dropbear: random.c annotate

annotate random.c @ 188:c9483550701b

- refactored random mp_int generation and byte->mp_int code - added RSA blinding

author	Matt Johnston <matt@ucc.asn.au>
date	Thu, 05 May 2005 03:58:21 +0000
parents	4bd4fc8023bd
children	06e326daf16a

rev	line source
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	1 /*
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	2 * Dropbear - a SSH2 server
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	3 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	4 * Copyright (c) 2002,2003 Matt Johnston
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	5 * All rights reserved.
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	6 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	7 * Permission is hereby granted, free of charge, to any person obtaining a copy
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	8 * of this software and associated documentation files (the "Software"), to deal
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	9 * in the Software without restriction, including without limitation the rights
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	11 * copies of the Software, and to permit persons to whom the Software is
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	12 * furnished to do so, subject to the following conditions:
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	13 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	14 * The above copyright notice and this permission notice shall be included in
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	15 * all copies or substantial portions of the Software.
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	16 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	23 * SOFTWARE. */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	24
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	25 #include "includes.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	26 #include "buffer.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	27 #include "dbutil.h"
188 c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	28 #include "bignum.h"
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	29
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	30 int donerandinit = 0;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	31
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	32 /* this is used to generate unique output from the same hashpool */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	33 unsigned int counter = 0;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	34 #define MAX_COUNTER 1000000/* the max value for the counter, so it won't loop */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	35
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	36 unsigned char hashpool[SHA1_HASH_SIZE];
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	37
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	38 #define INIT_SEED_SIZE 32 /* 256 bits */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	39
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	40 static void readrand(unsigned char* buf, unsigned int buflen);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	41
149 ed9ca2a9705c Cleaned up the random code, use /dev/random by default, Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	42 /* The basic setup is we read some data from /dev/(u)random or prngd and hash it
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	43 * into hashpool. To read data, we hash together current hashpool contents,
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	44 * and a counter. We feed more data in by hashing the current pool and new
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	45 * data into the pool.
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	46 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	47 * It is important to ensure that counter doesn't wrap around before we
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	48 * feed in new entropy.
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	49 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	50 */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	51
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	52 static void readrand(unsigned char* buf, unsigned int buflen) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	53
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	54 int readfd;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	55 unsigned int readpos;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	56 int readlen;
149 ed9ca2a9705c Cleaned up the random code, use /dev/random by default, Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	57 #ifdef DROPBEAR_PRNGD_SOCKET
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	58 struct sockaddr_un egdsock;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	59 char egdcmd[2];
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	60 #endif
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	61
149 ed9ca2a9705c Cleaned up the random code, use /dev/random by default, Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	62 #ifdef DROPBEAR_RANDOM_DEV
ed9ca2a9705c Cleaned up the random code, use /dev/random by default, Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	63 readfd = open(DROPBEAR_RANDOM_DEV, O_RDONLY);
70 b0316ce64e4b Merging in the changes from 0.41-0.43 main Dropbear tree Matt Johnston <matt@ucc.asn.au> parents: 4 diff changeset	64 if (readfd < 0) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	65 dropbear_exit("couldn't open random device");
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	66 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	67 #endif
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	68
149 ed9ca2a9705c Cleaned up the random code, use /dev/random by default, Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	69 #ifdef DROPBEAR_PRNGD_SOCKET
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	70 memset((void*)&egdsock, 0x0, sizeof(egdsock));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	71 egdsock.sun_family = AF_UNIX;
159 4bd4fc8023bd random.c: fix missed instance of DROPBEAR_EGD_SOCKET Matt Johnston <matt@ucc.asn.au> parents: 149 diff changeset	72 strlcpy(egdsock.sun_path, DROPBEAR_PRNGD_SOCKET,
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	73 sizeof(egdsock.sun_path));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	74
70 b0316ce64e4b Merging in the changes from 0.41-0.43 main Dropbear tree Matt Johnston <matt@ucc.asn.au> parents: 4 diff changeset	75 readfd = socket(PF_UNIX, SOCK_STREAM, 0);
b0316ce64e4b Merging in the changes from 0.41-0.43 main Dropbear tree Matt Johnston <matt@ucc.asn.au> parents: 4 diff changeset	76 if (readfd < 0) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	77 dropbear_exit("couldn't open random device");
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	78 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	79 /* todo - try various common locations */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	80 if (connect(readfd, (struct sockaddr*)&egdsock,
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	81 sizeof(struct sockaddr_un)) < 0) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	82 dropbear_exit("couldn't open random device");
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	83 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	84
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	85 if (buflen > 255)
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	86 dropbear_exit("can't request more than 255 bytes from egd");
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	87 egdcmd[0] = 0x02; /* blocking read */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	88 egdcmd[1] = (unsigned char)buflen;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	89 if (write(readfd, egdcmd, 2) < 0)
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	90 dropbear_exit("can't send command to egd");
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	91 #endif
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	92
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	93 /* read the actual random data */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	94 readpos = 0;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	95 do {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	96 readlen = read(readfd, &buf[readpos], buflen - readpos);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	97 if (readlen <= 0) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	98 if (readlen < 0 && errno == EINTR) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	99 continue;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	100 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	101 dropbear_exit("error reading random source");
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	102 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	103 readpos += readlen;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	104 } while (readpos < buflen);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	105
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	106 close (readfd);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	107 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	108
149 ed9ca2a9705c Cleaned up the random code, use /dev/random by default, Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	109 /* initialise the prng from /dev/(u)random or prngd */
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	110 void seedrandom() {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	111
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	112 unsigned char readbuf[INIT_SEED_SIZE];
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	113
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	114 hash_state hs;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	115
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	116 /* initialise so compilers will be happy about hashing it */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	117 if (!donerandinit) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	118 m_burn(hashpool, sizeof(hashpool));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	119 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	120
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	121 /* get the seed data */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	122 readrand(readbuf, sizeof(readbuf));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	123
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	124 /* hash in the new seed data */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	125 sha1_init(&hs);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	126 sha1_process(&hs, (void*)hashpool, sizeof(hashpool));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	127 sha1_process(&hs, (void*)readbuf, sizeof(readbuf));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	128 sha1_done(&hs, hashpool);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	129
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	130 counter = 0;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	131 donerandinit = 1;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	132 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	133
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	134 /* return len bytes of pseudo-random data */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	135 void genrandom(unsigned char* buf, unsigned int len) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	136
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	137 hash_state hs;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	138 unsigned char hash[SHA1_HASH_SIZE];
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	139 unsigned int copylen;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	140
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	141 if (!donerandinit) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	142 dropbear_exit("seedrandom not done");
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	143 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	144
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	145 while (len > 0) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	146 sha1_init(&hs);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	147 sha1_process(&hs, (void*)hashpool, sizeof(hashpool));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	148 sha1_process(&hs, (void*)&counter, sizeof(counter));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	149 sha1_done(&hs, hash);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	150
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	151 counter++;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	152 if (counter > MAX_COUNTER) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	153 seedrandom();
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	154 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	155
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	156 copylen = MIN(len, SHA1_HASH_SIZE);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	157 memcpy(buf, hash, copylen);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	158 len -= copylen;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	159 buf += copylen;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	160 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	161 m_burn(hash, sizeof(hash));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	162 }
188 c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	163
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	164 /* Generates a random mp_int.
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	165 * max is a *mp_int specifying an upper bound.
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	166 * rand must be an initialised *mp_int for the result.
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	167 * the result rand satisfies: 0 < rand < max
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	168 * */
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	169 void gen_random_mpint(mp_int max, mp_int rand) {
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	170
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	171 unsigned char *randbuf = NULL;
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	172 unsigned int len = 0;
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	173 const char masks[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	174
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	175 const int size_bits = mp_count_bits(max);
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	176
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	177 len = size_bits / 8;
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	178 if ((size_bits % 8) != 0) {
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	179 len += 1;
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	180 }
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	181
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	182 randbuf = (unsigned char*)m_malloc(len);
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	183 do {
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	184 genrandom(randbuf, len);
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	185 /* Mask out the unrequired bits - mp_read_unsigned_bin expects
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	186 * MSB first.*/
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	187 randbuf[0] &= masks[size_bits % 8];
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	188
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	189 bytes_to_mp(rand, randbuf, len);
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	190
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	191 /* keep regenerating until we get one satisfying
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	192 * 0 < rand < max */
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	193 } while ( ( (max != NULL) && (mp_cmp(rand, max) != MP_LT) )
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	194 \|\| (mp_cmp_d(rand, 0) != MP_GT) );
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	195 m_burn(randbuf, len);
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	196 m_free(randbuf);
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	197 }

Mercurial > dropbear

annotate random.c @ 188:c9483550701b