crypto/dist/heimdal/lib/hcrypto/rand-egd.c

   1 /*
   2  * Copyright (c) 2007 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include <config.h>
  36 #endif
  37
  38 __RCSID("$Heimdal: rand-egd.c 21156 2007-06-18 22:00:59Z lha $"
  39         "$NetBSD$");
  40
  41 #include <sys/types.h>
  42 #ifdef HAVE_SYS_UN_H
  43 #include <sys/un.h>
  44 #endif
  45
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #ifdef HAVE_UNISTD_H
  49 #include <unistd.h>
  50 #endif
  51 #include <assert.h>
  52
  53 #include <rand.h>
  54 #include <randi.h>
  55
  56 #include <roken.h>
  57
  58 static const char *egd_path = "/var/run/egd-pool";
  59
  60 #define MAX_EGD_DATA 255
  61
  62 static int
  63 connect_egd(const char *path)
  64 {
  65     struct sockaddr_un addr;
  66     int fd;
  67
  68     memset(&addr, 0, sizeof(addr));
  69
  70     if (strlen(path) > sizeof(addr.sun_path))
  71         return -1;
  72
  73     addr.sun_family = AF_UNIX;
  74     strlcpy(addr.sun_path, path, sizeof(addr.sun_path));
  75
  76     fd = socket(AF_UNIX, SOCK_STREAM, 0);
  77     if (fd < 0)
  78         return -1;
  79
  80     if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) != 0) {
  81         close(fd);
  82         return -1;
  83     }
  84
  85     return fd;
  86 }
  87
  88 static int
  89 get_entropy(int fd, void *data, size_t len)
  90 {
  91     unsigned char msg[2];
  92
  93     assert(len <= MAX_EGD_DATA);
  94
  95     msg[0] = 0x02; /* read blocking data */
  96     msg[1] = len; /* wanted length */
  97
  98     if (net_write(fd, msg, sizeof(msg)) != sizeof(msg))
  99         return 0;
 100
 101     if (net_read(fd, data, len) != len)
 102         return 0;
 103
 104     return 1;
 105 }
 106
 107 static int
 108 put_entropy(int fd, const void *data, size_t len)
 109 {
 110     unsigned char msg[4];
 111
 112     assert (len <= MAX_EGD_DATA);
 113
 114     msg[0] = 0x03; /* write data */
 115     msg[1] = 0; /* dummy */
 116     msg[2] = 0; /* entropy */
 117     msg[3] = len; /* length */
 118
 119     if (net_write(fd, msg, sizeof(msg)) != sizeof(msg))
 120         return 0;
 121     if (net_write(fd, data, len) != len)
 122         return 0;
 123
 124     return 1;
 125 }
 126
 127 /*
 128  *
 129  */
 130
 131 static void
 132 egd_seed(const void *indata, int size)
 133 {
 134     size_t len;
 135     int fd, ret = 1;
 136
 137     fd = connect_egd(egd_path);
 138     if (fd < 0)
 139         return;
 140
 141     while(size) {
 142         len = size;
 143         if (len > MAX_EGD_DATA)
 144             len = MAX_EGD_DATA;
 145         ret = put_entropy(fd, indata, len);
 146         if (ret != 1)
 147             break;
 148         indata = ((unsigned char *)indata) + len;
 149         size -= len;
 150     }
 151     close(fd);
 152 }
 153
 154 static int
 155 get_bytes(const char *path, unsigned char *outdata, int size)
 156 {
 157     size_t len;
 158     int fd, ret = 1;
 159
 160     if (path == NULL)
 161         path = egd_path;
 162
 163     fd = connect_egd(path);
 164     if (fd < 0)
 165         return 0;
 166
 167     while(size) {
 168         len = size;
 169         if (len > MAX_EGD_DATA)
 170             len = MAX_EGD_DATA;
 171         ret = get_entropy(fd, outdata, len);
 172         if (ret != 1)
 173             break;
 174         outdata += len;
 175         size -= len;
 176     }
 177     close(fd);
 178
 179     return ret;
 180 }
 181
 182 static int
 183 egd_bytes(unsigned char *outdata, int size)
 184 {
 185     return get_bytes(NULL, outdata, size);
 186 }
 187
 188 static void
 189 egd_cleanup(void)
 190 {
 191 }
 192
 193 static void
 194 egd_add(const void *indata, int size, double entropi)
 195 {
 196     egd_seed(indata, size);
 197 }
 198
 199 static int
 200 egd_pseudorand(unsigned char *outdata, int size)
 201 {
 202     return get_bytes(NULL, outdata, size);
 203 }
 204
 205 static int
 206 egd_status(void)
 207 {
 208     int fd;
 209     fd = connect_egd(egd_path);
 210     if (fd < 0)
 211         return 0;
 212     close(fd);
 213     return 1;
 214 }
 215
 216 const RAND_METHOD hc_rand_egd_method = {
 217     egd_seed,
 218     egd_bytes,
 219     egd_cleanup,
 220     egd_add,
 221     egd_pseudorand,
 222     egd_status
 223 };
 224
 225 const RAND_METHOD *
 226 RAND_egd_method(void)
 227 {
 228     return &hc_rand_egd_method;
 229 }
 230
 231
 232 int
 233 RAND_egd(const char *filename)
 234 {
 235     return RAND_egd_bytes(filename, 128);
 236 }
 237
 238 int
 239 RAND_egd_bytes(const char *filename, int size)
 240 {
 241     void *data;
 242     int ret;
 243
 244     if (size <= 0)
 245         return 0;
 246
 247     data = malloc(size);
 248     if (data == NULL)
 249         return 0;
 250
 251     ret = get_bytes(filename, data, size);
 252     if (ret != 1) {
 253         free(data);
 254         return ret;
 255     }
 256
 257     RAND_seed(data, size);
 258
 259     memset(data, 0, size);
 260     free(data);
 261
 262     return 1;
 263 }