Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 1 | /* |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 2 | * Copyright (c) 2001-2002 Damien Miller. All rights reserved. |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions |
| 6 | * are met: |
| 7 | * 1. Redistributions of source code must retain the above copyright |
| 8 | * notice, this list of conditions and the following disclaimer. |
| 9 | * 2. Redistributions in binary form must reproduce the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer in the |
| 11 | * documentation and/or other materials provided with the distribution. |
| 12 | * |
| 13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 23 | */ |
| 24 | |
| 25 | #include "includes.h" |
| 26 | |
Damien Miller | 3717cda | 2006-03-15 14:02:36 +1100 | [diff] [blame] | 27 | #include <sys/types.h> |
| 28 | #include <sys/resource.h> |
| 29 | #include <sys/stat.h> |
| 30 | #include <sys/wait.h> |
Damien Miller | 8ec8c3e | 2006-07-10 20:35:38 +1000 | [diff] [blame] | 31 | #include <sys/socket.h> |
Darren Tucker | 4c65543 | 2006-08-05 15:57:40 +1000 | [diff] [blame^] | 32 | |
| 33 | #include <stdarg.h> |
Damien Miller | 2d00e63 | 2006-07-24 13:53:19 +1000 | [diff] [blame] | 34 | #include <stddef.h> |
Damien Miller | 8ec8c3e | 2006-07-10 20:35:38 +1000 | [diff] [blame] | 35 | |
| 36 | #include <netinet/in.h> |
Damien Miller | 3717cda | 2006-03-15 14:02:36 +1100 | [diff] [blame] | 37 | |
| 38 | #ifdef HAVE_SYS_UN_H |
| 39 | # include <sys/un.h> |
| 40 | #endif |
| 41 | |
Darren Tucker | deecec9 | 2006-07-12 22:44:34 +1000 | [diff] [blame] | 42 | #include <errno.h> |
Damien Miller | a1738e4 | 2006-07-10 21:33:04 +1000 | [diff] [blame] | 43 | #include <fcntl.h> |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 44 | #include <pwd.h> |
Damien Miller | 3717cda | 2006-03-15 14:02:36 +1100 | [diff] [blame] | 45 | #include <signal.h> |
Damien Miller | b8fe89c | 2006-07-24 14:51:00 +1000 | [diff] [blame] | 46 | #include <time.h> |
| 47 | #include <unistd.h> |
Damien Miller | 3717cda | 2006-03-15 14:02:36 +1100 | [diff] [blame] | 48 | |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 49 | #include <openssl/rand.h> |
| 50 | #include <openssl/sha.h> |
| 51 | #include <openssl/crypto.h> |
| 52 | |
| 53 | /* SunOS 4.4.4 needs this */ |
| 54 | #ifdef HAVE_FLOATINGPOINT_H |
| 55 | # include <floatingpoint.h> |
| 56 | #endif /* HAVE_FLOATINGPOINT_H */ |
| 57 | |
| 58 | #include "misc.h" |
| 59 | #include "xmalloc.h" |
| 60 | #include "atomicio.h" |
| 61 | #include "pathnames.h" |
| 62 | #include "log.h" |
| 63 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 64 | /* Number of bytes we write out */ |
| 65 | #define OUTPUT_SEED_SIZE 48 |
| 66 | |
| 67 | /* Length of on-disk seedfiles */ |
| 68 | #define SEED_FILE_SIZE 1024 |
| 69 | |
| 70 | /* Maximum number of command-line arguments to read from file */ |
| 71 | #define NUM_ARGS 10 |
| 72 | |
| 73 | /* Minimum number of usable commands to be considered sufficient */ |
| 74 | #define MIN_ENTROPY_SOURCES 16 |
| 75 | |
| 76 | /* Path to on-disk seed file (relative to user's home directory */ |
| 77 | #ifndef SSH_PRNG_SEED_FILE |
| 78 | # define SSH_PRNG_SEED_FILE _PATH_SSH_USER_DIR"/prng_seed" |
| 79 | #endif |
| 80 | |
| 81 | /* Path to PRNG commands list */ |
| 82 | #ifndef SSH_PRNG_COMMAND_FILE |
Damien Miller | 05eda43 | 2002-02-10 18:32:28 +1100 | [diff] [blame] | 83 | # define SSH_PRNG_COMMAND_FILE SSHDIR "/ssh_prng_cmds" |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 84 | #endif |
| 85 | |
Kevin Steves | 9443508 | 2001-12-25 04:32:58 +0000 | [diff] [blame] | 86 | extern char *__progname; |
Kevin Steves | 9443508 | 2001-12-25 04:32:58 +0000 | [diff] [blame] | 87 | |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 88 | #define WHITESPACE " \t\n" |
| 89 | |
| 90 | #ifndef RUSAGE_SELF |
| 91 | # define RUSAGE_SELF 0 |
| 92 | #endif |
| 93 | #ifndef RUSAGE_CHILDREN |
| 94 | # define RUSAGE_CHILDREN 0 |
| 95 | #endif |
| 96 | |
Damien Miller | c46cc54 | 2002-01-22 21:58:27 +1100 | [diff] [blame] | 97 | #if !defined(PRNGD_SOCKET) && !defined(PRNGD_PORT) |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 98 | # define USE_SEED_FILES |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 99 | #endif |
| 100 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 101 | typedef struct { |
| 102 | /* Proportion of data that is entropy */ |
| 103 | double rate; |
| 104 | /* Counter goes positive if this command times out */ |
| 105 | unsigned int badness; |
| 106 | /* Increases by factor of two each timeout */ |
| 107 | unsigned int sticky_badness; |
| 108 | /* Path to executable */ |
| 109 | char *path; |
| 110 | /* argv to pass to executable */ |
| 111 | char *args[NUM_ARGS]; /* XXX: arbitrary limit */ |
| 112 | /* full command string (debug) */ |
| 113 | char *cmdstring; |
| 114 | } entropy_cmd_t; |
| 115 | |
| 116 | /* slow command timeouts (all in milliseconds) */ |
| 117 | /* static int entropy_timeout_default = ENTROPY_TIMEOUT_MSEC; */ |
| 118 | static int entropy_timeout_current = ENTROPY_TIMEOUT_MSEC; |
| 119 | |
| 120 | /* this is initialised from a file, by prng_read_commands() */ |
| 121 | static entropy_cmd_t *entropy_cmds = NULL; |
| 122 | |
| 123 | /* Prototypes */ |
| 124 | double stir_from_system(void); |
| 125 | double stir_from_programs(void); |
| 126 | double stir_gettimeofday(double entropy_estimate); |
| 127 | double stir_clock(double entropy_estimate); |
| 128 | double stir_rusage(int who, double entropy_estimate); |
Kevin Steves | 4bdb547 | 2002-07-28 20:42:23 +0000 | [diff] [blame] | 129 | double hash_command_output(entropy_cmd_t *src, unsigned char *hash); |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 130 | int get_random_bytes_prngd(unsigned char *buf, int len, |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 131 | unsigned short tcp_port, char *socket_path); |
| 132 | |
| 133 | /* |
| 134 | * Collect 'len' bytes of entropy into 'buf' from PRNGD/EGD daemon |
| 135 | * listening either on 'tcp_port', or via Unix domain socket at * |
| 136 | * 'socket_path'. |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 137 | * Either a non-zero tcp_port or a non-null socket_path must be |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 138 | * supplied. |
| 139 | * Returns 0 on success, -1 on error |
| 140 | */ |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 141 | int |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 142 | get_random_bytes_prngd(unsigned char *buf, int len, |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 143 | unsigned short tcp_port, char *socket_path) |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 144 | { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 145 | int fd, addr_len, rval, errors; |
Damien Miller | 52c8afe | 2005-06-19 10:19:43 +1000 | [diff] [blame] | 146 | u_char msg[2]; |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 147 | struct sockaddr_storage addr; |
| 148 | struct sockaddr_in *addr_in = (struct sockaddr_in *)&addr; |
| 149 | struct sockaddr_un *addr_un = (struct sockaddr_un *)&addr; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 150 | mysig_t old_sigpipe; |
| 151 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 152 | /* Sanity checks */ |
| 153 | if (socket_path == NULL && tcp_port == 0) |
| 154 | fatal("You must specify a port or a socket"); |
| 155 | if (socket_path != NULL && |
| 156 | strlen(socket_path) >= sizeof(addr_un->sun_path)) |
| 157 | fatal("Random pool path is too long"); |
Damien Miller | 52c8afe | 2005-06-19 10:19:43 +1000 | [diff] [blame] | 158 | if (len <= 0 || len > 255) |
| 159 | fatal("Too many bytes (%d) to read from PRNGD", len); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 160 | |
| 161 | memset(&addr, '\0', sizeof(addr)); |
| 162 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 163 | if (tcp_port != 0) { |
| 164 | addr_in->sin_family = AF_INET; |
| 165 | addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK); |
| 166 | addr_in->sin_port = htons(tcp_port); |
| 167 | addr_len = sizeof(*addr_in); |
| 168 | } else { |
| 169 | addr_un->sun_family = AF_UNIX; |
| 170 | strlcpy(addr_un->sun_path, socket_path, |
| 171 | sizeof(addr_un->sun_path)); |
| 172 | addr_len = offsetof(struct sockaddr_un, sun_path) + |
| 173 | strlen(socket_path) + 1; |
| 174 | } |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 175 | |
| 176 | old_sigpipe = mysignal(SIGPIPE, SIG_IGN); |
| 177 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 178 | errors = 0; |
| 179 | rval = -1; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 180 | reopen: |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 181 | fd = socket(addr.ss_family, SOCK_STREAM, 0); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 182 | if (fd == -1) { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 183 | error("Couldn't create socket: %s", strerror(errno)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 184 | goto done; |
| 185 | } |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 186 | |
| 187 | if (connect(fd, (struct sockaddr*)&addr, addr_len) == -1) { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 188 | if (tcp_port != 0) { |
| 189 | error("Couldn't connect to PRNGD port %d: %s", |
| 190 | tcp_port, strerror(errno)); |
| 191 | } else { |
| 192 | error("Couldn't connect to PRNGD socket \"%s\": %s", |
| 193 | addr_un->sun_path, strerror(errno)); |
| 194 | } |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 195 | goto done; |
| 196 | } |
| 197 | |
| 198 | /* Send blocking read request to PRNGD */ |
| 199 | msg[0] = 0x02; |
| 200 | msg[1] = len; |
| 201 | |
Darren Tucker | 8661b56 | 2003-07-06 15:20:46 +1000 | [diff] [blame] | 202 | if (atomicio(vwrite, fd, msg, sizeof(msg)) != sizeof(msg)) { |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 203 | if (errno == EPIPE && errors < 10) { |
| 204 | close(fd); |
| 205 | errors++; |
| 206 | goto reopen; |
| 207 | } |
| 208 | error("Couldn't write to PRNGD socket: %s", |
| 209 | strerror(errno)); |
| 210 | goto done; |
| 211 | } |
| 212 | |
Damien Miller | 52c8afe | 2005-06-19 10:19:43 +1000 | [diff] [blame] | 213 | if (atomicio(read, fd, buf, len) != (size_t)len) { |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 214 | if (errno == EPIPE && errors < 10) { |
| 215 | close(fd); |
| 216 | errors++; |
| 217 | goto reopen; |
| 218 | } |
| 219 | error("Couldn't read from PRNGD socket: %s", |
| 220 | strerror(errno)); |
| 221 | goto done; |
| 222 | } |
| 223 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 224 | rval = 0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 225 | done: |
| 226 | mysignal(SIGPIPE, old_sigpipe); |
| 227 | if (fd != -1) |
| 228 | close(fd); |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 229 | return rval; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 230 | } |
| 231 | |
Darren Tucker | 8686ed7 | 2004-12-20 12:05:08 +1100 | [diff] [blame] | 232 | static int |
| 233 | seed_from_prngd(unsigned char *buf, size_t bytes) |
| 234 | { |
| 235 | #ifdef PRNGD_PORT |
| 236 | debug("trying egd/prngd port %d", PRNGD_PORT); |
| 237 | if (get_random_bytes_prngd(buf, bytes, PRNGD_PORT, NULL) == 0) |
| 238 | return 0; |
| 239 | #endif |
| 240 | #ifdef PRNGD_SOCKET |
| 241 | debug("trying egd/prngd socket %s", PRNGD_SOCKET); |
| 242 | if (get_random_bytes_prngd(buf, bytes, 0, PRNGD_SOCKET) == 0) |
| 243 | return 0; |
| 244 | #endif |
| 245 | return -1; |
| 246 | } |
| 247 | |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 248 | double |
| 249 | stir_gettimeofday(double entropy_estimate) |
| 250 | { |
| 251 | struct timeval tv; |
| 252 | |
| 253 | if (gettimeofday(&tv, NULL) == -1) |
| 254 | fatal("Couldn't gettimeofday: %s", strerror(errno)); |
| 255 | |
| 256 | RAND_add(&tv, sizeof(tv), entropy_estimate); |
| 257 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 258 | return entropy_estimate; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 259 | } |
| 260 | |
| 261 | double |
| 262 | stir_clock(double entropy_estimate) |
| 263 | { |
| 264 | #ifdef HAVE_CLOCK |
| 265 | clock_t c; |
| 266 | |
| 267 | c = clock(); |
| 268 | RAND_add(&c, sizeof(c), entropy_estimate); |
| 269 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 270 | return entropy_estimate; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 271 | #else /* _HAVE_CLOCK */ |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 272 | return 0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 273 | #endif /* _HAVE_CLOCK */ |
| 274 | } |
| 275 | |
| 276 | double |
| 277 | stir_rusage(int who, double entropy_estimate) |
| 278 | { |
| 279 | #ifdef HAVE_GETRUSAGE |
| 280 | struct rusage ru; |
| 281 | |
| 282 | if (getrusage(who, &ru) == -1) |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 283 | return 0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 284 | |
| 285 | RAND_add(&ru, sizeof(ru), entropy_estimate); |
| 286 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 287 | return entropy_estimate; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 288 | #else /* _HAVE_GETRUSAGE */ |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 289 | return 0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 290 | #endif /* _HAVE_GETRUSAGE */ |
| 291 | } |
| 292 | |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 293 | static int |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 294 | timeval_diff(struct timeval *t1, struct timeval *t2) |
| 295 | { |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 296 | int secdiff, usecdiff; |
| 297 | |
| 298 | secdiff = t2->tv_sec - t1->tv_sec; |
| 299 | usecdiff = (secdiff*1000000) + (t2->tv_usec - t1->tv_usec); |
| 300 | return (int)(usecdiff / 1000); |
| 301 | } |
| 302 | |
| 303 | double |
Kevin Steves | 4bdb547 | 2002-07-28 20:42:23 +0000 | [diff] [blame] | 304 | hash_command_output(entropy_cmd_t *src, unsigned char *hash) |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 305 | { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 306 | char buf[8192]; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 307 | fd_set rdset; |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 308 | int bytes_read, cmd_eof, error_abort, msec_elapsed, p[2]; |
| 309 | int status, total_bytes_read; |
| 310 | static int devnull = -1; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 311 | pid_t pid; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 312 | SHA_CTX sha; |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 313 | struct timeval tv_start, tv_current; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 314 | |
| 315 | debug3("Reading output from \'%s\'", src->cmdstring); |
| 316 | |
| 317 | if (devnull == -1) { |
| 318 | devnull = open("/dev/null", O_RDWR); |
| 319 | if (devnull == -1) |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 320 | fatal("Couldn't open /dev/null: %s", |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 321 | strerror(errno)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 322 | } |
| 323 | |
| 324 | if (pipe(p) == -1) |
| 325 | fatal("Couldn't open pipe: %s", strerror(errno)); |
| 326 | |
| 327 | (void)gettimeofday(&tv_start, NULL); /* record start time */ |
| 328 | |
| 329 | switch (pid = fork()) { |
| 330 | case -1: /* Error */ |
| 331 | close(p[0]); |
| 332 | close(p[1]); |
| 333 | fatal("Couldn't fork: %s", strerror(errno)); |
| 334 | /* NOTREACHED */ |
| 335 | case 0: /* Child */ |
| 336 | dup2(devnull, STDIN_FILENO); |
| 337 | dup2(p[1], STDOUT_FILENO); |
| 338 | dup2(p[1], STDERR_FILENO); |
| 339 | close(p[0]); |
| 340 | close(p[1]); |
| 341 | close(devnull); |
| 342 | |
| 343 | execv(src->path, (char**)(src->args)); |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 344 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 345 | debug("(child) Couldn't exec '%s': %s", |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 346 | src->cmdstring, strerror(errno)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 347 | _exit(-1); |
| 348 | default: /* Parent */ |
| 349 | break; |
| 350 | } |
| 351 | |
| 352 | RAND_add(&pid, sizeof(&pid), 0.0); |
| 353 | |
| 354 | close(p[1]); |
| 355 | |
| 356 | /* Hash output from child */ |
| 357 | SHA1_Init(&sha); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 358 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 359 | cmd_eof = error_abort = msec_elapsed = total_bytes_read = 0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 360 | while (!error_abort && !cmd_eof) { |
| 361 | int ret; |
| 362 | struct timeval tv; |
| 363 | int msec_remaining; |
| 364 | |
| 365 | (void) gettimeofday(&tv_current, 0); |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 366 | msec_elapsed = timeval_diff(&tv_start, &tv_current); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 367 | if (msec_elapsed >= entropy_timeout_current) { |
| 368 | error_abort=1; |
| 369 | continue; |
| 370 | } |
| 371 | msec_remaining = entropy_timeout_current - msec_elapsed; |
| 372 | |
| 373 | FD_ZERO(&rdset); |
| 374 | FD_SET(p[0], &rdset); |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 375 | tv.tv_sec = msec_remaining / 1000; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 376 | tv.tv_usec = (msec_remaining % 1000) * 1000; |
| 377 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 378 | ret = select(p[0] + 1, &rdset, NULL, NULL, &tv); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 379 | |
| 380 | RAND_add(&tv, sizeof(tv), 0.0); |
| 381 | |
| 382 | switch (ret) { |
| 383 | case 0: |
| 384 | /* timer expired */ |
| 385 | error_abort = 1; |
Damien Miller | 5a5da88 | 2002-10-21 10:13:35 +1000 | [diff] [blame] | 386 | kill(pid, SIGINT); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 387 | break; |
| 388 | case 1: |
| 389 | /* command input */ |
| 390 | do { |
| 391 | bytes_read = read(p[0], buf, sizeof(buf)); |
| 392 | } while (bytes_read == -1 && errno == EINTR); |
| 393 | RAND_add(&bytes_read, sizeof(&bytes_read), 0.0); |
| 394 | if (bytes_read == -1) { |
| 395 | error_abort = 1; |
| 396 | break; |
| 397 | } else if (bytes_read) { |
| 398 | SHA1_Update(&sha, buf, bytes_read); |
| 399 | total_bytes_read += bytes_read; |
| 400 | } else { |
| 401 | cmd_eof = 1; |
| 402 | } |
| 403 | break; |
| 404 | case -1: |
| 405 | default: |
| 406 | /* error */ |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 407 | debug("Command '%s': select() failed: %s", |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 408 | src->cmdstring, strerror(errno)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 409 | error_abort = 1; |
| 410 | break; |
| 411 | } |
| 412 | } |
| 413 | |
| 414 | SHA1_Final(hash, &sha); |
| 415 | |
| 416 | close(p[0]); |
| 417 | |
| 418 | debug3("Time elapsed: %d msec", msec_elapsed); |
| 419 | |
| 420 | if (waitpid(pid, &status, 0) == -1) { |
Damien Miller | b6f72f5 | 2005-07-17 17:26:43 +1000 | [diff] [blame] | 421 | error("Couldn't wait for child '%s' completion: %s", |
| 422 | src->cmdstring, strerror(errno)); |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 423 | return 0.0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 424 | } |
| 425 | |
| 426 | RAND_add(&status, sizeof(&status), 0.0); |
| 427 | |
| 428 | if (error_abort) { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 429 | /* |
| 430 | * Closing p[0] on timeout causes the entropy command to |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 431 | * SIGPIPE. Take whatever output we got, and mark this |
| 432 | * command as slow |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 433 | */ |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 434 | debug2("Command '%s' timed out", src->cmdstring); |
| 435 | src->sticky_badness *= 2; |
| 436 | src->badness = src->sticky_badness; |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 437 | return total_bytes_read; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 438 | } |
| 439 | |
| 440 | if (WIFEXITED(status)) { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 441 | if (WEXITSTATUS(status) == 0) { |
| 442 | return total_bytes_read; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 443 | } else { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 444 | debug2("Command '%s' exit status was %d", |
| 445 | src->cmdstring, WEXITSTATUS(status)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 446 | src->badness = src->sticky_badness = 128; |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 447 | return 0.0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 448 | } |
| 449 | } else if (WIFSIGNALED(status)) { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 450 | debug2("Command '%s' returned on uncaught signal %d !", |
| 451 | src->cmdstring, status); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 452 | src->badness = src->sticky_badness = 128; |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 453 | return 0.0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 454 | } else |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 455 | return 0.0; |
| 456 | } |
| 457 | |
| 458 | double |
| 459 | stir_from_system(void) |
| 460 | { |
| 461 | double total_entropy_estimate; |
| 462 | long int i; |
| 463 | |
| 464 | total_entropy_estimate = 0; |
| 465 | |
| 466 | i = getpid(); |
| 467 | RAND_add(&i, sizeof(i), 0.5); |
| 468 | total_entropy_estimate += 0.1; |
| 469 | |
| 470 | i = getppid(); |
| 471 | RAND_add(&i, sizeof(i), 0.5); |
| 472 | total_entropy_estimate += 0.1; |
| 473 | |
| 474 | i = getuid(); |
| 475 | RAND_add(&i, sizeof(i), 0.0); |
| 476 | i = getgid(); |
| 477 | RAND_add(&i, sizeof(i), 0.0); |
| 478 | |
| 479 | total_entropy_estimate += stir_gettimeofday(1.0); |
| 480 | total_entropy_estimate += stir_clock(0.5); |
| 481 | total_entropy_estimate += stir_rusage(RUSAGE_SELF, 2.0); |
| 482 | |
| 483 | return total_entropy_estimate; |
| 484 | } |
| 485 | |
| 486 | double |
| 487 | stir_from_programs(void) |
| 488 | { |
| 489 | int c; |
| 490 | double entropy, total_entropy; |
Kevin Steves | 4bdb547 | 2002-07-28 20:42:23 +0000 | [diff] [blame] | 491 | unsigned char hash[SHA_DIGEST_LENGTH]; |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 492 | |
| 493 | total_entropy = 0; |
| 494 | for(c = 0; entropy_cmds[c].path != NULL; c++) { |
| 495 | if (!entropy_cmds[c].badness) { |
| 496 | /* Hash output from command */ |
| 497 | entropy = hash_command_output(&entropy_cmds[c], |
| 498 | hash); |
| 499 | |
| 500 | /* Scale back estimate by command's rate */ |
| 501 | entropy *= entropy_cmds[c].rate; |
| 502 | |
| 503 | /* Upper bound of entropy is SHA_DIGEST_LENGTH */ |
| 504 | if (entropy > SHA_DIGEST_LENGTH) |
| 505 | entropy = SHA_DIGEST_LENGTH; |
| 506 | |
| 507 | /* Stir it in */ |
| 508 | RAND_add(hash, sizeof(hash), entropy); |
| 509 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 510 | debug3("Got %0.2f bytes of entropy from '%s'", |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 511 | entropy, entropy_cmds[c].cmdstring); |
| 512 | |
| 513 | total_entropy += entropy; |
| 514 | |
| 515 | /* Execution time should be a bit unpredictable */ |
| 516 | total_entropy += stir_gettimeofday(0.05); |
| 517 | total_entropy += stir_clock(0.05); |
| 518 | total_entropy += stir_rusage(RUSAGE_SELF, 0.1); |
| 519 | total_entropy += stir_rusage(RUSAGE_CHILDREN, 0.1); |
| 520 | } else { |
| 521 | debug2("Command '%s' disabled (badness %d)", |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 522 | entropy_cmds[c].cmdstring, |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 523 | entropy_cmds[c].badness); |
| 524 | |
| 525 | if (entropy_cmds[c].badness > 0) |
| 526 | entropy_cmds[c].badness--; |
| 527 | } |
| 528 | } |
| 529 | |
| 530 | return total_entropy; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 531 | } |
| 532 | |
| 533 | /* |
| 534 | * prng seedfile functions |
| 535 | */ |
| 536 | int |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 537 | prng_check_seedfile(char *filename) |
| 538 | { |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 539 | struct stat st; |
| 540 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 541 | /* |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 542 | * XXX raceable: eg replace seed between this stat and subsequent |
| 543 | * open. Not such a problem because we don't really trust the |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 544 | * seed file anyway. |
| 545 | * XXX: use secure path checking as elsewhere in OpenSSH |
| 546 | */ |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 547 | if (lstat(filename, &st) == -1) { |
| 548 | /* Give up on hard errors */ |
| 549 | if (errno != ENOENT) |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 550 | debug("WARNING: Couldn't stat random seed file " |
| 551 | "\"%.100s\": %s", filename, strerror(errno)); |
| 552 | return 0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 553 | } |
| 554 | |
| 555 | /* regular file? */ |
| 556 | if (!S_ISREG(st.st_mode)) |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 557 | fatal("PRNG seedfile %.100s is not a regular file", |
| 558 | filename); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 559 | |
| 560 | /* mode 0600, owned by root or the current user? */ |
| 561 | if (((st.st_mode & 0177) != 0) || !(st.st_uid == getuid())) { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 562 | debug("WARNING: PRNG seedfile %.100s must be mode 0600, " |
Damien Miller | c46b6bc | 2003-05-16 15:51:44 +1000 | [diff] [blame] | 563 | "owned by uid %li", filename, (long int)getuid()); |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 564 | return 0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 565 | } |
| 566 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 567 | return 1; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 568 | } |
| 569 | |
| 570 | void |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 571 | prng_write_seedfile(void) |
| 572 | { |
Damien Miller | ed462d9 | 2005-02-16 13:02:45 +1100 | [diff] [blame] | 573 | int fd, save_errno; |
Kevin Steves | 4bdb547 | 2002-07-28 20:42:23 +0000 | [diff] [blame] | 574 | unsigned char seed[SEED_FILE_SIZE]; |
Damien Miller | ed462d9 | 2005-02-16 13:02:45 +1100 | [diff] [blame] | 575 | char filename[MAXPATHLEN], tmpseed[MAXPATHLEN]; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 576 | struct passwd *pw; |
Damien Miller | ed462d9 | 2005-02-16 13:02:45 +1100 | [diff] [blame] | 577 | mode_t old_umask; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 578 | |
| 579 | pw = getpwuid(getuid()); |
| 580 | if (pw == NULL) |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 581 | fatal("Couldn't get password entry for current user " |
Damien Miller | c46b6bc | 2003-05-16 15:51:44 +1000 | [diff] [blame] | 582 | "(%li): %s", (long int)getuid(), strerror(errno)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 583 | |
| 584 | /* Try to ensure that the parent directory is there */ |
| 585 | snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir, |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 586 | _PATH_SSH_USER_DIR); |
Darren Tucker | daf6ff4 | 2006-07-05 21:35:48 +1000 | [diff] [blame] | 587 | if (mkdir(filename, 0700) < 0 && errno != EEXIST) |
| 588 | fatal("mkdir %.200s: %s", filename, strerror(errno)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 589 | |
| 590 | snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir, |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 591 | SSH_PRNG_SEED_FILE); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 592 | |
Damien Miller | ed462d9 | 2005-02-16 13:02:45 +1100 | [diff] [blame] | 593 | strlcpy(tmpseed, filename, sizeof(tmpseed)); |
| 594 | if (strlcat(tmpseed, ".XXXXXXXXXX", sizeof(tmpseed)) >= |
| 595 | sizeof(tmpseed)) |
| 596 | fatal("PRNG seed filename too long"); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 597 | |
Damien Miller | cafbcc7 | 2003-03-17 16:13:53 +1100 | [diff] [blame] | 598 | if (RAND_bytes(seed, sizeof(seed)) <= 0) |
Ben Lindstrom | da4d9cf | 2003-09-22 15:36:15 +0000 | [diff] [blame] | 599 | fatal("PRNG seed extraction failed"); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 600 | |
| 601 | /* Don't care if the seed doesn't exist */ |
| 602 | prng_check_seedfile(filename); |
| 603 | |
Damien Miller | ed462d9 | 2005-02-16 13:02:45 +1100 | [diff] [blame] | 604 | old_umask = umask(0177); |
| 605 | |
| 606 | if ((fd = mkstemp(tmpseed)) == -1) { |
| 607 | debug("WARNING: couldn't make temporary PRNG seedfile %.100s " |
| 608 | "(%.100s)", tmpseed, strerror(errno)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 609 | } else { |
Damien Miller | ed462d9 | 2005-02-16 13:02:45 +1100 | [diff] [blame] | 610 | debug("writing PRNG seed to file %.100s", tmpseed); |
| 611 | if (atomicio(vwrite, fd, &seed, sizeof(seed)) < sizeof(seed)) { |
| 612 | save_errno = errno; |
| 613 | close(fd); |
| 614 | unlink(tmpseed); |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 615 | fatal("problem writing PRNG seedfile %.100s " |
Damien Miller | ed462d9 | 2005-02-16 13:02:45 +1100 | [diff] [blame] | 616 | "(%.100s)", filename, strerror(save_errno)); |
| 617 | } |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 618 | close(fd); |
Damien Miller | ed462d9 | 2005-02-16 13:02:45 +1100 | [diff] [blame] | 619 | debug("moving temporary PRNG seed to file %.100s", filename); |
| 620 | if (rename(tmpseed, filename) == -1) { |
| 621 | save_errno = errno; |
| 622 | unlink(tmpseed); |
| 623 | fatal("problem renaming PRNG seedfile from %.100s " |
Damien Miller | 94cf4c8 | 2005-07-17 17:04:47 +1000 | [diff] [blame] | 624 | "to %.100s (%.100s)", tmpseed, filename, |
Damien Miller | ed462d9 | 2005-02-16 13:02:45 +1100 | [diff] [blame] | 625 | strerror(save_errno)); |
| 626 | } |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 627 | } |
Damien Miller | ed462d9 | 2005-02-16 13:02:45 +1100 | [diff] [blame] | 628 | umask(old_umask); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 629 | } |
| 630 | |
| 631 | void |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 632 | prng_read_seedfile(void) |
| 633 | { |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 634 | int fd; |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 635 | char seed[SEED_FILE_SIZE], filename[MAXPATHLEN]; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 636 | struct passwd *pw; |
| 637 | |
| 638 | pw = getpwuid(getuid()); |
| 639 | if (pw == NULL) |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 640 | fatal("Couldn't get password entry for current user " |
Damien Miller | c46b6bc | 2003-05-16 15:51:44 +1000 | [diff] [blame] | 641 | "(%li): %s", (long int)getuid(), strerror(errno)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 642 | |
| 643 | snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir, |
| 644 | SSH_PRNG_SEED_FILE); |
| 645 | |
| 646 | debug("loading PRNG seed from file %.100s", filename); |
| 647 | |
| 648 | if (!prng_check_seedfile(filename)) { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 649 | verbose("Random seed file not found or invalid, ignoring."); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 650 | return; |
| 651 | } |
| 652 | |
| 653 | /* open the file and read in the seed */ |
| 654 | fd = open(filename, O_RDONLY); |
| 655 | if (fd == -1) |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 656 | fatal("could not open PRNG seedfile %.100s (%.100s)", |
| 657 | filename, strerror(errno)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 658 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 659 | if (atomicio(read, fd, &seed, sizeof(seed)) < sizeof(seed)) { |
| 660 | verbose("invalid or short read from PRNG seedfile " |
| 661 | "%.100s - ignoring", filename); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 662 | memset(seed, '\0', sizeof(seed)); |
| 663 | } |
| 664 | close(fd); |
| 665 | |
| 666 | /* stir in the seed, with estimated entropy zero */ |
| 667 | RAND_add(&seed, sizeof(seed), 0.0); |
| 668 | } |
| 669 | |
| 670 | |
| 671 | /* |
| 672 | * entropy command initialisation functions |
| 673 | */ |
| 674 | int |
| 675 | prng_read_commands(char *cmdfilename) |
| 676 | { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 677 | char cmd[SEED_FILE_SIZE], *cp, line[1024], path[SEED_FILE_SIZE]; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 678 | double est; |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 679 | entropy_cmd_t *entcmd; |
| 680 | FILE *f; |
| 681 | int cur_cmd, linenum, num_cmds, arg; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 682 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 683 | if ((f = fopen(cmdfilename, "r")) == NULL) { |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 684 | fatal("couldn't read entropy commands file %.100s: %.100s", |
| 685 | cmdfilename, strerror(errno)); |
| 686 | } |
| 687 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 688 | num_cmds = 64; |
Darren Tucker | d8093e4 | 2006-05-04 16:24:34 +1000 | [diff] [blame] | 689 | entcmd = xcalloc(num_cmds, sizeof(entropy_cmd_t)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 690 | |
| 691 | /* Read in file */ |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 692 | cur_cmd = linenum = 0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 693 | while (fgets(line, sizeof(line), f)) { |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 694 | linenum++; |
| 695 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 696 | /* Skip leading whitespace, blank lines and comments */ |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 697 | cp = line + strspn(line, WHITESPACE); |
| 698 | if ((*cp == 0) || (*cp == '#')) |
| 699 | continue; /* done with this line */ |
| 700 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 701 | /* |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 702 | * The first non-whitespace char should be a double quote |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 703 | * delimiting the commandline |
| 704 | */ |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 705 | if (*cp != '"') { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 706 | error("bad entropy command, %.100s line %d", |
| 707 | cmdfilename, linenum); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 708 | continue; |
| 709 | } |
| 710 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 711 | /* |
| 712 | * First token, command args (incl. argv[0]) in double |
| 713 | * quotes |
| 714 | */ |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 715 | cp = strtok(cp, "\""); |
| 716 | if (cp == NULL) { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 717 | error("missing or bad command string, %.100s " |
| 718 | "line %d -- ignored", cmdfilename, linenum); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 719 | continue; |
| 720 | } |
| 721 | strlcpy(cmd, cp, sizeof(cmd)); |
| 722 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 723 | /* Second token, full command path */ |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 724 | if ((cp = strtok(NULL, WHITESPACE)) == NULL) { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 725 | error("missing command path, %.100s " |
| 726 | "line %d -- ignored", cmdfilename, linenum); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 727 | continue; |
| 728 | } |
| 729 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 730 | /* Did configure mark this as dead? */ |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 731 | if (strncmp("undef", cp, 5) == 0) |
| 732 | continue; |
| 733 | |
| 734 | strlcpy(path, cp, sizeof(path)); |
| 735 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 736 | /* Third token, entropy rate estimate for this command */ |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 737 | if ((cp = strtok(NULL, WHITESPACE)) == NULL) { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 738 | error("missing entropy estimate, %.100s " |
| 739 | "line %d -- ignored", cmdfilename, linenum); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 740 | continue; |
| 741 | } |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 742 | est = strtod(cp, NULL); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 743 | |
| 744 | /* end of line */ |
| 745 | if ((cp = strtok(NULL, WHITESPACE)) != NULL) { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 746 | error("garbage at end of line %d in %.100s " |
| 747 | "-- ignored", linenum, cmdfilename); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 748 | continue; |
| 749 | } |
| 750 | |
| 751 | /* save the command for debug messages */ |
| 752 | entcmd[cur_cmd].cmdstring = xstrdup(cmd); |
| 753 | |
| 754 | /* split the command args */ |
| 755 | cp = strtok(cmd, WHITESPACE); |
| 756 | arg = 0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 757 | do { |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 758 | entcmd[cur_cmd].args[arg] = xstrdup(cp); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 759 | arg++; |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 760 | } while(arg < NUM_ARGS && (cp = strtok(NULL, WHITESPACE))); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 761 | |
| 762 | if (strtok(NULL, WHITESPACE)) |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 763 | error("ignored extra commands (max %d), %.100s " |
| 764 | "line %d", NUM_ARGS, cmdfilename, linenum); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 765 | |
| 766 | /* Copy the command path and rate estimate */ |
| 767 | entcmd[cur_cmd].path = xstrdup(path); |
| 768 | entcmd[cur_cmd].rate = est; |
| 769 | |
| 770 | /* Initialise other values */ |
| 771 | entcmd[cur_cmd].sticky_badness = 1; |
| 772 | |
| 773 | cur_cmd++; |
| 774 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 775 | /* |
| 776 | * If we've filled the array, reallocate it twice the size |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 777 | * Do this now because even if this we're on the last |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 778 | * command we need another slot to mark the last entry |
| 779 | */ |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 780 | if (cur_cmd == num_cmds) { |
| 781 | num_cmds *= 2; |
Damien Miller | 3681209 | 2006-03-26 14:22:47 +1100 | [diff] [blame] | 782 | entcmd = xrealloc(entcmd, num_cmds, |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 783 | sizeof(entropy_cmd_t)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 784 | } |
| 785 | } |
| 786 | |
| 787 | /* zero the last entry */ |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 788 | memset(&entcmd[cur_cmd], '\0', sizeof(entropy_cmd_t)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 789 | |
| 790 | /* trim to size */ |
Damien Miller | 3681209 | 2006-03-26 14:22:47 +1100 | [diff] [blame] | 791 | entropy_cmds = xrealloc(entcmd, (cur_cmd + 1), |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 792 | sizeof(entropy_cmd_t)); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 793 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 794 | debug("Loaded %d entropy commands from %.100s", cur_cmd, |
| 795 | cmdfilename); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 796 | |
Darren Tucker | f58b29d | 2006-05-17 22:24:56 +1000 | [diff] [blame] | 797 | fclose(f); |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 798 | return cur_cmd < MIN_ENTROPY_SOURCES ? -1 : 0; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 799 | } |
| 800 | |
Damien Miller | 32e4818 | 2002-04-14 19:27:12 +1000 | [diff] [blame] | 801 | void |
| 802 | usage(void) |
| 803 | { |
| 804 | fprintf(stderr, "Usage: %s [options]\n", __progname); |
| 805 | fprintf(stderr, " -v Verbose; display verbose debugging messages.\n"); |
| 806 | fprintf(stderr, " Multiple -v increases verbosity.\n"); |
Damien Miller | 7daf044 | 2004-08-23 21:52:08 +1000 | [diff] [blame] | 807 | fprintf(stderr, " -x Force output in hexadecimal (for debugging)\n"); |
Damien Miller | 32e4818 | 2002-04-14 19:27:12 +1000 | [diff] [blame] | 808 | fprintf(stderr, " -X Force output in binary\n"); |
| 809 | fprintf(stderr, " -b bytes Number of bytes to output (default %d)\n", |
| 810 | OUTPUT_SEED_SIZE); |
| 811 | } |
| 812 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 813 | int |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 814 | main(int argc, char **argv) |
| 815 | { |
Damien Miller | 32e4818 | 2002-04-14 19:27:12 +1000 | [diff] [blame] | 816 | unsigned char *buf; |
| 817 | int ret, ch, debug_level, output_hex, bytes; |
| 818 | extern char *optarg; |
| 819 | LogLevel ll; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 820 | |
Damien Miller | 59d3d5b | 2003-08-22 09:34:41 +1000 | [diff] [blame] | 821 | __progname = ssh_get_progname(argv[0]); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 822 | log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1); |
| 823 | |
Damien Miller | 32e4818 | 2002-04-14 19:27:12 +1000 | [diff] [blame] | 824 | ll = SYSLOG_LEVEL_INFO; |
| 825 | debug_level = output_hex = 0; |
| 826 | bytes = OUTPUT_SEED_SIZE; |
| 827 | |
| 828 | /* Don't write binary data to a tty, unless we are forced to */ |
| 829 | if (isatty(STDOUT_FILENO)) |
| 830 | output_hex = 1; |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 831 | |
Damien Miller | 32e4818 | 2002-04-14 19:27:12 +1000 | [diff] [blame] | 832 | while ((ch = getopt(argc, argv, "vxXhb:")) != -1) { |
| 833 | switch (ch) { |
| 834 | case 'v': |
| 835 | if (debug_level < 3) |
| 836 | ll = SYSLOG_LEVEL_DEBUG1 + debug_level++; |
| 837 | break; |
| 838 | case 'x': |
| 839 | output_hex = 1; |
| 840 | break; |
| 841 | case 'X': |
| 842 | output_hex = 0; |
| 843 | break; |
| 844 | case 'b': |
| 845 | if ((bytes = atoi(optarg)) <= 0) |
| 846 | fatal("Invalid number of output bytes"); |
| 847 | break; |
| 848 | case 'h': |
| 849 | usage(); |
| 850 | exit(0); |
| 851 | default: |
| 852 | error("Invalid commandline option"); |
| 853 | usage(); |
| 854 | } |
| 855 | } |
| 856 | |
| 857 | log_init(argv[0], ll, SYSLOG_FACILITY_USER, 1); |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 858 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 859 | #ifdef USE_SEED_FILES |
| 860 | prng_read_seedfile(); |
| 861 | #endif |
| 862 | |
Damien Miller | 32e4818 | 2002-04-14 19:27:12 +1000 | [diff] [blame] | 863 | buf = xmalloc(bytes); |
| 864 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 865 | /* |
| 866 | * Seed the RNG from wherever we can |
| 867 | */ |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 868 | |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 869 | /* Take whatever is on the stack, but don't credit it */ |
Damien Miller | 32e4818 | 2002-04-14 19:27:12 +1000 | [diff] [blame] | 870 | RAND_add(buf, bytes, 0); |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 871 | |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 872 | debug("Seeded RNG with %i bytes from system calls", |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 873 | (int)stir_from_system()); |
| 874 | |
Darren Tucker | 8686ed7 | 2004-12-20 12:05:08 +1100 | [diff] [blame] | 875 | /* try prngd, fall back to commands if prngd fails or not configured */ |
| 876 | if (seed_from_prngd(buf, bytes) == 0) { |
| 877 | RAND_add(buf, bytes, bytes); |
| 878 | } else { |
| 879 | /* Read in collection commands */ |
| 880 | if (prng_read_commands(SSH_PRNG_COMMAND_FILE) == -1) |
| 881 | fatal("PRNG initialisation failed -- exiting."); |
| 882 | debug("Seeded RNG with %i bytes from programs", |
| 883 | (int)stir_from_programs()); |
| 884 | } |
Damien Miller | 7b10ef4 | 2002-01-21 23:44:12 +1100 | [diff] [blame] | 885 | |
| 886 | #ifdef USE_SEED_FILES |
| 887 | prng_write_seedfile(); |
| 888 | #endif |
| 889 | |
| 890 | /* |
| 891 | * Write the seed to stdout |
| 892 | */ |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 893 | |
| 894 | if (!RAND_status()) |
| 895 | fatal("Not enough entropy in RNG"); |
| 896 | |
Damien Miller | cafbcc7 | 2003-03-17 16:13:53 +1100 | [diff] [blame] | 897 | if (RAND_bytes(buf, bytes) <= 0) |
| 898 | fatal("Couldn't extract entropy from PRNG"); |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 899 | |
Damien Miller | 32e4818 | 2002-04-14 19:27:12 +1000 | [diff] [blame] | 900 | if (output_hex) { |
| 901 | for(ret = 0; ret < bytes; ret++) |
| 902 | printf("%02x", (unsigned char)(buf[ret])); |
| 903 | printf("\n"); |
| 904 | } else |
Darren Tucker | 8661b56 | 2003-07-06 15:20:46 +1000 | [diff] [blame] | 905 | ret = atomicio(vwrite, STDOUT_FILENO, buf, bytes); |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 906 | |
Damien Miller | 32e4818 | 2002-04-14 19:27:12 +1000 | [diff] [blame] | 907 | memset(buf, '\0', bytes); |
| 908 | xfree(buf); |
Damien Miller | 787b2ec | 2003-11-21 23:56:47 +1100 | [diff] [blame] | 909 | |
Damien Miller | 32e4818 | 2002-04-14 19:27:12 +1000 | [diff] [blame] | 910 | return ret == bytes ? 0 : 1; |
Damien Miller | 62116dc | 2001-12-24 01:41:47 +1100 | [diff] [blame] | 911 | } |
Darren Tucker | 7b48d25 | 2005-02-16 13:20:07 +1100 | [diff] [blame] | 912 | |
| 913 | /* |
| 914 | * We may attempt to re-seed during mkstemp if we are using the one in the |
Darren Tucker | 7a8619a | 2005-02-16 13:32:30 +1100 | [diff] [blame] | 915 | * compat library (via mkstemp -> _gettemp -> arc4random -> seed_rng) so we |
| 916 | * need our own seed_rng(). We must also check that we have enough entropy. |
Darren Tucker | 7b48d25 | 2005-02-16 13:20:07 +1100 | [diff] [blame] | 917 | */ |
| 918 | void |
| 919 | seed_rng(void) |
| 920 | { |
| 921 | if (!RAND_status()) |
| 922 | fatal("Not enough entropy in RNG"); |
| 923 | } |