/*
 * 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(char *msg, void *data, unsigned int length) {
        unsigned int len;
	unsigned char *base;

	base = data;

        printf("DUMP of %d bytes:  %s\n", length, msg);
        for (len = 0 ; len < length ; len++) {
                if (len % 16 == 0)
                        printf("\n");
                printf("%02x ", base[len]);
        }
        printf("\n");
}

static void
CHECK(const char *msg, isc_result_t result) {
	if (result != ISC_R_SUCCESS) {
		printf("FAILURE:  %s\n", msg);
		exit(1);
	}
}

int
main(int argc, char **argv) {
	isc_mem_t *mctx;
	unsigned char buffer[512];
	isc_entropy_t *ent;
	isc_entropysource_t *devrandom;
	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);

	devrandom = NULL;
	CHECK("isc_entropy_createfilesource()",
	      isc_entropy_createfilesource(ent, "/dev/random",
					   0, &devrandom));

	fprintf(stderr,
		"Reading 32 bytes of GOOD random data only, partial OK\n");

	flags = 0;
	flags |= ISC_ENTROPY_GOODONLY;
	flags |= ISC_ENTROPY_PARTIAL;
	result = isc_entropy_getdata(ent, buffer, 32, &returned, flags);
	if (result == ISC_R_NOENTROPY) {
		fprintf(stderr, "No entropy.\n");
		goto out;
	}
	hex_dump("good data only:", buffer, returned);

	isc_entropy_stats(ent, stderr);

	CHECK("isc_entropy_getdata()",
	      isc_entropy_getdata(ent, buffer, 128, NULL, 0));

	hex_dump("entropy data", buffer, 128);

out:
	{
		isc_entropy_t *entcopy1 = NULL;
		isc_entropy_t *entcopy2 = NULL;
		isc_entropy_t *entcopy3 = NULL;

		isc_entropy_attach(ent, &entcopy1);
		isc_entropy_attach(ent, &entcopy2);
		isc_entropy_attach(ent, &entcopy3);

		isc_entropy_stats(ent, stderr);

		isc_entropy_detach(&entcopy1);
		isc_entropy_detach(&entcopy2);
		isc_entropy_detach(&entcopy3);
	}

	isc_entropy_destroysource(&devrandom);
	isc_entropy_detach(&ent);
	isc_mem_stats(mctx, stderr);
	isc_mem_destroy(&mctx);

	return (0);
}