Damien Miller | 8b171bc | 2000-02-03 14:04:50 +1100 | [diff] [blame] | 1 | /* |
| 2 | ** |
| 3 | ** Random number collection |
| 4 | ** |
| 5 | ** Damien Miller <djm@ibs.com.au> |
| 6 | ** |
| 7 | ** Copyright 1999 Damien Miller |
| 8 | ** |
| 9 | ** Permission is hereby granted, free of charge, to any person |
| 10 | ** obtaining a copy of this software and associated documentation |
| 11 | ** files (the "Software"), to deal in the Software without |
| 12 | ** restriction, including without limitation the rights to use, copy, |
| 13 | ** modify, merge, publish, distribute, sublicense, and/or sell copies |
| 14 | ** of the Software, and to permit persons to whom the Software is |
| 15 | ** furnished to do so, subject to the following conditions: |
| 16 | ** |
| 17 | ** The above copyright notice and this permission notice shall be |
| 18 | ** included in all copies or substantial portions of the Software. |
| 19 | ** |
| 20 | ** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY |
| 21 | ** KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE |
| 22 | ** WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE |
| 23 | ** AND NONINFRINGEMENT. IN NO EVENT SHALL DAMIEN MILLER OR INTERNET |
| 24 | ** BUSINESS SOLUTIONS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 25 | ** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
| 26 | ** ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE |
| 27 | ** OR OTHER DEALINGS IN THE SOFTWARE. |
| 28 | ** |
| 29 | ** Except as contained in this notice, the name of Internet Business |
| 30 | ** Solutions shall not be used in advertising or otherwise to promote |
| 31 | ** the sale, use or other dealings in this Software without prior |
| 32 | ** written authorization from Internet Business Solutions. |
| 33 | ** |
| 34 | */ |
| 35 | |
| 36 | #include <stdio.h> |
| 37 | #include <stdlib.h> |
| 38 | #include <string.h> |
| 39 | #include <errno.h> |
| 40 | #include <unistd.h> |
| 41 | |
| 42 | #include <sys/types.h> |
| 43 | #include <sys/stat.h> |
| 44 | #include <sys/socket.h> |
| 45 | #include <sys/un.h> |
| 46 | #include <fcntl.h> |
| 47 | #ifdef HAVE_STDDEF_H |
| 48 | #include <stddef.h> |
| 49 | #endif |
| 50 | |
| 51 | #include "ssh.h" |
| 52 | #include "xmalloc.h" |
| 53 | #include "random.h" |
| 54 | |
| 55 | #ifndef offsetof |
| 56 | # define offsetof(type, member) ((size_t) &((type *)0)->member) |
| 57 | #endif |
| 58 | |
| 59 | #ifdef HAVE_EGD |
| 60 | |
| 61 | /* Collect entropy from EGD */ |
| 62 | void get_random_bytes(unsigned char *buf, int len) |
| 63 | { |
| 64 | static int random_pool; |
| 65 | int c; |
| 66 | char egd_message[2] = { 0x02, 0x00 }; |
| 67 | struct sockaddr_un addr; |
| 68 | int addr_len; |
| 69 | |
| 70 | memset(&addr, '\0', sizeof(addr)); |
| 71 | addr.sun_family = AF_UNIX; |
| 72 | |
| 73 | /* FIXME: compile time check? */ |
| 74 | if (sizeof(RANDOM_POOL) > sizeof(addr.sun_path)) |
| 75 | fatal("Random pool path is too long"); |
| 76 | |
| 77 | strcpy(addr.sun_path, RANDOM_POOL); |
| 78 | |
| 79 | addr_len = offsetof(struct sockaddr_un, sun_path) + sizeof(RANDOM_POOL); |
| 80 | |
| 81 | random_pool = socket(AF_UNIX, SOCK_STREAM, 0); |
| 82 | |
| 83 | if (random_pool == -1) |
| 84 | fatal("Couldn't create AF_UNIX socket: %s", strerror(errno)); |
| 85 | |
| 86 | if (connect(random_pool, (struct sockaddr*)&addr, addr_len) == -1) |
| 87 | fatal("Couldn't connect to EGD socket \"%s\": %s", addr.sun_path, strerror(errno)); |
| 88 | |
| 89 | if (len > 255) |
| 90 | fatal("Too many bytes to read from EGD"); |
| 91 | |
| 92 | /* Send blocking read request to EGD */ |
| 93 | egd_message[1] = len; |
| 94 | |
| 95 | c = atomicio(write, random_pool, egd_message, sizeof(egd_message)); |
| 96 | if (c == -1) |
| 97 | fatal("Couldn't write to EGD socket \"%s\": %s", RANDOM_POOL, strerror(errno)); |
| 98 | |
| 99 | c = atomicio(read, random_pool, buf, len); |
| 100 | if (c <= 0) |
| 101 | fatal("Couldn't read from random pool \"%s\": %s", RANDOM_POOL, strerror(errno)); |
| 102 | |
| 103 | close(random_pool); |
| 104 | } |
| 105 | #else /* HAVE_EGD */ |
| 106 | |
| 107 | /* Collect entropy from /dev/urandom or pipe */ |
| 108 | void get_random_bytes(unsigned char *buf, int len) |
| 109 | { |
| 110 | static int random_pool; |
| 111 | int c; |
| 112 | |
| 113 | random_pool = open(RANDOM_POOL, O_RDONLY); |
| 114 | if (random_pool == -1) |
| 115 | fatal("Couldn't open random pool \"%s\": %s", RANDOM_POOL, strerror(errno)); |
| 116 | |
| 117 | c = atomicio(read, random_pool, buf, len); |
| 118 | if (c <= 0) |
| 119 | fatal("Couldn't read from random pool \"%s\": %s", RANDOM_POOL, strerror(errno)); |
| 120 | |
| 121 | close(random_pool); |
| 122 | } |
| 123 | |
| 124 | #endif /* HAVE_EGD */ |