dropbear: random.c annotate

annotate random.c @ 662:d354464b2aa6 DROPBEAR_2012.55

- Improve CHANGES description

author	Matt Johnston <matt@ucc.asn.au>
date	Thu, 23 Feb 2012 21:45:36 +0800
parents	2d896267f16d
children	2b1bb792cd4d 167fdc091c05

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
198 65585699d980 * add a "label" argument to printhex() Matt Johnston <matt@ucc.asn.au> parents: 189 diff changeset	30 static int donerandinit = 0;
4 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 */
272 3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	33 static uint32_t counter = 0;
298 7dad470ad4aa minor cleanups for some warnings Matt Johnston <matt@ucc.asn.au> parents: 272 diff changeset	34 /* the max value for the counter, so it won't integer overflow */
7dad470ad4aa minor cleanups for some warnings Matt Johnston <matt@ucc.asn.au> parents: 272 diff changeset	35 #define MAX_COUNTER 1<<30
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	36
198 65585699d980 * add a "label" argument to printhex() Matt Johnston <matt@ucc.asn.au> parents: 189 diff changeset	37 static unsigned char hashpool[SHA1_HASH_SIZE];
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	38
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	39 #define INIT_SEED_SIZE 32 /* 256 bits */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	40
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	41 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	42
149 ed9ca2a9705c Cleaned up the random code, use /dev/random by default, Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	43 /* 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	44 * 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	45 * 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	46 * data into the pool.
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	47 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	48 * 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	49 * feed in new entropy.
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
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	53 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	54
185 5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	55 static int already_blocked = 0;
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	56 int readfd;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	57 unsigned int readpos;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	58 int readlen;
149 ed9ca2a9705c Cleaned up the random code, use /dev/random by default, Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	59 #ifdef DROPBEAR_PRNGD_SOCKET
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	60 struct sockaddr_un egdsock;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	61 char egdcmd[2];
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	62 #endif
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	63
149 ed9ca2a9705c Cleaned up the random code, use /dev/random by default, Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	64 #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	65 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	66 if (readfd < 0) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 458 diff changeset	67 dropbear_exit("Couldn't open random device");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	68 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	69 #endif
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	70
149 ed9ca2a9705c Cleaned up the random code, use /dev/random by default, Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	71 #ifdef DROPBEAR_PRNGD_SOCKET
225 ca7e76d981d9 - progress towards client agent forwarding Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	72 readfd = connect_unix(DROPBEAR_PRNGD_SOCKET);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	73
70 b0316ce64e4b Merging in the changes from 0.41-0.43 main Dropbear tree Matt Johnston <matt@ucc.asn.au> parents: 4 diff changeset	74 if (readfd < 0) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 458 diff changeset	75 dropbear_exit("Couldn't open random device");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	76 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	77
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	78 if (buflen > 255)
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 458 diff changeset	79 dropbear_exit("Can't request more than 255 bytes from egd");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	80 egdcmd[0] = 0x02; /* blocking read */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	81 egdcmd[1] = (unsigned char)buflen;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	82 if (write(readfd, egdcmd, 2) < 0)
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 458 diff changeset	83 dropbear_exit("Can't send command to egd");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	84 #endif
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	85
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	86 /* read the actual random data */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	87 readpos = 0;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	88 do {
185 5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	89 if (!already_blocked)
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	90 {
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	91 int ret;
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	92 struct timeval timeout;
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	93 fd_set read_fds;
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	94
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	95 timeout.tv_sec = 2; /* two seconds should be enough */
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	96 timeout.tv_usec = 0;
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	97
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	98 FD_ZERO(&read_fds);
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	99 FD_SET(readfd, &read_fds);
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	100 ret = select(readfd + 1, &read_fds, NULL, NULL, &timeout);
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	101 if (ret == 0)
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	102 {
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	103 dropbear_log(LOG_INFO, "Warning: Reading the random source seems to have blocked.\nIf you experience problems, you probably need to find a better entropy source.");
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	104 already_blocked = 1;
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	105 }
5ccad7634388 * warn if we seem to be blocking on /dev/random Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	106 }
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	107 readlen = read(readfd, &buf[readpos], buflen - readpos);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	108 if (readlen <= 0) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	109 if (readlen < 0 && errno == EINTR) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	110 continue;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	111 }
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 458 diff changeset	112 dropbear_exit("Error reading random source");
4 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 readpos += readlen;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	115 } while (readpos < buflen);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	116
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	117 close (readfd);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	118 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	119
149 ed9ca2a9705c Cleaned up the random code, use /dev/random by default, Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	120 /* 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	121 void seedrandom() {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	122
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	123 unsigned char readbuf[INIT_SEED_SIZE];
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	124
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	125 hash_state hs;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	126
272 3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	127 /* initialise so that things won't warn about
311 36d21680a9d3 A few more fixups, make sure that variable declarations are the Matt Johnston <matt@ucc.asn.au> parents: 298 diff changeset	128 * hashing an undefined buffer */
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	129 if (!donerandinit) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	130 m_burn(hashpool, sizeof(hashpool));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	131 }
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 /* get the seed data */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	134 readrand(readbuf, sizeof(readbuf));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	135
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	136 /* hash in the new seed data */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	137 sha1_init(&hs);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	138 sha1_process(&hs, (void*)hashpool, sizeof(hashpool));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	139 sha1_process(&hs, (void*)readbuf, sizeof(readbuf));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	140 sha1_done(&hs, hashpool);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	141
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	142 counter = 0;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	143 donerandinit = 1;
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
272 3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	146 /* hash the current random pool with some unique identifiers
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	147 * for this process and point-in-time. this is used to separate
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	148 * the random pools for fork()ed processes. */
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	149 void reseedrandom() {
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	150
311 36d21680a9d3 A few more fixups, make sure that variable declarations are the Matt Johnston <matt@ucc.asn.au> parents: 298 diff changeset	151 pid_t pid;
36d21680a9d3 A few more fixups, make sure that variable declarations are the Matt Johnston <matt@ucc.asn.au> parents: 298 diff changeset	152 hash_state hs;
36d21680a9d3 A few more fixups, make sure that variable declarations are the Matt Johnston <matt@ucc.asn.au> parents: 298 diff changeset	153 struct timeval tv;
272 3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	154
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	155 if (!donerandinit) {
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	156 dropbear_exit("seedrandom not done");
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	157 }
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	158
311 36d21680a9d3 A few more fixups, make sure that variable declarations are the Matt Johnston <matt@ucc.asn.au> parents: 298 diff changeset	159 pid = getpid();
36d21680a9d3 A few more fixups, make sure that variable declarations are the Matt Johnston <matt@ucc.asn.au> parents: 298 diff changeset	160 gettimeofday(&tv, NULL);
272 3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	161
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	162 sha1_init(&hs);
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	163 sha1_process(&hs, (void*)hashpool, sizeof(hashpool));
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	164 sha1_process(&hs, (void*)&pid, sizeof(pid));
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	165 sha1_process(&hs, (void*)&tv, sizeof(tv));
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	166 sha1_done(&hs, hashpool);
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	167 }
3be7ae2e8dfa Only read /dev/random once when the program starts Matt Johnston <matt@ucc.asn.au> parents: 198 diff changeset	168
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	169 /* return len bytes of pseudo-random data */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	170 void genrandom(unsigned char* buf, unsigned int len) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	171
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	172 hash_state hs;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	173 unsigned char hash[SHA1_HASH_SIZE];
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	174 unsigned int copylen;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	175
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	176 if (!donerandinit) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	177 dropbear_exit("seedrandom not done");
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	178 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	179
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	180 while (len > 0) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	181 sha1_init(&hs);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	182 sha1_process(&hs, (void*)hashpool, sizeof(hashpool));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	183 sha1_process(&hs, (void*)&counter, sizeof(counter));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	184 sha1_done(&hs, hash);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	185
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	186 counter++;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	187 if (counter > MAX_COUNTER) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	188 seedrandom();
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	189 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	190
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	191 copylen = MIN(len, SHA1_HASH_SIZE);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	192 memcpy(buf, hash, copylen);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	193 len -= copylen;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	194 buf += copylen;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	195 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	196 m_burn(hash, sizeof(hash));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	197 }
188 c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	198
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	199 /* 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	200 * 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	201 * 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	202 * 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	203 * */
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	204 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	205
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	206 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	207 unsigned int len = 0;
433 c216212001fc Fix for -pedantic -ansi compilation, change // to /*/, plus some signedness Matt Johnston <matt@ucc.asn.au>* parents: 405 diff changeset	208 const unsigned char masks[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
188 c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	209
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	210 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	211
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	212 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	213 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	214 len += 1;
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	215 }
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	216
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	217 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	218 do {
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	219 genrandom(randbuf, len);
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	220 /* 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	221 * MSB first.*/
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	222 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	223
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	224 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	225
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	226 /* 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	227 * 0 < rand < max */
405 00703f1df67a Remove extraneous tests in random mpint generation, Matt Johnston <matt@ucc.asn.au> parents: 311 diff changeset	228 } while (mp_cmp(rand, max) != MP_LT);
188 c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	229 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	230 m_free(randbuf);
c9483550701b - refactored random mp_int generation and byte->mp_int code Matt Johnston <matt@ucc.asn.au> parents: 159 diff changeset	231 }

Mercurial > dropbear

annotate random.c @ 662:d354464b2aa6 DROPBEAR_2012.55