading 32 bytes of GOOD random data only, partial OK\n");
+
+	flags = 0;
+	flags |= ISC_ENTROPY_GOODONLY;
+	flags |= ISC_ENTROPY_PARTIAL;
+#if 0
+	flags |= ISC_ENTROPY_BLOCKING;
+#endif
+	returned = 0;
+	result = isc_entropy_getdata(ent, buffer, 32, &returned, flags);
+	if (result == ISC_R_NOENTROPY) {
+		fprintf(stderr, "No entropy.\n");
+	}
+	hex_dump("good data only:", buffer, returned);
+
+	isc_entropy_stats(ent, stderr);
+
+	isc_entropy_destroysource(&source);
+	isc_entropy_detach(&ent);
+
+	isc_mem_stats(mctx, stderr);
+	isc_mem_destroy(&mctx);
+
+	return (0);
+}
+

lib/isc/include/isc/entropy.h

@@ -67,15 +67,11 @@ ISC_LANG_BEGINDECLS
 /*
  * Entropy callback function.
  */
-typedef isc_result_t (*isc_entropystart_t)(isc_entropy_t *ent,
-					   isc_entropysource_t *source,
-					   void *arg);
-typedef isc_result_t (*isc_entropyget_t)(isc_entropy_t *ent,
-					 isc_entropysource_t *source,
-					 void *arg);
-typedef void (*isc_entropystop_t)(isc_entropy_t *ent,
-				  isc_entropysource_t *source,
-				  void *arg);
+typedef isc_result_t (*isc_entropystart_t)(isc_entropysource_t *source,
+					   void *arg, isc_boolean_t blocking);
+typedef isc_result_t (*isc_entropyget_t)(isc_entropysource_t *source,
+					 void *arg, isc_boolean_t blocking);
+typedef void (*isc_entropystop_t)(isc_entropysource_t *source, void *arg);
 
 /***
  *** Flags.
@@ -179,12 +175,23 @@ isc_entropy_createcallbacksource(isc_entropy_t *ent,
  * Create an entropy source that is polled via a callback.  This would
  * be used when keyboard input is used, or a GUI input method.  It can
  * also be used to hook in any external entropy source.
+ *
+ * Samples are added via isc_entropy_addcallbacksample(), below.
+ * _addcallbacksample() is the only function which may be called from
+ * within an entropy API callback function.
  */
 
 void
 isc_entropy_stopcallbacksources(isc_entropy_t *ent);
+/*
+ * Call the stop functions for callback sources that have had their
+ * start functions called.
+ */
 
 isc_result_t
+isc_entropy_addcallbacksample(isc_entropysource_t *source, isc_uint32_t sample,
+			      isc_uint32_t extra);
+isc_result_t
 isc_entropy_addsample(isc_entropysource_t *source, isc_uint32_t sample,
 		      isc_uint32_t extra);
 /*
@@ -195,6 +202,9 @@ isc_entropy_addsample(isc_entropysource_t *source, isc_uint32_t sample,
  *
  * The "extra" parameter is used only to add a bit more unpredictable
  * data.  It is not used other than included in the hash of samples.
+ *
+ * When in an entropy API callback function, _addcallbacksource() must be
+ * used.  At all other times, _addsample() must be used.
  */
 
 isc_result_t

lib/isc/include/isc/result.h

@@ -67,8 +67,8 @@
 #define ISC_R_MULTICAST			43	/* invalid use of multicast */
 #define ISC_R_NOTFILE			44	/* not a file */
 #define ISC_R_NOTDIRECTORY		45	/* not a directory */
-
-#define ISC_R_NRESULTS 			46	/* Number of results */
+#define ISC_R_QUEUEFULL			46	/* queue is full */
+#define ISC_R_NRESULTS 			47	/* Number of results */
 
 ISC_LANG_BEGINDECLS
 

lib/isc/result.c

@@ -81,7 +81,8 @@ static const char *text[ISC_R_NRESULTS] = {
 	"out of entropy",			/* 42 */
 	"invalid use of multicast address",	/* 43 */
 	"not a file",				/* 44 */
-	"not a directory"			/* 45 */
+	"not a directory",			/* 45 */
+	"queue is full"				/* 46 */
 };
 
 #define ISC_RESULT_RESULTSET			2

lib/isc/unix/entropy.c

@@ -177,6 +177,8 @@ samplesource_allocate(isc_entropy_t *ent, sample_queue_t *sq) {
 		return (ISC_R_NOMEMORY);
 	}
 
+	sq->nsamples = 0;
+
 	return (ISC_R_SUCCESS);
 }
 
@@ -359,20 +361,35 @@ get_from_filesource(isc_entropysource_t *source, isc_uint32_t desired) {
 }
 
 static unsigned int
-get_from_callback(isc_entropysource_t *source, unsigned int desired) {
+get_from_callback(isc_entropysource_t *source, unsigned int desired,
+		  isc_boolean_t blocking)
+{
 	isc_entropy_t *ent = source->ent;
 	isc_cbsource_t *cbs = &source->sources.callback;
 	unsigned int added;
+	unsigned int got;
 	isc_result_t result;
 
-	added = 0;
-	while (desired > 0) {
-		if (!cbs->start_called && cbs->startfunc != NULL)
-			cbs->startfunc(ent, source, cbs->arg);
-		result = cbs->getfunc(ent, source, cbs->arg);
-		added += crunchsamples(ent, &cbs->samplequeue);
+	if (desired == 0)
+		return (0);
 
-		desired -= added;
+	if (!cbs->start_called && cbs->startfunc != NULL) {
+		result = cbs->startfunc(source, cbs->arg, blocking);
+		if (result != ISC_R_SUCCESS)
+			return (0);
+		cbs->start_called = ISC_TRUE;
+	}
+
+	added = 0;
+	result = ISC_R_SUCCESS;
+	while (desired > 0 && result == ISC_R_SUCCESS) {
+		result = cbs->getfunc(source, cbs->arg, blocking);
+		if (result == ISC_R_QUEUEFULL) {
+			got = crunchsamples(ent, &cbs->samplequeue);
+			added += got;
+			desired -= ISC_MIN(got, desired);
+			result = ISC_R_SUCCESS;
+		}
 	}
 
 	return (added);
@@ -415,22 +432,13 @@ fillpool(isc_entropy_t *ent, unsigned int desired, isc_boolean_t blocking) {
 	 * to build up.
 	 */
 	if (needed == 0) {
-		isc_uint32_t needed_ent, needed_ps;
-
 		REQUIRE(!blocking);
 
 		if ((ent->pool.entropy >= RND_POOLBITS / 4)
 		    && (ent->pool.pseudo <= RND_POOLBITS / 4))
 			return;
-		needed_ent = 0;
-		needed_ps = 0;
-		if (ent->pool.entropy < THRESHOLD_BITS)
-			needed_ent = THRESHOLD_BITS;
-		if (ent->pool.pseudo > RND_POOLBITS / 4)
-			needed_ps = THRESHOLD_BITS;
-		needed = ISC_MAX(needed_ent, needed_ps);
-		if (needed == 0 && ent->initialized >= THRESHOLD_BITS)
-			return;
+
+		needed = THRESHOLD_BITS * 4;
 	} else {
 		needed = ISC_MAX(needed, THRESHOLD_BITS);
 		needed = ISC_MIN(needed, RND_POOLBITS);
@@ -479,10 +487,7 @@ fillpool(isc_entropy_t *ent, unsigned int desired, isc_boolean_t blocking) {
 
 		added += got;
 
-		if (remaining > got)
-			remaining -= got;
-		else
-			remaining = 0;
+		remaining -= ISC_MIN(remaining, got);
 
 		source = ISC_LIST_NEXT(source, link);
 		if (source == NULL)
@@ -507,25 +512,19 @@ fillpool(isc_entropy_t *ent, unsigned int desired, isc_boolean_t blocking) {
 	 * check to see if we have a callback source.  If so, call them.
 	 */
 	source = ISC_LIST_HEAD(ent->sources);
-	while (remaining != 0 && source != NULL) {
+	while ((remaining != 0) && (source != NULL)) {
 		unsigned int got;
 
 		got = 0;
 
 		if (source->type == ENTROPY_SOURCETYPE_CALLBACK)
-			got = get_from_callback(source, remaining);
+			got = get_from_callback(source, remaining, blocking);
 
 		added += got;
+		remaining -= ISC_MIN(remaining, got);
 
-		if (remaining > got)
-			remaining -= got;
-		else
-			remaining = 0;
-
-#if 0
 		if (added >= needed)
 			break;
-#endif
 
 		source = ISC_LIST_NEXT(source, link);
 	}
@@ -601,28 +600,6 @@ isc_entropy_getdata(isc_entropy_t *ent, void *data, unsigned int length,
 
 	LOCK(&ent->lock);
 
-	/*
-	 * If we are blocking, we will block when actually extracting data.
-	 * Otherwise, if we cannot block, there is a limit on how much data
-	 * we can actually extract if good data is required.
-	 *
-	 * Here, clamp length to be the amount of data we can extract
-	 * if goodonly and partial are both set, otherwise return an
-	 * error.
-	 */
-	if (goodonly && !blocking) {
-		fillpool(ent, length * 8, ISC_FALSE);
-
-		/*
-		 * To extract good data, we need to have at least
-		 * enough entropy to fill our digest.
-		 */
-		if (ent->pool.entropy < THRESHOLD_BITS) {
-			UNLOCK(&ent->lock);
-			return (ISC_R_NOENTROPY);
-		}
-	}
-
 	remain = length;
 	buf = data;
 	total = 0;
@@ -652,9 +629,12 @@ isc_entropy_getdata(isc_entropy_t *ent, void *data, unsigned int length,
 			else
 				fillpool(ent, fillcount, blocking);
 
-			if (!partial)
-				if (ent->pool.entropy < THRESHOLD_BITS)
+			if (ent->pool.entropy < THRESHOLD_BITS) {
+				if (!blocking && !partial)
 					goto zeroize;
+				else if (partial)
+					goto partial_output;
+			}
 		} else {
 			/*
 			 * If we've extracted half our pool size in bits
@@ -696,6 +676,8 @@ isc_entropy_getdata(isc_entropy_t *ent, void *data, unsigned int length,
 		add_pseudo(ent, count * 8);
 	}
 
+ partial_output:
+
 	memset(digest, 0, sizeof(digest));
 
 	if (returned != NULL)
@@ -809,8 +791,10 @@ destroysource(isc_entropysource_t **sourcep) {
 		break;
 	case ENTROPY_SOURCETYPE_CALLBACK:
 		cbs = &source->sources.callback;
-		if (cbs->start_called && cbs->stopfunc != NULL)
-			cbs->stopfunc(ent, source, cbs->arg);
+		if (cbs->start_called && cbs->stopfunc != NULL) {
+			cbs->stopfunc(source, cbs->arg);
+			cbs->start_called = ISC_FALSE;
+		}
 		samplequeue_release(ent, &cbs->samplequeue);
 		break;
 	}
@@ -1049,6 +1033,8 @@ isc_entropy_createcallbacksource(isc_entropy_t *ent,
 	ISC_LIST_APPEND(ent->sources, source, link);
 	ent->nsources++;
 
+	*sourcep = source;
+
 	UNLOCK(&ent->lock);
 	return (ISC_R_SUCCESS);
 
@@ -1074,8 +1060,10 @@ isc_entropy_stopcallbacksources(isc_entropy_t *ent) {
 	while (source != NULL) {
 		if (source->type == ENTROPY_SOURCETYPE_CALLBACK) {
 			cbs = &source->sources.callback;
-			if (cbs->start_called && cbs->stopfunc != NULL)
-				cbs->stopfunc(ent, source, cbs->arg);
+			if (cbs->start_called && cbs->stopfunc != NULL) {
+				cbs->stopfunc(source, cbs->arg);
+				cbs->start_called = ISC_FALSE;
+			}
 		}
 
 		source = ISC_LIST_NEXT(source, link);
@@ -1124,6 +1112,8 @@ isc_entropy_createsamplesource(isc_entropy_t *ent,
 	ISC_LIST_APPEND(ent->sources, source, link);
 	ent->nsources++;
 
+	*sourcep = source;
+
 	UNLOCK(&ent->lock);
 	return (ISC_R_SUCCESS);
 
@@ -1189,7 +1179,7 @@ crunchsamples(isc_entropy_t *ent, sample_queue_t *sq) {
 	unsigned int ns;
 	unsigned int added;
 
-	if (sq->nsamples < 5)
+	if (sq->nsamples < 6)
 		return (0);
 
 	added = 0;
@@ -1210,6 +1200,17 @@ crunchsamples(isc_entropy_t *ent, sample_queue_t *sq) {
 	entropypool_adddata(ent, sq->samples, sq->nsamples * 4, added);
 	entropypool_adddata(ent, sq->extra, sq->nsamples * 4, 0);
 
+	/*
+	 * Move the last 4 samples into the first 4 positions, and start
+	 * adding new samples from that point.
+	 */
+	for (ns = 0 ; ns < 4 ; ns++) {
+		sq->samples[ns] = sq->samples[sq->nsamples - 4 + ns];
+		sq->extra[ns] = sq->extra[sq->nsamples - 4 + ns];
+	}
+
+	sq->nsamples = 0;
+
 	return (added);
 }
 
@@ -1228,9 +1229,9 @@ addsample(sample_queue_t *sq, isc_uint32_t sample, isc_uint32_t extra) {
 	sq->nsamples++;
 
 	if (sq->nsamples >= RND_EVENTQSIZE)
-		return (ISC_R_SUCCESS);
+		return (ISC_R_QUEUEFULL);
 
-	return (ISC_R_NOENTROPY);
+	return (ISC_R_SUCCESS);
 }
 
 isc_result_t
@@ -1248,30 +1249,37 @@ isc_entropy_addsample(isc_entropysource_t *source, isc_uint32_t sample,
 
 	LOCK(&ent->lock);
 
-	switch (source->type) {
-	case ENTROPY_SOURCETYPE_SAMPLE:
 	sq = &source->sources.sample.samplequeue;
 	result = addsample(sq, sample, extra);
-		if (result == ISC_R_SUCCESS) {
+	if (result == ISC_R_QUEUEFULL) {
 		entropy = crunchsamples(ent, sq);
 		add_entropy(ent, entropy);
 	}
-		break;
-	case ENTROPY_SOURCETYPE_CALLBACK:
-		sq = &source->sources.sample.samplequeue;
-		result = addsample(sq, sample, extra);
-		break;
-	default:
-		result = ISC_R_UNEXPECTED;
-		REQUIRE(source->type == ENTROPY_SOURCETYPE_SAMPLE
-			|| source->type == ENTROPY_SOURCETYPE_CALLBACK);
-	}
 
 	UNLOCK(&ent->lock);
 
 	return (result);
 }
 
+isc_result_t
+isc_entropy_addcallbacksample(isc_entropysource_t *source, isc_uint32_t sample,
+			      isc_uint32_t extra)
+{
+	isc_entropy_t *ent;
+	sample_queue_t *sq;
+	isc_result_t result;
+
+	REQUIRE(VALID_SOURCE(source));
+	REQUIRE(source->type == ENTROPY_SOURCETYPE_CALLBACK);
+
+	ent = source->ent;
+
+	sq = &source->sources.callback.samplequeue;
+	result = addsample(sq, sample, extra);
+
+	return (result);
+}
+
 void
 isc_entropy_putdata(isc_entropy_t *ent, void *data, unsigned int length,
 		    isc_uint32_t entropy)